Bench-press and preacher-curl weight workout stations incorporate improved safety features to reduce the likelihood of injury to the weight lifter during the workouts. A bench assembly of the bench-press station has includes a platform and a base supporting the platform. The safety feature in the bench assembly is a platform height adjusting mechanism operable to permit one end of the platform to undergo pivotal movement from an upper position to a lower position relative to the base to where the body of the weight lifter is clear of the barbell so that the weight lifter can slide out from under the barbell and off the platform at the end of a workout session. A stand assembly of the preacher-curl station includes an elongated base and a support post attached to and extending upright from the base, and an elongated arm mounted above the base to the support post to undergo pivotal movement and extending outwardly in cantilevered fashion from the support post to an outer end supporting a shelf for holding a barbell. The safety feature in the stand assembly is a height adjusting mechanism operable to permit the elongated arm to undergo pivotal movement from a lower position to an upper position and thereby move the shelf from a start weight rest position to a finish weight rest position higher than the start position to where the barbell can be placed at the end of a workout session.

1. Field of the Invention
The present invention generally relates to body building and exercising equipment and, more particularly, to bench-press and preacher-curl weight workout stations incorporating safety features designed to reduce the likelihood of injury to the weight lifter.
2. Description of the Prior Art
An increasingly popular form of weight lifting is the bench press. In a bench-press weight workout, the lifter lies with his or her back resting on a horizontal or declined bench (angled so that the head is lower than the knees). A barbell is raised from a rest position on the weight lifter's chest, to full extension of the arms, and then back to the chest again. It is important in the bench-press weight workout that the lifter be working near his or her maximum weight limit for several repetitions, and that, in each repetition, the lifter be able to lower the barbell down to the chest.
Normally, the weight lifter will raise the barbell from a support rack located above the lifter's head when the bench-press workout begins and return the barbell to the same support rack when finished so that the lifter can then easily exit the bench. However, if the weight lifter is unable to return the barbell to the support rack at the finish of the workout, then the barbell will remain on the lifter's chest, pinning the lifter to the bench and subjecting the lifter to potentially serious injury. Because of this risk, it is common practice to require additional persons to be present to act as spotters who can assist in raising a barbell off a trapped weight lifter before serious injury occurs.
In recent years, an increasing trend has been for many weight lifters to workout by themselves, particularly in a home environment. In recognition of this trend, a number of mechanical devices have been proposed in an attempt to protect the weight lifter and/or raise the barbell after a failed lift. Representative of the prior art devices are those disclosed in U.S. Pat. Nos. to Flowers (3,874,658), Niles (4,216,959), Faust (4,249,726), Milnar (4,411,425), Comier (4,635,930), Cruz (4,773,642), Barrett (4,799,672), Selle (4,799,673) and Tanski (4,807,875). Most of these prior art devices contain one or more shortcomings which make them less than an optimum solution to the problem of protecting the solo weight lifter from the consequences of a failed lift.
One shortcoming of some of the prior art devices is that they simply prevent the barbell from being lowered far enough during the workout to pin the weight lifter. These devices will also prevent a weight lifter from fully completing the downward movement which is generally deemed necessary for maximum workout. As a result, such safety devices are seldom used by serious weight lifters.
Another shortcoming of other prior art devices is that they require that the barbell be raised or pushed by the pinned weight lifter in order to remove the barbell from the lifter's chest to a position where the barbell can be safely held clear of the lifter. A weight lifter who is unable to complete the lift and becomes pinned by the barbell will have extremely limited ability or energy to maneuver the barbell to such a position.
In order to avoid such shortcomings while still enabling the barbell to be raised, some of the prior art devices have provided means for mechanically raising the barbell from a trapped or pinned weight lifter. However, such devices are complicated and expensive and require an external power source for operation.
With respect to equipment used by weight lifters in preacher-curl weight workouts, a problem exist that is comparable to that described above with respect to bench-press weight workouts. Weight lifters using a standard preacher-curl stand must reach below the chest platform to remove the barbell from a fixed bracket. This can be extremely uncomfortable and can cause overextension of the elbows and lower back area. Further, at the completion of the lifting repetitions, many weight lifters drop the barbell into the fixed bracket in order to avoid possible overtension injury. Dropping the barbell into the bracket not only can damage the equipment, but also increases the risk of injury to the weight lifter and to other persons in the immediate vicinity.
Consequently, a need exists for the design of improved safety features on bench-press and preacher-curl workout stations which will avoid the aforementioned problems and shortcomings.

Bench-press weight workout station with safety features


Optimized routing in localized dense networks is provided. A packet is received at a first network device in a network. An optimal route for the packet to a neighbor network device in the network is determined using a Source Routing Table (SRT), wherein the SRT includes an optimized routing table and a standard routing table, and wherein the optimized routing table comprises a list of neighbor network devices that the first network device can route to directly and wherein the standard routing table comprises a ZigBee source routing table. The packet is routed using the optimal route.

ZigBee is a low-cost, low-power, wireless mesh network standard targeted at the wide development of long battery life devices in wireless control and monitoring applications. ZigBee devices have low latency, which further reduces average current. ZigBee chips are typically integrated with radios and with microcontrollers that have some amount of memory, currently typically between 60-256 KB of flash memory. ZigBee operates in the industrial, scientific, and medical (ISM) radio bands. The ZigBee network layer natively supports generic mesh networking. Every network must have one coordinator device, tasked with its creation, the control of its parameters, and basic maintenance.
In a wireless mesh network, such as but not limited to a ZigBee wireless network, a message (or packet) is routed from one node to another node using intermediary nodes. This is normally done when the two end nodes are not in radio range of one another, but all of the intermediary nodes and the end nodes in the chain are in radio range of the previous and the next node in the chain. Each time the packet is forwarded to the next node in the chain, this is a hop. In theory, using meshing, any node may talk to any other node in the ZigBee network, but often all nodes will talk to just one node and that one node will talk back to them. In such a configuration, the one node through which all traffic flows is the concentrator, and ZigBee has special allowances for this type of configuration. In this configuration, communication may be made to be more efficient through a mechanism called source routing. Essentially, all the non-concentrator nodes just need to know how to route a packet back to the concentrator. (In actuality, each node only knows the next node in the route to get back to the concentrator, and that next node knows its next node, and so on). The concentrator, however, needs to know the route to every single device on the network, and it needs to know the entire route. This puts most of the onus on the concentrator, which usually needs to be more intelligent and have more resources (memory, processing, communication, etc.) as a result.
The way the routes are formed in this configuration is that each node keeps track of its neighbors (devices within radio range) using its neighbor table and by listening to special types of messages called Link Status messages. These messages are not re-transmitted, so if a node hears one, it knows that it is in radio range of the device that sent the Link Status message. Periodically an MTORR (Many-to-One Route Request) packet or message is broadcast by the concentrator throughout the network. Devices build up their route back to the concentrator by using their neighbor tables and the propagation of the MTORR packet or message (routing cost back to the concentrator gets written to it by devices as it is re-broadcasted). Thus, Device A needs to be in Device B's neighbor table in order for Device A to route directly to Device B (and vice-versa).

This patent is subject to a terminal disclaimer.

Route optimization using star-mesh hybrid topology in localized dense AD-HOC networks


In a pulsed Fabry-Perot laser, such as a Q-switched laser or a mode-locked laser, one of the resonator reflectors comprises a waveguide loop coupled to the gain medium via a circulator. In one embodiment, only a modulator is located in the loop. In another embodiment, the circulator is switchable and the loop may contain either an unidirectional device, such as an isolator, or may contain only the waveguide itself, depending on which states of the circulator are utilized in the switching process. Also described are several arrangements for multiplexing lasers of different operating wavelengths.

Pulsed lasers are used in wide variety of applications ranging from signal sources in telecommunications systems to optical sources in sensing and measuring equipment. Q-switched lasers, for example, provide high power, short duration pulses for optical sensing functions, optical time domain reflectometry, and the measurement of nonlinearities in optical fibers. Illustratively, Q-switched lasers are capable of generating peak pulse powers of the order of a few hundred watts or more at repetition rates in the tens of kilohertz range. Pulse durations of a about 1-100 nanoseconds are typical. Mode-locked lasers, on the other hand, may serve as high speed (e.g., multi-gigabit) signal sources in telecommunication systems, particularly soliton transmission systems. As such, the mode-locked laser may generate peak pulse powers of a few hundred milliwatts at repetition rates in excess of 10 GHz. Pulse durations of a few picoseconds are typical.
Q-switched and mode-locked lasers have been extensively reported in the scientific literature. Two basic structures have been successfully demonstrated: a fiber laser ring topology of the type described by F.Fontana et al. in U.S. Pat. No. 5,381,426 issued on Jan. 10, 1995 and a Fabry-Perot (FP) fiber laser configuration of the type shown in U.S. Pat. No. 5,450,427 granted to M. E. Fermann et al. on Sep. 12, 1995. Both of these structures suffer from a similar malady, that is, relatively high insertion losses and hence relatively high lasing thresholds.
More specifically, in the ring topology, the single pass gain through the active medium has to exceed the optical insertion loss of the other intracavity components (i.e., the modulator, filter, isolator, etc.) in order to produce lasing. Similarly, in the case of the FP configuration the double pass gain of the active medium has to offset the double pass insertion loss produced by the same type of intracavity components.
One approach to alleviating this problem is to arrange for the laser radiation to make a double pass through its active medium for every single pass through the other intracavity components, thereby reducing the insertion loss introduced by those components. Such a design produces better performance in terms of lower lasing threshold and higher pump conversion efficiency. These indicia translate into higher power, shorter duration, and more stable pulses in both Q-switched and mode-locked lasers. See, for example, the mode-locked Er-fiber laser described by T. F. Carruthers et al. in Optic Letters, Vol. 21, No. 23, pp. 1927-1929, Dec. 1, 1996. In the Carruthers laser one mirror of the FP design is formed by a conventional Faraday rotator, but the other mirror comprises a polarization-maintaining (PM) fiber loop which is coupled to the active medium by a polarization splitter-combiner (PSC). A polarization dependent modulator is located in the loop along with a polarization-rotating splice, an isolator, and an output coupler. However, this design suffers from several disadvantages. First, in order that light in the Carruthers loop be coupled back through the PSC to the gain medium, the polarization must be rotated by 90.degree.; hence the loop includes a polarization-rotating splice. Second, the loop contains an isolator to provide isolation to the input side of the modulator. (To enhance performance the design might in practice very well include a second isolator on the output side of the modulator.) Third, the behavior of the modulator and the pulse quality (i.e., the shape and/or timing) may be adversely affected by the presence of the multiplicity of other components (i.e., the isolator, coupler, polarization-rotating splice) in the loop. Lastly, the presence of these additional elements in the loop increases the complexity of the design as well as the number of splices, and hence the total insertion loss.
Thus, a need remains in the art for simpler FP laser design that reduces insertion loss without the disadvantages attendant prior art FP designs.

