Abstract: An improved control method and control system for controlling the upshifting of an AMT (10) system including a compound splitter type semi-blocked transmission (12) is provided. In particular, different control logic is utilized to implement simple and compound upshifts of the transmissions.

Abstract: A power shift transmission is operably controlled by a microprocessor that will effect a deceleration of the vehicle at relatively high speeds by effecting a downshifting of the transmission in response to a sensing of the rate of rotation of the output shaft such that the gears in the transmission are selected so that the transmission and/or the vehicle engine becomes a load for decelerating the vehicle. The microprocessor does not effect a downshifting of the transmission whenever the sensed rate of rotation of the output shaft would cause an overspeeding of the engine in the lower gear. The microprocessor runs a strategy determination check prior to entering a high speed deceleration routine to determine if a more efficient deceleration routine would be more effective, as based upon the pre-sensed rate of rotation of the output shaft.

Abstract: In an automatic transmission, a double transition closed throttle downshift to a target range requires the release of two off-going clutches and the engagement of two on-coming clutches. The shift is made in two stages. The first stage involves a first off-going clutch and a first on-coming clutch and effects an upshift to a third range having a speed ratio lower than both the initial range and the target range, so that a momentary input speed decrease occurs. The speed decrease is managed by a closed-loop control of the first on-coming clutch until the clutch reaches a synthronous speed for the third range. The second stage is a downshift from the third ratio to the second ratio by a second off-going clutch and a second on-coming clutch and results in a speed increase. The second on-coming clutch is also managed by a closed-loop control. In each case, the closed-loop control parameter is on-coming clutch slip speed which is controlled to a calculated slip speed profile.

Abstract: A microprocessor controlling a shuttle shift transmission may be programmed to effect a calibration of the final drive clutches in the transmission so that the microprocessor can efficiently effect engagement of each respective said clutch by applying the proper hydraulic pressure to cause proper engagement thereof. This method of calibrating the final drive clutches in the transmission includes braking the output shaft of the transmission so that any engagement of the selected final drive clutch being calibrated will cause a load to be applied to the engine. The hydraulic pressure is then incrementally increased until the engine RPM's decrease because of the load being placed on the engine. The value of this engagement hydraulic pressure is stored in the microprocessor for use when effecting engagement of the selected clutch during operation of the transmission. Service indicators are programmed into the microprocessor should the selected clutch not be capable of being calibrated.

Abstract: A device designed to actuate the positive clutches of gearbox sliding gears following synchronization of the respective pairs of gears. A cylinder mechanism is provided on each sliding plate of the gearbox, as well as solenoid valves which are controlled by an electronic calculator to select and actuate the cylinders. Each cylinder mechanism includes two oppositely acting pistons, each connected to the sliding plate, and each sliding in its own cylinder which also includes a return spring which operates against each piston and which practically eliminates the clearance above the piston as the piston is about to be acutated.

Abstract: A variable speed transmission includes parallel drive and driven shafts which mount respective series of intermeshing gears of progressively increasing gear ratio for selectively transmitting power from one shaft to the other. A series of two-way roller clutches are interposed between the driven shaft and respective gear members of the series of driven gears. The roller clutches are engageable for rotatively coupling the respective gear members to the driven shaft and are disengageable for permitting relative rotation between the respective gear members and the driven shaft. Each of the roller clutches includes a cam disk having a plurality of recesses formed in its peripheral surface and a roller retainer circumferentially supporting a plurality of rollers within respective recesses in the cam disk. A hydraulically controlled actuator is connected to each of the retainers for indexing the roller retainers together with the plurality of rollers between respective limit positions within the recesses.

Abstract: A transmission for an agricultural tractor featuring a large number of gears and comprising a first six-gear stage and a second reverse-reduction stage having three forward and one reverse speed ranges. The first stage comprises a pair of drive shafts selectively connectable to an input shaft via respective hydraulic clutches and to an output shaft via constant mesh gears respectively defining the odd and even number gears and engaging the output shaft via sliding couplings controlled by three-position hydraulic actuators. The actuators are operated by respective pairs of on-off solenoid valves supplied via a proportional-response solenoid valve, further proportional-response solenoid valves controlling engagement and release of the aforementioned clutches. All the aforementioned solenoid valves are controlled by an electronic control unit for appropriately controlling engagement of the clutches and actuators as a function of the actual service conditions of the tractor.

Abstract: A process for effecting controlled gear change in a vehicle having a transmission capable of automated shifting. A control circuit is provided with memory functions storing values of torque available from the vehicle engine at various operative r.p.m. values and at various throttle positions. When the vehicle is in operation, throttle position is compared to the torque/throttle position memory to derive a signal representing available torque for the throttle position. Likewise, engine r.p.m. is compared to the related memory function to derive a signal representing the torque available at such r.p.m. These two available torque values are compared to derive a signal representing relative load on the engine. A further memory function stores predetermined comparative values of load level and r.p.m. at which shifting of the transmission should occur. When load level is below a predetermined value, and simultaneously the r.p.m. is above a predetermined value, an upshift of the transmission is called for.

