A clamp that locks two telescoping components such as a vehicle receiver hitch and a draw bar, for substantially reducing if not eliminating the "banging" or "rattling" between the two components. The clamp includes a standard sized U-bolt, whose throat rests in a seat formed by a receiver hitch collar and a receiver hitch tube. A bar has an arc-shaped cross-section and includes two holes adapted for receiving the threaded ends of the U-bolt. When the draw bar is inserted into the receiver hitch, the arc-shaped side of the bar is positioned within a seat formed by the receiver hitch collar and the draw bar. Standard locking style nuts are threaded onto the legs of the U-bolt and tightened, causing the arc-shaped side of the bar to be wedged against the receiver hitch collar and the draw bar, while wedging the U-bolt throat against the opposite side of the receiver hitch collar and the receiver hitch. This effectively "clamps" or locks the draw bar and the receiver hitch together, eliminating any movement of the two pieces.

1. Field of the Invention
The present invention relates in general to clamps. It specifically relates to a clamp for securing a vehicle draw bar and a receiver hitch with minimal relative movement therebetween. The clamp of the present invention can be used in various applications beside vehicles, including but not limited to any application where two tubes and/or bars are telescopically connected.
2. Background Art
Sport Utility Vehicles (SUV) have become quite popular, and many SUV are capable of being fitted with a draw bar incorporating a receiver hitch. Receiver hitches are generally designed to tow a non-motorized wheeled vehicle, such as a boat and/or trailer, behind a motorized vehicle. Other devices can be secured to a vehicle for the purpose of hauling several kinds of cargo. For example, roof top style cargo carriers are known to accommodate luggage, bicycles, and skis. However, lifting the cargo can be difficult, if not impossible without a ladder or some other mechanism to increase the range of the user's height. Access to the cargo is cumbersome and the mounting hardware does not lend itself to convenient installation and dismantling. Also, low height clearances may present some concern.
Several types of carrying devices which utilize the receiver hitch are available. However, these devices are designed with limited functions and for specialized purposes, and are not adaptable to accommodate a multitude, or a wide variety of cargo or accessories. For instance, a carrying device designed to carry bicycles is not readily adaptable, if at all, to accommodate luggage. As a result, the user, and more specifically the consumer, has to acquire several carrying devices to haul various types of cargo and accessories.
In some instances the support structure employed is one and the same with the carrying device. U.S. Pat. No. 5,067,641 to Johnson et al. describes a support structure which is incorporated with the carrying device, for the purpose of carrying bicycles. U.S. Pat. No. 5,038,983 to Tomososki et al., describes a support structure and a carrying tub that form integral units, and which are designed to carry only the content of the tub. The support structure in U.S. Pat. No. 4,635,835 to Cole is designed solely for transporting "All Terrain" vehicles. U.S. Pat. No. 5,145,308 to Vaughn is designed mainly for supporting a platform to haul a motorcycle.
A number of devices which use the vehicle bumper and/or bumper mounting brackets are used as a mounting point, as exemplified in U.S. Pat. No. 5,269,446 to Biehm. Vehicle manufacturers have integrated the bumpers into the vehicle design and attachment to integrated bumpers and/or access to the bumper mounting hardware can be very limited and in some cases impossible.
Also, in recent years, the auto/truck bumper design incorporates plastic or composite materials rather than steel. Sufficient weight bearing characteristics are critical. It is known that many bumpers and bumper mounting hardware are not structurally capable of handling significant weight loads safely. In addition, passenger safety can be affected if bumper safety design is compromised by adding affixments to the bumper or the bumper mounting points.
Additionally, ground clearance at the rear of the vehicle is crucial. Extension of the horizontal plane of the receiver hitch behind the vehicle can damage the carrying device and/or the cargo when a load is placed on the carrying device. Safety issues arise, with the vehicle in motion, if the carrying device collides with an obstruction or some other roadway obstacle. Also, with a load at a lower horizontal plane, user safety is compromised by lifting heavy objects from the carrying device.
Furthermore, conventional devices are installed in a fixed position, and significantly limit access to the rear of the vehicle. The cargo and/or the carrying device must be removed for the rear of the vehicle to become accessible. Yet another limitation of the conventional devices is that the carrying device remains in one fixed position when not in use.
Such exemplary conventional devices are illustrated in the following references:
U.S. Pat. No. 5,219,105 to Kravitz, PA1 U.S. Pat. No. 5,145,308 to Vaughn, PA1 U.S. Pat. No. 5,137,411 to Eul et al., PA1 U.S. Pat. No. 5,122,024 to Stokes, PA1 U.S. Pat. No. 5,067,641 to Johnson et al., PA1 U.S. Pat. No. 5,011,361 to Peterson, PA1 U.S. Pat. No. 4,971,509 to Sechovec, PA1 U.S. Pat. No. 4,938,399 to Hull et al., PA1 U.S. Pat. No. 4,934,894 to White, PA1 U.S. Pat. No. 4,915,276 to Devito, PA1 U.S. Pat. No. 4,813,584 to Wiley, PA1 U.S. Pat. No. 4,741,660 to Kent, PA1 U.S. Pat. No. 4,640,658 to Webb, Jr., PA1 U.S. Pat. No. 4,635,835 to Cole, and PA1 U.S. Pat. No. 1,849,046 to Arndt.
Rattling between a vehicle draw bar and a receiver hitch is a persistent concern for the industry. Typically, a square draw bar or tube is sized to fit and to be inserted into a receiver hitch, which is also a square tube. The draw bar and the receiver hitch are not generally manufactured to exacting tolerances, which allows ease of installation and removal by the user. The two pieces are maintained in position relative to one another by way of a locking pin that passes through transversely aligned pairs of holes in both pieces.
When a draw bar is utilized to tow a trailer, for example, swaying motion as well as side to side movement, can occur when the vehicle is moving over a road surface, causing the draw bar to shift within the receiver hitch and resulting in significant "banging" or vibration. When this occurs, the result can be quite alarming to the driver of the towing vehicle. If the vibration or "banging" is severe enough, damage could result to the draw bar, receiver hitch and/or locking pin, and other vehicle control problems could develop. A similar vibration or "banging" condition occurs when accessories, such as bike or ski mounts, or cargo/accessory carriers are inserted into the receiver hitch.
Over the years, different configurations have been designed to eliminate "rattling" between the receiver hitch and the draw bar. One attempted solution is illustration in U.S. Pat. No. 5,593,172 to Breslin, which describes a collar that surrounds the receiver hitch and draw bar combination which is "pinned" together by way of screws that press against the exterior walls of the receiver hitch and draw bar tubes. Another attempted solution is described in U.S. Pat. No. 4,050,714 to Epp, wherein two "plates" surround the draw bar tube. Two "rectangular portions" are affixed to the draw bar tube and, by way of a series of nuts and bolts, a force is applied to move the draw bar away from the receiver hitch in a direction parallel to the longitudinal axis of the hitch.
Other clamps are described in the following references:
U.S. Pat. No. 5,449,101 to Van Dusen, shows a rack carrier mounted into a receiver hitch which incorporates a bolt that keeps the rack from "rattling" in the receiver hitch;
U.S. Pat. No. 5,344,175 to Speer, shows a spring loaded pin that eliminates movement between the receiver hitch and the trailer hitch;
U.S. Pat. No. 5,333,888 to Ball, illustrates a wedge that eliminates play between the trailer hitch and the receiver hitch;
U.S. Pat. No. 5,025,932 to Jay, shows a bicycle rack and a carrier that includes a bolt used to minimize movement between the bicycle rack and the receiver hitch;
U.S. Pat. No. 4,072,257 to Hall, shows a load carrying device that includes many parts attached to the load carrying apparatus to assist in minimizing movement;
U.S. Pat. No. 2,763,498 to Vaugoyeau, shows a means of taking up play in vehicle couplings constituted by between hooks and rings; and
U.S. Pat. No. 1,875,969 to Weiss, relates to a drawbar apparatus for trailers.
However, none of these conventional clamps combines all the following features and advantages: simplicity, effectiveness, extensive use of standard hardware, and minimum fabrication.

Clamp for minimizing interplay between two components


An apparatus and method are disclosed for eliminating a noise signal from at least one source during an acoustic measurement of a subsurface geological formation or borehole. The apparatus includes a longitudinal body for positioning in the borehole and a transmitter supported by the body for transmitting acoustic signals into the formation and borehole. A sensor, substantially isolated within the body, is used to detect one or more noise signals and a receiver is carried by the body for receiving acoustic signals traversing the formation and borehole, and for receiving one or more noise signals. A processor is connected to the sensor and receiver for processing the acoustic signals and noise signals coupled from the receiver and the noise signal coupled from the sensor into a preferred formation or borehole signal by determining the noise signal received at the receiver using the noise signal received in the sensor and a propagation factor for the noise signal between the sensor and receiver. The determined noise signal is used to identify and eliminate the noise signals from the acoustic signals traversing the formation and borehole.

