In a piezoelectric transformer control circuit, when a load (2) is disconnected from a piezoelectric transformer (1) and changes to an open state, an output detection voltage (Vdet) becomes higher than a reference voltage (Vref2), and the output from a voltage comparator (10a) goes xe2x80x9cLowxe2x80x9d. When the output of the piezoelectric transformer (1) is short-circuited to GND, the output detection voltage (Vdet) abruptly drops to almost xe2x80x9c0xe2x80x9d and becomes lower than a reference voltage (Vref3). The output from a voltage comparator (10b) goes xe2x80x9cLowxe2x80x9d. A voltage-controlled oscillation circuit (6) detects the signal xe2x80x9cLowxe2x80x9d to stop the generation of the oscillation signal to a driving circuit (7) for driving the piezoelectric transformer (1).

The present invention relates to a control circuit and method for a piezoelectric transformer and, more particularly, to a control circuit and method for a piezoelectric transformer suited for use in a driving apparatus for a cold-cathode fluorescent lamp.
Recently, liquid crystal displays are extensively used as display devices of, e.g., portable notebook personal computers. These liquid crystal display devices incorporate a cold-cathode fluorescent lamp as a so-called back light in order to illuminate a liquid crystal display panel from the back. Turning on this cold-cathode fluorescent lamp requires an inverter capable of converting a low DC voltage of a battery or the like into a high AC voltage of 1,000 Vrms or more in an initial lighting state and about 500 Vrms in a steady lighting state. Conventionally, a winding transformer is used as a boosting transformer of this inverter. In recent years, however, a piezoelectric transformer which performs electric conversion via mechanical energy and thereby performs boosting is beginning to be used. This piezoelectric transformer has a generally unpreferable characteristic, i.e., largely changes its boosting ratio in accordance with the magnitude of an output load (load resistance) such that the boosting ratio is high for a small output load (large load resistance) and is low for a large output load (small load resistance). On the other hand, this dependence upon a load resistance is suited to the characteristics of an inverter power supply for a cold-cathode fluorescent lamp. Accordingly, a piezoelectric transformer has attracted attention as a small-sized, high-voltage power supply meeting the demands for a low profile and a high efficiency of a liquid crystal display. An example of a control circuit for this piezoelectric transformer will be described below with reference to FIG. 1.
FIG. 1 is a block diagram of a piezoelectric transformer control circuit as the prior art.
In FIG. 1, reference numeral 101 denotes a piezoelectric transformer; 102, a load such as a cold-cathode fluorescent lamp connected to the output terminal of the piezoelectric transformer 101; 103, a detecting resistor Rdet for detecting a current flowing in the load; 104, a rectifying circuit for converting an AC voltage generated in the detecting resistor 103 into a DC voltage; 105, an error amplifier for comparing a voltage Vri rectified by the rectifying circuit 104 with a reference voltage Vref and amplifying the difference as a comparison result; 106, a voltage-controlled oscillation circuit for outputting an oscillation signal in accordance with the output voltage from the error amplifier 105; and 107, a driving circuit for driving the piezoelectric transformer 101 in accordance with the oscillation signal from the voltage-controlled oscillation circuit 106. The operation of the control circuit with the above configuration will be described below with reference to FIGS. 2A and 2B.
FIGS. 2A and 2B are graphs for explaining an example of frequency characteristics for the output voltage and load current of a piezoelectric transformer.
As shown in FIG. 2A, the piezoelectric transformer 101 has a hilly resonance frequency characteristic whose peak is the resonance frequency of the piezoelectric transformer 101. It is generally known that a current flowing in the load 102 due to the output voltage from the piezoelectric transformer 101 also has a similar hilly characteristic. In FIG. 2B, this load current is represented by a load current detection voltage Vri. Control using a right-side (falling) portion in this characteristic will be described below. When the power supply of this control circuit is turned on, the voltage-controlled oscillation circuit 106 starts oscillating at an initial frequency fa. Since no current flows in the load 102 at that time, the voltage generated in the detecting resistor (Rdet) 103 is zero. Accordingly, the error amplifier 105 outputs a negative voltage, as a result of comparison of the load current detection voltage Vri with the reference voltage Vref, to the voltage-controlled oscillation circuit 106. In accordance with this voltage, the voltage-controlled oscillation circuit 106 shifts the oscillation frequency of an oscillation signal to a lower frequency. Therefore, as the frequency is shifted to a lower frequency, the output voltage from the piezoelectric transformer 101 rises, and the load current (load current detection voltage Vri) also increases. When the load current (load current detection voltage Vri) become equal to the reference voltage Vref, the frequency stabilizes (fb). Even if the resonance frequency changes due to a temperature change or a change with time, the frequency shifts accordingly to always hold the load current substantially constant.
In the control circuit shown in FIG. 1, therefore, frequency control is so performed that the load current detection voltage Vri becomes equal to the reference voltage Vref, and the load current is held at a predetermined value by this frequency control. When a cold-cathode fluorescent lamp is used as a load in this piezoelectric transformer control circuit and the control circuit is used as a lighting device for the cold-cathode fluorescent lamp, a function of holding the luminance of the cold-cathode fluorescent lamp at a predetermined luminance can be achieved since the luminance of the cold-cathode fluorescent lamp is proportional to a lamp current flowing in the cold-cathode fluorescent lamp.
In this conventional piezoelectric transformer control circuit, however, when the load connected to the output terminal of the piezoelectric transformer is disconnected due to some reason, and the output terminal changes to a so-called open state, a high voltage is generated at the output terminal of the piezoelectric transformer in accordance with the open state.
At this time, if the frequency of the oscillation signal for driving the piezoelectric transformer does not vary, such a high voltage as to induce physical damage to the piezoelectric transformer is not generated because the operating point of the piezoelectric transformer shifts from the resonance frequency. However, when the output terminal of the piezoelectric transformer 101 actually changes to the open state, for example, the above control circuit shown in FIG. 1 detects that no current flows through the load current detecting resistor (Rdet) 103, and the oscillation frequency (operating point) of the voltage-controlled oscillation circuit 106 is swept to a lower frequency by the function of keeping the load current substantially constant. As a result, the operating point of the piezoelectric transformer 101 becomes equal to the resonance frequency to generate such a high voltage (10 kV or higher) as to physically damage the piezoelectric transformer 101 at the output terminal.
In the control circuit of FIG. 1, assume that the output of the piezoelectric transformer 101 is short-circuited to, e.g., ground (GND) (so-called grounding) due to some reason (note that the output may be short-circuited to a negative potential). Even in this state, if the frequency of the oscillation signal for driving the piezoelectric transformer 101 does not vary, no physical damage to the piezoelectric transformer 101 is induced. In practice, however, similar to the open state, when the control circuit detects that no current flows through the load current detecting resistor (Rdet) 103, the operating point of the piezoelectric transformer 101 is swept to a lower frequency by the voltage-controlled oscillation circuit 106 with the function of keeping the load current substantially constant, and the operating point of the piezoelectric transformer 101 may pass a resonance point (near the peaks in FIGS. 2A and 2B). Since the piezoelectric transformer 101 is in a series resonance state at a resonance frequency unique to the piezoelectric transformer, and the output of the piezoelectric transformer 101 is short-circuited to GND, the input impedance of the piezoelectric transformer 101 becomes very small. Accordingly, a large current may flow through the piezoelectric transformer 101 to physically damage it.
For example, Japanese Patent Publication No. 59-40313 and Japanese Patent Laid-Open No. 5-64436 disclose the technique of detecting the load current using a resistor to detect an increase in current caused by a short circuit. In these references, however, the short-circuiting state means a short circuit between the output terminals of a piezoelectric transformer connected to a load, and a short circuit between the output of the piezoelectric transformer and GND cannot be detected. In the control circuit disclosed in these references, when a short circuit occurs between the output terminals of the piezoelectric transformer connected to the load, the load current is detected, and the frequency is shifted to a higher frequency to prevent damage to the piezoelectric transformer.
It is an object of the present invention to provide a control circuit and method for a piezoelectric transformer in which damage to the piezoelectric transformer can be prevented upon occurrence of an abnormal state at the output of the piezoelectric transformer.
To achieve the above object, a piezoelectric transformer control circuit of the present invention has the following arrangement.
That is, a piezoelectric transformer control circuit having oscillation means for generating an oscillation signal in accordance with a control voltage, driving means for driving a piezoelectric transformer by an AC voltage generated in accordance with the oscillation signal from the oscillation means, and control means for detecting a load current of a load connected to an output side of the piezoelectric transformer and controlling an oscillation frequency of the oscillation means so as to keep the load current substantially constant, is characterized by comprising protective means for detecting an output voltage from the piezoelectric transformer and protecting the piezoelectric transformer on the basis of the output voltage.
For example, the protective means is characterized by comprising detecting means for detecting an open state or short-circuiting to ground on the output side of the piezoelectric transformer in accordance with a result of comparing the detected output voltage with a predetermined value. The protective means preferably stops generation of the oscillation signal by the oscillation means or sweeps a frequency of the oscillation signal by the oscillation means to a predetermined frequency so as to protect the piezoelectric transformer when the detecting means detects the open state or the short-circuiting to ground.
To achieve the above object, a piezoelectric transformer control method of the present invention has the following steps.
That is, a piezoelectric transformer control method of generating an oscillation signal in accordance with a control voltage, driving a piezoelectric transformer by an AC voltage generated in accordance with the oscillation signal, detecting a load current of a load connected to an output side of the piezoelectric transformer, and controlling an oscillation frequency so as to keep the load current substantially constant, is characterized by comprising the steps of detecting an output voltage from the piezoelectric transformer, and detecting an open state or short-circuiting to ground on the output side of the piezoelectric transformer in accordance with a result of comparing the detected output voltage with a predetermined value.
The method preferably further comprises stopping generation of the oscillation signal or sweeping a frequency of the oscillation signal to a predetermined frequency so as to protect the piezoelectric transformer when the open state or the short-circuiting to the ground is detected.
With the above arrangement and steps, damage to the piezoelectric transformer can be prevented upon occurrence of the open state or the short-circuiting to ground on the output side of the piezoelectric transformer.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.

