Abstract: The invention is directed to a system for automatically adjusting the gear ratio of a continuously variable transmission mounted next to the motor of a vehicle. The gear ratio is adjusted with a specific speed. The essence of the invention is that a mechanism is provided which facilitates a determination of the speed of the adjustment of the gear ratio of the transmission in dependence upon detected operating parameters. With the system of the invention, an adjustment characteristic of the transmission is obtained which is comfortable for the driver of the vehicle.

Abstract: A control system and method is provided for changing the shiftpoints of a transmission for part throttle shifting. A input section delivers a actual gear signal, a engine speed signal and a torque converter output speed signal A controller receives the input signals and varies the transmission shiftpoints relative to the received signals. The controller also delivers signals to the transmission to upshift, downshift or that no shift is necessary.

Abstract: A system and method for decreasing the time required to complete a ratio change in an electronically enhanced powertrain system is provided. The powertrain system includes a number of devices for providing a retarding torque to engine rotation to increase the decay rate of the engine speed during an upshift. These devices include an engine brake and an input shaft brake. A retarding torque is also provided by increasing engine accessory load by controlling various engine accessories such as a cooling fan, an air compressor, a hydraulic pump, an air conditioning compressor, and an alternator.

Abstract: The hydraulically operated clutch elements of a powershift transmission have hold pressures and fast-fill times which are calibrated as a function of the rotation speed of an internal component of the transmission. The engine speed remains substantially constant and no or substantially no torque is transmittted to the output shaft of the transmission.

Abstract: An automatic transmission of an automotive vehicle is set into a neutral position in response to a command instructing gear shifting of the automatic transmission when release of an accelerator pedal of the vehicle is detected. The automatic transmission has a plurality of speed clutches. The opening of a throttle valve arranged in an intake passage of an internal combustion engine installed on the vehicle is controlled such that the rotational speed of an input side of one of the speed clutches to be selected for the gear shifting and the rotational speed of the one of the speed clutches becomes substantially equal to each other when the automatic transmission is held in the neutral position. The one of the speed clutches is engaged upon detection that the rotational speed of the input side thereof and the rotational speed of the output side thereof becomes substantially equal to each other.

Abstract: An apparatus for controlling a transmission includes a shifting actuator with an plurality of electric motors for shifting gears of the transmission. A load on the synchronizer is measured when shifting the gears of the transmission. The load is measured by sensors on the load fork. Compensating springs can alternatively be included. The position of the fork relative to the synchronizer mechanism is determined by a position sensor in communication with the rod or in communication with the load fork itself.

Abstract: A control method/system for controlling engagement of reverse ratios in automated vehicular transmission systems (10) having a controller (38) issuing command output signals to non-manually controlled actuators (30, 34) is provided. The controller includes logic rules for (i) sensing predetermined reverse ratio enabling conditions, including remaining in neutral for at least a predetermined period of time (N.sub.T >REF.sub.2) prior to selecting reverse, and (ii) issuing commands to cause a reverse ratio to be engaged only upon sensing such conditions, to minimize accidental engagement of reverse ratios without requiring mechanical interlocks.

Abstract: In an electric vehicle provided with an electric motor (M), a motor drive circuit (17) and a control circuit section (15) for outputting an operation command to the motor drive circuit, a variable speed drive unit for electric vehicles has a transmission apparatus (20) which engages or disengages a drive shaft (7a) which receives the drive force from a propelling motor and a driven shaft (5a) which is interconnected with propelling wheels by an electromagnetic engagement clutch (30), the transmission apparatus has the electromagnetic clutch comprised of a first clutch (22) interconnected with the drive shaft, a second clutch (25) having a rotational speed different from the first clutch, and an output side clutch (21) interconnected with the driven shaft; and the output side clutch and the first clutch or the second clutch are alternatively connected to selectively change the motor output.