Fabry-perot pulsed laser having a circulator-based loop reflector


An electric vehicle whose wheels are powered by a d.c. power supply includes a combination of a rechargeable high-energy battery and a rechargeable high-power battery or to a hybrid electric vehicle whose wheels are powered by the d.c. power supply and an internal combustion engine. The d.c. power supply is formed by connecting a d.c. circuit which comprises a rechargeable high-power battery and a current-stiff two-quadrant chopper in parallel with the rechargeable high-power battery. When an current of the rechargeable high-power battery is increased to a value which is greater than a specified value, the chopper is activated to charge or discharge the rechargeable high-power battery, thereby reducing an current of the rechargeable high-power battery to a value which is smaller than the specified value.

1. Field of the Invention
The present invention relates to an electric vehicle whose wheels are powered by a d.c. power supply comprising a combination of a high-energy rechargeable battery and a rechargeable high-power battery (an electric vehicle such as that powered solely by batteries will be hereinafter simply referred to as an "electric vehicle," as needed), and to a power supply system for a hybrid electric vehicle powered by a combination of a d.c. power supply and an internal combustion engine.
2. Description of the Related Art
FIG. 5 is a view showing a power train of a publicly-known series-type hybrid electric vehicle. In the drawing, reference numeral 1 designates an engine; 2 designates a generator (both the engine and the generator may also be collectively referred to as an "engine generator"); 3 designates a rectifier; 4 designates a main battery; 5 designates an inverter; 6 designates a vehicle drive motor; 7 designates a reduction gear; 8 designates a differential gear; 91 designates a right wheel; 92 designates a left wheel; 10 designates an auxiliary battery; 11 designates a DC-DC converter for recharging the auxiliary battery 10; 12 designates an auxiliary power supply for use with accessories; and 13 designates collectively-grouped accessories such as an air-conditioner.
In terms of efficiency of power generation and a cutback in exhaust gas of an engine, an engine generator is usually operated at an optimum engine speed under optimum load. Specifically, the engine generator is operated in a specified drive condition without reference to a vehicle speed, thereby recharging the main battery 4 via the rectifier 3.
An effort has been made to achieve a further improvement in efficiency and a further reduction in pollution by deactivating the generator 2 when the main battery 4 is recharged to or greater than a specified amount.
In this system, the power of the engine 1 is reduced to a power level smaller than the maximum power generally required to accelerate the vehicle, and the power required to accelerate the vehicle is supplied from the main battery 4. When the power of the engine 1 is greater than a vehicle driving force in constant driving, the main battery 4 becomes recharged by means an excess of power of the engine by way of the generator 2 and the rectifier 3.
When the vehicle is under braking, part of kinetic energy of the vehicle is stored in the main battery 4 through regeneration via the motor 6 and the inverter 5. Simultaneously, the rectifier 3 is operated in inverter mode, and the generator 2 is operated in motor mode. As a result, an engine brake is applied to the vehicle as in the case of an engine-driven vehicle. If there is a deficiency of electric braking force, the vehicle is mechanically braked as in the case of an unillustrated engine-driven vehicle.
Further, when the engine 1 is shut down, the generator 2 does not generate any power. In such a state, the vehicle driving force and the power used for accessories are supplied from the main battery 4.
The power train of the electric vehicle is the same as that shown in FIG. 5, except that the vehicle is not provided with the engine 1, the generator 2, and the rectifier 3. All the power required by the vehicle is supplied from the main battery 4. The main battery 4 is recharged by an unillustrated external power supply.
This electric vehicle does not produce any exhaust gas which would be otherwise produced as a result of operation of an engine, and hence corresponds to a zero-emission vehicle.
As mentioned previously, the publicly-known series-type hybrid electric vehicle is powered by the engine generator in constant driving, and a deficiency of the power required to accelerate the vehicle is remedied by the supply from the main battery 4. In a case where running power required when the engine is in an inactive state or power required by accessories is greater than the power generated by the engine generator, or where the required running power is greater than the power generated by the engine generator even in constant driving, a deficiency of power must be remedied by the power supplied from the main battery 4. For these reasons, the main battery 4 must be formed from a battery which produces high power, i.e., a high-power (or high power density) battery.
The presently dominant main battery for use with a publicly-known electric vehicle is a chemical battery which utilizes a chemical reaction, such as a lead battery, a nickel-hydrogen battery, or a lithium-ion battery. As a matter of course, the main battery is in principle the same as the main battery for use with a hybrid electric vehicle and, hence, is of high power type. There is a desire for a battery which produces greater power.
Next, regenerative braking featuring the hybrid electric vehicle or ordinary electric vehicle will be described. As mentioned previously, when the vehicle is under braking, the kinetic energy of the vehicle is stored in the main battery 4 through regeneration by way of the motor 6 and the inverter 5. The principle characteristic of the electric vehicle of this type is that part of the energy accumulated in the vehicle at the time of an accelerating operation can be regenerated when the vehicle is braked.
The same amount of power is usually generated by braking in a shorter period of time than by acceleration. This means that braking power is greater than accelerating power. Further, the chemical battery usually suffers greater losses at the time of recharge than at the time of discharge.
For these reasons, it is impossible for the hybrid electric vehicle or ordinary electric vehicle to regenerate all the power produced by braking. As things stand, the majority portion of energy produced by braking is converted into heat through mechanical braking.
This means that the bulk of generated power is discarded in the form of heat. Improving the efficiency of utilization of energy by regenerating as much power as possible at the time of a braking operation presents a significant problem.

Power supply system for electric vehicle


A method for driving an AC type plasma display panel includes the steps of performing initialization at least once for each frame so as to clear binary setting of wall charge quantity in a screen by discharge except for micro discharge in which electrodes covered with a plurality of fluorescent materials become cathodes, and performing special initialization at frequency of once for M frames, where M=two or more, so as to erase unnecessary wall charge in the screen by discharge in which electrodes become cathodes and that is stronger than the discharge in the initialization.

1. Field of the Invention
The present invention relates to a method for driving a plasma display panel (PDP).
2. Description of the Prior Art
A method for driving an AC type plasma display panel utilizes wall voltage generated by charge in a dielectric that covers display electrode pairs for a display. Quantity of wall charge in cells to generate display discharge is made larger than quantity of wall charge in other cells in a screen. Binary setting of this wall charge quantity is called addressing. After the addressing, an appropriate sustain pulse (that is also called a display pulse) is applied to all cells simultaneously. By the application of the sustain pulse, drive voltage is added to wall voltage. Display discharge is generated only in cells in which a cell voltage that is the sum of the drive voltage and the wall voltage exceeds a discharge start voltage. Light emission by the display discharge is called "lighting". By utilizing the wall voltage, it is possible to light only cells to be energized selectively.
In a display of a frame, the addressing is performed at fixed intervals, and initialization is performed in each addressing. The initialization means to clear the binary setting of the wall charge quantity that is kept in the screen at the start time point thereof, namely to equalize wall charge quantity of all cells. When the initialization is finished, the wall charge quantity depends on a form of the addressing. If write form addressing is performed, wall charge quantity of all cells is set to a quantity that cannot generate discharge when the sustain pulse is applied. If an erasing form of addressing is performed, wall charge quantity of all cells is set to a quantity that can generate discharge when the sustain pulse is applied.
As methods for initialization, there are known a method of applying a rectangular waveform pulse having a width smaller than the sustain pulse, a method of applying an obtuse waveform pulse such as a ramp waveform pulse, and a method of applying a rectangular waveform pulse plus an obtuse waveform pulse. These methods generate discharge that is weaker than display discharge and have an advantage that background light emission is little. The background light emission is a phenomenon that a dark portion of an image emits light slightly. In addition, if an obtuse waveform pulse is applied, quantity of the background light emission can be reduced while fine adjustment of the wall charge quantity for compensating variation of the discharge start voltage among cells can be performed. Japanese unexamined patent publication No. 11-352924 describes in detail about the initialization that utilizes "micro discharge" generated by applying an obtuse waveform pulse.
The micro discharge is a very weak discharge responding to the application of an obtuse waveform pulse whose amplitude changes gradually and is distinguished from one-shot discharge responding to the application of a rectangular waveform pulse having sufficient amplitude. The micro discharge starts when the sum of the applied voltage and the wall voltage exceeds the discharge start voltage and lasts until the applied voltage of the obtuse waveform pulse becomes a maximum value (a final voltage) in a continuous manner or a similar intermittent manner.
The conventional driving method has some problems. One is irregularity in a display that becomes conspicuous as time passes from the start of a continuous display that lasts approximately a few hours. Another problem is that the background light emission color becomes not an achromatic color (a dark gray color) but a chromatic color (a reddish, greenish or bluish color) when the initialization by the micro discharge is performed for a color display. Concerning the problem of the background light emission color, Japanese unexamined patent publication No. 2002-278510 discloses a driving method in which amplitude of the obtuse waveform pulse is optimized for each light emission color of a cell. However, this disclosed driving method needs a complicated structure of driving circuit.