Control circuit and method for protecting a piezoelectric transformer from an open state and a short-circuited state


The horizontal blanking interval (HBI) of a normal video signal is modified to enhance the playability of the applied copy protected video signal while maintaining the copy protection effectiveness. As generally known, a copy protected video signal with positive-going pulses in a back porch region causes possible black level depression. The addition of a negative-going pulse and/or negative-going and positive-going pulse pair immediately prior to the H sync signal in the front porch region causes a reduction in such black level depression while resulting in enhanced playability. In other embodiments, an amplitude extending pulse is added to a latter portion of the H sync pulse or to a latter portion of a pseudo sync pulse, to increase the negative-going amplitude of the respective pulse. Various combinations of the added pulses also are possible.

The present invention relates to a video signal copy protection process and apparatus, and more particularly to a technique for providing or enhancing copy protection of video signals via the addition of special negative-going pulses as well as special positive-going pulses in some embodiments, within selected portions of front porch regions in the video signal horizontal blanking interval (HBI).
In the field of video signal copy protection, copy protection processes are well known for modifying a video signal so that a normal color picture may be produced by a television receiver receiving the copy protected video signal, but wherein videotape recording of the copy protected video signal is inhibited and/or is so degraded in quality as to be unwatchable. In addition, many processes have been developed which enhance or otherwise improve upon the many basic copy protection processes.
Typical of such processes is that disclosed in U.S. Pat. No. 4,631,603 issued to J. Ryan in Dec. 23, 1986, and herein incorporated by reference, which capitalizes on the fact that a typical video cassette recorder's (VCR) automatic gain control (AGC) system cannot distinguish between the normal sync pulses of a conventional video signal (including equalizing or broad pulses) and added pseudo-sync pulses. Pseudo-sync pulses are defined here as any other pulses which extend down to a normal sync tip level and which have a duration of at least 0.5 microseconds. A plurality of such pseudo-sync pulses is added to the conventional video signal during the vertical blanking interval, and each of such pseudo-sync pulses is followed by a positive pulse of suitable amplitude and duration. As a result, the automatic gain control system in a videotape recorder will make a false measurement of video level which causes an improper recording of the video signal. The result is unacceptable picture quality during playback. However, this approach utilizes positive-going pulses which occur at a time not ordinarily used for black-level restoration in typical television receivers and therefore does not give rise to black level depression in such typical television sets, whereby a television set (TV) displays a picture of fully acceptable quality.
Another copy protection process is disclosed in U.S. Pat. No. 4,819,098 issued to J. Ryan on Apr. 4, 1989 and incorporated herein by reference, which capitalizes on the fact that VCRs include the AGC system which here measures the sync pulse level in a video signal and develops a gain correction signal for keeping the video level applied to an FM modulator in the VCR system at a fixed, predetermined value. A plurality of positive pulses are added to the video signal with each immediately following a respective trailing edge of a normally occurring sync pulse. These added pulses are clustered at the vertical blanking interval of each field to minimize the affect of the same on the watchability of the picture defined by the signal, but still cause the automatic level control circuit in a VCR to assess the video level at many times its actual value thereby providing a copy of unacceptable picture quality. The sync pulses themselves can also be at a reduced level, in order to enhance the effectiveness of the copy protection process.
A further copy protection process is disclosed in U.S. Pat. No. 4,163,253 issued to M. Morio et al. on Jul. 31, 1979, wherein the AGC circuit of a VCR again prevents recording an acceptable copy of a copy protected video signal. A pulse whose amplitude is substantially equal to the peak white level of the video signal is inserted into respective horizontal blanking intervals of the video signal. If this modified video signal is recorded on a conventional type of video signal recorder, the presence of the inserted pulse signal is detected by the AGC detector which, in turn, controls an AGC amplifier to substantially attenuate the modified video signal which then is recorded. The resulting recording is of unacceptable picture quality.
It has been found that the copy protection signals of various copy protection processes which employ positive-going pulses, such as AGC pulses, in the back porch region of the HBI, may experience various degrees of playability problems such as for example black level depression. In the field of copy protection, it obviously is necessary to maximize the effectiveness of the copy protection of a recorded video signal. However, it is equally necessary to maintain the playability of the copy protected video signal by reducing the amount of side effects such as darkening of the TV set monitor during playback of the video signal, playback of a legal copy of the video signal, etc. It follows that it would be advantageous to maximize not only the effectiveness of a copy protection process against illegal copying but also the playability of the video signal by a legitimate TV set.

Method and apparatus for providing or enhancing copy protection by adding selected negative-going and positive-going pulses in a video signal HBI


Sequences of pre-coded radio control signals are rearranged to enhance diversity transmission. In one example, a sequence of uplink control bits is segmented to form a plurality of groups. The bits of each of the plurality of groups are error correction encoded and encoded into symbols. The symbols are mapped to different ports for diversity transmission through a plurality of ports.

Transmit diversity seeks to vary the transmission path for different aspects of a radio signal. The diversity may be created by sending two signals at different times, on different frequencies, or from different locations. More complex forms of transmit diversity send variations of a single packet more than once so that a receiver may combine the two signals to reconstruct the original packet. In some transmit diversity systems, the two signals both contain all of the information while in other systems, the two signals each contain a different part of the information. Even if all of the bits are not received from one signal or the other, the original packet might be reconstructed using error correction, depuncturing, maximum likelihood sequence estimation or other techniques.
In Long Term Evolution (LTE), transmit diversity for some signals is provided by dividing a packet into parts. The parts are each sent in a different time slot and on a different subcarrier. In addition, different antennas may be used for the two slots. This provides time and frequency diversity and options for spatial diversity.
LTE uses orthogonal frequency division multiplexing (OFDM) in the downlink and discrete Fourier transform (DFT)-spread OFDM in the uplink. The basic LTE downlink physical resource may thus be seen as a time-frequency grid as illustrated in FIG. 1, where each resource element corresponds to one OFDM subcarrier during one OFDM symbol interval. FIG. 1 is a grid diagram of the LTE downlink physical resource (3GPP TS 36.211, Third Generation Partnership Project Technical Specification No. 36.211).
In the time domain, LTE downlink transmissions are organized into radio frames of 10 ms, each radio frame consisting of ten equally-sized subframes of length Tsubframe=1 ms. FIG. 2 is a diagram of the LTE time domain structure where time moves from left to right across the frame.
The resource allocation in LTE is typically described in terms of resource blocks, where a resource block corresponds to one slot (0.5 ms) in the time domain and 12 contiguous subcarriers in the frequency domain. Resource blocks are numbered in the frequency domain, starting with 0 from one end of the system bandwidth. Downlink (DL) transmissions are dynamically scheduled, i.e., in each subframe the base station transmits control information to the remote terminals to indicate the resource blocks assigned to transmit data to each terminal, in the current downlink subframe. The remote terminals are typically referred to in LTE as user equipment or UE. This control signaling is typically transmitted in the first 1, 2, 3 or 4 OFDM symbols in each subframe. A downlink system with 3 OFDM symbols as control is illustrated in FIG. 3. FIG. 3 is a grid diagram of a DL subframe showing control in the first blocks followed by data traffic, with reference symbols dispersed through the grid.
LTE uses hybrid-ARQ (HARQ), where ARQ refers to Automatic Repeat Request or Automatic Repeat Query, where, after receiving downlink data in a subframe, the terminal attempts to decode it and reports to the base station whether the decoding was successful (acknowledgement, ACK) or not (negative acknowledgment, NACK). In case of an unsuccessful decoding attempt, the base station may retransmit the erroneous data.
Uplink control signaling from the terminal to the base station in LTE consists of hybrid-ARQ acknowledgements for received downlink data; terminal reports related to the downlink channel conditions, used as assistance for the downlink scheduling; and scheduling requests, indicating that a mobile terminal needs uplink resources for uplink data transmissions.
If the mobile terminal has not been assigned an uplink resource for data transmission, the L1/L2 (Layer 1/Layer 2) control information (channel-status reports, hybrid-ARQ acknowledgments, and scheduling requests) is transmitted in uplink resources (resource blocks) specifically assigned for uplink L1/L2 control on Release 8 of the Physical Uplink Control Channel (Rel-8 PUCCH).
FIG. 4 is a grid diagram of a PUCCH showing resources assigned for a signal uplink control message. As illustrated in FIG. 4, these resources are located at the edges of the total available cell bandwidth. Each such resource consists of 12 "subcarriers" (one resource block) within each of the two slots of an uplink subframe. In order to provide frequency diversity, these frequency resources are frequency hopping on the slot boundary, i.e. one "resource" consists of 12 subcarriers at the upper part of the spectrum within the first slot of a subframe and an equally sized resource at the lower part of the spectrum during the second slot of the subframe or vice versa. If more resources are needed for the uplink L1/L2 control signaling, e.g. in case of very large overall transmission bandwidth supporting a large number of users, additional resources blocks may be assigned next to the previously assigned resource blocks.
The PUCCH resource blocks are located at the edges of the overall available spectrum to maximize the frequency diversity experienced by the control signaling. In addition, Assigning uplink resources for the PUCCH at other positions within the spectrum, i.e. not at the edges, would fragment the uplink spectrum, making it impossible to assign very wide transmission bandwidths to a single mobile terminal and still retain the single-carrier property of the uplink transmission
When carrier aggregation is used in LTE, one uplink carrier is designed to carry the HARQ-ACK/NACK bits for all DL carrier Physical Downlink Shared Channel (PDSCH) transmissions. To enable the possibility to transmit more than four bits of ACK/NACK, PUCCH format 3 may be used. The basis for Format 3 is DFT-pre-coded OFDM, as diagrammed in FIG. 5 described below.
If the number of ACK/NACK bits is up to 11, then the multiple ACK/NACK bits (which may also include scheduling request (SR) bits) are Reed-Müller (RM) encoded to form 48 coded bits. The coded bits are then scrambled with cell-specific sequences. 24 bits are transmitted within the first slot and the other 24 bits are transmitted within the second slot. The 24 bits per slot are converted into 12 QPSK symbols, spread across five DFTS (DFT Spread)-OFDM symbols using an orthogonal cover code, DFT pre-coded and transmitted within one resource blocks (bandwidth) and five DFTS-OFDM symbols (time). The spreading sequence is specific to each terminal (UE) and enables multiplexing of up to five users within the same resource blocks.
For the reference signals, cyclic shifted constant amplitude zero autocorrelation (CAZAC) sequences are used. This is shown as a processing diagram in FIG. 5 in which input bits are encoded, scrambled and modulated, then applied to weighting multiplexers and DFTs. The DFTs are applied to inverse fast Fourier transform (IFFT) blocks as shown. This is the DFTS-OFDM based PUCCH format 3 for a UE supporting more than 4 HARQ bits in normal contention period (CP) subframes.
The bandwidth of one resource block during one subframe is too large for the control signaling needs of a single terminal. Therefore, to efficiently exploit the resources set aside for control signaling, multiple terminals may share the same resource block. This is done by assigning the different terminals different orthogonal phase rotations of a cell-specific length-12 frequency-domain sequence and/or different orthogonal time-domain covers covering the subframes within a slot or subframe.
If the number of ACK/NACK bits exceeds 11, then the bits are split into two parts and two RM encoders are used, one for each part respectively. This is known as the dual-RM code. Up to 20 ACK/NACK bits (plus one SR bit) may therefore be supported by PUCCH Format 3. Each encoder in the dual-RM code outputs 24 bits which are converted to 6 quaternary phase-shift keying (QPSK) symbols per slot and the two sets of 6 QPSK symbols are interleaved over the subcarriers so that the first encoder maps its 6 symbols onto odd subcarriers and the second encoder onto even subcarriers. These 12 QPSK symbols are then spread across the five DFTS-OFDM symbols using one out of five orthogonal cover codes, as in the single-RM code case. The encoding and multiplexing are diagrammed in FIGS. 6A and 6B.
FIG. 6A shows encoding and multiplexing up to 11 uplink control information (UCI) bits into slot 0 and slot 1. FIG. 6B shows segmenting 12-21 UCI bits into Segment 1 and Segment 2. These are encoded and mapped to 12 QPSK symbols and then to slot 0 and slot 1.
In LTE Release 10, space orthogonal transmit diversity is used for PUCCH Format 3 to achieve transmit diversity. Transmission with two antenna ports is supported and the Format 3 encoding and mapping shown in FIG. 5 is repeated for each of the two antennas apart from the cyclic shift of the reference signals and the orthogonal cover codes on the data, which are different to provide orthogonality between the antenna ports.