Abstract: An apparatus for controlling a transmission includes a detecting device for detecting the speed of rotation of an electric motor of a selecting actuator and a learning device for learning angular positions of the motor which correspond respectively to gear selecting positions based on a detected signal from the detecting device. Gear selecting operation of the selecting actuator is controlled by the learned angular positions of the motor.

Abstract: An automatic transmission includes a fluid-pressure differential cylinder for select operation of the transmission and a fluid-pressure differential cylinder for shift operation of the transmission, each of the differential cylinders being built up into one block and joined with the mating differential cylinder with intake and discharge holes in one block held in communication with intake and discharge holes, respectively, in the other block. A piston rod of each of the differential cylinders has an annular groove and a cylinder block is provided with a locking member engageable with the groove to provide a reference position for the piston rod.

Abstract: In a gear shifting device for the manual transmission of a motor vehicle with a gearshfit lever, with which the individual gear steps can be engaged over a gearshift rod, the gear shifting motion of the gearshift lever is transferred to the gearshift rod in a nonmechanical manner. The movement of the gearshift lever from the neutral position into the gear shifting position takes place in two steps, the first step acting as a preselection step and the function of the second step being to engage the selected gear step. A locking device permits movement of the gearshift lever from the first into the second step only when the necessary conditions exist for engaging the selected gear step perfectly; that is, when the clutch is disengaged and the gear wheels of the gear steps to be engaged are synchronized.

Abstract: In an automatic transmission for obtaining a necessary transmission gear ratio by disposing a plurality of gear trains on an input shaft 8 and an output shaft 19 which are parallel to each other, the present invention disposes two electromagnetic multiple-disk clutches C.sub.1 (or C.sub.2) and C.sub.5 (transmitting torque varying means) between the input shaft 8 and the output shaft 19 so that a torque is borne by the electromagnetic multiple-disk clutch C.sub.5 to make a shift operation at the time of shift-up and the torque is borne by the electromagnetic multiple-disk clutches C.sub.1 (or C.sub.2) and C.sub.5 to make the shift operation at the time of shiftdown. Accordingly, the torque from the engine can always be kept applied to the output shaft 19 during the gear change operation, and the occurrence of non-transmission of torque as well as the shock resulting from clutch connection can be prevented.

Abstract: A system for automatically shifting the gears of a drag racing car transmission each time engine RPM reaches a predetermined level after leaving the starting line. The actual value of the predetermined level may be selectively adjusted by means of a potentiometer connected to the vehicle tachometer. A manually operable switch permits adjustment while racing an eight cylinder engine to only one-half the predetermined RPM level during adjustment. Additional potentiometers are preferably provided for limiting engine RPM to a first maximum value while racing the engine with the vehicle in first gear and held stationary at the starting line by the foot brake, and a second, higher, maximum value after leaving the starting line, both the first and second maximum RPM values being selectively and independently adjustable.

Abstract: A gearbox with a large number of ratios can be operated according to the laws of pressure variation with respect to the friction clutches provided for the engagement of the various ratios wherein the laws of pressure variation are no longer fixed but can be adapted to the various requirements for effective operation of the gearbox according to operative conditions of the vehicle in which the gearbox is installed. The valve units are exclusively electro-hydraulic proportional-responsive valve units. The operating conditions of the gearbox and the tractor in which it is installed are monitored by suitable devices which generate electrical signals indicative of the operating conditions. An electronic control unit is supplied with these signals and is arranged to pilot the electro-hydraulic proportional-responsive valves so as to regulate the manner of combined engagement and disengagement of the hydraulic clutches in dependence on the operative conditions.

Abstract: An electrically actuated shift mechanism (100) is provided that is mountable upon a manual mechanical change gear transmission and operable to move a shift finger (20) in an (X--X) direction into registration with a selected shift rail and then move the shift rail in a (Y--Y) direction to effect the gear shift is response to either a selected operator input signal (S.sub.1) or a speed signal (S.sub.2).

Abstract: A hill holder device for a vehicle manual transmission includes a releasable one-way clutch which is coupled to the countershaft of the transmission. In particular, the one-way clutch includes a sprag clutch having an inner race secured to the countershaft, and an outer race secured to the vehicle transmission case by means of a releasable locking mechanism. When the locking mechanism is in its locked position, the sprag clutch enables rotation of the countershaft in only one direction. Thus, if the transmission is in a forward gear and comes to a stop on an ascending grade, the hill holder will lock the vehicle drive train and prevent the vehicle from rolling back down the grade, without requiring the driver to apply the brakes. Similarly, if the vehicle is in a reverse gear and is stopped on a descending grade, the hill holder will prevent the vehicle from rolling in a forward direction down the grade.