Abstract: The invention relates to a hydraulic changing device for a multi-ratio vehicle transmission, especially for a commercial vehicle such as a mobile excavator. The hydraulic changing device feeds gear actuator (3, 4) with pressure medium conveyed by a servopump (10). There is a control slide (26) which is acted upon by the effect of a control spring (33), on the one hand, and by a pressure in a low-pressure chamber (23), on the other. The low-pressure chamber (23) is coupled to a low-pressure pump (20) operating in dependence upon the engine speed. The arrangement is completed by a shuttle valve (6) and a leakage valve (5). The pressure prevailing in the low-pressure chamber (23) actuates the control slide (26), against the force of the control spring (23), in such a way that undesired changes from a higher to a lower gear are prevented. The hydraulic changing device, of the invention, is advantageously distinguished by its low structural and design expenditures.

Abstract: A control system is provided for a vehicle with a power source connected to a transmission, a transmission controller, a clutch and a clutch control element for controlling clutch engagement and disengagement. The control system includes a gear shift lever with a neutral and non-neutral position, a relay circuit coupled to the gear shift lever and the clutch control element that responds to neutral and non-neutral signals from the gear shift lever, and a limp-home switch coupled to the clutch control element to control the application of power to the clutch control element by providing power to the clutch control element when the switch is actuated and the gear shift lever is not in neutral and interrupting power to the clutch control element when either the limp-home switch is not actuated or the gear shift lever is in the neutral position.

Abstract: Disclosed is a transmission control system for an electric vehicle, comprising: a motor; a transmission connected to the motor; a shift fork rod connected to the transmission; a shift lever for speed shifting having a lower end; a shift rod having an end secured to the shift fork and the other end having a hollow hole which has an elastic member; a linkage having an end supported by the elastic memeber and the other end hinged to a lower end of the shift lever; a shift lever sensor for detecting movement of the shift lever; a motor speed sensor for detecting motor speed; a wheel speed sensor for detecting wheel speed; a shift fork sensor for detecting movement of the shift fork; an inverter for controlling the motor; and a control unit for controlling the inverter in accordance with signals of the motor speed sensor, the wheel speed sensor and the shift lever sensor.

Abstract: A control system is provided for selectively placing a vehicle transmission in a neutral condition after startup of the vehicle. The transmission is of the type including a plurality of intermeshing gears and associated clutches. The clutches are engageable and disengageable in predetermined combinations in response to energization and de-energization of actuator coils to establish predetermined gear ratios between input and output shafts of the transmission. The control system includes a neutral circuit and a control circuit. The neutral circuit causes a current carrying path through the coils to be interrupted under the control of the control circuit. The neutral circuit preferably also causes the transmission to be placed in a neutral condition upon startup of the vehicle engine.

Abstract: A control system and method for controlling start-from-stop operation in an automated mechanical transmission system, including a multiple-speed change-gear transmission (10) having a lowest grouping of ratios (first-fourth) suitable for start-from-stop operation, is provided. Upon a request or requirement for a shift into a default start ratio, the system controller (106) will cause initiation of a shift into the highest gear ratio (fourth) of the lowest group of ratios.

Abstract: An electronic transmission shift control is provided wherein an input device such as a vehicle control lever is connected to a sensor. The sensor sends out a substantially continuous signal to an electronic control module. The electronic control module controls the current going through a solenoid that, in one application, is controlling the pressure of a valve to engage a clutch in a transmission.

Abstract: The invention relates to an improved method and arrangement for implementing that method, for obtaining in motor vehicles with mechanical stepped gearboxes with automatic gear changing a gentle and quiet engine adjustment during downshifts in normal operating situations and automatically in operating situations where a need for quicker downshifts requires quicker engine synchronisation. In normal operating situations, downshifts involve using only a limited fuel quantity, preferably corresponding to 20% of full-load fuel quantity, in order to raise the engine speed to the synchronous speed for the next gear, resulting in quieter engine adjustment without the occurrence of obvious disturbance of comfort, risk of losing downshifts or safety disadvantages.