Hitachi Plasma Patent Licensing Co., Inc.


A wheel speed correction device for use in a vehicle corrects for the change of the circumferential wheel speed caused by variations in the wheel tire diameter, differences in the paths of the left and right wheels when the vehicle turns, and/or abnormal slipping between the tire and the road surface. The wheel speed correction device has a device for measuring a wheel rotation angular speed of each wheel, a device for correcting a coefficient representing a tire diameter and producing a corrected coefficient for each wheel, a device for calculating, from the measured angular speed, a diameter-corrected wheel speed using the corrected coefficients, a device for obtaining a turning correction amount from a difference between diameter-corrected wheel speeds of the left and right wheels, and a device for correcting the diameter-corrected wheel speed using the turning correction amount.

1. Field of the Invention
The present invention relates to a wheel speed correction device, and more particularly, to a wheel speed correction device which appropriately corrects each wheel speed with respect to the changes in the diameter of the corresponding tire and the changes in wheel speed which occur when the vehicle turns, and thereby accurately calculates the wheel speed of each wheel.
2. Description of the Prior Art
For a wheel behavior control, such as an antilock brake control or a traction control, it is necessary to obtain the circumferential wheel speed. However, because it is difficult to directly measure the circumferential wheel speed, the wheel rotation angular speed is generally measured and converted to the circumferential wheel speed using appropriate coefficient representing the tire diameter. The term "wheel speed" generally used herein means circumferential wheel speed. The wheel speed thus obtained is known, however, to become offset from the real vehicle speed for a variety of reasons. Causes for the difference between the wheel speed and vehicle speed, i.e., the deviation, include: (i) in the long-term, differences in the real tire diameter and the tire diameter used in the calculation; (ii) in the mid-term, differences in the paths of the left and right wheels followed when the vehicle turns; and (iii) in the short-term, abnormal slipping between the tire and road surface. Variations in the tire diameter may arise due to differences in operating conditions, such as the tire air pressure and/or amount of tire wear.
However, in conventional control systems, specifically in wheel behavior control such as the antilock brake control which should be applied only to the variations caused by factor (iii) above, control is usually applied based on the wheel speed which includes deviations caused by the tire diameter and deviations caused by turning of the vehicle. Thus, when these deviations have become so great that they cannot be ignored, special logic which accounts for abnormal tire diameter becomes necessary to handle the deviations caused by factor (i), and special logic which accounts for vehicle turning becomes necessary to handle the deviations caused by factor (ii), and the wheel behavior control logic therefore tends to become complex.

Wheel speed correction device which compensates for changes in tire diameter and during vehicle turns


A sanitation device includes a mobile body, a surface cleaning component, and a source of UV radiation. The surface cleaning component and the source of UV radiation are mounted to the mobile body, which is configured to travel over a surface. The surface cleaning component is configured to engage the surface and the source of UV radiation is configured to direct UV radiation to the surface.

There are many different types of surface cleaners that are configured for cleaning various surfaces such as, for example, streets, hard floors, and carpet. Examples of such cleaning machines are disclosed in U.S. Pat. Nos. 6,162,542, 6,585,827, 6,671,925, 6,705,332, and 6,735,812, which are assigned to Tennant Company of Minneapolis, Minn. and are incorporated herein by reference in their entirety. Such surface cleaners can be configured as riding or towed-behind units that are typically power driven. The surface cleaners machines includes a surface cleaning component that engages the surface over which the machine travels. The cleaning components can include rotatable scrubbers, which are typically found on carpet cleaners and extractors and hard floor surface cleaners, and rotatable sweepers, which are typically found on street or floor sweepers, for example.
Although such surface cleaners may provide excellent results, some environments (e.g., hospitals, food processing plants, etc.) require additional efforts to be made to ensure sanitization of the surface being cleaned. In those instances, the surface cleaners can apply a chemical disinfectant to the surface. Unfortunately, such chemicals can be hazardous requiring the user to take safety precautions before handling the chemicals, and special care in their disposal. As a result, the use of such chemicals can be dangerous, time consuming, and expensive.


A facsimile apparatus from which paper sheets bearing an index mark is disclosed. The apparatus has: a counter for counting the number of connections between the apparatus and other facsimile apparatuses; an index signal generator for generating an index signal which represents an index mark; and an index mark-position adjuster for determining the position of an index mark in accordance with the number of connections. The image forming unit of the apparatus prints an index mark corresponding to the index signal, on a paper sheet and at a position determined by the index mark-position adjuster.

1. Field of the Invention
This invention relates to a facsimile apparatus for receiving image signals from another facsimile apparatus and forming images corresponding to the received image signals, on image receiving sheets such as paper sheets.
2. Description of the Prior Art
When transmitting images formed on several paper sheets from a facsimile apparatus (sending apparatus) to another facsimile apparatus (receiving apparatus), each of the original sheets are optically scanned one by one so that the images are transformed into electrical signals (image signals) each representing the pixels of the images, and a connection between the two apparatuses is established via a transmission line (hereinafter, communication established by such a connection is referred to as "a unit of communication"). Then, the image signals are transmitted from the sending apparatus to the receiving apparatus. In the receiving apparatus, the transmitted image signals are converted to the images printed on the same number of image receiving sheets or paper sheets. Usually, as shown in FIG. 5, additional data such as a page number PN and the sender's name or facsimile number are marked at the top of each paper sheet P in accordance with the CCITT recommendation. When another unit of communication is performed between the receiving apparatus and the same or other sending apparatus, another set of paper sheets P for the other unit of communication are output from the receiving apparatus.
The use of such a facsimile apparatus is rapidly increasing in offices, shops or the like. Accordingly, the number of paper sheets P output from a facsimile apparatus used in one place is expanded, and there are chances that paper sheets P of different units of communication may intermix in the course of handling the paper sheets or when they happen to drop from a tray of the apparatus and are scattered on a floor. In such a case, the problem is that the page numbers PN printed on paper sheets P cannot be utilized in rearranging in order the paper sheets of each unit of communication, because the page numbers PN are not given consecutively for all units of communication but for each unit of communication. Usually, paper sheets P are identified according to the sender's name or facsimile number printed at the top. Such a practice involves inefficient and bothersome works, and may often cause wrong recognition of some paper sheets, thereby making the subsequent handling of paper sheets difficult.


A semiconductor memory device including an address decode signal transmission circuit comprising address buffers; a predecoder; address buses provided before a main decode; a transmission circuit for outputting predecoded signals to the address buses while limiting amplitude thereof; and a receiving circuit provided before the main decoder for differentially amplifying signals from the address buses, wherein the memory cell array is divided into a plural number of sub-blocks and power can be selectively supplied to at least one of the sub-blocks.

1. Field of the Invention
The present invention relates to a semiconductor memory device capable of realizing the high-speed transmission of predecoded address signals, and of reducing power consumption using only part of its large-capacity memory.
2. Description of the Prior Art
It is well known that a CMOS memory has a construction shown in FIG. 1, wherein address signals A.sub.1 to An are supplied through address buffers 1a to 1n to a predecoder 2 and are predecoded.
The predecoded signals are then transmitted through predecoded signal lines 3a to 3n to a main decoder 4.
As shown in FIG. 1, the predecoded signal lines 3a to 3n have parasitic wire capacities C. The capacities C become larger with the increased length of the predecoded signal lines 3a to 3n. As the chips become larger in size along with increase in the memory capacity, the capacities C become larger.
In transmitting signals through the predecoded signal lines 3a to 3n with the capacities C, the capacities C need to be charged and discharged. Accordingly, it takes a long time to discharge and discharge the increased wire capacities C. Therefore, with the longer predecoded signal lines 3a to 3n, a delay time due to the capacities C is not ineligible, thus preventing address signals from being transmitted in high-speed.
Along with increase in the memory capacity, memory areas in the chip tend to be partly but not fully utilized.
However, in using only part of memory areas, all of its memory areas have been activated. Therefore, a stand-by current consumed by a semiconductor memory device is constant irrespective of memory bits to be used. As a result, even when only a limited number of bits are used, a large amount of stand-by current have been used in the same manner as in using all its memory areas.
Thus, in the case that a large-capacity memory device is contained in a system using large memory areas in the future but only part of its memory areas in the beginning, there causes such inconvenience that a large stand-by current is consumed even when the use of its memory areas is limited. Particularly, in a battery-operation system, the continuous operative time is shortened with the large current consumption, and consequently it is desired to reduce the current consumption. Therefore, in the case that a large-capacity semiconductor memory devices are contained in the system requiring only part of memory areas, it becomes advantageous that a large stand-by current is consumed.

Semiconductor memory device with high speed transmission of address signals between a predecoder and a main decoder


The invention relates to particular orthoester based polymers as well as the use of specific orthoester beased polymers as a demulsifier for water/oil emulsions.