Acoustic logging tools for measuring various formation properties adjacent a borehole are well known. Measurement of subsurface geological formations may be taken by wireline logs after the well has been drilled or by MWD tools during the drilling of a well, sometimes referred to as an earth borehole. In either application, bulk porosity and elastic properties of the formation may be derived by measuring formation resistivity, neutron, gamma ray and sonic velocities. Important information taken from sonic logs may be used in a variety of applications, including correlation between wells, seismic plots, porosity determination, lithology determination, detection of overpressured formation zones, and the conversion of a seismic time trace to an indication of varying lithology based upon the velocity of sonic waves in the earth formation.
Typically, in a drillstring used in drilling an earth borehole, an MWD acoustic or sonic logging tool includes a sonic source positioned at one location along the drill collar to transmit to one or more locations positioned along the drill collar. The sonic source emits acoustic energy that propagates into the formation and which also travels along the borehole through the borehole fluid. Receivers in the drill collar detect the acoustic energy which comes from the formation to determine the acoustic velocity in the formation. Normally, both the shear wave velocity and the compressional wave velocity in the formation are greater than the velocity of acoustic waves in the borehole fluid. The difference in propagation times of the various acoustic signals allows their separation and measurement. For example, a typical prior art acoustic signal is generated to propagate through the borehole fluid and the formation, as well as along the logging tool body itself, to at least one receiving transducer. Depending upon the various propagation effects of the acoustic signal traveling along the tool body, and through the borehole and the formation, two or more receiving transducers may be necessary. The time it takes for the acoustic energy to propagate from the transmitter to a receiver, or from one receiver to another receiver, is then measured. Since the commence time of the transmission is known and the time of the first arrival of acoustic energy at each receiver after having passed through the formation is measured, the propagation time of the signal through the formation, referred to as "interval transit time," is thus determined. Variations in interval transit time, either between the transmitter and one or more receivers, or between receivers in one or more receiver pairs are thus measured and calculated in a conventional sonic Delta-T Sensor as part of the MWD tool, "T" being an abbreviation for time. A Sonic Delta-T sensor, like many other sensors, is simply an array of sensors designed to measure borehole or formation properties. Although sonic logs provide valuable information for various formation properties, certain disadvantages exist in either application due to "propagation effects" of the transmitted acoustic signals through the formation and the borehole fluid, as well as along the drill collar.
During drilling of the well, a number of different paths are available for acoustic energy propagation. Energy propagating along one path travels through the earth formation surrounding the borehole, while energy propagating along another path travels through the annular space between the borehole and the exterior surface of the drill collar, normally filled with drilling fluid. Energy propagating along another path travels directly through the drill collar at an acoustic velocity typically greater than the acoustic velocity of the formation and which may reverberate through the drill collar housing the acoustic logging sensors and associated circuitry.
Depending upon the path or paths along which the acoustic energy propagates, the acoustic energy may propagate as certain wave fields or modes which include: (1) compressional, torsional and lateral waves that propagate along and through the tool itself , (2) compressional waves that propagate within the borehole; (3) compressional and shear waves that propagate through the formation; and (4) leaky-p, tube and pseudo-Rayleigh waves that propagate along the interface between the formation and borehole.
In borehole logging, studies of the different acoustic modes propagating in the formation or at the formation/borehole interface provide information about the elastic contents of the formation, rock texture, porosity, fluid content, rock fracturing, and other data. For quantitative analysis, it is necessary to isolate the various waveform modes. Consequently, conventional logging tools are designed to suppress undesired waveforms (noise) either by structural design or by post-processing software.
It is normally desired that the detected signal remain free of any acoustic energy emitted by the transmitter into the tool body and propagating along and through the tool body to the one or more receivers. Since the speed of sound in the borehole or in the tool body is usually faster than that of the formation, the tool signal and the borehole signal arrivals in such cases usually occur before the formation signal arrives. Since the sonic logging device merely records signals as they are received, it is difficult to distinguish whether a signal has traversed the borehole, the formation or the tool body. Thus, such first arriving signals propagating through the borehole and/or the tool body may falsely be assumed to be first arriving signals propagating through the formation.
Although various solutions have been developed in the wireline logging industry for attenuating or suppressing the propagated tool signal so that formation arrival may be detected without interference from the propagated tool signal, such solutions are generally limited to an alteration of the structural design of the wireline tool which are not feasible for use on MWD tools. For example, since wireline tools are not required to function as a load bearing member, it is possible to form an array of staggered openings along the length of a sidewall of the wireline tool's housing. The openings serve to lengthen the total path that a housing propagated acoustic signal must follow. As a result, the signal is not only delayed, but is also attenuated due to the increased path length and additional openings that the scattered signal must traverse.
In MWD applications, however, the acoustic tool is incorporated into a drill collar which must be able to withstand the immense forces and accelerations encountered during the drilling of the well. Numerous holes or indentations in the sidewalls of the drill collar would weaken the collar so that it would not be able to withstand normal wear and tear during drilling operations. Moreover, the fluid isolation between the inside of the drill collar and its exterior would be lost or reduced. Additionally, conventional convoluting of the sidewall of an acoustic tool so that the tool takes on a uniform thickness, yet tortuous longitudinal cross-section, is equally problematic in that such shapes either are too weak or require an impractically large portion of the limited diameter of the tool.
One attempt to resolve the propagation of an acoustic signal traveling through a wireline tool body is found in U.S. Pat. No. 5,036,945 to Hoyle et al. Hoyle et al disclose a sonic well tool having a first and second attenuation and delay apparatus for attenuating and delaying the signal traversing the tool body. The first attenuation and delay apparatus includes interleaved rubber and metal-like washers for attenuating compressional and flexural waves propagating along the tool body, and a bellows section having a corrugated shape and a thin traversed dimension. The second attenuation and delay apparatus includes a mass loading ring surrounding the housing of the well tool, and a bellows section having a corrugated shape and a thin traverse dimension.
U.S. Pat. No. 5,229,553 to Lester et al discloses an acoustic isolator for use with a well logging tool having transducers in a first and third tool segment which are to be acoustically isolated from receivers in a second and fourth tool segment. The acoustic isolator consists of vertebrate links of spools encased by resilient boots which are arranged end to end in tandem configuration. A plurality of split shells interconnect the spools by externally gripping the boots covering the end portions of the respective adjacent spools.
U.S. Pat. No. 4,872,526 to Wignall et al, deals with a wireline logging tool that utilizes various mechanical means for isolating the transmitter from the receiver.
Since most solutions to resolving the "propagation effects" of an acoustic signal traveling through a wireline tool body are impractical for use on MWD tools, and it is preferable to measure characteristics of the formation adjacent the well bore in a timely fashion while drilling, a number of different attempts have been made to remove unwanted acoustic noise as a result of the "propagation effects" of a transmitted acoustic signal using an MWD tool.
For example, U.S. Pat. No. 5,467,320 to Maki, Jr. discloses an acoustic formation apparatus having first and second receivers with a common azimuth spaced vertically along the drill stem and connected, respectively, to first and second amplifiers, first and second band pass filters, first and second clipping circuits, a single delay circuit and a cross-correlating circuit. The signals are received, filtered, amplified, clipped, delayed, and then cross-correlated utilizing variable time delays. The resulting cross-correlation function is analyzed using a microprocessor which removes stationary correlation peaks and ignores very short correlation delay times. This enables removal of the substantially fixed aspect of the drill pipe transmitted signal and the very fast propagating waves so that the processed cross-correlation function output is substantially related to the formations and the larger, overpowering signal transmitted along and through the drill collars is substantially avoided.
Another example is U.S. Pat. No. 5,357,481 to Lester et al which discloses an MWD borehole logging tool having a sonde constructed of a plurality of segments that are axially rotatable with respect to each other. Each one of two of the segments includes a compartment in which is mounted a dipoled bender bar transmitting transducer. Two additional segments each contain one or more binaurally sensitive receiver transducers. Monopole transmitting and receiving transducers are also included in the respective appropriate segments. An acoustic isolator separates the transmitting transducers from the receiving transducers. The borehole logging tool is said to be capable of reducing noise during the acoustic logging process such as: (1) random noise by use of multiple receivers to make redundant measurements, and (2) phasing the receivers to exclude noise from certain directions.