Abstract: An improved gear change mechanism is provided for semi-automatically selecting a change up or change down gear change. The mechanism includes a shaft (31) which is movable in its axial direction and about its axis to make one such movement or a combination of such movements according to the gear to be selected. The shaft (31) is moved by pistons (36, 37) coaxial with the shaft for the axial movement and a piston (46) at a right angle to the shaft for the rotational movement. In practice the axial movement is a translating movement and the rotary movement is a movement into and out of engagement with the gears. Throttle and clutch control functions are also provided so that a gear change is initiated and brought about by switches (19A and 19B).

Abstract: A controlled method to automate a power train transmission of a vehicle with a manual gearbox considering all moments of inertia in clutch actuations through dual servomotors, executing controlled up and down gearshifts automatically. The control system encompasses a central microprocessor controller unit that executes functions based on special equations that reflects instantaneous moments of inertia wherein gearshifts are decided based upon the vehicle's instantaneous speed and the increase or decrease of motor RPM, whether it is gas pedal sensed or road inclination derived. A fuel flow control is activated in each gearshift to insure RPM control within the next gear engaging range.

Abstract: A shift by wire transmission system enables a driver to manually select a next desired gear and the system completes the shift automatically without requiring the driver to operate the clutch. The system includes an electronic transmission control unit that communicates with an electronic engine control unit to control engine speed during a shift in order to synchronize the speed of an engine shaft and the transmission shaft. The driver manually chooses a gear shift by moving a shift lever to thereby produce electrical signals indicative of the desired change in gears. Multiple or skip shifting is possible along with a method of automatically choosing a default gear in the event that the vehicle transmission is placed in neutral while the vehicle is in motion.

Abstract: In an automatic transmission in which a shifting command can be output by a manual operation of a manual shift lever, in addition to an automatic shifting based on a usual shifting map, the shifting command is possibly executed while preventing an over-revolution and stalling of an engine due to an inappropriate shifting command. If the vehicle speed is in a shifting prohibiting range with a possibility that an over-revolution or stalling of the engine may be caused, when a shifting command is output, the shifting is prohibited, and a timer is set. When the present vehicle speed is translated from the shifting prohibiting range to a shifting permitting range as a result of change in vehicle speed, during counting by the timer, the shifting which has been prohibited is executed.

Abstract: Broadly, the present invention is directed to a method for controlling the shifting of a drag race vehicle with a controller for controlling an actuatable shifter assembly. This method includes resetting the controller followed by actuating the controller and launching the vehicle. At a predetermined engine speed value or after a first timed duration based on a predetermined engine speed value, the shifter assembly is actuated for a second timed duration to shift to a next higher gear. Finally, shifter assembly actuation is repeated until all of the gears of the vehicle desired to be shifted have been shifted. Another aspect of the present invention is a controller for controlling the shifting of a drag race vehicle shifter with an actuatable shifter assembly and which is activatable by a first duration timer or an rpm switch based on a predetermined engine speed value.

Abstract: A system for discriminating operation state of a lockup clutch of a torque converter of a transmission of a vehicle, more particularly to a system for detection a lockup clutch failure. In the system, three discrimination areas are preestablished with respect to the throttle opening and vehicle speed and reference value are determined in response to a selected discrimination area. The converter slip ratio is compared with the data and when the ratio is out of a range determined by the data, the lockup clutch operation is discriminated to be not normal. At that time, however, when the area is in a weak-engaged region, the engaging force is forcibly increased and the discrimination is conducted once again, thereby making it possible to conduct failure detection in the slip-engaged region and enhancing detection accuracy.