Crude oil produced from geological formations can contain various amounts of water. The water contents normally vary both between production wells and during the lifetime of one and the same production well. Water and crude oil are immiscible by nature and are normally in different phases in an oil-containing geological formation. However, as oil is produced, it is inevitable that at the same time water is also produced. As the crude oil and water are transported through production tubing and equipment, they are subject to significant mixing energy, especially at points of pressure release. This mixing energy together with naturally occurring emulsifying compounds in the crude oil can create quite persistent emulsions. The nature of these emulsions can vary widely depending on the composition of the crude oil, the production method, etc.
For economical and logistics reasons as well as demands from downstream operations (refineries, etc.) it is very important to separate water from the produced oil as rapidly and completely as possible already at the production site. This separation is severely hampered by the above-mentioned emulsification prior to the separation stage. Traditionally, both physical and chemical methods have been utilized to quickly break these emulsions in the separation equipment.
In a large majority of cases, the addition of organic chemicals ("demulsifiers") is used either as the single method or in combination with physical methods. Demulsifiers can be used as a single compound, but due to the great variation in the nature of the water-in-crude oil emulsions, blends of demulsifiers are commonly utilized to achieve the highest possible technical efficiency in each single case.
Types of demulsifiers commonly used include mainly nonionic ethylene oxide/propylene oxide block polymers (polyglycols), alkylphenol-formaldehyde resin alkoxylates, and epoxy resin-based alkoxylates. (See "Something Old, Something New: A Discussion about Demulsifiers", T. G. Balson, pp. 226-238, esp. pp 232-236 in Proceedings of the Chemistry in the Oil Industry VIII Symposium", 3-5 Nov. 2003, Manchester, UK, published by The Royal Society of Chemistry, UK).
Some examples of patent publications relating to demulsifiers follow below.
U.S. Pat. No. 3,835,060 teaches that conventional demulsifiers include, e.g., polyoxyalkylene glycol and block polymers of polyoxyethylene-polyoxypropylene.
U.S. Pat. No. 5,401,439 discloses oil demulsifiers containing an alkoxylate of an alkylphenol-formaldehyde resin, an alcohol, a bisphenol or an amine, wherein the alkoxylate has a polydispersity of at least 1.7.
US 2004/0266973-A1 describes the use of an alkoxylated alkylphenol-arylaldehyde polymer for resolving water-in-oil emulsions, especially emulsions of water in crude oil, and US 2005/0080221-A1 describes the use of an alkoxylated alkylphenol-formaldehyde-diamine polymer for the same purpose.
U.S. Pat. No. 3,903,006 discloses a hydraulic pressure transmission fluid consisting of, or comprising, a synthetic orthoester. The orthoester is either the hydraulic pressure transmission fluid itself or, present in only minor amounts, as a water scavenger; i.e. it will remove minor amounts of water (moisture) present in the hydraulic fluid by participating in a chemical reaction with the water.
For a number of years there has been strong pressure for the use of more environmentally adapted chemicals in various application areas. This is also the case for oilfield production chemicals including demulsifiers, especially as regards their use in off-shore oil production. The presently used demulsifiers are for the most part biologically persistent, i.e. they exhibit a very poor biodegradability. Thus, there is a great need for new demulsifiers with an acceptable biodegradation profile combined with a low ecotoxicity and an excellent technical performance.
Thus, the aim of the present invention is to provide new efficient demulsifiers for breaking water-in-oil emulsions. In addition, said demulsifiers should also have an improved biodegradability profile compared to previously mentioned standard types of demulsifiers and exhibit a low ecotoxicity.
Now it has surprisingly been found that an orthoester based polymer having the general formula
wherein R1 is hydrogen or a hydrocarbyl group with 1-4 carbon atoms, R2, R3, and R4 are, independently, a group comprising C3-C4, preferably C3, alkyleneoxy groups and/or ethyleneoxy groups in any order, preferably in blocks, preferably with both ethyleneoxy groups and C3-C4 alkyleneoxy groups being present, and an end group Y, which is, independently, hydrogen, a hydrocarbyl group with 1-30, preferably 1-8, more preferably 1-6, and most preferably 1-4 carbon atoms, a group —(CH2)zNR5R6 or —(CH2)zN+R5R6R7, wherein each of R5, R6, and R7 is, independently, an alkyl group with 1-22 carbon atoms or —CH2CH2OH, and z is 2 or 3; the end group Y preferably being H or a hydrocarbyl group, provided that at least one of the groups R2, R3, and R4 comprises at least one block of at least on average 4 alkyleneoxy groups with 3 and/or 4 carbon atoms, and provided that if Y is hydrogen, then at least one ethyleneoxy or alkyleneoxy group is connected to Y; or a di- or polycondensate of the polymer via free hydroxyl groups in R2, R3 or R4, is an excellent demulsifier for water/oil emulsions, and at the same time has a better biodegradability than the prior art compounds.
In one embodiment R1 is hydrogen or a hydrocarbyl group with 1-4 carbon atoms, R2, R3, and R4 are, independently, a group -(A)n(CH2CH2O)mY or —(CH2CH2O)m(A)nY, wherein each A is, independently, an alkyleneoxy group with 3-4, preferably 3, carbon atoms, n and m are, on average and independently, a number of 0-100, preferably 1-100, more preferably 2-100, even more preferably 3-100, still more preferably 5-100, and most preferably 10-100, provided that at least one of the groups R2, R3, and R4 comprises at least one block of at least on average 4 alkyleneoxy groups with 3 and/or 4 carbon atoms, and each Y is, independently, hydrogen, a hydrocarbyl group with 1-30, preferably 1-8, more preferably 1-6, and most preferably 1-4 carbon atoms, a group —(CH2)zNR5R6 or —(CH2)zN+R5R6R7, wherein each of R5, R6, and R7 is, independently, an alkyl group with 1-22 carbon atoms or —CH2CH2OH, and z is 2 or 3; Y preferably is hydrogen or a hydrocarbyl group; provided that if Y is hydrogen, then at least one of n and m is a number of 1-100, or a di- or polycondensate of the polymer via free hydroxyl groups in R2, R3 or R4.
In another embodiment, the sum of all n in the polymer is 10-1200 and at least one of the groups R2, R3, and R4 comprises at least one block with 6-20 alkyleneoxy groups with 3-4 carbon atoms. The blocks containing alkyleneoxy groups with 4 carbon atoms can be made using either butylene oxide, in which case the blocks consist of branched alkyleneoxy groups, or polytetrahydrofuran, wherein the alkyleneoxy groups are linear. The blocks (A)n and (CH2CH2O)m can be added in any order, but preferably the (A)n block is closer to the orthoester bond than the (CH2CH2O)m block.
In still another embodiment, the orthoester based polymer for use as a demulsifier for water/oil emulsions is a product wherein R1 is hydrogen, (A)n is a block (CH2CH2CH2CH2O)n, Y is hydrogen, and m is at least 3; preferably, the ortho ester is a di- or polycondensate of the polymer via free hydroxyl groups in R2, R3 and R4.
The amount of ethyleneoxy groups in the orthoester based polymer preferably is 40-85%, more preferably 50-75%, by weight of the total molecular weight.
As a consequence of the synthesis route, each product manufactured will be a mixture of a lot of molecular species. This results in a very broad span of molecular weights, with the lowest weights being around 600, more preferably around 1,000, and the highest molecular weights being around 100,000.
The weight average molecular weight (Mw) of the polymer preferably is at least 1,500, more preferably at least 2,000, and at most 40,000, more preferably at most 30,000.
In one further embodiment, the orthoester based polymer for use as a demulsifier for water/oil emulsions is a product wherein R1 is hydrogen, A is an alkyleneoxy group with 3 carbon atoms, and Y is hydrogen, and wherein the amount of ethyleneoxy groups is 50-75% by weight of the total molecular weight, the molecular weight span is 1,000-100,000, and the weight average molecular weight (Mw) is 2,000-30,000.
The orthoester polymers (I) can be produced by reacting an orthoester of the general formula
wherein R1 has the same meaning as above and R8 is a hydrocarbyl group with 1-4 carbon atoms, in one or several steps, with reactants comprising C3-C4, preferably C3, alkyleneoxy groups and/or ethyleneoxy groups in any order, preferably in blocks, an end group Y, which is H or a hydrocarbyl group with 1-30 carbon atoms, and one hydroxyl group at the other end of the molecule, herein denoted as reactants having the formula HO(A)n(CH2CH2O)mY, and/or R5R6N(CH2)zOH or R5R6R7N+(CH2)zOH, wherein the symbols n, m, Y, z, R5, R6, and R7 have the same meaning as above. The reaction is performed under removal, preferably by evaporation, of liberated hydroxyl-containing compounds of the formula R8OH. As regards products (I) comprising the group —(CH2)zN+R5R6R7, these are preferably made by quaternizing an orthoester product comprising the group —(CH2)zNR5R6 with an alkylating agent R7-X, wherein R7 is a C1-C4 alkyl group and X is any conventional source for an anion of a quaternary ammonium compound, such as a halogen atom or OSO3CH3.
Because of the method used to produce the orthoester polymers, it should be realized that formula (I) only represents an average orthoester molecule and that specific individual species may have a structure deviating from formula I. For each starting orthoester molecule there are three positions that can be substituted by the reactants. If, e.g., 2 moles of HO(A)n(CH2CH2O)mY and 1 mole of R5R6N(CH2)zOH are added to the starting orthoester, this will result in some molecules wherein one of the R8 groups is replaced by -(A)n(CH2CH2O)mY and two of the R8 groups are replaced by —(CH2)zNR5R6, some molecules wherein two of the R8 groups are replaced by -(A)n(CH2CH2O)mY and one of the R8 groups is replaced by —(CH2)zNR5R6, some molecules wherein all three groups R8 are replaced by -(A)n(CH2CH2O)mY, and some molecules wherein all three groups R8 are replaced by —(CH2)zNR5R6. The product resulting from the reaction described above thus is a mixture of several components, but the average molecule will be an orthoester wherein two of the groups R8 have been replaced by -(A)n(CH2CH2O)mY and one of the groups R8 has been replaced by —(CH2)zNR5R6.
The above method has been described in detail in the patent publications EP-B 909 286, EP-B 1 042 266, and WO 03/018534. It is noted that the products of the present invention differ from the products described in the last publication in that the former must contain at least one block of at least on average 4 alkyleneoxy groups with 3 and/or 4 carbon atoms.
However, when an orthoester compound contains free hydroxyl groups, i.e. when Y is H, then several orthoester molecules may condensate into polymeric structures having higher molecular weights. In formula (I) the average individual orthoester compound is displayed, but formula (I) also symbolizes the polymeric structures that may result from the condensation of several orthoester molecules having free hydroxyl groups. An example of such a polymeric structure is shown below. Here five orthoester molecules have reacted together to form a polycondensate via free hydroxyl groups of the individual orthoester molecules. To obtain this structure, an orthoester of formula II can be reacted with a polypropylene glycol (PPG) and an alcohol ethoxylate of the formula RO(CH2CH2O)mH, wherein R is a hydrocarbyl group having 1-30 carbon atoms. The resulting polymer (III) can react further with more orthoester molecules, since there is still one terminal hydroxyl group left in the molecule. The symbols R1, R8, m, and n have the same meaning as stated above.