U.S. Pat. No. 3,982,606 to Drumheller et al, deals with the suppression of acoustic noise from a transmitter, through a borehole, to a receiver, utilizing mechanical means to obstruct the travel path of unwanted acoustic signals traveling within the borehole fluid between the transmitter and the receiver. Thus, the obstructed path will delay the arrival time of the unwanted acoustic signals at the receiver.
U.S. Pat. No. 5,475,731 to Rasmusson discloses an echo canceling system and method in a cellular telephone system using an echo estimate to modify an error signal which is obtained by the difference between an echo signal and the echo estimate. The modified error signal, rather than the error signal itself, is transmitted. By using the echo estimate as a parameter for modifying the error signal, improved hands free performance may be obtained in a cellular telephone. The echo estimate signal is transmitted with the original signal in order to cancel the echo error when it is received.
U.S. Pat. Nos. 5,418,335 and 5,371,330 to Winbow disclose first and second end acoustic sources and an intermediate acoustic source positioned to enhance the signal to noise ratio and substantially eliminate tube wave interference. Each first end and second end acoustic source create a partial acoustic pressure null proximate the first and second longitudinal ends of the apparatus, thereby preventing at least a portion of the intermediate source acoustic pressure waves from propagating through the borehole beyond the longitudinal ends of the apparatus. Consequently, tube wave dominance in the regions above and below the apparatus is minimized by the creation of the near zero acoustic pressure condition around and beyond each end of the apparatus using the first end and second end acoustic sources to block the tube wave affect of the intermediate acoustic source from propagating through the borehole above and below the apparatus.
U.S. Pat. No. 5,309,404 to Kostek et al pertains to reducing the effects of quadrupole and higher order moments of acoustic signals transmitted from a transversely mounted acoustic source in a MWD tool by angular displacement of the receiver such that the quadrupole mode of the acoustic signal is rendered insignificant. In another embodiment, a plurality of receivers are uniquely positioned to eliminate the quadrupole mode by timing each receiver's individual signal to obtain a resulting signal by the summation of the individual signals and averaging the same to eliminate the quadrupole mode.
U.S. Pat. No. 5,274,606 to Drumheller et al presents an electronic circuit for digitally processing analog electrical signals produced by at least one acoustic transducer. Preconditioned data is used to counteract distortions caused by the drill string, the distortion corresponding to the effects of multiple pass bands and stop bands having characteristics dependent upon the properties of the drill string. The preconditioned data is transmitted to the first end of the drill string and detected at a second end of the drill string.
U.S. Pat. No. 4,796,237 to Hutchens et al is directed to determining the presence of defects in cement surrounding a casing set within a well bore by using the amplitude of the casing reverberation noise from a known signal source such as a transmitter, and the time between the transmission of the known signal and the reception of the first casing reverberation noise. This amplitude and delay time are then used to eliminate the casing reverberation noise by either transmitting a series of negative signals having amplitudes equal to the immediately preceding received acoustic reverberation at a time later than the positive signal so that the acoustic reverberations are driven to a null, or scaling the amplitude of the known signal delayed a time between the transmission of the known signal and the reception of the signal, and subtracting the scaled signal from the stored known signal to generate or refine a signal from which casing reverberation noise has been removed. In either method, the noise signal is known and since the transmitter abuts the casing adjacent the surrounding cement, propagation effects due to other borehole noise are not considered.
U.S. Pat. No. 4,590,593 to Rodney deals with an electronic noise filtration system for use in improving the signal to noise ratio of acoustic data transmitted from a downhole transducer in a MWD system. A pair of acoustic receiving transducers are spaced apart on a given flow path for generating a respective output signal responsive to acoustic pulses propagating through the drilling fluid. The difference in output signals of the transducers is determined by selectively delaying one of the output signals to a difference determining means and which is then compared to the difference during the absence of purposely-generated downhole data to effectively minimize the difference and eliminate acoustic noise in the flow path.
U.S. Pat. No. 4,153,815 to Chaplin et al discloses a method of reducing the amplitude of vibrations received at a selected location from a source of reoccurring noise by feeding to the location a specifically generated secondary vibration which at least partially nulls the vibrations from the noise source at the selected location. A triggering signal derived from the selected source is used to synchronize the generation of the secondary vibration with that of the vibration to be at least partially nulled. Since the noise source is reoccurring, the amplitude of the vibrations is known and the cancellation signal may be easily simulated. However, the process relies solely on the derivation of a cancellation signal from a known source. Noise originating from unknown sources cannot easily be estimated and/or eliminated. Moreover, the process does not provide for distinguishing between a preferred signal hidden within an unknown noise signal that arrives simultaneously at a receiver as noise.
U.S. Pat. No. 4,215,425 to Waggener relates to a communication system and apparatus for receiving and interpreting data signals being telemetered to the surface of the earth in an MWD system. A filter is provided for use and detection in a phase shift keying transmission system of the type where modulation is achieved by temporary inter-directional modification of a carrier frequency.
U.S. Pat. No. 5,510,582 to Birchak et al provides an apparatus for sonic well logging having at least one transmitter and at least one receiver. Positioned between the transmitter and receiver is an acoustical attenuation section intended to attenuate sonic waves traversing the sonic logging tool. This acoustical attenuation section generally includes one or more fluid filled cavities in the sonic logging tool, into which are inserted inertial masses. The cavities are generally shaped to receive the attenuators and are slightly larger so that a gap will exist between the walls of the cavities and the inertial masses (attenuators) as the attenuators are positioned in the cavity. Therefore, the tool body, the fluid and the inertial masses are designed to act together to mechanically attenuate undesired acoustic signal propagation.
British Patent Number GB 2,266,372 A to Scherbatskoy discloses a sonic logging arrangement having an MWD telemetry system in which a drilling fluid pump at the earth's surface circulates drilling fluid through a drill string and produces a high differential pressure between the inside and outside of the string, thereby producing acoustic pressure waves in the formation surrounding the borehole.
British Patent Number 2,300,048 A and U.S. Pat. No. 5,639,997 to Mallett is directed to an acoustic noise canceling apparatus for well logging that is said to cancel interfering signals propagating through the tool body by transmitting an acoustic signal into the formation that also traverses the tool body for receipt by two receivers. The first receiver is isolated, receiving only the acoustic signal propagating through the tool body, and the second receiver receives acoustic signals traversing both the formation and the tool body. A processor then subtracts the tool signal of the first receiver from the combined tool and formation signal of the second receiver resulting in a single formation signal. The apparatus is restricted to canceling noise from a known signal such as a transmitter, and does not take into account propagation effects resulting from the signal passing through the borehole fluid and/or the formation. Moreover, the apparatus is limited to placing each isolated first receiver immediately adjacent each second receiver precluding the ability to consider propagation effects of multiple noise signals propagating from above and below the tool body.
Other publications of general interest describing mechanical means for suppressing noise interference and signal processing of sonic arrays in MWD tools include:
J. Aron, S. K. Chain, R. Dworak, K. Hsu, T. Lau, J-P. Masson, J. Mayes, G. McDaniel, C. Randall, S. Kostek, T. J. Plona, Sonic Compressional Measurements While Drilling, SPWLA 35th Annual Logging Symposium, Jun. 19-22, 1994, paper SS. PA1 John Minear, Robert Birchak, Carl Robbins, Eugene Linyaev, Bruce Mackie, David Young and Robert Malloy, Compressional Slowness Measurements While Drilling, SPWLA 36th Annual Logging Symposium, Jun. 26-29, 1995, paper VV. PA1 Christopher V. Kimball, Thomas L. Marzetta, Semblance processing of borehole acoustic array data, Geophysics, Vol. 49, No. 3, March, 1984, pp 274-281. PA1 A. L. Krkijan, S. W. Lang, and K. Hsu, Slowness estimation from sonic logging waveforms, Geoexploraton, Vol. 27, 1991, pp 215-256. PA1 C. F. Morris, T. M. Little, and W. Letton, III, A New Sonic Array Tool for Full Waveform Logging, 59th Annual Technical Conference and Exhibition, Sep. 16-19, 1984, paper SPE 13285.
In view of the prior art and its limitations, a specific need exists to provide an apparatus and method for determining a preferred acoustic signal indicative of borehole and/or formation characteristics by eliminating acoustic noise signals that may propagate through the drill collar or tool body, as well as the formation, borehole and borehole/formation interface as acoustic measurements are taken using an MWD tool.