Transmit diversity for pre-coded radio control signals


An electronic cigarette is provided, which includes: a housing having a chimney formed therein; a liquid reservoir for storing liquid in the housing; and an atomizer assembly received in the housing. The atomizer assembly includes a heating tube capable of absorbing liquid. The heating tube defines a plurality of micropores on a wall thereof; an inner surface of the heating tube is in contact with the air in the chimney.

The electronic cigarette is also known as a virtual cigarette or an electronic atomizer. As a replacement for cigarettes, the electronic cigarette is usually used for smoking cessation. The appearance and taste of the electronic cigarette are similar to that of the conventional cigarette, while it does not contain tar, suspended particles and other harmful ingredients such as the conventional cigarette.
The electronic cigarette is mainly composed of an atomizer and a battery assembly. The atomizer is the core device of the electronic cigarette to generate atomizing gas; the quality and taste of the smoke are dependent on the atomization effect. A conventional heating element of the atomizer can only heat and atomize the liquid located close to the heating wire. As such the atomization effect of the liquid located away from the heating wire is poor. Or even if the liquid can be atomized, the atomized particles are relatively large due to the low atomization temperature.


A tool and kit for removal of a broken spark plug from a cylinder head may include first and/or second tools, and/or a supplemental tool. The first tool is designed to position a broken porcelain element into the spark plug tip so that a second tool may be utilized to engage the tip by threading into the tip and thereafter axially withdrawing the plug tip from the cylinder head into the hollow tubular member. The supplemental tool may be utilized to engage the plug wire contact of a plug with axially projecting, elastic cantilever segments and axially withdraw the attached plug contact into a hollow tubular member.

In a principal aspect the present invention relates to a tool and an associated kit of tools for removal of a broken spark plug from a cylinder head.
Motor vehicle internal combustion engines typically include spark plugs threaded into the engine cylinder head to provide an electric ignition spark for igniting combustible gasses within each cylinder. Each spark plug includes a distributor wire contact for attachment of a spark plug wire to a current source. The contact comprises the exposed end of a wire conductor axially extending through the plug leading to a spark gap at the tip of the plug inside the cylinder. Ignition of a fuel/air mixture in the cylinder is effected by a spark in the gap at the tip of the plug which projects through the cylinder head into the cylinder.
Spark plugs utilized for such an ignition system have a variety of constructions. Typically, a spark plug will include an axial conductor encased in a porcelain insulator. The conductor connects the outer end contact terminal of the plug to the spark gap tip. A threaded cylindrical body surrounds the insulator and supports and encases the component parts of the spark plug thereby enabling threaded insertion or removal of the plug from a threaded bore in the cylinder head of an internal combustion engine.
Spark plugs are typically periodically removed from the cylinder head to permit replacement. On occasion a plug will break during removal. Thus, the problem of removal from and replacement of spark plugs in a cylinder head is exacerbated by factors such as the design of the plug and the manner in which the plug is inserted into the cylinder head. This topic is described in Technical Service Bulletin #TSB 06-15-2 of the Ford Motor Company incorporated herewith by reference. The Service Bulletin discusses the problem associated with spark plug replacement and also suggests a solution to effect removal of a broken spark or damaged plug from the cylinder head of a motor vehicle engine.
An example of a tool used for removal of a broken spark plug from a cylinder head is described in an instruction memorandum for an OTC Product No. 6918 entitled "Ford Spark Plug Removal Tool" issued Oct. 17, 2012. The described spark plug removal tool employs the use of a collet for gripping the wire connector and porcelain body of a spark plug to effect removal from a cylinder head. The operating instructions and circular are incorporated herewith by reference.
Nonetheless, during attempted removal of a plug, the cylindrical spark plug tip may break and separate from the body of the threaded plug. As such, the tip remains positioned within the cylinder head and must be removed before a new plug can be threaded into the cylinder head.
Applicant's assignee developed tools to address various issues associated with the removal of a broken spark plug from the cylinder head of a motor vehicle, and, in particular, from the cylinder head of a vehicle of the type described in the Technical Service Bulletin referenced above, among others. Specifically, U.S. Pat. No. 7,814,814 entitled "Tool Kit for Removal of Broken Spark Plugs", incorporated herein by reference, discloses a tool for removal of a broken spark plug from a cylinder head wherein the spark plug tip is separated from the remainder of the plug.
The subject matter of U.S. Pat. No. 7,814,814 is marketed by applicant's assignee, Lisle Corporation, as Spark Plug Removal Kit Number 65600. The kit was developed to facilitate the removal of certain spark plug components of a broken plug from the cylinder head of an engine. That is, during a plug removal procedure, the spark plug may occasionally break leaving the firing tip element in the head whereas the remainder of the spark plug may be successfully removed from the cylinder head. In this circumstance the insulator tip of the spark plug, which is typically a porcelain material, is pushed into the firing tip element to allow a firing tip removal tool to engage the firing tip and effect removal.
However, in certain instances removal of the spark plug may result in breakage of plug parts of the plug other than the tip causing such parts to remain within the cylinder head. For example, the porcelain insulator at the upper end of the plug may remain intact or partially intact within the cylinder head. When this occurs, the outer annular body of the plug may remain within the cylinder head along with various other components associated with the spark plug. The annular body may be removed by unthreading it from the head. However, the porcelain insulator may remain within the cylinder head along with other parts of the spark plug. Thus, the porcelain insulator must be removed from the cylinder head before a firing tip 38 can be removed using the tool such as described in U.S. Pat. No. 7,814,814. However, gripping the wire contact or wire connector which may remain lodged in the cylinder head is difficult and is compounded by the problem of removing the porcelain insulator. Needle nose pliers is often used by a mechanic to attempt to effect removal of the porcelain insulator. Again, this is a difficult operation to perform and may result in breakage of the component parts thus rendering the situation much more complex.

Tool kit for removal of broken spark plugs


A system is disclosed that can be used in precision farming to apply crop product to a field. The system includes a remote terminal connected with a network. The remote terminal includes a scanning application configured to allow the remote terminal to scan a unique product identifier associated with a crop product to be applied to a field. A server is connected with the remote terminal via the network. A transmission application is associated with the remote terminal that is configured to transmit the unique product identifier to the server. A lookup application associated with the server is configured to query a crop product database to retrieve one or more crop product data properties associated with the crop product. A prescription map generation application is configured to generate a prescription map for the field as a function of the one or more crop product data properties. A map transmission application is configured to transmit the prescription map to a field terminal associated with a piece of farming equipment which applies the crop product to the field according to the prescription map.