From the above it is evident that when an orthoester (II) is reacted with compounds having two hydroxyl groups, such as PPG or PEG, then two orthoester molecules of formula (II) may react with the same PPG or PEG molecule, and consequently the ratios between (II) and PPG or PEG can be varied within a wide range to yield products having widely different molecular weights. Further, it is possible to stop the reaction at a certain degree of condensation by discontinuing the heating and removal of R8OH, followed by neutralization of the acid catalyst.
Another possible route to obtaining products of formula (I) wherein Y is H and n and m are 1-100 is to react an orthoester of general formula (II) with a reactant having the formula HO(A)nY, wherein Y is hydrogen, and then to react the obtained intermediate with Σm moles of ethylene oxide. The latter reaction is preferably catalyzed by alkaline catalysts, preferably an alkali metal hydroxide such as NaOH or KOH, or an alkali metal alkoxide such as NaOCH3 or KOCH3. Since the orthoester will rearrange under acid conditions, the use of an acid catalyst is less preferred for the ethoxylation step. The ethoxylation reaction is performed in a manner which is well known in the art. It is also possible to react an orthoester of formula (II) with a reactant HO(CH2CH2O)mY, wherein Y is hydrogen, and then react the obtained intermediate with Σn moles of an alkylene oxide having 3-4 carbon atoms using alkaline catalysis. Also the conditions for performing such an alkoxylation reaction are well known to the man skilled in the art.
Wherever the degree of alkoxylation is discussed, the numbers referred to are molar average numbers. Consequently, all numbers m and n referred to above and henceforth, as well as the numbers o and p referred to below, are molar average numbers.
The ethoxylation of orthoesters not containing any hydroxyl groups has been disclosed in U.S. Pat. No. 2,867,667. In this method boron trifluoride is used as a catalyst, and the reaction is performed in the neighborhood of 0° C. or lower due to the sensitivity of the orthoester to the catalyst at higher temperatures.
Some of the orthoester based polymers are new, and the invention also relates to these compounds per se.
Thus the invention relates to an orthoester based polymer according to formula (I), wherein R1 is hydrogen or a hydrocarbyl group with 1-4 carbon atoms, R2 is a group comprising C3-C4, preferably C3, alkyleneoxy groups and/or ethyleneoxy groups in any order, preferably in blocks, and an end group Y, which is H or a hydrocarbyl group with 1-4 carbon atoms, R4 is a group -(A)o(CH2CH2O)pZ or —(CH2CH2O)p(A)oZ, wherein Z is a hydrocarbyl group with 5-30 carbon atoms, each A is, independently, an alkyleneoxy group with 3-4 carbon atoms, o is a number of 0-100, preferably 0-5, and p is on average a number of at least 1, preferably of at least 5, and of at most 100, preferably of at most 20, or a group —(CH2)zNR5R6 or —(CH2)zN+R5R6R7, wherein R5, R6, and R7 are, independently, an alkyl group with 1-22 carbon atoms or —CH2CH2OH and z is 2 or 3, and R3 is selected from the group R2, R4, and a hydrocarbyl group with 1-4 carbon atoms, and provided that at least one of the groups R2, R3, and R4 comprises at least one block of at least 4 alkyleneoxy groups with 3 and/or 4 carbon atoms, or a di- or polycondensate of the polymer via free hydroxyl groups in R2 or R3.
A method for producing a polymer or polymer mixture as defined above comprising one or several steps is performed by reacting an orthoester having general formula (II), wherein R1 has the same meaning as above and R8 is a hydrocarbyl group with 1 to 4 carbon atoms, with reactants comprising C3-C4, preferably C3, alkyleneoxy groups and/or ethyleneoxy groups in any order, preferably in blocks, an end group Y, which is H or a hydrocarbyl group with 1-4 carbon atoms, and one hydroxyl group at the other end of the molecule, HO(A)o(CH2CH2O)pZ, HO(CH2CH2O)p(A)oZ, wherein A, 0, p, and Z have the same meaning as above, and R5R6N(CH2)zOH or R5R6R7N+(CH2)zOH, wherein the symbols z, R5, R6, and R7 have the same meaning as above, under removal of liberated hydroxyl-containing compounds of the formula R8OH, or alternatively, to obtain an orthoester based polymer wherein R4 is a group —(CH2)zN+R5R6R7, by quaternizing an orthoester based polymer wherein R4 is —(CH2)zNR5R6 with an alkylating agent R7X, wherein R7 is a C1-C4 alkyl group and X is a conventional source for an anion of a quaternary ammonium compound, such as a halogen atom or OSO3CH3.
More specifically, the invention relates to an orthoester based polymer according to formula (I), wherein R1 is hydrogen or a hydrocarbyl group with 1-4 carbon atoms, R2 is a group -(A)n(CH2CH2O)mY or —(CH2CH2O)m(A)nY, wherein each A is an alkyleneoxy group with 3-4 carbon atoms, n and m are, on average and independently, a number of 0-100, Y is H or a hydrocarbyl group with 1-4 carbon atoms, provided that if Y is hydrogen, then at least one of n or m in the same substituent as said Y is a number of 1-100 for that group, R4 is a group -(A)o(CH2CH2O)pZ or —(CH2CH2O)p(A)oZ, wherein Z is a hydrocarbyl group with 5-30 carbon atoms, o is a number of 0-100, preferably 0-5, and p is on average a number of at least 1, preferably of at least 5, and of at most 100, preferably of at most 20, or a group —(CH2)zNR5R6 or —(CH2)zN+R5R6R7, wherein R5, R6, and R7 are, independently, an alkyl group with 1-22 carbon atoms or CH2CH2OH and z is 2 or 3, and R3 is selected from the group R2, R4, and a hydrocarbyl group with 1-4 carbon atoms, and provided that at least one of the groups R2, R3, and R4 comprises at least one block of at least 4 alkyleneoxy groups with 3 and/or 4 carbon atoms, or a di- or polycondensate of the polymer via free hydroxyl groups in R2 or R3.
A method for producing a polymer or polymer mixture as defined above comprising one or several steps is performed by reacting an orthoester having the general formula (II), wherein R1 has the same meaning as above and R8 is a hydrocarbyl group with 1 to 4 carbon atoms, with reactants selected from the group having the formulae HO(A)n(CH2CH2O)mY, HO(CH2CH2O)m(A)nY, wherein A, n, m, and Y have the same meaning as above, HO(A)o(CH2CH2O)pZ or HO(CH2CH2O)p(A)oZ, wherein A, o, p, and Z have the same meaning as above, and R5R6N(CH2)zOH or R5R6R7N+(CH2)zOH, wherein the symbols z, R5, R6, and R7 have the same meaning as above, under removal of liberated hydroxyl-containing compounds of the formula R8OH, or alternatively, to obtain an orthoester based polymer wherein R4 is a group —(CH2)zN+R5R6R7, by quaternizing an orthoester based polymer wherein R4 is —(CH2)zNR5R6 with an alkylating agent R7X, wherein R7 is a C1-C4 alkyl group and X is a conventional source for an anion of a quaternary ammonium compound, such as a halogen atom or OSO3CH3.
One of the preferred new products of the invention is an orthoester based polymer according to formula (I), wherein R1 is hydrogen or a hydrocarbyl group with 1-4 carbon atoms, R2 is a group -(A)n(CH2CH2O)mY or —(CH2CH2O)m(A)nY, wherein each A is an alkyleneoxy group with 3-4 carbon atoms, n and m are a number of 0-100, Y is H or a hydrocarbyl group with 1-4 carbon atoms, provided that if Y is hydrogen, then at least one of n or m in the same substituent as said Y is a number of 1-100 for that group, R4 is a group -(A)o(CH2CH2O)pZ or —(CH2CH2O)p(A)oZ, wherein Z is a hydrocarbyl group with 5-30 carbon atoms, o is on average a number of 0-100, preferably 0-5, and p is on average a number of at least 1, preferably of at least 5, and of at most 100, preferably of at most 20, and R3 is selected from the group R2, R4, and a hydrocarbyl group with 1-4 carbon atoms, and provided that at least one of the groups R2, R3, and R4 comprises at least one block of at least 4 alkyleneoxy groups with 3 and/or 4 carbon atoms, or a di- or polycondensate of the polymer via free hydroxyl groups in R2 or R3.
A method for producing a polymer or polymer mixture as defined for the preferred product above, comprising one or several steps, is performed by reacting an orthoester having general formula (II), wherein R1 has the same meaning as stated earlier and R8 is a hydrocarbyl group with 1 to 4 carbon atoms, with reactants having the formulae HO(A)n(CH2CH2O)mY or HO(CH2CH2O)m(A)nY and HO(A)o(CH2CH2O)pZ or HO(CH2CH2O)p(A)oZ, wherein A, n, m, Y, o, p, and Z have the same meaning as above, under removal, preferably by evaporation, of liberated hydroxyl-containing compounds of the formula R8OH.
Another preferred new product of the invention is an orthoester based polymer according to formula (I), wherein R1 is hydrogen or a hydrocarbyl group with 1-4 carbon atoms, R2 is a group -(A)n(CH2CH2O)mY or —(CH2CH2O)m(A)nY, wherein each A is an alkyleneoxy group with 3-4 carbon atoms, n and m are a number of 0-100, Y is H or a hydrocarbyl group with 1-4 carbon atoms, provided that when Y is hydrogen, at least one of n or m is a number of 1-100 for that group, R4 is a group —(CH2)zNR5R6 or —(CH2)zN+R5R6R7, wherein R5, R6, and R7 are, independently, an alkyl group with 1-22 carbon atoms or —CH2CH2OH and z is 2 or 3, and R3 is selected from the group R2, R4, and a hydrocarbyl group with 1-4 carbon atoms, and provided that at least one of the groups R2, R3, and R4 comprises at least one block of at least 4 alkyleneoxy groups with 3 and/or 4 carbon atoms, or a di- or polycondensate of the polymer via free hydroxyl groups in R2 or R3.
A method for producing a polymer or polymer mixture as defined for the preferred product above, comprising one or several steps, is performed by reacting an orthoester having general formula (II), wherein R1 has the same meaning as stated earlier and R8 is a hydrocarbyl group with 1 to 4 carbon atoms, with reactants having the formulae R5R6N(CH2)zOH or R5R6R7N+(CH2)zOH and HO(A)n(CH2CH2O)mY or HO(CH2CH2O)m(A)nY, wherein the symbols n, m, Y, z, R5, R6, and R7 have the same meaning as above, under removal, preferably by evaporation, of liberated hydroxyl-containing compounds of the formula R8OH, or alternatively, to obtain an orthoester based polymer wherein R4 is a group —(CH2)zN+R5R6R7, preferably an orthoester polymer wherein R4 is —(CH2)zNR5R6 is quaternized by an alkylating agent R7X, wherein R7 is a C1-C4 alkyl group and X is a halogen atom or OSO3CH3, preferably a halogen atom. The most preferred alkylating agents are methyl chloride and dimethyl sulfate.
Suitable starting materials HO(A)n(CH2CH2O)mY, wherein Y is H, are polyethylene glycols (PEG), polypropylene glycols (PPG), polybutylene glycols, polytetrahydrofurans, block or random copolymers of ethylene oxide and propylene oxide, or of ethylene oxide and butylene oxide, and ethoxylated polytetrahydrofurans. Suitable starting materials wherein Y is an alkyl group are poly(ethylene glycol) monomethyl ether, poly(ethylene glycol) monoethyl ether, poly(ethylene glycol) monopropyl ether, poly(ethylene glycol) monobutyl ether, diethylene glycol monobutyl ether, and ethoxylated alcohols, such as ethoxylated n-hexanol, n-octanol, 2-ethylhexanol, nonanol, n-decyl alcohol, 2-propylheptanol, n-dodecyl alcohol, tridecyl alcohol, C10-C12-alkyl alcohol, C9-C11-alkyl alcohol, or C16-C18-alkyl alcohol. Suitable starting materials wherein Y is a group —(CH2)zNR5R6 are 2-(dimethylamino)ethanol, 3-dimethylamino-1-propanol, 2-(diethylamino)ethanol, 3-diethylamino-1-propanol, 2-(diisopropylamino)ethanol, 2-(dibutylamino)ethanol, and primary alkylamines ethoxylated with two moles of ethylene oxide (EO), such as n-hexyl amine+2EO, 2-ethylhexyl amine+2EO, 2-propylheptyl amine+2EO, n-decyl amine+2EO, n-dodecyl amine+2EO, (coco alkyl)amine+2EO, n-tetradecyl amine+2EO, n-hexadecyl amine+2EO, n-octadecyl amine+2EO, oleyl amine+2EO, (tallow alkyl)amine+2EO, (rape seed alkyl)amine+2EO, (soya alkyl)amine+2EO, and erucyl amine+2EO.
The orthoester polymer can be used as a demulsifier for separating water/oil emulsions in the production of oil. The polymer can also be used as a demulsifier in a fermentation process, e.g. in the production of penicillin. In this production process an extraction is performed which gives rise to a persistent o/w emulsion, which breaks when the demulsifiers according to the present invention are added. The demulsifiers according to the invention may be used in any process where a water/oil emulsion is formed, and their use is not restricted to the applications mentioned above, By the term water/oil emulsion is meant here any emulsion between water and oil, i.e. both w/o and o/w are included. It is noted that the water/oil emulsions that are demulsified are not hydraulic pressure transmission fluids.
The demulsifier can be combined with solvents and other chemicals typically used in these applications, and consequently it can be used either as such or in a formulation. The amount of water present in the w/o emulsion to be demulsified may range from 0.5 to 98%, based on the total amount of w/o emulsion. Preferably, at least 1% water is present in the emulsion, more preferably at least 2%, even more preferably at least 3%, still more preferably at least 4%, and most preferably at least 5% is present.
A common way to characterize demulsifiers is by their relative solubility number (RSN value). The test is carried out by dissolving a specific amount of demulsifier in a defined volume of an organic solvent mixture and then titrating this solution with water. Once a certain volume of water has been added, the solution will turn from clear (transparent) to cloudy. The water volume (in mL) at which this change takes place is the RSN value. Ordinarily, more hydrophilic (water-soluble) demulsifiers have a higher RSN value than more hydrophobic (oil-soluble) ones. For a very large majority of commercially used demulsifiers, the RSN value found is in the range of 5-25. For the specific solvent mixture and test conditions used to characterize the products of the present invention, see the experimental section.
The composition of crude oils (and production water) can differ considerably between different wells and even, with time, for the same well. This means that the composition of demulsifiers has to be especially adapted for each well and stage of production to give a good performance. The demulsifiers should fulfill four main performance criteria, rapid separation of the oil-and-water phase, creation of a distinct interface, giving low residual water contents in the separated oil phase, and giving a good quality of the separated water phase. The last demand is important in order to minimize pollution by discharged water and/or the need for further water treatment before discharge. To a person skilled in surface chemistry, it will be obvious that it is very difficult to find single molecules that fulfill all four of these demands. For this reason blends of demulsifiers are very commonly used in practice to get optimal results. Often demulsifiers with both comparatively high and comparatively low RSN values are used in the optimized blend. Thus, it is very valuable if the same type of basic chemistry can be utilized to produce demulsifiers with both high and low RSN values. It is demonstrated in the examples that a wide variety of RSN values can be achieved with the types of compounds of the present invention.
When used for separation of the water/oil emulsions that result from a process for the production of oil, an orthoester polymer demulsifier according to the present invention may be applied at the well head, at a suitable injection point downstream, or at any stage of crude oil processing. A suitable amount of orthoester polymer added to the oil or emulsion can for example be from 1 to 500 mg/kg (mg/kg=ppm by weight, ppmw), normally from 1 to 50 mg/kg, calculated on the amount of water and oil. The exact amount of demulsifier is dependent on the type of oil, some oils requiring more and others requiring less demulsifier. Mixtures of demulsifiers according to the invention can be used, but also one or more demulsifiers according to the invention can be used together with one or more conventional demulsifiers. For other applications, such as for breaking emulsions arising in fermentation processes, larger amounts of demulsifier may be needed, e.g. up to 0.5% based on the total amount of broth.
The present invention is further illustrated by the following examples.