Method and apparatus for cancellation of unwanted signals in MWD acoustic tools


A device for controlling all airbags for a vehicle is provided, and also a control unit for forming a control signal for all airbags for a vehicle, as well as a system of this device and this control unit. The device has a trigger circuit control and also an energy reserve, in order to control power switches in a trigger circuit as a function of the control signal that comes from the control unit, and to use the energy from the energy reserve to trigger the trigger elements for the airbags. The control unit receives at least parts of the energy supply from the device.

1. Field of the Invention
The present invention relates to a device for controlling all airbags for a vehicle, a control unit for forming a control signal for all airbags for a vehicle, and a system having the device and the control unit.
2. Description of Related Art
Published German patent application document DE 10 2004 015 125 A1 describes providing a trigger circuit control separated from a control unit having the evaluation circuit, which is designed as a microcontroller. The sensor system for detecting accident signals is also disposed outside of the control unit.

Device for controlling all airbags for a vehicle, a control unit for forming a control signal for all airbags for a vehicle, and a system of the device and the control unit


A zero-insertion force connector having a frame which includes a selectively deformable base. Contacts are supported by the base and are selectively displaced from an insertion path when the base is deformed, allowing insert elements, such as wire from flat cable, or a printed circuit board, to be inserted between the contacts without substantial resistance. Releasing the force which is deforming the base allows the base to return to its rest shape under a natural resiliency of the material used to make the base, which causes the contacts to move against the inserted element and establish electrical communication.

A conventional ZIF connector typically includes a housing having an elongated slot along a front surface which is sized and shaped to receive a circuit board or flexible flat cable (hereinafter called insert elements). Located within the housing are typically a plurality of terminals which are adapted to contact at least one surface of the insert element. The terminals are biased to a predetermined overlapping position and will therefore exert a controlled amount of contact force against the insert element to achieve the required electrical contact. As is well known in the art, many of the circuit boards and flat cable used today are delicate and include fragile electrical contacts, such as thin film deposition layers and high gauge wire (extremely fine). Such delicate insert elements are easily damaged during insertion into the slot of a ZIF connector even by the relatively low contact force exerted by the terminals. It is for this reason that ZIF connectors include provisions to reduce the magnitude of the contact force during insertion of the insert elements and thereafter reapply the force so that proper electrical contact may be achieved. A common technique used with prior art ZIF connectors to release or reduce the contact force of the contact terminals during insertion of the inserted elements is to mechanically displace each contact terminal from the path of insertion, during the insertion process. This displacement of terminals may be achieved using a lever arm which mechanically engages each contact terminal, or, as in the connector disclosed in U.S. Pat. No. 5,542,855 issued to Asai, the contact terminals are already positioned away from the path of insertion during the insertion process and are forced into tight engagement, as required, by inserting a key element into a second slot which effectively deforms each contact terminal in the desired manner.
A problem with the prior art ZIF connectors is that they are expensive to manufacture owing to the relatively complex internal mechanisms used to simultaneously displace the contact terminals. These prior art ZIF connectors are designed for repeated use, such as removably securing an IC chip to a circuit board for possible removal at a later time. The prior art ZIF connectors are not intended to be permanently attached (soldered) to both the inserted elements and the circuit board.
It is therefore a first object of the present invention to provide a zero-insertion-force connector which is simple in construction and inexpensive to manufacture.
It is another object of the invention to provide such a ZIF connector that includes contacts that are adapted to be soldered to corresponding electrical contacts located on the insert element.
It is another object of the invention to provide such a ZIF connector that otherwise overcomes the deficiencies of the prior art.


In order to output event content of a related match during execution of a main match, there is provided a virtual start time decider for deciding virtual start times for a plurality of matches, a related match selector for selecting, from the plurality of matches, at least one match, taking place at least partially at the same time as a main match a player's team is taking part in, as one or more matches related to the main match based on virtual start times for each match, a related match simulator for simulating the related matches, event storage unit for storing event time and event content for prescribed types of events occurring in the related matches, a main match executor for executing the main match, an event time arrival monitor for monitoring for arrival of the event time stored by the event storage unit during execution of the main match, and an event content output unit for outputting event content corresponding to the event time when it is determined that the event time has arrived during execution of the main match.

The present invention relates to a game device, program, and program distribution device.
Games such as various sports games etc. where a player replicates tournament format or league format match as a result of matches being provided that are automatically executed (simulated) by a computer such as a game machine etc. separately from matches in which a player's team is taking part are well known. For example, in the case of a football simulation game, a multiplicity of soccer teams other than the soccer team that is the player's team is provided. In a match in which a soccer team that is the player's team takes part (main match), game operations made by the player are received, while in other matches, match results are calculated as a result of simulations by computer on the game machine side.
However, with related games, match results are calculated merely through simple simulations and it was not possible to create an atmosphere that another match was taking place at the same time as the main match for the player. However, if it were to become possible to provide latest news bulletins etc. during a match for other matches related to the main match, then this may contribute to the tactics a player uses, and it is anticipated that this would serve to further heighten tension.


A wobble plate engine assembly incorporating as offset mount between the wobble plate and each connecting rod to a piston such that a line of action of the connecting rod at the wobble plate is resolved into a centripetal and tangential component thereby minimizing the component of applied forced directed through the wobble plate and maximizing the force the force applied along the wobble plate. The connections between the wobble plate, connecting rod and pistons incorporate spherical bearings. Also a wobble plate internal combustion engine incorporating the wobble plate engine assembly is presented.

Wobble plate engines have been known for many years. Early engines of this type comprised a number of parallel pistons disposed about a central driven shaft. Lateral displacement of the pistons is transformed to rotational motion of the shaft by a wobble or smash plate fixed at an angle on the shaft. Reciprocation of the piston causes a tangential displacement of the wobble plate thereby rotating the shaft.
Australian Patent number 14759/23 in the name of Crankless Engines (Aus.) Pty Ltd describes a dual swash-plate engine wherein the swash-plates are driven by double ended pistons sharing a common combustion chamber. This engine, and other engines developed by Crankless Engines (Aus.) Pty Ltd where incorporated in motor vehicles.
Although wobble plate engines have been known for 70 years they have not been generally accepted as internal combustion engines. The use has been limited to hydraulic pumps and other driven devices as opposed to driving devices. Various attempts have been made to improve or modify the basic wobble plate design for use in internal combustion engines.
Australian Patent Application number 41322/85 in the name of S.V. Engine Co. Pty Ltd described a number of improvements that could be made to the design of a wobble plate engine. These included a damping system for stabilization; a balancing arrangement; a linkage arrangement enabling variation in the tilt of the wobble plate; and improved overall construction features.
Reference may also be made to United Kingdom Patent number 2101226 in the name of Star Motors which describes a high pressure vapour driven engine based on a swash plate. The cylinders are arranged around a central power shaft in conventional manner. The swash-plate is rotatably mounted on the shaft and is connected to the pistons by connecting rods incorporating ball joints at each end. The engine is designed to be driven by high pressure steam derived from geothermal or solar energy.
Despite the many years of development the wobble plate engine has failed to be accepted for internal combustion engine manufacture. This is because of vested interests in cranked engines and because of fundamental design problems. One such design problem is the direct load placed on the wobble plate by the pistons when they fire. The line of action of the pistons is parallel to the axis of rotation of the wobble plate, thus there is a large component of force directed through the wobble plate. Only a portion of the applied force is directed along the wobble plate to force it to rotate. This results in high frictional loads and reduced efficiency of the motor.


A cross-type wrench including a connector in which a dogging cavity and a receiving space are formed and an adjustment member accommodated in the dogging cavity and the receiving space. The adjustment member has a downward extending engaging section formed with multiple fixing holes. A press button is disposed on top end of the adjustment member. The press button is connected with a downward extending shaft rod formed with an axial shaft hole. A second fixing member is passed through a bottom end of the connector and inserted in the shaft hole. A resilient member is fitted around the shaft rod. The outer circumference of the connector is formed with multiple fixing tunnels for several rotary members to insert therein.

The present invention is related to a cross-type wrench which can multidirectionally wrench a work piece and can be easily assembled/disassembled.
FIGS. 5 and 6 show a conventional cross-type wrench having a connector 6. The connector 6 is formed with an axial recess 61 having a first threaded section 611. An adjustment member 7 having a second threaded section 71 can be screwed into the recess 61. Several through holes 62 are radially formed on the connector 6 at equal intervals. Several rotary members 8 can be inserted in the through holes 62. The adjustment member 7 can be screwed for fixing the rotary members 8 to form the cross-type wrench for wrenching a work piece.
In the above structure, the connector 6 and the adjustment member 7 are connected by means of the first and second threaded sections 611, 71. Accordingly, after the adjustment member 7 and the connector 6 are produced, it is necessary to additionally process the adjustment member 7 and the connector 6 to form the threaded sections. Such operation is time-consuming and laborious so that the manufacturing cost is higher.
Moreover, in a working site, it is necessary to frequently replace the rotary member 8 according to the size of the wrenched work piece. When replacing the rotary member 8, it is necessary to first screw the adjustment member 7 to a certain position. Such procedure is time-consuming and laborious. Therefore, the working efficiency will be affected.
Furthermore, the connector 6 and the adjustment member 7 are connected by means of the first and second threaded sections 611, 71. After a period of use, the threads will be worn out. This will lead to slippage between the first and second threaded sections 611, 71.


A vehicle includes an engine configured to generate power and noise. The vehicle includes a transmission configured to operate in a first gear corresponding to a first gear ratio and a second gear corresponding to a second gear ratio. The second gear ratio is less than the first gear ratio. The vehicle also includes a noise reduction device coupled to the engine and configured to operate in a first state to reduce the noise of the engine to a first volume and a second state to reduce the noise of the engine to a second volume that is greater than the first volume. The vehicle also includes an electronic control unit (ECU) coupled to the engine, the transmission and the noise reduction device and configured to control the noise reduction device to switch to the second state when the transmission shifts from the second gear to the first gear.