The present invention relates generally to soil sampling and more particularly, to a system and method of soil sampling to determine the nutrient level of soil in fields so that a variable-rate nutrient pattern or prescription can be generated for a particular field.
The present invention also relates generally to a system and method for tracking farm product applied to a field and generating prescription maps based on a unique identifier scanned from a container containing the farm product.
The present invention also relates to a system and method in which soil samples can be ordered through work orders issued by various farming companies across vast geographic areas, processed, tracked, and results reported back to the farming companies for further processing and use.
The agricultural industry uses soil samples to determine the nutrient level of soil in fields. Soil sampling and testing provides an estimate of the capacity of the soil to supply adequate nutrients to meet the needs of growing crops. In some instances, the test results are compared to standard response data associated with specific types of crops to estimate the need to supply additional nutrients for optimum crop production. The test results are then used as a basis for profitable and environmentally responsible fertilizer application.
Typically, about a teaspoonful of soil is actually used for laboratory analysis. That small amount represents the entire area for which the fertilizer recommendation is made for that particular area. Several soil samples are typically taken from a given field and represent an area of the field. The soil samples are often taken using different soil sampling pattern options. A grid pattern is usually the best way to ensure that the entire field is represented. In this form, a given field is divided up into various cells with each cell representing an area of the field. For illustrative purposes only, a sixty acre field could be divided up into thirty cells with each cell representing two acres of the field. A sample is taken from each cell to generate a representative nutrient map of the field.
Currently, most soil samplers use a computer to guide them to the correct location of the field from which samples are taken. The soil samplers use a probe to take the soil sample and the soil is then placed in a container which is sent to a lab for soil analysis. The soil samplers must have some way of identifying one container from another. One way to do this is to handwrite specific information on each container. For example, each container may have handwritten material placed on them identifying a client name, farm name, field name and a sample identification. This method is very time consuming and can be filled with errors at the lab by misreading the written information.
A second way is to print labels ahead of time in the office and take them out to the field when gathering samples. After each soil probe, the soil sampler applies a label to the container, thereby distinguishing it from other containers. This method is also problematic because of the tendency to put the wrong label on the container and it is also time consuming. When the soil sampler is done collecting the samples they are shipped off to the lab where the samples can be processed and fertilizer recommendations can be made. Both of the above-described techniques for container identification are very time consuming for lab technicians as well as the soil samplers. Receiving containers with either handwritten information or printed labels causes the lab technicians to have to re-enter this information into a computer at the lab. This is also another area in which mistakes are easily made thereby causing samples to fail to get matched up with the right information. Once the samples are processed or analyzed at the lab, the test results are sent to the customer who may then import that data into a software application for processing of application maps for fertilizer or other farming operations.
If a farming company wants to obtain a soil sample, typically a call is placed to a soil sampling company and an order is placed over the phone. The soil sampling company will then take the samples and send the samples to a laboratory. This process can take some time and generally requires the soil sampling company to maintain an office in the general geographic location in which the field is located. As such, a need exists for a system in which a soil sampling company can be located in one location yet service farm companies or farmers across an entire country or region.
Currently, in the agriculture industry, a farmer that wants to record what type of seed gets planted or what type of chemical gets applied to a field has to enter the information about the particular seeds or chemicals manually into a field computer. The field computer is programmed to prompt the farmer to enter information about the product being planted or applied and then the farmer can either type that information in or select a product from a drop down menu or list that appears on the field computer. If the farmer switches to a different seed, or chemical, and continues operation, the field computer will continue to record as if it is the previous seed or chemical resulting in bad data. Sometimes, if the name of the product is manually entered, the name gets entered wrong or the wrong product can get selected from the dropdown menu or list.
Also, currently systems available today require that a predetermined application map be made ahead of time and loaded into the field computer at some point in the process. If the application map is not available, the farmer has to stop and wait for the application map or applies the product without the map. As such, a need exists for farmers to be able to plant crop or apply chemicals "on the fly" without the need to wait for application maps.


The present invention relates to a glazing element for facing building facades or window systems, in particular for motor vehicles, trains or aircraft, having at least two panes, which enclose an intermediate space, and on one pane surface facing said intermediate space a coating buildup is provided, having an electrically conductive layer applied to one pane surface, thereupon an electrochromic, and thereupon an ion-conducting and thereupon an electrocatalytic layer. The invention is distinguished by the fact that, in addition to the coating buildup in the intermediate space, which is free of water, solely a reducing or oxidizing gas or gas mixture comprising a reducing or an oxidizing gas or a gas mixture comprising a reducing or an oxidizing gas and an inert gas is provided and that an electric voltage of less than 1.2 volts between the electrically conductive and the electrocatalytic layer is applied.

The present invention relates to a glazing element, in particular for motor vehicles, trains or aircraft. The glazing element is provided with two panes which enclose an intermediate space. On at least one pane surface facing the intermediate space, a coating buildup is provided having applied thereupon an electrically conductive layer, thereupon an electrochromic layer, thereupon an ion-conductive layer and thereupon an electrocatalytic layer.
In many areas, such as for example in buildings, motor vehicles, aircraft or trains, an optically switchable glazing element able to regulate solar radiation is desirable. Optically switchable mirrors, switchable optical components or large-surface displays are further examples for use of optically switchable glazing elements.
A known buildup of an optically switchable component comprises a transparent electrode, an electrochromic layer, an ion conductor, a counter electrode as well as another transparent electrode layer. A buildup of this type is, for example, in the article by S. K. Deb in Solar Energy Materials and Solar Cells, 1992.
In order to improve the optical transparency of electrochromic components of this type, suggestions have been made to replace the counter electrode layer by optical materials such as for instance water. Thus since the 70s, a buildup called xe2x80x9cDeb cellxe2x80x9d has been known, in which the counter electrode is obviated by water that is located inside the ion-conducting layer which is separated by the applied voltage and with the thus formed H+-ions the electrochromic layer is colored. For this see the article by S. K. Deb in Proc. 24th Electronic Components Conf. (IEEE Washington 1974, pp. 11-14) as well as by C. B. Thomas, P. Lloyd, Microelectronics Vol. 7(3), pp. 29-43 (1976).
The layer buildup described in the abovementioned articles comprises a transparent electrode layer, an electrochromic layer, a water containing ion conductor layer and, as usual in systems of this type, a thin gold layer. The water separated by electrolytic action is subsequently supplied from the air via the gold layer. However, the water content inside the ion-conducting layer and the high electric voltages necessary for water separation lead to low stability of the overall electrochromic elements and very greatly limit its life-time. Thus, for example, there is a risk of chemical reactions inside the layers which can destroy the layer bonding. Moreover, the switching behavior of the known electrochromic elements is greatly dependent on humidity.
Another electrochromic arrangement is disclosed in DE 24 36 174 A1 and describes a layer arrangement, the purpose of which, in particular, is for use In solid state displays. This layer arrangement comprises a transparent electrode, which is applied to a transparent substrate. An, electrochromic layer is applied on the electrode layer on top which an ion-permeable insulator layer is provided. An electrocatalytic layer applied on the ion-permeable insulator layer serves as the counter electrode to the transparent electrode layer. A sponge structure provided on the electrocatalytic layer serves as the reservoir layer for atoms and/or molecules, which are electrolytically dissociated by the predominating potential conditions and the electrically charged ions migrate through the ion-permeable insulator layer into the eletrochromic layer respectively are driven out of it. This printed publication also proposes to introduce essentially water into the sponge structure which delivers H+-ions following electrolytic separation. Consequently, with regard to this device, all the drawbacks previously discussed in connection with the xe2x80x9cDeb cellxe2x80x9d can be mentioned.
Finally U.S. Pat. No. 5,136,419 describes an electrochromic component which is provided with an intermediate space in which a gas mixture comprising inert gases and vapor of higher dielectricity constants, such as for instance a mixture of nitrogen and water vapor. This is particularly pointed out in column 1, lines 65 to 68 as well as column 4, lines 13 to 15. The highly dielectric material, preferably water, is ionized within an electric field. In this case, too, the known component is connected with all the previously discussed drawbacks that are inherent to a xe2x80x9cDeb cellxe2x80x9d.
U.S. Pat. No. 4,505,538 also describes a type of improved Deb cell which is provided with a gas-filled intermediate space. In col. 5, lines 28 and 29, the printed publication mentions that there must be sufficient moisture in the gas-filled intermediate space so that a sufficient number of protons can be made available due to the moisture. This content and the examples listed in the printed publication indicate that a type of improved xe2x80x9cDeb cellxe2x80x9d is described which separates water by applying a voltage and injects the forming protons into the electrochromic layer.
The object of the present invention is to improve a glazing element for facing building facades or window systems, in particular for motor vehicles, trains or aircraft, having at least two panes which enclose an intermediate space and on at least one of the panes surfaces facing the intermediate space a coating system being provided having applied to one pane surface an electrically conductive, thereupon an electrochromic, thereupon an ion-conducting and thereupon an electrocatalytic layer applied in such a manner that the drawbacks connected with the use of water are obviated. In particular, the high control voltages to coloring and decoloring the electrochromic as possible layer are obviated. The glazing element should be designed optically transparent, i.e. should not possess any individual layers that subsequently influence the optical transmission properties.
The solution to the object on which the present invention is base is given in claim 1. Further features that advantageously develop the inventive ideas are the subject matter of the subclaims.
An element of the present invention is to design a glazing element for facing building facades or window systems, in particular for vehicles, trains or aircraft according to the generic part of claim 1 in such a manner that, in addition to the coating buildup in the intermediate space, which is free of water, is solely a reducing or oxidizing gas or a gas mixture comprising a reducing or oxidizing gas and an inert gas is provided and that an electric voltage of less than 1.2 volts is applied between the electrically conductive and the electrocatalytical layer.
The present invention is based on the idea of obviating all intermediate layers which impair the optical transmission properties of the invented glazing element. Instead of the sponge structure described in DE 24 36 174 A1, the present invention provides only a gas atmosphere which preferably comprises a mixture of a reducing gas, such as for instance hydrogen gas and an inert gas, such as for instance argon or nitrogen. An essential aspect of the present invention is that the electrochromic glazing element operates without the use of water. It was possible to demonstrate that the invented system can operate at voltages distinctly below the water separation voltage (1.2 V). In this manner the element can be operated at lower operating voltages so that the lifetime of the glazing element can be increased considerably.
The invented glazing element is provided with two panes which can be made of glass or plastic. On at least one pane surface, which faces the intermediate space between the two panes facing each other, a transparent, electrically conductive layer is applied on which, for its part, electrochromic material, such as for instance wolfram dioxide, molybdenum oxide, titanium oxide, vanadium oxide, chromium oxide, nickel oxide, cerium oxide, niobium oxide, yttrium oxide, or viologene is precipitated. Furthermore, an ion conductor, such as for instance made of aluminum oxide, silicon oxide, tantalum oxide, or a polymer electrolyte or an ion-conducting foil, is applied onto the electrochromic material layer. Finally an electrocatalytic layer is precipitated on the ion-conducting layer on which, if need be, another grid structure is applicable, which is made of an electrically conductive material and possesses transparent and hydrogen-permeable properties. The grid layer is, in particular, applied onto the electrocatalytic layer if, in the case of large-surface systems, the electric line of the electrocatalytic layer is dimensioned too small. As an alternative, an electrically conductive, transparent H2 respectively H conducting layer can be applied e.g. even above respectively below the catalyst layer.
As previously mentioned, over this layer build up there is a gas atmosphere of a mixture of a reducing gas, such as for instance hydrogen gas and an inert gas, such as for instance argon or nitrogen. Small admixtures of oxygen gas, as may occur in the course of time due to small leaks, do not disturb the function of the element significantly. If too much hydrogen gas escapes or too much oxygen gas diffuses into the intermediate space between the two panes, the gas atmosphere can be replaced. It is especially important to note that the concentration of the hydrogen gas can be maintained distinctly below the explosion limit.
Another variant is the use of oxidizing gases respectively gas mixtures such as for instance air, in the case of anodic instead of cathodic electrochromic materials such as for instance NiOx instead of WO3.
The manner of function of the invented glazing element is described below:
In the gas mixture introduced between the glass panes, the H2-molecules are absorbed at the electrocatalytic layer and are catalytically dissociated and ionized at this layer. Oxygen molecules entering the intermediate oxygen molecules as a result of leaks are also dissociated and ionized by the catalytic action. If a voltage is applied to the electrically conductive layer, applied immediately to the pane surface, so that this layer becomes the cathode, the electric field caused by it draws H+-ions via the ion conductor into the wolfram oxide layer Due to the opposite polarity of the O2xe2x88x92-ions, these ions do not penetrate the layer sequence, in which the H+-ions migrate due to the potential conditions. At the same time, electrons migrate from the transparently designed electrically conductive layer into the electochromic layer and color the same. The charge neutrality of the electrochromic layer remains ensured by the simultaneous entry of H+-ions and electrons.
If the voltage is cut off, the electric field is maintained by the electrochemical potential of the electrochromic layer due to the coloring as is the coloring.
If however the electrically conductive layer becomes the anode, the HH+H-ions and the electrons are drawn off again from the electrochromic layer resulting in decoloring.
Thus by applying voltage between the electrically conductive, transparent layer on the pane and the electrocatalytic layer, the electrochromic layer can be colored and can be decolored again by pole reversal. Depending on the duration of the applied voltage, the coloring and decoloring is infinitely variable. If the voltage is cut off, the abovementioned color state is retained.