Abstract: A twin-clutch-type transmission which can suitably change a power transmitting route, corresponding to the gear shifting conditions, without requiring complex a control, includes a first clutch mechanism, a second clutch mechanism, a first gear mechanism connected to the first output member of the first clutch mechanism, a second gear mechanism connected to the second output member of the second clutch mechanism, a control device, and an interlocking member.The first clutch mechanism includes an input member, a first output member, a first pressure plate and a first thrust means which engages the first output member to the input member through the first pressure plate. The second clutch mechanism includes an input member, a second output member, a second pressure plate and a second thrust means which engages the second output member to the input member through the second pressure plate.

Abstract: A gearshift control system comprises an electrical control unit which operates hydraulic valves controlling a hydraulic gearshift actuator. The vehicle in which the system operates has a dashboard control to preselect a gear change, which is actuated by depressing the clutch pedal operating a switch, both the switch and control being connected to the unit. The system includes means for updating the electronic stored values representative of the position of the gearshift actuator. The system also includes means for aborting a gearshift if, after given time periods, either the shift has not been completed, or the clutch pedal is released. In any event the gearshift will be aborted if the clutch is released during a change. The system will not initiate a gearshift unless the clutch pedal is held down for a given period of time.

Abstract: A drive device comprises a gearbox (1) of the motorcycle type in which a selector shaft (10), via its angular position, enables the gear ratio in which the gearbox will be engaged to be determined. The device is provided with an electronic control device (DCE) designed to automatically place the gearbox (1), or in other words the selector shaft (10), in the position corresponding to the gear selected by the driver or automatically determined as a function of the speed of the vehicle. The electronic control device (DCE) comprises, in particular, means for down-shifting gently despite the absence of a synchronizer in the gearbox.

Abstract: A method is provided for operating a hydraulic control system for a transmission having first and second torque transmission paths arranged in parallel with one another between a common input shaft and a common output shaft, first and second hydraulically controlled clutches arranged in the first and second torque transmission paths, respectively, and a hydraulically controlled gear synchronizer in the second torque transmission path for selectively coupling a shaft for rotation with a gear wheel to effect a change in the transmission ratio through the second torque path while the second clutch is disengaged. To prevent wear on the synchronizer and the gear, prior to activating the hydraulic control for moving the synchronizer into engagement with the gear wheel, the hydraulic control system is operative first to move the synchronizer into a neutral position in which torque cannot be transmitted through the first torque transmission path.

Abstract: A method of shifting in a manual mode of an electronically-controlled automatic transmission system includes the steps of determining whether a shift lever of a shift lever mechanism is presenting a position error when the shift lever is in a manual position, determining whether at least one switch on the shift lever mechanism is presenting an error if a shift lever position error is not determined, determining whether a temperature of an automatic transmission or engine coolant temperature exceeds a predetermined threshold if the at least one switch is not presenting an error, determining whether the manual position conditions have been met, determining whether an upshift or downshift of the automatic transmission is scheduled if the manual position conditions have been met, and executing either an upshift or a downshift of the automatic transmission based on the determined upshift or downshift being scheduled.

Abstract: A system for automatically effecting a range shift between high and low ranges in a multi-speed transmission includes a control that monitors the output speed of both the engine and the transmission. The ratio of the two speeds is compared to available ratios in a look-up table such that the control is constantly determining the engaged gear. In one embodiment, a driver provides an intention of the next gear to be selected to the control. Should the intended gear shift require a range shift from thee engaged gear, the control actuates the range shift once the transmission has been moved to neutral. In a second embodiment, no driver intention is provided to the controller. Instead, the control compares the engine output speed to threshold values. If the threshold values predict a gear shift that would require a range shift to be effected from the currently engaged gear, then the range shift will be effected once the transmission has been moved to neutral.

Abstract: A manually shifted, range-type compound transmission (110) is provided with enhanced automatic range shifting. A controller (222) receives input signals indicative of shift lever position in the shift pattern (low range/high range) and of vehicle speed (OS) and automatically commands range shifts as a function of both system parameters.