Field
The present disclosure relates to systems and methods for adjusting a volume of engine noise heard in a cabin of a vehicle and, more particularly, for increasing the volume of engine noise heard in the cabin based on a downshift event.
Description of the Related Art
The experience of driving a vehicle can vary from person to person. Some people focus on the vehicle's acceleration, some focus on the noise of the engine, some focus on a combination of these and so forth. Furthermore, most drivers likely still notice features that they do not focus on. For example, a driver who focuses on acceleration may still notice the engine noise from time to time. As vehicle technology advances, some of these features that drivers focus on are becoming more and more difficult to notice from the cabin. For example, the noise reduction technology advanced to the point that the engine noise may be barely audible in the vehicle's cabin. Those drivers who focus on the engine noise during a driving experience may find the lack of noise undesirable. In certain situations, all drivers may find the lack of engine noise to be concerning.
The engine noise of a vehicle changes in volume and pitch as the vehicle performs various functions. For example, as acceleration is requested and the angular velocity of the engine increases, the volume and/or pitch of the engine noise may increase. Drivers with experience driving vehicles that have relatively little noise reduction may find the lack of noise corresponding to an increased angular velocity concerning. For example, they may be concerned that the engine and/or the transmission are not functioning properly. This may be especially true in situations in which the angular velocity of the engine rapidly increases, such as during a downshift of the transmission.
The angular velocity of the engine rapidly increases as a downshift occurs due to the effects of the higher gear ratio of the transmission. Thus, the volume of the engine noise of traditional vehicles increases rapidly as the transmission downshifts. However, the engine noise heard in the cabin of vehicles having certain noise reduction systems may not increase in volume as the transmission downshifts. This may be especially concerning to drivers who may think that the transmission is not operating properly due to the lack of change of volume of the engine noise.
Thus, there is a need for systems and methods for adjusting the volume of the engine noise heard during and after a downshift of a transmission.

System and method for increasing engine sound during a downshift

Toyota Motor Engineering & Manufacturing North America, Inc.


Embodiments of the invention provide a method and apparatus for accessing a twin cell memory device. In one embodiment, a twin memory cell is accessed using a first bitline and a second bitline. The method includes precharging the first bitline and the second bitline to a low voltage. A wordline voltage is asserted to access the twin memory cell. A voltage difference between the first and second bitline is created by a data value and a complement of the data value stored in the twin memory cell, and the voltage difference is sensed.

1. Field of the Invention
The invention generally relates to semiconductor memory devices. Specifically, the invention relates to reducing power consumption in semiconductor memory devices.
2. Description of the Related Art
Modern semiconductor memory devices are typically used in a wide variety of electronic devices such as portable data assistants (PDAs), cell phones, and the like. Because the electronic devices are typically powered by batteries, there is a desire to reduce power consumption of the memory devices.
One type of memory device with reduced power consumption is a twin cell dynamic random access memory (twin cell DRAM). FIG. 1 is a circuit diagram depicting an exemplary memory cell 100 of a twin cell DRAM. As depicted, the memory cell 100 may contain two NMOS access transistors 112, 114 which are used to access two capacitors 122, 124 which store data for the memory cell 100. The NMOS transistors 112, 114 may be controlled by a wordline WL 106 connected to the gates of the transistors 112, 114. The memory cell 100 typically stores a binary bit of information and a complement of the bit (e.g., a '0 and 1', respectively, or a '1' and a '0', respectively). The bit and the complement of the bit may be stored as charges in the capacitors 122, 124. When the memory cell 100 is accessed, the stored bit and the complement of the bit may be output on a bitline (bitline true, BLt) 104 and a complementary bitline (BLc) 102, respectively.
FIG. 2 is a timing diagram depicting an exemplary access of the memory cell 100. At some time T0 before the access, the wordline voltage VWL may be a low voltage (e.g., a ground voltage VGND or a wordline off voltage VWLOFF), thereby disconnecting capacitors 122, 124 from the bitlines 102, 104. In some cases, VWLOFF may be a low voltage which is boosted downward by a charge pump. As depicted, a high voltage (VNT=VCC) representing a logic value '1' may be stored in the "true" capacitor 122 of the memory cell 100 and a low voltage (VNC=VGND) representing a logic value '0' may be stored in the complementary capacitor 124.
Before the memory cell 100 is accessed, the bitlines 102, 104 may be precharged (also referred to as equalized) to a precharge voltage (the equalize voltage, VBLEQ). Precharging may be performed to equalize a voltage level remaining on the bitlines 102, 104 from a previous access which used the bitlines 102, 104. Precharging prevents destruction of data stored in the memory cell 100 and allows the small voltage signals used to store information in the memory cell 100 to be properly sensed.
The access of the memory cell 100 may begin at time T1 when VWL is asserted to the wordline on voltage VWLON. VWLON may be sufficient to turn the NMOS transistors 112, 114 on (e.g., to place the transistors 112, 114 in a conducting state). In some cases, VWLON may be a high voltage (VPP) which is boosted upward by a charge pump. When the NMOS transistors 112, 114 are turned on, the voltages VNT, VNC stored in the capacitors 122, 124 may be driven onto the bitlines 102, 104, thereby pulling VNT down and VNC up towards VBLEQ. As the voltages stored in the capacitors 122, 124 are driven onto the bitlines 102, 104, a voltage difference (VBLT−VBLC) between the voltage of the true (VBLT) and complementary (VBLC) bitlines 122, 124 may be created, e.g., by time T2.
At time T3, a sense amplifier connected to the bitlines 102, 104 may be enabled. The sense amplifier may be used to sense and amplify the voltage difference VBLT−VBLC created by the memory cell 100 on the bitlines 102, 104. Thus, at time T3 and continuing to time T4, the voltage difference VBLT−VBLC may be amplified, driving VBLT upwards to the bitline high voltage (VBLH) and driving VBLC downwards to the bitline low voltage (VBLL). Because the transistors 112, 114 may continue to be turned on (e.g., because VWL=VWLON), VNT may also be driven upwards to VBLH while VNC is driven downwards to VBLL. In some cases, the voltages stored in VNT and VNC deteriorate over time, e.g., due to leakage from the memory cell 100. However, when the depicted access is performed and VNT is driven to VBLH and VNC is driven to VBLL (or vice versa), the values stored by the capacitors 122, 124 in the memory cell 100 are refreshed.
At time T5, VWL may be lowered (e.g., to VWLOFF or VGND), thereby disconnecting the capacitors 122, 124 from the bitlines 102, 104 and completing the access. Later, at time T6, the bitlines 102, 104 may be precharged by driving VBLT and VBLC to VBLEQ, thereby preparing the bitlines 102, 104 for a subsequent access.
In some cases, leakage mechanisms in the memory cell 100 may increase the power consumption of the memory device. In low power applications, reducing such leakage mechanisms may become important. One example of a leakage mechanism is a bitline-wordline (BL-WL) short 130, depicted in FIG. 1, formed between a bitline and a wordline. When the bitlines 102, 104 are precharged (e.g., as depicted at time T0) to VBLEQ and the wordline voltage is lowered (deactivating the wordline 106), a voltage difference VWL−VBLC =VBLEQ−VWLOFF (or VWL−VBLC=VBLEQ−VGND) may develop across the short 130, causing current to flow across the short 130 between the wordline 106 and bitline 102, thereby consuming power.
Another example of a leakage mechanism which may occur during precharge is diffusion leakage (also referred to as junction leakage). Diffusion leakage may be cause by a diffusion leakage current (IL) from a junction, for example, a source of a transistor which is turned off, into a well or substrate in which the junction is located. The leakage current is similar to a reverse-biased diode leakage, with the junction and the well forming the reverse-biased diode.
As depicted in FIG. 1, the junction leakage IL may flow from the bitline side of transistors 112, 114 to the bitlines 102, 104. During precharge, the voltage drop from across the junction from the bitlines 102, 104 to the substrate may be VBLEQ−VBB, where VBB is the back bias voltage of the transistor 112, 114. In some cases, VBB may be a low voltage (e.g., VGND) or a downward driven low voltage (e.g., a voltage lower than VGND). Because the junction leakage may be proportional to the junction voltage (VBLEQ−VBB, during precharge), the junction leakage current, and thus the power consumption, during precharge may be substantial.
As described above, the bitlines 102, 104 in the memory device may be precharged between accesses, e.g., during a standby mode. In some cases, the memory device may spend a majority of the time in standby mode (with the bitlines 102, 104 being precharged), e.g., while waiting for user input to the electronic device containing the memory device. Accordingly, the current consumption during precharge and/or a standby mode, typically classified as standby current, is an important parameter in low power memory devices.
Accordingly, what is needed is a method and apparatus for reducing power consumption of a memory device.