Fraunhofer Gesellschaft zur Forderung der angewandten Forschung e.V.


A current controlled oscillator circuit comprising a "variable-ratio current mirror", for providing a variable output current that varies in response to process. The "variable-ratio current mirror" having a reference MOS transistor and a mirrored MOS transistor, and the reference MOS transistor has a greater predetermined channel length than the channel length of the mirrored MOS transistor. A second current mirror is coupled to the "variable-ratio current mirror" to provide a control current that decreases in response to an increase in the variable output current of the "variable-ratio current mirror." A multi-stage ring oscillator having a plurality of series-connected inverter stages is responsive to the control current of said second current mirror for controlling the frequency of oscillation of said multi-stage ring oscillator.

The invention relates to a CMOS current controlled ring oscillator (VCO) and particularly to a method and system for obtaining a well-controlled output range over varying process.
The VCO is an oscillator whose frequency is proportional to an externally applied voltage. VCO's are commonly used in phase-locked loop (PLL) designs. A block diagram of a basic PLL system is shown in FIG. 1. The elements of the system are a phase detector (12), a loop filter (14), and a VCO (16) interconnected to form a feedback system. The phase detector compares the phase of the input signal Vs(t) with the output frequency Vo(t) of the VCO and generates an error voltage Vd(t) corresponding to the difference. The error voltage signal Vd(t) is then filtered by the loop filter and applied to the control terminal of the VCO in the form of an error voltage Ve(t) to control its frequency of oscillation.
A problem that has plagued VCO designs in the past has been that of maintaining a constant VCO Ve(t) error voltage characteristic over the wide process variations that are inherent in the CMOS devices (i.e. changes in the manufacturing process, such as changes in doping levels and lithography variations). Process variations can cause a huge shift in the gain of a delay element that forms the ring oscillator. This in turn changes the gain constant, tuning slope, and the frequency (FIG. 2). Good PLL designs require a knowledge and control of several loop parameters--one of which is the VCO gain. Thus, the VCO circuit needs to be de-sensitized to the process variations so that the PLL dynamics are not disturbed.
A patent assigned to National Semiconductor Corporation and issued to Rasmussen, U.S. Pat. No. 5,061,907 discloses a VCO that includes a multistage ring oscillator, a voltage-to-current converter, process compensation circuitry, and a trip-point compensation circuit. This VCO achieves immunity from process variations by the use of the process compensation circuitry and the trip-point compensation circuitry. The process compensation circuitry in Rasmussen responds to the error voltage input signal to provide a current dump output signal that is dependent on transistor strength, i.e., dependent on process variation. The trip-point compensation circuit in Rasmussen generates a net current created by subtracting the process compensation current from the current generated by the voltage-to-current converter, and then steers a variable percentage of that net current to the ring oscillator in accordance with the strength of the N- and P-channel transistors in the device.
The output currents from both the voltage-to-current converter and the process compensation circuitry in Rasmussen are dependent on the error voltage input signal and the relative strengths of the N and P channel devices. However, under certain conditions where the N and P channel devices are particularly strong and the error voltage is at a particularly high level, an inappropriate current dump output signal can exist. This condition exists when the process compensation current (current dump) becomes too high and thereby too much current is starved from the ring oscillator via the trip point compensation circuitry. The present invention avoids this inappropriate current dump output signal condition by never allowing the ring oscillator current level to become too low.
Another drawback to Rasmussen is that the process compensation current (current dump) will vary with VCC supply voltage. Thus, changes in VCC supply voltage may cause the current dump to become too low or too high. The present invention avoids this dependency on the VCC supply voltage by using only the error voltage and process strength to establish the proper current levels.
A patent assigned to National Semiconductor Corporation and issued to Jelinek et al., U.S. Pat. No. 5,331,295 discloses a VCO that includes a multistage ring oscillator that includes a plurality of series-connected current-starved inverter stages. The VCO utilizes a first current source to provide a substantially constant current independent of process variations and a second current source to provide a variable current that varies in response to process variations. An attenuator, responsive to the VCO's input voltage signal (typically from a phase-locked loop filter) provides a control current signal to the ring oscillator. The attenuator receives a supply current created by subtracting the second current from the first current, and utilizes a differentiation subcircuit that attenuates the supply current in response to changes in an input voltage to produce a current control signal that sets the current level in the ring oscillator's cells. The frequency of oscillation of the ring oscillator is determined by the control current signal.
A drawback to Jelinek is the requirement of the first current source to provide an accurate current that is independent of process variations. This first current source requires the use of complex circuitry and accurate resistor elements which increases the size and power consumption of the overall circuit. The present invention avoids the use of such a large and complicated current source.

Process compensation method for CMOS current controlled ring oscillators


Folding blade (1) that is particularly applicable to devices for the closure of flexible tubular packaging, taking the form of a flat plate, provided on one of its lateral edges with a tab (5) in the form of a hook that is adapted to hold the packaging, of the type that is disposed opposite and perpendicular to a lateral portion of the packaging and attached to an axis of rotation (3) that transmits thereto a reciprocating rotational movement around the axis. This folding blade (1) comprises a main body (2) that can be attached to the axis of rotation; an end portion (4) provided with a tab (5) that is joined by articulation to the main body by its free end opposite the axis of rotation (3); and an elastic means (6) that exerts a permanent pulling force on said end portion, thus maintaining it in the initial position, folded over the main body of the blade.