Abstract: An interactive cruise control system and method for providing automatic speed control of a vehicle with improved shifting of an automatic transmission. The system and method controls speed of a vehicle equipped with cruise control and minimizes downshifts in an automatic transmission of the vehicle. Vehicle speed is detected and compared with a setpoint speed which is associated with the cruise control system. Transmission gear shifting is determined based on predetermined shift schedule points. Determined transmission gear downshifts are prevented for a kickdown delay period based on vehicle speed loss and the presence of vehicle deceleration. Also provided is an overspeed reduction method for causing a transmission downshift during an overspeed condition with the throttle closed. Further, the system provides hunting prevention between both second gear and third gear as well as between third gear and fourth gear of a four speed automatic transmission.

Abstract: A hydraulic pressure system for a frictional engaging element such as clutches for a vehicle automatic transmission. The engagement state of the clutches is detected from the clutch slip rate, and the desired change rate of the rotational speed of the transmission input shaft (the main shaft rotational speed) during the gearshift operation period is varied based thereon. The hydraulic pressures supplied to the clutches are controlled for bringing the actual rotational speed change rate to the desired value. Since the clutch engagement state can therefore be controlled based on the desired value, irrespective of the temperature of the oil (ATF) and aging of the clutches, it is at all times possible to secure optimum gearshift characteristics and to avoid the occurrence of gearshift shock.

Abstract: A control system and method for a semi-automatic mechanical transmission system (10) is provided for sensing rolling start conditions (OS>REF, GR=N, (CLUTCH MANUAL DISENGAGED=TRUE)) and upon sensing such conditions, allowing operator request for a direct shift into an appropriate rolling start gear ratio (GR.sub.RS) determined as a function of current and/or expected output shaft speed (GR.sub.RS .gtoreq.ES.sub.IDLE /OS).

Abstract: A system and method for decreasing the time required to complete a ratio change in an electronically enhanced powertrain system is provided. The powertrain system includes a number of devices for providing a retarding torque to engine rotation to increase the decay rate of the engine speed during an upshift. These devices include an engine brake and an input shaft brake. A retarding torque is also provided by increasing engine accessory load by controlling various engine accessories such as a cooling fan, an air compressor, a hydraulic pump, an air conditioning compressor, and an alternator.

Abstract: A failure detecting method and apparatus for an automatic transmission of a vehicle having a vehicle speed sensor mounted on said vehicle for sensing a vehicle speed and an inhibitor switch attached on said automatic transmission for detecting a gear shift range position, The method is carried out by judging whether the vehicle speed is larger than a predetermined value; checking whether a neutral range position is detected; detecting whether another gear shift range position is absent after a predetermined time has lapsed; and then controlling the automatic transmission as if the gear shift range position is in a drive range. This enables one to precisely detect a failure of the range signal line and to control the automatic transmission in an optimum condition under any driving conditions.

Abstract: A drive transmission system for a working vehicle for transmitting power of an engine to running devices through a main clutch, a main change speed device and an auxiliary change speed device is disclosed. The main change speed device includes a first group of hydraulic clutches and a group of control valves for operating these clutches. The auxiliary change speed device includes a second group of hydraulic clutches and control valves for operating these clutches. Pressure oil is supplied to selected clutches of the first and second groups of hydraulic clutches to obtain the desired speed.

Abstract: A fail-safe device for an automatic transmission system outputs a signal to control the transmission operation according to vehicle speed and engine rpm (revolution per minute) when normal transmission operation is not achieved because of a malfunction of input equipment or an automatic transmission controller. The device includes a vehicle driving sensor, a signal converter, a signal processor, and a signal-output member. The vehicle driving sensor outputs a corresponding signal by sensing both a vehicle speed and an engine rpm that are varied according to a vehicle driving state. The signal converter is connected with the vehicle driving sensor, and converts the signal from the vehicle driving sensor into the corresponding AC (alternating current) voltage by varying each pulse generating rate according to the vehicle speed and the engine rpm.