Low equalized sense-amp for twin cell DRAMs


A method and an apparatus are disclosed for combining information from two sources and for separating the combined information after transmission over one physical channel. A mask which represents a specified piece of information such as a control command or logic state of an input is exclusively ORed with an encoded input signal, thereby inducing a violation of an error control code. At the receiving end of the system, each of a set of masks is exclusively ORed with the received data stream. One of the masks is the same as the mask initially combined with the encoded input signal. Accordingly, once that mask is combined with the received data stream and so indicated by the favorable outcome of an error control code check, the original encoded input as well as the specified piece of information are recreated and produced.

1. Technical Field of the Invention
The present invention relates to digital communication systems, and in particular to systems for deriving a primary and a secondary logical channel from a common physical channel without increasing the bandwidth needed to accommodate the physical channel.
2. Description of Related Art
The purpose of a digital communication system is to enable the exchange of bit-encoded information among various electronic devices located at various places. The functions necessary to accomplish this purpose can be divided into seven groups, each group corresponding to one of the layers of a seven-layer data-communications protocol model adopted by the international standards community, as described in Section 3,1 of Data Networks by Bertsekas and Gallagher (Prentice-Hall, 1987).
The lowest layer of this model, known as the physical layer, encompasses the methods and apparatus needed to move bits from a source to a destination. These methods and apparatus include such things as transmission wires, connectors, and antennas; modulators and demodulators; and the associated electronics and components needed to communicate a bit stream between adjacent nodes in a communication network by means of fiber optics, coaxial cables, parallel conductor transmission lines, wireless radio links, or some combination of these. In this context, the resulting bitstream is called a physical channel.
Once a physical channel is established and a bitstream can be communicated between network nodes, the bits provided by the bitstream can be organized for the benefit of a user or a plurality of users, thereby providing these users with logical channels derived from the raw bit-moving capacity of the physical channel. The functions needed to accomplish this organization are generally encompassed by the higher layers of the seven-layer protocol model mentioned above.
For example, the North American telephone network includes a transmission method and format known as T1-rate service. This service moves bits between network nodes at the rate of 1.536 million bits per second (Mbps). In one use, the full capacity of the T1 physical channel can be employed to provide a single broadband channel for the benefit of a single user, for example to connect a first high-capacity computer server in a first city to a second high-capacity server in a second city. In a different situation, the capacity of the T1-rate physical channel can be subdivided by multiplexing apparats into a twenty-four channels each having a transmission capacity of 64,000 bits per second (64 Kbps). Through functions encompassed by the higher layers of the protocol model, each of these 64 Kbps channels can be configured to support a different digital conversation or application, thereby subdividing the physical channel into a plurality of logical channels.
One of the organizational functions routinely present in a data-communication network is an error-control mechanism intended to provide some degree of protection against transmission errors. Such errors typically arise from the coupling of external disturbances often called noise into the physical channel, and have the undesired effect of altering the logical state of bits as they transmit the physical channel, and thereby altering the logical state of bits delivered by one or more of the logical channels. This error-control mechanism is typically provided by the data-link-control (DLC) functions encompassed by the higher layers of the protocol model.
Under the operation of a standard DLC, a plurality of bits to be communicated are collected and grouped into a data packet. To the beginning of the packet is appended a packet header comprising flag, address, and control fields needed to enable and assist the operation of other network functions. To the end of the packet is appended a packet trailer comprising flag bits and parity bits. Together, the header, packet, and trailer is called a frame. The purpose of the parity bits carried by the frame is to provide a means of detecting the presence of any bit errors introduced into the frame during its transit across the physical channel.
One particular method of generating and processing parity bits is the cyclic redundancy check (CRC), whose operation can be envisioned most clearly as a series of multiplication and division operations among polynomials having modulo-2 coefficients in recognition of their representation of digital bits. In this representation, the contents of a partial frame (i.e., the frame excluding its header flag and its trailer) can be thought of as an N-degree polynomial, where N is the number of bits in the partial frame. This polynomial is divided by a second polynomial known as the CRC generator polynomial. On completion of the division, the resulting remainder is incorporated into the packet trailer as the parity bits, and the frame is passed to the physical channel for transmission.
Upon receipt of the frame, the receiver again computes the polynomial division, and compares the resulting remainder with the received remainder. Transmission errors are indicated by any disagreement between the remainder as conveyed by the received frame and the remainder as re-computed by the receiver.
The polynomial model as well as the limitations and capabilities inherent in CRCs derived from various generator polynomials in widespread commercial use are described more fully by Boudreau, Bergman, and Irvin, in "Performance of a cyclic redundancy check and its interaction with a data scrambler" (IBM Journal of Research and Development, vol. 38, no. 6, November 1994, pp. 651-658). From mathematical results laid out in this paper, it can be shown that current error-protection schemes often provide excess error-control capacity.
This excess error-control capacity arises from practical design constraints. For example, the number of redundancy bits provided by a commercially useful CRC is normally an integral multiple of eight, due to the byte-oriented nature of today's digital communication apparatus. Moreover, in commercial reality most useful CRC generator polynomials are chosen from a small list of accepted industry standards that provide either eight, sixteen, or thirty-two redundancy bits. For this reason, a system architect might select a 32-bit CRC, which might have an abundance of capacity relative to the task at hand, rather than select a 16-bit CRC whose adequacy might be questionable. Thus, the inflexibility of granularity often leads to a wasteful excess of error-control capacity.
In the problem at hand, excess CRC capacity has important commercial considerations that follow from the nature of the DLC of which the CRC is part. In addition to its error-control functions, the DLC typically controls access to the physical transmission medium, and in this sense imposes the logical channel upon the physical channel. In doing so, the DLC also imposes all of the limits inherent in its predetermined frame structure, and in particular thereby constrains transmission efficiency by cementing-in excess CRC capacity.
The DLC's cementing-in of excess CRC capacity has adverse economic consequences to the end-user of the communication system. If the end-user has a need for a small amount of additional transmission capacity, for example to implement a secondary channel for the purpose of carrying network-management information or for extending the reach of an exhausted control field, that user is required to procure additional physical-channel bandwidth from a common carrier, thereby incurring a penalty in complexity and in operating cost. Such problems become particularly acute when the physical channel is provided by a wireless communication network such as a cellular or satellite network, where the limitations imposed by regulatory agencies to conserve the finite electromagnetic spectrum may make the purchase of additional transmission capacity prohibitively expensive.
Thus, there is a need to enable the DLC to recapture excess error-control capacity and apply this recaptured capacity toward providing a secondary logical channel over which the end-user or the common carrier itself may communicate incidental information without increasing the bandwidth needed to accommodate the physical channel, and in this way to conserve spectral resources in a wireless communication system or to minimize wasteful expenditures in a wireline communication system.

Secondary channel for communication networks


A semiconductor device includes conductive lines spaced from a substrate, and an insulating spacer structure between the conductive lines and defining a contact hole. The insulating spacer structure is adjacent a side wall of at least one of the conductive lines. The device also includes an insulating pattern on the conductive lines and insulating spacer structure, and another insulating pattern defining a landing pad hole connected to the contact hole. A contact plug is formed in the contact hole and connects to the active area. A landing pad is formed in the landing pad hole and connects to the contact plug. The landing pad vertically overlaps one of the pair of conductive line structures.

1. Field
One or more embodiments described herein relate to a semiconductor device.
2. Description of the Related Art
As the degree of integration of a semiconductor device increases, the rules for designing various features of the semiconductor device decrease. In a highly integrated semiconductor device, cross-sectional areas of conductive lines, and a contact plug between the conductive lines, decrease. For example, the lower electrode of a capacitor formed on the contact plug may have a reduced cross-sectional area. When such a lower electrode is connected to an active area of a substrate through the contact plug, the contact area with the plug is limited. As a result, the degree to which contact resistance may be reduced is limited, which adversely affects performance of the semiconductor device.

Semiconductor device including landing pad


A chip of a chip package comprises a substrate having a chip circuit, a chip selection terminal connecting to the chip circuit, multiple first conductors separated at different levels by multiple insulation layers, multiple first vertical connections respectively connecting to the first conductors and extending to a substrate surface, multiple second vertical connections respectively connecting to the first conductors and extending to a surface of the insulation layers, a third vertical connection electrically connecting to the chip selection terminal and extending to the substrate surface, a fourth vertical connection formed through the insulation layers and the substrate, a second conductor formed on the surface of the insulation layers and connecting to the fourth vertical connection, multiple first pads respectively connecting to the first vertical connections and the third vertical connection, and multiple second pads respectively connecting to the second vertical connections.

1. Technical Field
The present invention relates to a chip package including at least one stackable chip.
2. Background
Chip stacking technology can bring two chips close together, thereby enabling faster data transmission between the two chips and consuming less power. Memory chips can be stacked together to obtain a memory module with a large storage capacity. In addition to stacking two of the same chip, two chips with different functions may also be stacked together to combine different functions.
In a memory chip stack, each memory chip has a chip select (CS) terminal, which is used to enable the memory chip. For example, a DRAM chip can have a row address strobe (RAS), column address strobe, or chip select pin as a chip select terminal. When a signal is applied to the chip select terminal of a chip in a memory chip stack, the chip can be accessed, while other chips cannot.
Conventionally, signals applied to the chip select terminals of the memory chip stack flow through wires. Such wires need additional processes to form, which increases the manufacturing cost. Moreover, long wires cause signal delays by occupying more space, and results in a large chip package.