There is a large variety of known automatic filling machines for flexible tubular packaging, such as mesh bags for packaging fruit and vegetable products, which generally comprise a pair of clips that hold the packaging to be filled through its upper aperture, in an open position, while the packaging is filled. Once the packaging has been filled, it is then closed, which is normally achieved by pushing together the clips holding the packaging, closing its upper part, then joining the two opposite closure portions of the edge of the packaging's upper aperture.
In order to ensure an optimum closure of the packaging, it is common to fold the lateral portions of the packaging between the closure portions that have been joined, so that the resulting folds are positioned, at least partially, between said joined portions, these lateral portions being folded similarly to an accordion.
A particular type of folding device that is applicable to the closure of this type of packaging comprises two folding blades disposed opposite each other in a direction perpendicular to a respective lateral portion of the packaging, attached to a respective axis of rotation that transmits thereto a reciprocating rotational movement around the axis. In each operational cycle, the folding blades rotate first in the direction towards the packaging to be closed, its ends pushing the respective lateral portion of the packaging and creating an inward fold, and subsequently rotating in the opposite direction, recovering their initial position in order to receive the next portion of packaging to be filled and closed.
The folding blades take the form of a flat plate and they are provided on their lateral edges with a tab in the form of a hook. This tab is adapted to hold and push the packaging during the folding operation by retaining at least one of the openings in the mesh of the opposite portion of packaging.
The use of the aforementioned folding blades tends to put a strain on the threads or tapes of the mesh of the packaging when the blades rotate and push the respective lateral portions inwards and the tabs pull on one of the openings in the mesh. This strain can cause the mesh of the packaging to be damaged or even broken during the subsequent handling of the filled packaging.
Furthermore, in the use of devices for the closure of packaging by sticking together said opposite portions that include the formation of lateral folds, it is normal for small sections of the strands that form the threads or tapes of the packaging to protrude from the opposite lateral portions that are stuck together, causing a flawed outer appearance or a poor presentation of the packaging filled with the product.


A precision guided munition with a fin assembly comprising a free spinning hub to which the fins attach addresses the need to roll control a projectile while eliminating the problems of the fin kit. The fin hub, to which the fins are attached, is radially decoupled from the mortar tail boom thus allowing it and the fins to spin freely relative to the body without coupling any of the spin. Advantageously, the need for a bearing between the hub and the tail boom is negated.

The invention relates in general to precision guided projectiles and in particular to fin stabilized precision guided projectiles.
Mortars are an indirect firing capability used to defeat enemy troops, materiel, bunkers and other infantry-type targets. Conventional mortars typically require warfighters to fire multiple rounds as they adjust fire to accurately hit their target. Precision guided mortars, in contrast, allow for more precise engagement of a target than conventional mortars.
Precision guided mortars are necessary when warfighters can't afford for a mortar round to be off target, such as in an urban environment where there is a potential for collateral damage. By allowing for mortar fire in an otherwise off-limits environment, warfighters may not have to risk engaging targets with direct-fire weapons. Additionally, a precision mortar fire allows an operator to effectively engage a target in a shorter amount of time thereby allowing them to reposition before receiving counter-fire. Finally, precision guided mortars reduce the logistical burden for troops as troops as the quantity of rounds fired may be reduced thereby reducing the quantity of rounds that must be supplied, stored and carried.
For precision guided mortars, typically an initial phase of ballistic flight exists on the up-leg and then a roll controlled guided phase occurs after apogee. To implement the control scheme on the round, it is necessary to control the roll of the airframe during the guided phase. Precision munitions that use deflectable canards to create maneuvers experience a reduction in their control authority in the roll direction due to roll torque created by the fins, either by design or due to tolerance asymmetries, and by downwash effects of the canard on their fins.
Fin stabilized projectiles, such as mortars, typically use small fin cant angle or beveled edges to generate a small amount of roll torque on the airframe to aid in stability and reduce ballistic dispersion. Any fin induced roll torque needs to be fought by the canard actuation system which executes the roll control and thus takes away from the overall maneuverability. Eliminating all of the roll torque completely from the fins is one solution; however this requires costly machining and inspection of the piece parts and assemblies to ensure no small asymmetries exist.
However, even if all of the roll torque induced by the fins alone can be eliminated, undesirable roll commands are still induced by the canard-fin interaction. Downwash effects on the fins causing a pressure differential to develop on the fins which in turn reduces roll control authority. This is especially an issue for projectiles with shorter bodies, such as mortar rounds, as opposed to longer rounds like rockets. In shorter rounds, the flow has less travel distance to normalize before the fins.
There exists a need for a precision guided projectile which can mitigate roll control issues caused by deflectable canards while maintaining canard control of the weapon.

Free spinning hub for mortar projectiles

U.S. Government as Represented by the Secretary of the Army


The present invention is a single site or multiple site chemotaxis test apparatus or chemotaxis chamber for measuring the effect of concentration gradients of diffusible chemicals upon the directional response of biological cells. The chemotactic test apparatus of the present invention comprise two compartments separated by a thin passage. The dimensions of the thin passage are selected such that cells cannot flow through the thin passage, but must deform themselves by flattening out and then "crawl" or migrate through the passage. These chambers can be used to study the migration or orientation of mobile adherent or non-adherent cells.

1. Field of the Invention
The present invention relates to chemotaxis chambers, i.e., to chambers for measuring the effect of concentration gradients of diffusible chemicals upon the directional response of biological cells. More specifically, the present invention relates to chemotaxis chambers comprising two compartments separated by a thin passage, used to study the migration or orientation of adherent mobile cells.
2. Background of the Invention
Chemotaxis is the directional response of biological cells or organisms to concentration gradients of mobile chemicals. Conventional chemotaxis chambers comprise two compartments separated by a filter, with one or both of the compartments open to air. Cells in suspension are placed in the upper compartment, and a chemotactic factor or control is placed in the bottom compartment. The chemotactic factor can be used in various dilutions to get a dose-response curve. The controls are generally of two kinds: negative, when the same medium is used to suspend the cells above and below the filter; and chemokinetic, when a chemotactic factor is placed in the same concentration in the medium with the cells and on the opposite side of the filter. Chemokinetic controls allow the user to distinguish heightened random activity of the cells, due to contact with the chemotactic factor, from directional response in a concentration gradient of the chemotactic factor.
Chemotactic activity is measured by first establishing a stable concentration gradient in the chemotaxis chamber. The chamber is incubated for a predetermined time, then the filter is removed from the apparatus. The cells that have migrated through the filter (or into the filter to a certain depth) are then counted. A comparison is then made between the activity of the cells in a concentration gradient of the chemotactic factor being tested, and the activity of the cells in the absence of the concentration gradient.
The apparatus can also be used to measure the response of cells of different origins--e.g., immune cells from patients suffering from diseases--to a chemotactic factor of known chemotactic activity. In this case the cells in question are challenged by both a negative control and the chemotactic factor to see if the differential response is depressed or normal.
Cell orientation in response to a concentration gradient of chemotactic factor can be determined using a Zigmond chamber. A Zigmond chamber is a 2 mm thick microscope slide with two 1 mm deep.times.4 mm wide grooves ground across the slide, leaving a 1 mm wide unground section between the grooves. Cells are allowed to adhere to a microscope coverglass, which is then inverted so that the cells and some fluid media are positioned over the 1 mm wide unground section of the slide. The coverglass is clamped in this position at each end of the slide, chemotactic factor is pipetted into one of the two grooves, and media is pipetted into the other groove. Capillary action draws the fluid into the grooves. The slide is incubated at 37.+-.1.degree.0C. for about 30 minutes. It is then viewed under a microscope at a magnification of 100 to 1,000 X, and the extent of cell orientation is observed. Migration of the cells can also be studied using elaborate time-lapse image analyzers. Usually, however, the chamber is only used to check the proportion of cells that orient towards a chemotactic factor concentration gradient, compared to the proportion of oriented cells in a control chamber that does not have a chemotactic factor concentration gradient.
Microchemotaxis chambers and some of their applications are described in Falk et al., 37 A 48 Well Micro Chemotaxis Assembly for Rapid and Accurate Measurement of Leukocyte Migration," Journal of Immunological Methods, 33, 239-247 (1980); Harvath et al., "Rapid Quantification of Neutrophil Chemotaxis: Use of a Polyvinylpyrrolidone-free Polycarbonate Membrane in a Multiwell Assembly," Journal of Immunological Methods, 37, 39-45 (1980); Richards et al., 37 A Modified Microchamber Method for Chemotaxis and Chemokinesis," Immunological Communications, 13 (1), 49-62 (1984); Falk et al., "Only the Chemotactic Subpopulation of Human Blood Monocutes Expresses Receptors for the Chemotactic Peptide N-Formylmethionyl-Leucyl-Phenylalanine," Infection and Immunity, 36, 450-454 (1982); Zigmond, Sally, Gatewood, Beth and Joe, John, "CD45 is Not Involved in the Processing of Spatial Information Required for Chemotaxis," Journal of Immunology (to be published); Zigmond, Sally and Lauffenburger, Douglas A., "Assays of Leukocyte Chemotaxis," Annual Reviews of Medicine, 37, 149-155 and Harvath et al., "Two Neutrophil Populations in Human Blood with Different Chemotactic Activities: Separation and Chemoattractant Binding," Infection and Immunity, 36 (2), 443-449 (1982), all of which are expressly incorporated by reference herein.
Multiple-site chemotaxis chambers are described in patent application Ser. No. 07/672,561, filed on Mar. 20, 1991, which is expressly incorporated by reference herein.


The invention provides a disk playback device wherein a disk (1) is irradiated with a laser beam from an optical head (4) to reproduce signals from the disk, and which comprises an external synchronizing signal producing circuit (8) and a delay circuit (12) for producing a reproduction synchronizing signal providing reference timing at which a reproduced signal is detected by reading an output signal from the optical head (4), a circuit (7) for detecting the reproduced signal by reading the output signal from the optical head (4) based on the reproduction synchronizing signal, and a system controller (10) for determining an optimum phase for a normal reproduction operation by altering the phase of the reproduction synchronizing signal and executing a reproduction operation, the controller (10) being operable to make a phase adjustment for the reproduction synchronizing signal prepared by the delay circuit (12). A normal reproduction operation can be performed at all times by assuring the reproduction synchronizing signal of the optimum phase.