Abstract: A hydraulic pressure control system for a frictional engagement element such as clutches for a vehicle automatic transmission. The engagement state of the clutches, i.e., the normality of clutch state or operation is discriminated by detecting the degree of clutch engagement (clutch slippage), specifically by calculating a ratio between the input rotational speed and the output rotational speed, and by comparing the calculated ratio with the gear ratio designated by the shift command at that time. When the clutch is found to be normal, the hydraulic pressures on the releasing and engaging clutches are controlled for temporarily bringing the total torque transferred by the two clutches below the transmission input torque, i.e., for reducing the co-engagement amount to the required minimum. On the other hand, when it is ascertained that the clutch is not normal, the hydraulic pressures of the two clutches are controlled in a conventional manner.

Abstract: A control system for shifting a vehicle transmission, such as in work vehicles, includes sensors for detecting the output speed of the vehicle engine, the output speed of the transmission and the vehicle ground speed. A controller receives signals from the sensors and command devices and controls engagement and disengagement of combinations of fluid clutches in the transmission to obtain desired gear ratios. The controller implements a ground-speed-matching control routine following operator-induced disengagement and re-engagement signals in which the controller compares the current ground speed to a threshold speed and enters into either a ground-speed-matching sequence or an alternative gear ratio selection sequence depending upon whether the ground speed is higher or lower than the threshold speed. Each routine results in selection of a gear ratio. The selected gear ratio is then limited by the last commanded gear ratio.

Abstract: A diagnostic system is provided for detecting a fault condition in a transmission having a plurality of rotating components, a plurality of clutches, and a transmission control. The diagnostic system includes speed sensors producing speed and direction signals representative of the rotational velocity of the rotating components, a processor for calculating the relative rotational speed between two or more clutches and for indicating a fault condition in response to the relative rotational speed and a period of time.

Abstract: The proposal is for a process for controlling and regulating the load take-up in an automatic transmission. To this end, in an overlapping gear change, the torque take-up of a first engaging clutch is derived from feedback values. The feedback values control or regulate the operation of a second disengaging clutch.

Abstract: The present invention provides a sensing system and method for providing information relating to a drivetrain during shifting operations. The drivetrain includes an engine, a torque converter and a transmission. The system includes sensors for detecting the output speed of the engine, the output speed of the torque converter, and the output speed of the transmission. The system detects the starting condition of a shifting operation, responsively determines a set of performance parameters, and produces a set of performance parameter signals.

Abstract: A control system and method for an automated mechanical transmission system (310) operable in a hold mode of operation (H) is provided. When operating in the hold mode of operation, if override conditions (ES>ES.sub.MAX, ES<ES.sub.MIN, cruise control resume mode) are sensed, the hold mode is overridden and a shift from the currently engaged gear ratio (GR.sub.C) into a desirable gear ratio (GR.sub.D) is automatically initiated.

Abstract: A method is provided for controlling overspeed conditions of an electronically controlled transmission and engine wherein the transmission has an output shaft and is electronically shiftable by an electronic shift control module between forward and reverse gears to rotate the output shaft in forward and reverse directions and a neutral gear without shaft rotation. The transmission has an operator controlled shift lever for requesting a gear from the forward, neutral and reverse gears and operates in a present gear from among the forward, reverse and neutral gears. The method includes determining forced downshift shift points, overspeed downshift shift points, overspeed upshift shift points, a directional shift inhibit speed, and overspeed values for each gear based on transmission speed; determining output shaft speed; and operating the shift lever to request a gear.

Abstract: In one aspect of the present invention, a method of effecting shifts in a vehicle is disclosed. The method modifies the transmission shiftpoints in response the wheel power of the vehicle in order to optimize vehicle shifting, while reducing the potential for shift cycling.