In a battery-driven portable computer, a battery pack is constituted by m battery sets connected in series each including n lithium-ion secondary battery cells connected in parallel. A voltage monitor for monitoring the voltage of the terminal electrode of each battery set and a charger for independently appropriately charging each battery set in accordance with a monitor result are arranged, thereby realizing battery driving by a lithium-ion secondary battery pack having a large capacity.

1. Field of the Invention
The present invention relates to a battery pack used as a main power supply for a portable computer and a charge/discharge control apparatus therefor.
2. Related Art
A plurality of series-connected nickel-cadmium (Ni-Cd) or nickel-hydrogen (Ni-MH) secondary battery cells are generally used as a conventional main power supply battery for a portable computer. Along with the development of the functions of the above portable computer, a load increases, and user demand has arisen for prolonging a battery drive time. For these reasons, demand has increasingly arisen for a secondary battery having a larger capacity.
Under the above circumstances, a lithium-ion secondary battery can be used as a main power supply battery.
If eight lithium-ion battery cells are connected in series with each other as in the conventional arrangement so as to meet the needs for a large capacity, thereby constituting a battery pack, the following problem is posed. The upper limit of a terminal voltage of a cell itself of the lithium-ion battery is about 4.2 V, while its lower limit is about 2.7 V. The upper limit of the voltage range of the eight series-connected lithium-ion battery cells is 33.6 V, while its lower limit is 21.6 V. The voltage range is widened, and the absolute value of the voltage is increased, resulting in inconvenience. In addition, a conventional AC adapter is of 15 or 18 V, the voltage of the eight series-connected lithium-ion battery cells becomes about twice the AC adapter voltage. A circuit size becomes undesirably increased due to the circuit design of a protection circuit if the voltage exceeds 20 V. For this reason, three parallel circuits each consisting of three series-connected lithium-ion battery cells are prepared, and any one of the three series circuits is selectively used, as shown in FIG. 1. In this case, the voltage of one series circuit of the lithium-ion battery cells falls within the range of 15 V, and matching with the AC adapter can be improved. A lithium-ion battery (e.g., a lithium-ion battery of 3.6 V.times.1,000 mAh) has a higher internal impedance than that of the Ni-CD or Ni-MH battery. When a larger current flows through the lithium-ion battery, a battery voltage is reduced by an increase in current accordingly. A smaller current is required to extract a maximum energy stored in the battery. That is, as shown in FIG. 3, the product of time and ampere is kept unchanged in the Ni-Cd or Ni-MH battery. The energy extracted in 8-hour use at 2 A is equal to that in 2-hour use at 8 A. In the lithium-ion battery, however, as shown in FIG. 4, the energy extracted in 2-hour use at 8 A is smaller than that in 8-hour use at 2 A. For this reason, in the arrangement of series-connected lithium-ion battery cells, as shown in FIG. 1, the energy stored in the battery cells cannot be satisfactorily extracted. The lithium-ion battery tends to be exploded against overcharge. The battery voltage must be strictly monitored for each battery cell. In the arrangement shown in FIG. 1, a monitor circuit must be arranged for each lithium-ion battery cell so as to perform charge/discharge control. The circuit is complicated, and the circuit size is increased, resulting in impractical applications.
In the parallel circuit consisting of the three series circuits each having three series-connected lithium-ion battery cells, as shown in FIG. 2, when any one of the lithium-ion battery cells of each series circuit is broken due to short-circuiting or the like, the remaining two battery cells are charged with an energy of three lithium-ion battery cells, resulting in overcharge. To prevent this, a diode may be added to the above circuit. However, both a charge diode and a discharge diode must be added to each battery cell, and the circuit size is undesirably increased.
In a conventional charge circuit which can incorporate a plurality of single lithium-ion secondary battery cells, a plurality of battery sets thereof, or a plurality of battery packs using the single lithium secondary battery cells or lithium battery sets, a charge scheme shown in FIGS. 36A and 36B is employed.
More specifically, the secondary battery (Batt 1) of the first pack is charged with a constant current (constant current charge). When the battery voltage is increased and reaches a specified voltage, charge is continued with a constant voltage (constant voltage charge).
In a constant voltage charge state, the charge current is gradually decreased. A full charge state is set when the charge current becomes smaller than a specified value.
Upon detection of the full charge state of the secondary battery (Batt 1) of the first pack, the secondary battery (Batt 2) of the second pack is charged in the same manner as in the secondary battery of the first pack.
In the above conventional charge scheme, however, charge of the next battery pack is not started until the full charge state of the preceding battery pack is detected. For this reason, the total charge time of a plurality of battery packs becomes (Charge Time of Battery).times.(Number of Battery Packs).
In the constant voltage charge mode, the charge current of the lithium-ion secondary battery is gradually reduced due to its battery characteristics. Along with this decrease, the current supply capacity has a sufficient margin. In the conventional scheme, however, the power corresponding to the sufficient margin cannot be used for the next charge operation, thus wasting the power.
In a conventional scheme, in charging a secondary battery required for constant voltage charge, as shown in FIG. 9, first of all, charge is started with a constant current. When a battery voltage 5 in the charge ON state is detected to reach a target value 3, and charge is switched to charge with a constant voltage at a point A. A charge current 7 is then gradually reduced. Charge with a constant voltage continues until a voltage 1 of the battery itself becomes the same potential as that of the target value 3 and a charge current does not flow (i.e., until the state reaches a full charge state).
As described above, when the battery voltage in the charge ON state reaches the target value 3, charge with a constant current is switched to charge with a constant voltage. At this time, the charge state is not yet the full charge state because the battery voltage includes a voltage drop caused by an internal resistance and the like. A long period of time is required until the full charge state is obtained after charge is switched to charge with a constant voltage.
In a conventional battery set obtained by series-connecting lithium-ion secondary battery cells, variations in secondary voltages during charge is corrected as follows.
More specifically, when a battery set obtained by series-connecting two secondary battery cells is taken as an example, the half of the battery set voltage is input to an amplifier, and an output from the amplifier is supplied to a connection point between the series-connected secondary battery cells, thereby setting the output voltage of the amplifier to 1/2 the total voltage of the battery set. The output from the amplifier is connected to the connection point of the secondary battery cells through a current limit resistor. Therefore, a correction current flows due to a potential difference and resistance between the output voltage of the amplifier and that of the connection point between the secondary battery cells.
The following problem is posed in a battery voltage measuring means having the above conventional arrangement. When the battery voltage of each secondary battery cell in the battery set is measured outside the battery set, a value including a voltage drop caused by the internal current limit resistance in the battery set is measured, and an accurate battery voltage cannot be measured.

Battery set structure and charge/discharge control apparatus for lithium-ion battery


A MEMS mass spectrometer having metal walls connected between a lid and base, with the walls defining a plurality of interior chambers including sample gas input chambers, an ionizer chamber, a plurality of ion optics chambers and a ion separation chamber. A detector array at the end of the ion separation chamber includes a plurality of V-shaped detector elements positioned along two parallel lines and arranged to intercept all of the ionized beams produced in the mass spectrometer.

1. Field of the Invention
The invention in general relates to the analysis of an unknown gas, and more particularly to a solid state miniature mass spectrometer.
2. Description of Related Art
A mass spectrometer is a device that permits rapid analysis of an unknown gas sample. A small amount of the gas to be analyzed is introduced into the mass spectrometer where it is ionized, focused and accelerated, by means of magnetic and/or electric fields toward a detector array. Different ionized gas constituents travel along different paths to the detector array in accordance with their mass to charge ratios. The outputs from the individual detector elements of the array will then provide an indication of the gas constituents.
Industrial mass spectrometers are generally large, heavy and expensive. Therefore a need exists for a miniature, relatively inexpensive light-weight solid state mass spectrometer for use by the military, homeland security, hazmet crews and industrial concerns, by way of example.
One such miniature solid state mass spectrometer is a MEMS (microelectromechanical system) device described in U.S. Pat. No. 5,386,115. Basically, the described device is comprised of two semiconductor substrates joined together by an epoxy seal. Each half includes intricate cavities formed by a lithographic process. Although the device meets the requirement for small size, due to the depth and intricacy of the cavities, the lithographic process is extremely expensive. Further, under vacuum conditions, the epoxy seal may tend to outgas into the device thus contaminating the readings obtained and limiting its sensitivity.
Accordingly, the mass spectrometer of the present invention is a MEMS device which obviates the drawbacks of the prior art.