For use as recording media in disk recording-playback devices adapted to record signals on disks and reproduce signals therefrom, magneto-optical disks have been developed which permit rewriting and have a great memory capacity and high reliability. Such disks have found wide use as external memories in computers and audio visual devices.
Developed especially in recent years are techniques for achieving improved recording densities by forming lands 17 and grooves 18 alternately on the signal bearing surface of a magneto-optical disk 1 as shown in FIG. 12 and recording signals on both the land 17 and the groove 18. The lands 17 and the grooves 18 are wobbled as illustrated, and the wobbling frequency is a predetermined center frequency as frequency-modulated. A wobble signal is detected by signal reproduction, and the rotation of the magneto-optical disk is so adjusted that the wobble signal has the center frequency at all times, whereby constant linear velocity control is realized. Various items of information (wobble information) such as address information are contained in the wobble signal which is frequency-modulated as stated above. Various control operations are realized based on the wobble information at the time of signal reproduction.
With the disk recording-playback device for use with such magneto-optical disks serving as recording media, an optical head projects a laser beam onto the disk along the land or groove for signal recording or reproduction, and laser spots are formed on the signal bearing surface of the disk as shown in the form of traces in FIGS. 6(a), (b) and (c). As a result, the recording signal is recorded on the disk in crescent recording areas illustrated. Accordingly, it is desired to read the signal at the position of center of each recording area for signal reproduction. For this purpose, a reproduction synchronizing signal as shown in FIG. 6 is produced so as to read the signal as timed with the synchronizing signal.
The size of laser spots to be formed on the signal bearing surface of the magneto-optical disk is determined according to the magnitude of the laser power and the heat transfer characteristics of the disk. When the spot diameter varies as shown in FIGS. 6(a), (b) and (c), the position of the center of the crescent signal recording area correspondingly shifts as illustrated. Accordingly, even if the reproduction synchronizing signal shown in FIG. 6 has an optimum phase for the arrangement of recording areas shown in FIG. 6(b), the phase of the synchronizing signal will differ from the optimum value for the arrangement of recording areas shown in FIG. 6(a) or (c).
For example with disk recording-playback devices adapted for constant angular velocity control, the inner peripheral side of the disk and the outer peripheral side thereof are different in linear velocity to result in a corresponding difference in optimum laser power, so that the inner peripheral side of the disk and the outer peripheral side thereof differ in the optimum phase of reproduction synchronizing signal. Furthermore, the optimum phase will differ locally, for example, due to local deterioration of the disk. If the phase of the reproduction synchronizing signal is held constant in such a case, the phase will differ from the optimum value.
If the phase of the reproduction synchronizing signal differs from an optimum value P as shown in FIG. 13, the bit error rate of the reproduced signal increases, and difficulty is encountered in performing a normal reproduction operation if the bit error rate exceeds a given threshold value Rbt. No measure has been taken against an increase in bit error rate due to such a difference of the phase of the reproduction synchronizing signal.
Accordingly, a first object of the present invention is to provide a disk playback device which is capable of performing a normal reproduction operation at all times by an optimum phase of the reproduction synchronizing signal.
Further when disk recording-playback devices are in operation for reproducing or recording signals, focusing servo or tracking servo is performed for the actuator incorporated in the optical head, based on a focus error signal or tracking error signal so as to obtain a satisfactory focus state or tracking state. When the disk recording-playback device is initiated into operation, an offset adjustment is made for focusing or tracking to thereby ensure accurate focusing servo and tracking servo for the subsequent signal reproduction or recording operation.
With disk recording-playback devices, however, variations in the ambient temperature leads to the distortion of the housing or parts of the optical head, a shift of position of the optical sensor, variations in the laser wavelength, etc., altering the offset value from an optimum value and consequently impairing the accuracy of focusing servo and tracking servo. If the offset value deviates from the optimum value T greatly as shown in FIG. 14, the bit error rate of reproduced signal exceeds the threshold value Rbt, presenting difficulty in effecting normal reproduction.
Accordingly, a second object of the invention is to provide a disk playback device wherein focusing servo or tracking servo can be performed with high accuracy at all times despite variations in the ambient temperature.


High flow brominated polycarbonates, useful as flame retardant additives for other polymers such as polyesters, are obtained by equilibration of a brominated aromatic polycarbonate such as a tetrabromobisphenol A homo- or copolycarbonate with a di- or polyhydroxy aromatic compound such as bisphenol A, or a diaryl carbonate, and an equilibration catalyst, under conditions such that the weight average molecular weight of the brominated polycarbonate is reduced by at least 35%. Preferred equilibration catalysts are Group I metal carboxylates, such as sodium stearate, and hexaalkylguanidinium salts.

This invention relates to flame retardant additives for polymers, and more particularly to a method for preparing brominated polymers useful as flame retardants.
The use of brominated polymers, especially polycarbonates, as flame retardant additives for other polymers has been known for some time. For example, U.S. Pat. Nos. 3,915,926 and 3,936,400 describe the preparation of polycarbonates derived from such brominated monomers as 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, hereinafter sometimes designated "TBBPA", and the use of said polycarbonates as flame retardants for polyesters, such as poly(ethylene terephthalate) and poly(butylene terephthalate). Typically, the polymer employed is a TBBPA homopolymer or a copolymer of TBBPA with 2,2-bis(4-hydroxyphenyl)propane, hereinafter sometimes "bisphenol A". For the most part, it is an oligomer having a weight average molecular weight in the range of about 1,500-5,000, all weight average molecular weights herein being determined by gel permeation chromatography relative to polystyrene, since high molecular weight TBBPA polycarbonates tend to produce such high viscosities and glass transition temperatures in the flame retardant blend that processing is difficult or impossible.
Several disadvantages are encountered in the use of such TBBPA oligopolycarbonates as flame retardants. First, they are often expensive to manufacture, particularly since their preparation may require redirection of an existing polycarbonate manufacturing facility with a resulting loss in production of conventional polymers such as bisphenol A polycarbonates. Second, the molecular weights of the blends in which the TBBPA oligopolycarbonates are incorporated tend to change markedly when they are exposed to thermal aging in air. A typical TBBPA copolymer, for example, doubles the molecular weight of a base poly(1,4-butylene terephthalate) in which it is incorporated after about a day at 190.degree. C., and the blend then loses molecular weight.
U.S. Pat. Nos. 5,021,521 and 5,414,057 describe the preparation of various types of polycarbonates by equilibration or redistribution. In such reactions, a high molecular weight polycarbonate is heated in the presence of a catalyst, and optionally a diaryl carbonate or di- or polyhydroxyaromatic compound, to produce a redistributed or equilibrated polycarbonate of a different, usually lower, molecular weight.
The catalysts employed according to said patents include a wide variety of chemical compounds, chiefly bases and Lewis acids. A strictly non-exhaustive list of examples includes alkali and alkaline earth metal carboxylates such as lithium stearate, hydrides such as sodium hydride, borohydrides such as sodium borohydride, organotin compounds such as di(n-butyl)tin oxide, titanate esters such as tetra-n-propyl titanate, and tetraalkylammonium compounds such as tetramethylammonium hydroxide, tetramethylammonium acetate and tetra-n-butylammonium tetraphenylborate. Copending, commonly owned application Ser. No. 08/768,871 discloses hexaalkylguanidinium bisphenolates which are also useful as catalysts in a wide variety of equilibration reactions of this type.
Such an equilibration reaction (the word "equilibration" being used hereinafter for brevity to designate both equilibration and redistribution reactions) might be expected to be useful for producing brominated polycarbonates having suitable viscosity properties for use as flame retardants. It has been discovered, however, that many of the previously disclosed equilibration catalysts are not effective in the presence of brominated polycarbonates. This is true even though said catalysts are effective for equilibration of other polycarbonates, such as bisphenol A homopolycarbonates.
It is of interest, therefore, to develop a method of preparing brominated polycarbonates having high stability under thermal air aging conditions and having viscosities which are a good match for the polymers in which they are to be incorporated as flame retardant additives. It is further of interest to prepare such polymers by a relatively simple method such as equilibration.

Method for preparing brominated polycarbonates, and products obtained thereby


A stationary tucker bar mechanism attached to a vertical form, fill, and seal packaging machine used to construct a vertical stand-up pouch and a gusseted flat bottom bag. The invention involves producing a vertical stand-up pouch or flat bottom bag from a single sheet of packaging film by forming one or two vertical creases along opposing sides of the packaging film tube prior to forming a transverse seal on the tube. The vertical crease is formed using the stationary tucker bar gusseting mechanism positioned outside the packaging film tube and positioned between two forming plates located inside the packaging film tube. While the tucker bar gusseting mechanism is stationary during operation, it is fully adjustable along multiple axes of orientation.