Abstract: The invention relates to an improved method and an arrangement for implementation of that method for obtaining safer and quicker upshifts while maintaining gear change comfort, using computer-assisted systems for gear change in mechanical gearboxes in motor vehicles, preferably without clutch disengagement between engine and gearbox. In connection with upshift, an exhaust brake is activated, (EB.sub.on) at time t.sub.1 in parallel with the fuel (FUEL) to the engine being reduced to zero quantity. The engine speed n.sub.2 is thereby reduced more quickly to the speed n.sub.1 which is the synchronous engine speed for the next higher gear. The speed reduction is monitored with a view to achieving rapid engine speed bracketing to synchronous speed, and also good gear change smoothness and safe gear engagement. The exhaust brake switch-off point EB.sub.off at time t.sub.2 is adjusted adaptively for subsequent upshift by a connection factor EBA.sub.

Abstract: A control method/system for sensing deflection-type gear neutral signal (GNS) errors in an automated mechanical transmission system (10) is provided. A gear neutral sensor (76/76A) provides signals indicative of axial position in a remote shift shaft (56) from which the neutral and not-neutral positioning of associated jaw clutch members (144) is inferred. Deflections in the shift members, such as the shift yokes (50), may result in erroneous indications of a neutral condition, which is a deflection-type gear neutral signal error sensed by the control of the present invention.

Abstract: Disclosed is an automatic transmission system in which an ECU calculates change of the running speed to automatically shift the gears under optimal conditions. The automatic transmission system used for heavy construction equipment for variably changing a rotative speed of an output shaft by selectively engaging any one of a plurality of change gears according to the selection of oil passages of a solenoid valve includes a speed sensor for sensing the rotative speed of the output shaft or a running speed of the heavy construction equipment, a converter connected to the speed sensor, for converting a value sensed by the speed sensor into an electrical signal and a controller for receiving the electrical signal output from the converter and comparing the electrical signal with a pre-stored value, to apply a driving signal to the solenoid valve if the electrical signal is within a predetermined range, so as to shift gears.

Abstract: A control system/method for an automated transmission system including a splitter-type, semi-blocked mechanical transmission (12) is provided. The control provides a technique for sensing auxiliary section engagement faults or auxiliary section and main section engagement faults and for operation in a fault-tolerant mode upon sensing such faults. In one embodiment, auxiliary section (214) engagement faults are sensed when the main section (212) is confirmed as engaged in an appropriate ratio and the transmission is confirmed as engaged in a ratio (GR.sub.N) other than the target ratio (GR.sub.T). In another embodiment, engagement faults are sensed when one section is confirmed as properly engaged and the transmission does not achieve engagement in a target ratio after a preset period of time.

Abstract: A gear shift mechanism particularly suited for a drag racing car is disclosed that causes the gear shifts of a transmission to be sequenced upon the attainment of selectable predetermined conditions so that the drag racing car obtains its desired acceleration in an optimum manner. The gear shift mechanism comprises electrically or pneumatically operated cylinders that move the gear shift lever upon sensing optimum conditions related to the acceleration performance of the drag racing car. The cylinders are positioned on opposite sides of the gear shift lever and provide counter-forces during shifting through at least one gear and yet allow the gear shifting to preferably be accomplished in a single direction. The counter-acting cylinders eliminate overshooting of the gear shift lever during movement of the lever arm. Alternatively, manual input instead of predetermined conditions may be substituted into the gear shift mechanism.

Abstract: An engine stall prevention control method according to the present invention is a method for eliminating troublesome inching pedal operation, automatically preventing engine stall and relieving an operator from physical exhaustion.

Abstract: A three-position actuator assembly for selectively shifting a three-speed splitter type auxiliary transmission section (14) is provided. The actuator assembly includes a piston portion (160) for axially moving a selected one of two shift forks (142/148) and a pneumatic control circuit (162) comprising three three-way, two-position solenoid controlled valves (202/204/206) and two three-way shuttle valves (214/216). Only one solenoid is energized for each selectable actuator position and a failure of the pneumatic (200) or electrical power sources to the control circuit will not cause the actuator to shift out of an engaged ratio.