Environmentally friendly water/oil emulsions


Vascular endothelial function in terms of flow-mediated dilation (FMD) of peripheral arteries can be assessed reliably by measuring beat-to-beat pulse-wave conduction time (PCT) simultaneously for two symmetric segments of arteries locating on the right and left sides of body. When reactive hyperemia is induced in the peripheral tissues on one side, the time dependent changes in PCT caused by FMD on that side can be detected as the beat-to-beat differences in PCT between two sides (ΔPCT). ΔPCT would provide a sensitive and specific assessment of the FMD response, because the influences of the systemic changes in hemodynamic and neurohumoral factors common to both sides are subtracted out. In addition, measurement of PCT requires no skillful technique and is advantageous in that the apparatus is inexpensive.

1. Field of the Invention
This invention relates to a method and apparatus for assessing vascular endothelial function.
2. Description of the Related Art
Vascular endothelium is a cell group that constitute a layer of lining blood vessels, functioning not only to line the inner wall of blood vessels and separate blood components from body tissues but also to produce or release substances which control the biological characteristics of blood vessels including dimension, elasticity, permeability and reactivity. Since impairment of vascular endothelial function is found in earlier stages of arteriosclerosis where arteriosclerosis has not yet developed or clinically manifested, it is possible to prevent the development or treat the arteriosclerosis earlier by detecting the impairment of vascular endothelial function.
A non-invasive method for assessing flow-mediated dilation induced by reactive hyperemia by using an ultrasonic device is known as a method for assessing vascular endothelial function (for example, as shown in the non-patent literature 1). The above reactive hyperemia is a transient increase in organ blood flow that takes place following a brief period of ischemia (arterial occlusion) and subsequent release. The flow-mediated dilation is a reaction in which an increased arterial blood flow stimulates vascular endothelium of the artery concerned, thus secreting from vascular endothelium endothelium-derived relaxing factors (EDRF; nitrogen monoxide and analogous substances), which are substances to dilate blood vessels, resulting in an increase in the diameter of the artery concerned. As a result, since endothelium-derived relaxing factors are secreted at a smaller quantity when the vascular endothelial function is impaired, the diameter of the artery will not increase as expected even after an increase in arterial blood flow caused by the reactive hyperemia. Thus, vascular endothelial function can be assessed by referring to the extent of the increase in diameter of the artery with the peripheral reactive hyperemia.
In the method described in the non-patent literature 1, an ultrasonic probe was used to provide consecutive images of an artery by which a maximum increase rate of the arterial diameter after release from ischemia in relation to that before the ischemia was calculated to assess vascular endothelial function based on the maximum increase rate. The above maximum increase rate is called % FMD (flow mediated dilatation), which is about 10% for healthy adults. 3 to 4% FMD is indicative of endothelial dysfunction and likely that arteries in major organs have already been atherosclerotic or may have an increased risk for arteriosclerosis.
Methods for inducing release of endothelium-derived relaxing factors from vascular endothelium include methods for causing the above hyperemic reaction or increased blood flow and for injecting into an artery substances stimulating the release of EDRF such as acetylcholine.
[Non-patent Literature 1]
Page 104 to 106, "Pulse Wave Velocity," First edition compiled by Toshio Ozawa and Yoshiaki Masuda, Published by Medical Review Co., Ltd. May 1, 2002
However, the following problems are found in the method for calculating % FMD by referring to the vasodilation response assessed by an ultrasonic device. First, a major problem with the method is the large variation in results, as high as 2 to 3%, among examiners and laboratories. Since the % FMD is considered normal at about 10% and abnormal at 3 to 4%, a variation of as high as 2 to 3% poses a serious problem. The great variation is due to the need for skill in detecting correct signals such as placing an ultrasonic probe vertically to a vessel, and variation in the point of time in determining a diameter of the vessel because it is necessary to detect from consecutive images of a pulsating blood vessel the timing when the greatest dilation of the vessel takes place after release from ischemia, and also to determine a diameter of the blood vessel at the end of diastolic phase of the heart. Therefore, it may take several months to acquire this skill, and it is reported that % FMD is not reliable unless the result is obtained from an examiner with substantial experience (for example, about six-months). Second, this method has an inevitable theoretical limitation. The arterial diameter shows not only pulsation but also spontaneous variations. The arterial diameter is dependent on heart rate and blood pressure, both of which show, even in a short term, physiological fluctuation such as those relating respiration and Mayer wave (10-second rhythm). Also, neurohumoral, thermoregulatory and emotional factors (which could accompany arterial occlusion) affect the vascular tone directly and indirectly through heart rate and blood pressure. The influences of these systemic factors confound the assessment of endothelium-dependent vascular responses and partly contribute to the large variation of % FMD. Finally, in case of the brachial artery, the diameter of blood vessel is about 5 mm and expected change of the diameter would be less than 0.5 mm, or dilation corresponding to less than 10% of a diameter of the vessel. Thus, such exact detection requires a high-performance and highly priced ultrasonic device, which is another problem.