A bypass circuit includes a planar electrode layer which is mounted between a pair of dielectric layers. The electrode layer generally is centered inwardly with respect to the dielectric layers leaving an outward margin of dielectric material. One of the dielectric layers has two spaced apart contact members, each having a different polarity from the other. A resistive layer is centered on the other dielectric layer. The contact members extend onto end portions of the dielectric layers and electrically connect to opposite ends of the resistive layer. The electrode layer is isolated from electrical contact with any conductor and is buried within the dielectric layers. The electrode layer, in combination with the dielectric layer on which the contact members are mounted and the contact members, allow development of a selected value of capacitance between the contact members. Providing trimmed contact members as well as controlling their size and spacing allow for convenient preselection of desired operative characteristics of the bypass circuit. The contact members could be positioned on a substrate to which a buried electrode is mounted.

This invention relates generally to bypass circuits and more particularly to a bypass circuit incorporating a ceramic capacitor which utilizes a buried layer.
Prior art relating to solid state capacitors includes such patents as U.S. Pat. No. 4,665,465 to Tanabe and U.S. Pat. No. 5,107,394 to Naito et al. Construction of these capacitors includes multiple electrode layers which are fastened by means of a soldering process to a mechanical end cap. A soldering process introduces a degree of unreliability as a result of residual stresses formed in a capacitor during its manufacture. Additional unreliability results from stresses which are imposed on a solder joint due to differential rates of thermal expansion and contraction of various components of the capacitor; including its electrode, its dielectric material, its solder material and its end cap; when the capacitor is exposed to temperature variations and extremes, with or without stressful influences, during use. Also relevant is U.S. Pat. No. 5,576,926 to the present Application.
It is an object of the present invention to provide a bypass circuit that is particularly effective at very high frequencies.
Another object of the invention is to provide a bypass circuit which performs with highly reliability.
Another object of the invention is to provide a bypass circuit which is capable of highly reliability over a broad range of operating temperatures.
Yet another object of the invention is to provide a bypass circuit which can be manufactured in quantity at a low unit cost while maintaining high levels of quality.
The foregoing and other objects and advantages of the invention will appear more clearly hereinafter.
In accordance with the invention there is provided a bypass circuit which includes a planar electrode layer mounted between a pair of dielectric layers. Length and width dimensions of the dielectric layers are somewhat greater than corresponding length and width dimensions of the electrode layer and the electrode layer generally is centered with respect to the dielectric layers. One layer of the pair of dielectric layers has a pair of spaced apart contact members, each having a different polarity from the other. A resistive layer is mounted onto the other dielectric layer. The contact members extend onto end portions of the dielectric layers and electrically connect to opposite ends of the resistive layer. The contact member design helps facilitate testing of the circuit. The dielectric layer which is attached to the contact member has a selected thickness which allows the dielectric layer, in combination with the electrode layer, to develop a desired value of capacitance between the contact members. Similarly, the resistive layer has a selected dimension and thickness to develop a desired value of resistance in parallel with the capacitance value.
In an alternative embodiment of the invention, the electrode layer extends outwardly to connect to one of the contact members.
In another alternative embodiment of the invention, the pair of spaced apart contact members is replaced by a pair of metallized areas (each having a different polarity from the other) and the dielectric layer in combination with the electrode layer develop a desired value of capacitance between the two metallized areas. The metallized areas facilitate mounting the bypass circuit on a circuit board while using minimum surface area of the circuit board.

Bypass circuit with buried isolated electrode


A gas reaction system is disclosed which comprises a vaporizer (230) for generating a reaction gas by vaporizing a liquid material and a reaction chamber (221A) wherein the reaction gas is reacted. The vaporizer (230) is integrally formed with a component member which defines the reaction chamber (221A). The reaction gas generated in the vaporizer (230) is directly introduced into the reaction chamber (221A). The vaporization chamber (232) of the vaporizer (230) is a space between an upper plate (230A) and a cap (230B) attached to the upper surface of the upper plate (230A). A narrow passage (233) is formed between the cap (230B) and the upper plate (230A) which passage (233) communicates with the vaporization chamber (232).

Generally, in a fabrication line of a semiconductor, a liquid crystal display or the like, a gas reaction apparatus for performing various processes by introducing a source gas into a reaction chamber is utilized. For example, as for a film forming apparatus for forming an insulation thin film on a surface of a substrate to be processed such as a semiconductor wafer or the like, a chemical vapor deposition apparatus (CVD apparatus) for performing a film formation by a gas reaction has been known. Recently, the CVD apparatus is used for forming a multi-component metal oxide thin film such as PZT (lead zirconate titanate).
Generally, since an organic metal compound, which is a source material of a thin film such as PZT or the like, is solid at room temperature under atmospheric pressure, it is necessary to gasify this kind of a solid source material to supply it into a processing chamber to be used in the CVD apparatus. In this case, the solid source material is dissolved into a liquid by using a proper solvent (referred to as a solution source), and vaporized in a vaporizer to be supplied into the processing chamber. Such a source supply method is referred to as a solution vaporizing method. The solution vaporizing method has been actively studied and developed as a promising gasifying method capable of substituting a bubbling method or a solid sublimation method (e.g., see Japanese Patent Laid-open Application No. 7-94426).
Here, an example of forming a ternary metal oxide thin film by the solution vaporizing method will now be discussed. FIG. 10 is a schematic diagram showing an entire conventional gas reaction apparatus (film forming apparatus). As shown in FIG. 10, in a film forming apparatus 100, source material solutions, which are different from each other, are stored in source vessels divided into plural systems, respectively. For example, these source vessels are formed of a source vessel 101a for storing a lead based source material solution; a source vessel 101b for storing a zirconium based source material solution; and a source vessel 101c for storing a titanium based source material solution.
The source material solutions are respectively extracted into supply lines 103a, 103b and 103c to be flown through a main line 107 via respective flow rate controllers 105a, 105b and 105c by a pressurized gas A supplied through a force feed gas line 102. A carrier gas B such as a nonreactive gas (e.g., He, Ar or the like) or the like is supplied into the main line 107 through a flow rate controller 115. The source material solutions are mixed with the carrier gas in the main line 107, and thus transferred to a vaporizer 110 in a gas-liquid mixed state. Further, there is prepared a solvent vessel 101d for accommodating therein a solvent, e.g., butyl acetate, octane or THF (tetrahydrofuran). In the same manner, the solvent accommodated in the solvent vessel 101d is extracted to the supply line 104 by the pressurized gas A to be flown into the main line 107 through a flow rate controller 106.
A nozzle 111 is disposed at the vaporizer 110, to which the main line 107 is connected. Further, a carrier gas C is supplied to the nozzle 111 through a line 108 via a flow rate controller 109. At the nozzle 111, there is provided a nozzle port of a double tube structure. For example, the solution source materials supplied into an inner tube are sprayed into a vaporizing chamber 112 by the carrier gas C supplied into an outer tube. Here, a nozzle part is cooled below a room temperature to prevent the solvent having a low vaporization temperature from being vaporized first since a vaporization temperature of the solvent to be used is different from that of the source material itself, generally.
An inner surface of the vaporizer 112 corresponds to a vaporizing surface 112a for vaporizing the source material, and is heated to about, e.g., 200° C. Misty solution source materials ejected from the nozzle 111 collide with the vaporizing surface 112a to be vaporized instantaneously to become a source gas in the vaporizing chamber 112. The source gas is drained from a gas draining port 113 through a filter 114 to be supplied into a processing chamber 121 of a film forming apparatus main body 120 through a gas transporting line 116. The gas transporting line 116 is heated such that the source gas passing therethrough is not solidified or liquefied.
In the processing chamber 121, there are disposed a showerhead 122 to which the gas transporting line 116 is connected; and a susceptor 123 for mounting thereon a substrate W to be processed. An oxidizing gas, such as O2, N2O, NO2 or the like, which reacts with the source gas in the processing chamber 121, is supplied into the showerhead 122 through a reaction gas supply line 117. In the processing chamber 121, a thin film is formed on the substrate to be processed W by reactions between the source gas and the oxidizing gas.
However, in the conventional film forming apparatus 100, the gas transporting line 116 between the vaporizer 110 and the processing chamber 121 is long so that particles are likely to be produced in the source gas, or a supply amount of source gas is fluctuated, thereby deteriorating the uniformity in a film composition or a film thickness.
Further, an inside of the entire gas transporting line 116 must be heated to a temperature higher than a vaporization temperature of the source and at the same time lower than a decomposition temperature thereof, such that the source gas is not solidified or liquefied during the transportation. In this case, since a heating unit and a temperature control unit are required, the overall structure gets complicated. Moreover, the vaporizer 110, the gas transporting line 116 and the processing chamber 121 need to be heated individually, resulting in an increase of power consumption. In addition, the vaporizer 110 and the gas transporting line 116 need to be equipped with a heating unit, so that the entire apparatus becomes large-scaled.

This patent is subject to a terminal disclaimer.

Gas reaction system and semiconductor processing apparatus