1. Technical Field
The present invention relates to a stationary tucker bar mechanism attached to a vertical form, fill, and seal packaging machine and method for using the same to construct a vertical stand-up pouch and a gusseted flat bottom bag, that provides for a single piece construction of a vertical stand-up bag suitable for retail snack food distribution. The invention allows for use of existing film converter and packaging technology to produce a stand-up package with minimal increased costs and minimal modifications.
2. Description of the Related Art
Vertical form, fill, and seal packaging machines are commonly used in the snack food industry for forming, filling, and sealing bags of chips and other like products. Such packaging machines take a packaging film from a sheet roll and forms the film into a vertical tube around a product delivery cylinder. The vertical tube is vertically sealed along its length to form a back seal. The machine applies a pair of heat-sealing jaws or facings against the tube to form a horizontal transverse seal. This transverse seal acts as the top seal on the bag below and the bottom seal on the package being filled and formed above. The product to be packaged, such as potato chips, is dropped through the product delivery cylinder and formed tube and is held within the tube above the bottom transverse seal. After the package has been filled, the film tube is pushed downward to draw out another package length. A transverse seal is formed above the product, thus sealing it within the film tube and forming a package of product. The package below said transverse seal is separated from the rest of the film tube by cutting horizontally across the sealed area.
The packaging film used in such process is typically a composite polymer material produced by a film converter. For example, one prior art composite film used for packaging potato chips and like products is illustrated in FIG. 1, which is a schematic of a cross-section of the film illustrating each individual substantive layer. FIG. 1 shows an inside, or product side, layer 16 which typically comprises metalized oriented polypropylene ("OPP") or metalized polyethylene terephtalate ("PET"). This is followed by a laminate layer 14, typically a polyethylene extrusion, and an ink or graphics layer 12. The ink layer 12 is typically used for the presentation of graphics that can be viewed through a transparent outside layer 10, which layer 10 is typically OPP or PET.
The prior art film composition shown in FIG. 1 is ideally suited for use on vertical form, fill, and seal machines for the packaging of food products. The metalized inside layer 16, which is usually metalized with a thin layer of aluminum, provides excellent barrier properties. The use of OPP or PET for the outside layer 10 and the inside layer 16 further makes it possible to heat seal any surface of the film to any other surface in forming either the transverse seals or back seal of a package. Alternatively, a material can be used on the outside layer 12 that will not seal on itself, such as a paper layer or a non-sealing polymer layer, so that only the inside layer 16 is used as a sealing surface.
Typical back seals formed using the film composition shown in FIG. 1 are illustrated in FIGS. 2a and 2b. FIG. 2a is a schematic of a "lap seal" embodiment of a back seal being formed on a tube of film, which can be used when the outside and inside layers are sealable together. FIG. 2b illustrates a "fin seal" embodiment of a back seal being formed on a tube of film, which can be used when the outside layer is not suitable as a sealing surface.
With reference to FIG. 2a, a portion of the inside metalized layer 26 is mated with a portion of the outside layer 20 in the area indicated by the arrows to form a lap seal. The seal in this area is accomplished by applying heat and pressure to the film in such area. The lap seal design shown in FIG. 2a insures that the product to be placed inside the formed package will be protected from the ink layer by the metalized inside layer 26.
The fin seal variation shown in FIG. 2b also provides that the product to be placed in the formed package will be protected from the ink layer by the metalized inside layer 26. Again, the outside layer 20 does not contact any product. In the embodiment shown in FIG. 2b, however, the inside layer 26 is folded over and then sealed on itself in the area indicated by the arrows. Again, this seal is accomplished by the application of heat and pressure to the film in the area illustrated.
Regardless of whether a lap seal or fin seal is used for constructing a standard package using a vertical form, fill, and seal packaging machine, the end result is a package as shown in FIG. 3a with horizontally oriented top and bottom transverse seals 31, 33. Such package is referred to in the art as a "vertical flex bag" or "pillow pouch," and is commonly used for packaging snack foods such as potato chips, tortilla chips, and other various sheeted and extruded products. The back seal discussed with reference to FIGS. 2a and 2b runs vertically along the bag and is typically centered on the back of the package shown in FIG. 3a, thus not visible in FIG. 3a. Because of the narrow, single edge base on the package shown in FIG. 3a formed by the bottom transverse seal 33, such prior art packages are not particularly stable when standing on one end. This shortcoming has been addressed in the packaging industry by the development of a horizontal stand-up pouch such as the embodiment illustrated in FIGS. 4a, 4b, and 4c. As can be seen by reference to said figures, such horizontal stand-up pouch has a relatively broad and flat base 47 having two contact edges. This allows for the pouch to rest on this base 47 in a vertical presentation. Manufacture of such horizontal stand-up pouches, however, does not involve the use of standard vertical form, fill, and seal machines but, rather, involves an expensive and relatively slow 3-piece construction using a pouch form, fill, and seal machine.
Referring to FIGS. 4b and 4c, the horizontal stand-up pouch of the prior art is constructed of three separate pieces of film that are mated together, namely, a front sheet 41, a rear sheet 43, and a base sheet 45. The front sheet 41 and rear sheet 43 are sealed against each other around their edges, typically by heat sealing. The base sheet 45 is, however, first secured along its outer edges to the outer edges of the bottom of the front sheet 41 and rear sheet 43, as is best illustrated in FIG. 4c. Likewise, the mating of the base sheet 45 to the front sheet 41 and the rear sheet 43 is also accomplished typically by a heat seal. The requirement that such horizontal stand-up pouch be constructed of three pieces results in a package that is significantly more expensive to construct than a standard form, fill, and seal vertical flex bag.
Further disadvantages of using horizontal stand-up pouches include the initial capital expense of the horizontal stand-up pouch machines, the additional gas flush volume required during packaging as compared to a vertical flex bag, increased down time to change the bag size, slower bag forming speed, and a decreased bag size range. For example, a Polaris model vertical form, fill, and seal machine manufactured by Klick Lock Woodman of Georgia, USA, with a volume capacity of 60-100 bags per minute costs in the range of $75,000.00 per machine. A typical horizontal stand-up pouch manufacturing machine manufactured by Roberts Packaging of Battle Creek, Mich., with a bag capacity of 40-60 bags per minute typically costs $500,000.00. The film cost for a standard vertical form, fill, and seal package is approximately $0.04 per bag with a comparable horizontal stand-up pouch costing roughly twice as much. Horizontal stand-up pouches further require more than twice the oxygen or nitrogen gas flush. Changing the bag size on a horizontal stand-up pouch further takes in excess of two hours, typically, while a vertical form and fill machine bag size can be changed in a matter of minutes. Also, the typical bag size range on a horizontal stand-up pouch machine is from 4 oz. to 10 oz., while a vertical form and fill machine can typically make bags in the size range of 1 oz. to 24 oz.
One advantage of a horizontal stand-up pouch machine over a vertical form, fill, and seal and seal machine, however, is the relatively simple additional step of adding a zipper seal at the top of the bag for reclosing of the bag. Vertical form, fill, and seal machines typically require substantial modification and/or the use of zipper seals premounted on the film oriented horizontally to the seal facings used to seal the horizontal transverse seals.
An alternative approach taken in the prior art to producing a bag with more of a stand-up presentation is the construction of a flat bottom bag such as illustrated in FIG. 3b. Such bag is constructed in a method very similar to that described above with regard to prior art pillow pouches. However, in order to form the vertical gussets 37 on either side of the bag, the vertical form, fill, and seal machine must be substantially modified by the addition of two movable devices on opposite sides of the sealing carriage that move in and out to make contact with the packaging film tube in order to form the tuck that becomes the gussets 37 shown in FIG. 3b. Specifically, when a tube is pushed down to form the next bag, two triangular shaped devices are moved horizontally towards the packaging film tube until two vertical tucks are formed on the packaging film tube above the transverse seals by virtue of contact with these moving triangular shaped devices. While the two triangular shaped devices are thus in contact with the packaging tube, the bottom transverse seal 33 is formed. The package is constructed with an outer layer 30 that is non-sealable, such as paper. This causes the formation of a V-shaped gusset 37 along each vertical edge of the package when the transverse seals 31, 33 are formed. While the triangular shaped devices are still in contact with the tube of packaging material, the product is dropped through the forming tube into the tube of packaging film that is sealed at one end by virtue of the lower transverse seal 33. The triangular shaped devices are then removed from contact with the tube of packaging film and the film is pushed down for the formation of the next package. The process is repeated such that the lower transverse seal 33 of the package above and upper transverse seal 31 of the package below are then formed. This transverse seal is then cut, thereby releasing a formed and filled package from the machine having the distinctive vertical gussets 37 shown in FIG. 3b.
The prior art method described above forms a package with a relatively broad base due to the V-shaped vertical gussets 37. Consequently, it is commonly referred to in the art as a flat bottom bag. Such a flat bottom bag is advantageous over the previously described horizontal stand-up pouch in that it is formed on a vertical form, fill, and seal machine, albeit with major modifications. However, the prior art method of making a flat bottom bag has a number of significant drawbacks. For example, the capital expense for modifying the vertical form, fill, and seal machine to include the moving triangular-shaped devices is approximately $30,000.00 per machine. The changeover time to convert a vertical form, fill, and seal machine from a standard pillow pouch configuration to a stand-up bag configuration can be substantial, and generally in the neighborhood of one-quarter man hours. The addition of all of the moving parts required for the triangular-shaped device to move in and out of position during each package formation cycle also adds complexity to the vertical form, fill, and seal machine, inevitably resulting in maintenance issues. Importantly, the vertical form, fill, and seal machine modified to include the moving triangular-shaped devices is significantly slower than a vertical form, fill, and seal machine without such devices because of these moving components that form the vertical gussets. For example, in the formation of a six inch by nine inch bag, the maximum run speed for a modified vertical form, fill, and seal machine using the triangular-shaped moving devices is in the range of 15 to 20 bags per minute. A standard vertical form, fill, and seal machine without such modification can construct a similarly sized pillow pouch at the rate of approximately 40 bags per minute.
Consequently, a need exists for a method to form a stand-up pouch, similar in appearance and functionality to the prior art horizontal stand-up pouches and flat bottom bags, using vertical form, fill, and seal machine technology and a single sheet of packaging film. This method should allow for reduced film cost per bag as compared to horizontal stand-up pouches, ease in size change, little capital outlay, and the ability to easily add a zipper seal to the bags, all while maintaining bag forming speeds typical of vertical form, fill, and seal machine pillow pouch production. Such method should ideally produce a vertical stand-up pouch or a flat bottom bag constructed of materials commonly used to form standard vertical flex bags.

This patent is subject to a terminal disclaimer.