Method and apparatus for examining vascular endothelial functions


The electrodes of a flat panel cold cathode discharge lamp are each formed from a block of metal with holes arranged side-by-side along the electrode which open into the gas-discharge volume of the lamp. The holes extend at an angle of about 25-35 degrees away from the normal to the surface of the electrode and are formed by laser machining.

This invention relates to cold cathode discharge lamps and their electrodes.
Conventional gas discharge lamps take one of two forms. They are either of the hot-cathode or cold-cathode kind. In the hot-cathode kind, the electrodes are heated so that electrons are emitted from the cathode by primary emission; in the cold-cathode kind, ion bombardment of the cathode causes the secondary emission of electrons. Although hot-cathode lamps have a greater electrical efficiency, cold-cathode lamps have the advantage of a considerably longer life and maintain a more constant brightness over their life than hot-cathode lamps.
The electrodes of cold-cathode lamps are generally hollow, that is, they take the shape of a short tube having an open end and a closed end, the open end facing the opposite electrode. Electrodes of this shape have been found to produce a more stable discharge and require lower operating voltages than flat plate electrodes.

Smiths Industries Public Limited Company


An exposure apparatus includes a stage configured to hold an original thereon and to move in a horizontal direction, a first interferometer configured to emit first measurement light used for measuring a position of the stage in a vertical direction thereof, a first mirror provided on a bottom surface of the stage, and a second mirror provided directly below the first mirror. The second mirror is disposed so as to guide the first measurement light emitted from the first interferometer to the first mirror.

1. Field of the Invention
The present invention relates to exposure apparatuses used in manufacturing processes of devices, such as semiconductor and liquid crystal devices, and having high controllability of stages, and to device-manufacturing methods performed using such exposure apparatuses.
2. Description of the Related Art
In related art, when devices such as semiconductor or liquid crystal devices are to be manufactured, a projection-type exposure apparatus is used. Specifically, in such an exposure apparatus of a projection type, a pattern drawn on a reticle by photolithography is de-magnified and projected by a projection optical system, and the pattern is then transferred onto a wafer.
In order to perform an exposure process with high precision, the reticle is held by a reticle stage and moves together with the reticle stage.
If the exposure apparatus is of a scanning type, the reticle stage needs to move by a long stroke along one of its axes. There have been proposed technologies in which an interferometer is used to enhance the mobility of the reticle stage that moves by a long stroke along the one axis.
One example of such a technology is proposed in Japanese Patent Laid-Open No. 2001-345254, which discloses a compact stage device that has a laser interferometer for achieving high-precision measurement and that can move with high precision.
A reticle stage described in Japanese Patent Laid-Open No. 2001-345254 will be described below with reference to FIGS. 7A and 7B. In detail, the position of a reticle stage 110 in a Y-axis direction is measured on the basis of measurement light Y1 or Y2 from a laser interferometer. The position of the reticle stage 110 in an X-axis direction is measured on the basis of measurement light X1. The position of the reticle stage 110 in a Z-axis direction is measured on the basis of measurement light Z. For the position measurement in the Z-axis direction, a mirror 119e is provided on the reticle stage 110, and a mirror 111d is provided above the reticle stage 110. The measurement light from the laser interferometer is reflected orthogonally upward by the mirror 119e and is subsequently reflected by the mirror 111d provided above the reticle stage 110. The measurement light is reflected again by the mirror 119e so as to be guided to the laser interferometer.
Providing the mirrors 119e and 111d allows for high-precision measurement of the position of the reticle stage 110 in the Z-axis direction.
In order to measure the position of the reticle stage 110 in the Z-axis direction in the related art described above, the mirror 111d above the reticle stage 110 needs to extend over the stroke range. In this case, a supporting structure for supporting the mirror 111d is necessary. However, since an optical system for guiding exposure light to the reticle is disposed above the reticle stage 110, there is not enough space for such a structure.
Furthermore, because the position of the reticle stage 110 is determined on the basis of a projection optical system, it is desirable that the mirror 111d be supported by a supporting structure that supports the projection optical system.
However, there are serious design limitations in providing such a supporting structure that supports the projection optical system above the reticle stage 110. In other words, it is desirable that a projection optical system be similarly disposed below the reticle stage 110 and that the space between the reticle and the projection optical system be reduced to enhance the optical performance of the exposure apparatus. However, if the laser interferometer is disposed directly below the reticle stage 110, there is not enough space for the projection optical system and the like.

Exposure apparatus configured to minimize effects of mechanism for measuring stage position on peripheral mechanism and device-manufacturing method


A fuel adding valve (14), an HC adsorbing and oxidation catalyst (11), and a NOx storing catalyst (12) are successively arranged in an exhaust passage of an internal combustion engine toward the downstream side. When the NOx storing catalyst (12) should release NOx, particulate fuel is added from the fuel adding valve (14). This fuel is adsorbed once at the HC adsorbing and oxidation catalyst (11), then gradually evaporates to make the air-fuel ratio of the exhaust gas flowing into the NOx storing catalyst (12) rich. Due to this, NOx is released from the NOx storing catalyst (12).

Known in the art is an internal combustion engine having arranged in an engine exhaust passage an NOx storing catalyst which stores NOx contained in exhaust gas when the air-fuel ratio of the inflowing exhaust gas is lean and releases the stored NOx when the oxygen concentration in the inflowing exhaust gas falls. In this internal combustion engine, the NOx produced when burning fuel under a lean air-fuel ratio is stored in the NOx storing catalyst.
However, when using such an NOx storing catalyst, it is necessary to make the NOx storing catalyst release the NOx before the NOx storing capability of the NOx storing catalyst becomes saturated. In this case, if making the air-fuel ratio of the exhaust gas flowing into the NOx storing catalyst rich, it is possible to make the NOx storing catalyst release the NOx and to reduce the released NOx. Therefore, in conventional internal combustion engines, the NOx storing catalyst is made to release NOx by making the air-fuel ratio in the combustion chamber rich or by feeding fuel into the engine exhaust passage upstream of the NOx storing catalyst to make the air-fuel ratio of the exhaust gas flowing into the NOx storing catalyst rich.
However, to make an NOx storing catalyst release NOx well, sufficiently gasified rich air-fuel ratio exhaust gas has to be made to flow into the NOx storing catalyst. In this case, if making the air-fuel ratio in the combustion chamber rich, the sufficiently gasified rich air-fuel ratio exhaust gas flows into the NOx storing catalyst, so it is possible to make the NOx storing catalyst release the NOx well. However, if making the air-fuel mixture in the combustion chamber rich, there is the problem that a large amount of soot is produced. Further, if injecting additional fuel into the expansion stroke or exhaust stroke so as to make the air-fuel ratio of the exhaust gas exhausted from the combustion chamber rich, the injected fuel sticks to the inside walls of the cylinder bore, i.e., bore flushing occurs.
As opposed to this, when injecting fuel into the engine exhaust passage upstream of an NOx storing catalyst, the problems of soot being produced or bore flushing occurring as explained above no longer arise. However, when injecting fuel into the engine exhaust passage upstream of the NOx storing catalyst, there is the problem that the injected fuel is not sufficiently gasified and therefore the NOx storing catalyst cannot be made to release NOx well.
On the other hand, known in the art is an internal combustion engine arranging a hydrocarbon, that is, HC adsorbing catalyst for adsorbing HC contained in exhaust gas in the engine exhaust passage upstream of the NOx storing catalyst (see Japanese Unexamined Patent Publication (Kokai) No. 2003-97255). In this internal combustion engine, the HC produced when burning fuel under a lean air-fuel ratio is adsorbed by the HC adsorbing catalyst and the NOx produced at that time is stored in the NOx storing catalyst.
However, in this internal combustion engine, when the temperature of the HC adsorbing catalyst becomes near the activation temperature, that is, near 200° C., the oxidation reaction of the adsorbed HC becomes active and as a result the oxygen in the exhaust gas is rapidly consumed, so the oxygen concentration in the exhaust gas rapidly falls. Therefore, at this time, if additionally supplying a small amount of fuel, it is possible to make the air-fuel ratio of the exhaust gas rich. Therefore, in this internal combustion engine, it is detected whether a sufficient amount of oxygen has been consumed at the HC adsorbing catalyst, and the air-fuel ratio of the exhaust gas is made rich when a sufficient amount of oxygen is being consumed in the HC adsorbing catalyst so as to make the NOx storing catalyst release NOx.
However, in this internal combustion engine, the air-fuel ratio in the combustion chamber is made rich. Fuel is not injected into the engine exhaust passage. Therefore, the above problem arises. Further, in this internal combustion engine, the period when the temperature of the HC adsorbing catalyst becomes near the activation temperature, that is, the period when a sufficient amount of oxygen is consumed in the HC adsorbing catalyst, is limited, so the temperature of the HC adsorbing catalyst will not become the activation temperature in the period required as seen from the action of the NOx storing catalyst releasing the NOx and consequently there is the problem that the NOx storing catalyst cannot release NOx when the NOx storing catalyst has to release the NOx.

Exhaust purification device of compression ignition type internal combustion engine


A folding wrench cluster may include at least four wrenches of different sizes and/or configurations, each selectively extendible from a single body portion. The body portion comprises a flat plate with a wrench secured to a pivot point extending from each side at each end of the body. The pivot points are laterally offset from the longitudinal centerline of the body. A laterally offset stop pin also extends from each side at each end of the body, with the stop pins being opposite the wrench pivot points. The stop pins are positioned to limit the arcuate motion of the wrenches when they are unfolded, so each wrench is closely aligned with the elongate body plate when it is fully extended, with the body plate serving as an extension handle. Spacers are provided between adjacent body plates or retaining members, to allow for a relatively thick wrench head for greater durability for the tool. The eye formed in the wrench handle for attachment to the pivot pin is also relatively heavy in order to absorb the shear stresses when torque is applied to the wrench and extended handle. Additional embodiments may include a plurality of plates each sandwiching two wrenches therebetween for further versatility, and a body plate having two wrench pivot points extending from each side at each end, with a stop pin disposed between each of the wrench pivot points on each side at each end, to effectively double the number of wrenches in a wrench cluster.

1. Field of the Invention
The present invention relates generally to hand tools, and more specifically to a combination tool comprising a plurality of open or box end wrenches, all pivotally connected to a common central plate or plates which serves as an extension handle for an unfolded wrench. Stop means is also provided to lock a selected wrench in a fully extended position as desired.
2. Description of the Related Art
All persons who have had occasion to work with threaded fasteners, recognize the need for a wrench or wrenches which are capable of accommodating a wide variety of sizes of hexagonal bolt heads and nuts. Essentially two alternatives have been provided in the past: Either (1) the adjustable wrench, or (2) a plurality of separate wrenches, each having a different size.
While the adjustable wrench has its place in a mechanic's tool box, it is generally not considered suitable for most work due to the lack of precision provided in such tools to allow for the adjustability. The jaws are all too easily shifted from a precise fit on the fastener, and may round off the corners of a fastener to which they are applied.
While a complete set of separate open or box end wrenches of good quality obviates the above problem, the result is more complex due to the sheer number of individual tools which must be carried. A set of metric wrenches, for example, would number approximately fifteen wrenches in order to cover all of the fastener sizes which are in more or less common use up to about one inch in diameter. And this only covers metric sizes, with fractional inch fasteners requiring another complete set of about the same quantity. Obviously, it is very easy to misplace a wrench from a set from time to time, thus adding to the expense for a mechanic to maintain a complete set of tools, meanwhile at least inconveniencing the mechanic until the missing wrench can be replaced.
Accordingly, a need will be seen for a folding wrench cluster, incorporating several commonly used sizes of open or box end wrenches in a single unit. The wrench cluster must provide for the folding of the wrenches into a relatively compact unit for storage when not in use, preferably of sufficiently small size to allow the cluster to be carried easily in a pocket. Yet, the device must provide for the extension of a selected wrench from the cluster to a practicable working length in order to provide the leverage required of such tools. Also, the cluster must provide a positive locking means when a selected wrench is extended, in order to provide sufficient rigidity for the unit in its extended state.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 1,003,997 issued on Sep. 26, 1911 to Albert Dudly, Sr., titled "Wrench," describes a folding double open end wrench unit, in which the two wrenches are secured to one another by a slip joint. When the two wrenches have been opened relative to one another, they are extended along their mutual longitudinal axis in order to lock them in an extended position. This system requires two manipulations of the device in order to first extend and then to lock the wrenches in the extended configuration, with the two manipulations being reversed for folding. Also, the Dudly, Sr. wrench configuration cannot be expanded to provide more than two wrenches in a single assembly, which would still require a relatively large number of dual wrench units. The present invention may provide any practicable number of wrenches as desired, for greater versatility.
U.S. Pat. No. 1,186,807 issued on Jun. 13, 1916 to John L. Litomy, titled "Tool," describes a multiple wrench tool wherein each of the wrenches is secured in a common holder by an elongate slot in each wrench, forming a slip joint. As in the Dudly, Sr. wrenches discussed immediately above, each of the Litomy wrenches is relatively thin, with the handle portion being as thick as the head portion of each wrench. This is a relatively light duty construction, and is not as durable as the wrench configuration of the present invention, wherein each of the wrenches has a relatively thicker head for greater strength. Moreover, Litomy provides for multiple sizes in each of his wrench heads, thus requiring each head to be relatively large in diameter and bulky.
U.S. Pat. No. 1,402,373 issued on Jan. 3, 1922 to Charles G. Palmer, titled "Combination Wrench," describes a tool having a single common handle or body portion with a plurality of wrenches secured thereto. The title "Combination Wrench" is not accurate in the present sense of the term, as all of the wrenches of the Palmer assembly are open end wrenches, rather than being a combination of an open end and closed end wrench each having the same wrench size, as the term is presently used. Palmer describes a cam type locking system to hold a selected wrench in an open position, but such a system is prone to slippage, as it does not provide a positive stop as does the extension lock of the present wrench cluster. Again, the Palmer wrenches are all relatively thin stampings offering relatively little gripping strength in the head portions, as in the other wrenches discussed above. The present wrench cluster provides wrenches having heads of sufficient thickness to provide substantial strength and durability.
U.S. Pat. No. 1,503,084 issued on Jul. 29, 1924 to Foree Bain, titled "Wrench," describes an open end wrench assembly having a generally U-shaped clamp securing all of the wrenches together pivotally at one end thereof. The clamp also serves as a locking means to prevent a selected wrench from pivoting beyond a maximally extended position, but the handle means comprises the remaining wrenches in the assembly, rather than there being a separate handle provided. Again, as in the other wrench assemblies discussed above, each of the Bain wrenches is relatively thin, offering relatively low structural strength compared to the present wrenches.
U.S. Pat. No. 2,097,361 issued on Oct. 26, 1937 to John J. Bagley, titled "Wrench," describes an assembly of flat, thin wrenches extending from each end of a flat central bar member, which is also configured as a wrench. Each of the wrenches is secured to one or the other side of the bar by a transverse hinge. As the hinge pin is in the plane of rotation of the wrenches, it serves as a lock to preclude folding of the wrenches when in use. However, the relatively thin hinge pin does not provide particularly good strength for such a purpose, in comparison to the extension locking means of the present wrench cluster. Also, the Bagley wrenches are each formed of a relatively thin, flat stamping or the like, with the problem of structural strength in such relatively thin components having been noted in each of the other devices of the related art discussed above. Moreover, the central bar of the Bagley assembly precludes complete folding of the assembly, thus precluding any particularly compact storage for the device, whereas the present folding wrench cluster may be compactly folded for carriage in a pocket or the like if desired.
U.S. Pat. No. 2,466,884 issued on Apr. 12, 1949 to Harvey W. English et al., titled "Open Ended Multiple Wrench Holder," describes a plural wrench assembly wherein each of the wrenches may be telescopingly extended from a central holder portion. No pivoting action is provided by English et al., as provided in the present invention. As in the other devices discussed above, the English et al. wrenches are each formed of relatively thin, flat stampings having comparatively little strength in the head portions.
U.S. Pat. No. 4,269,311 issued on May 26, 1981 to Jackson E. Rich, titled "Portable Hand Carried Kit For A Set Of Wrenches And The Like," describes an elongate box-like closure having a transverse pin therethrough, with a plurality of wrenches pivotally extendible from the pin when the box is opened. At least one slot extends across the end of the box when it is closed, for securing a selected wrench in the extended position for work. The box structure is relatively long, as it must provide for the complete enclosure of all of the wrenches when they are folded for storage. The same problem as discussed above is apparent with the Rich wrench assembly, in that each of the Rich wrenches is formed of a relatively thin, flat stamping offering comparatively little structural strength for providing the required torque to secure or unfasten a threaded nut or bolt. The wrenches of the present invention each have a considerably thicker head, and provide significantly greater strength.
U.S. Pat. No. 4,606,247 issued on Aug. 19, 1986 to Charles H. Graham, titled "Versatile Chained Tool Set," describes a tool comprising a series of interconnected links forming a closed loop, loosely similar to a roller chain loop. Each of the links has a wrench head formed integrally therewith, or some other tool component extending therefrom. The device is intended to fold flat when not in use, or to use the folded flat loop as a handle for an extended tool. The wrench heads are accordingly relatively thin in order to provide for compact folding, resulting in a reduction of strength in comparison to the thicker heads of the present tool.
Italian Patent Publication No. 294,821 published in June, 1936 illustrates a wrench comprising a single socket extension which is foldable along a transverse handle. Foldable handle extensions are provided at each end of the transverse handle. No multiple wrenches are apparent, and the device does not appear to be adaptable to open or box end wrenches, as provided by the present invention.
German Patent Publication No. 2,107,628 published on August 26, 1971 illustrates a foldable combination screwdriver and nut driver. The basic structure comprises a hollow stem with two arms foldably extendible therefrom to form a T in their extended positions. Each of the three components forming the T includes a socket wrench at its distal end. The stem of the T is hollow for housing a square drive shaft providing for the attachment of additional tool heads or the like thereon. While the square drive shaft provides for the removable attachment of an open end wrench head thereto, no multiple open or box end wrenches are disclosed, nor is any combination of two or more wrenches disclosed which have a common pivotal axis, as in the present folding multiple wrench cluster.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.