Abstract: An automatic transmission for an automotive vehicle, having an input shaft connected to an engine of the vehicle via a primary clutch, an output shaft parallel to the input shaft and operatively connected to drive wheels of the vehicle, a plurality of pairs of gears for transmitting a drive force of the input shaft to the output shaft at different speed reduction ratios, respectively, at least one shift member for selectively placing the individual pairs of gears into an operative position, and an actuator device for automatically activating each shift member. The transmission includes a secondary clutch connected to the primary clutch by the input shaft, and disposed between the input and output shafts, an intermediate shaft disposed in a transmission line between the input and output shafts. The intermediate shaft is provided with one of the gears of each of at least one of the pairs of gears.

Abstract: An apparatus for controlling a transmission having a synchromesh has a shifting actuator having an electric motor for shifting gears of the transmission. A load on the synchromesh is measured when shifting the gears of the transmission. A shifting stroke value for the shifting actuator when the measured load on the the synchromesh falls within a predetermined range is learned and stored. Based on the stored shifting stroke value, the electric motor of the shifting actuator is controlled when shfting the transmission gears.

Abstract: An electric shift apparatus for use with a motor vehicle having an automatic transmission. The apparatus includes a power module adapted to be mounted on the housing of the transmission proximate the transmission mode select shaft and a control module adapted to be mounted in the passenger compartment of the vehicle. The power module includes an electric motor driving a speed reduction unit and the lower exposed end of the output shaft of the reduction unit is adapted to be drivingly coupled to the exposed upper end of the mode select shaft of the automatic transmission. The control module includes a plurality of push button members corresponding respectively to the transmission shift positions. An encoder wheel positioned in the housing of the speed reduction unit provides a constant coded signal indicating the instantaneous position of the transmission mode select shaft and this coded signal is compared by comparator means in the logic of the control unit with the selected shift position.

Abstract: An apparatus for automatically operating the transmission of a small internal combustion engine includes an elongate actuator rod pivotally attached at one end to a pivotally mounted gear shift lever. The other end of the rod is contained in a housing, and attached to a diaphragm reciprocable in the housing and dividing the housing into two fluid chambers. Separate fluid conduits join each chamber with the air intake passage of the engine, and are normally open to maintain a relative vacuum in each chamber. A microprocessor receives electrical input signals corresponding to engine RPM, vehicle velocity, throttle setting and other vehicle operating parameters, and generates output signals for momentarily and selectively closing the fluid conduit to one of the chambers, and simultaneously opening the selected chamber to a source of atmospheric pressure.

Abstract: A shift actuator in an automatic shift mechanism of a geared transmission for an automotive vehicle includes a shift rod mounted in a casing so as to slide freely in mutually opposing directions and coupled to a fork shaft to acutate the same by sliding in either of the directions, thereby effecting a gear shift, actuating means attached to the shift rod for urging the shift rod in either of the directions by hydraulic pressure switched by a changeover valve, and a CPU for switching the changeover valve. Hydraulic pressure is switchingly applied to the actuating means by the changeover valve in response to a command from the CPU, thereby urging the shift member coupled to the fork shaft in the shift direction intended. As a result, when synchronization with the rotational speed of the engine is achieved, the fork shaft automatically slips into in a desired shift postion.

Abstract: The present invention is an electrical control apparatus for control of a manual transmission apparatus in a motor vehicle. The transmission state is selected by clockwise or counter-clockwise motion of a shift select lever via a first motor and forward or rearward motion of the shift select lever via a second motor. The electrical control apparatus includes first set of microswitches for indicating the left, center, right location of the shift select lever, and a second set of microswitches for indicating the forward, neutral or rearward location of the shift select lever. A logic control unit generates a sequence of motor drive signals corresponding to the sequence of motions required for movement of the shift select lever from the present transmission state to the desired transmission state. The control apparatus also includes a motor drive circuit for controlling the first and second motors in response the sequence of drive signals.

Abstract: A vehicle transmission system has an internal lever for changing transmission gears, a select actuator for moving the internal lever to neutral positions N1, N2, N3 in a first direction, a shift actuator for moving the internal lever to 1st-5th gear positions and a reverse position in a second direction substantially normal to the first direction, and a clutch actuator for actuating a clutch. While any one of the actuators is in operation, the pressure of a fluid discharged from the operating actuator is prevented from acting on the select actuator and/or the shift actuator which is not in operation by applying a fluid pressure to the inoperative select actuator and/or the shift actuator to fix the actuator or actuators in a current position against operation, thereby allowing the transmission gears to be changed accurately and smoothly.

Abstract: A first clutch control is operated in response to an accelerator position signal so as to set a clutch from a disengaged state to a half engaged state. A second clutch control is provided for gradually engaging the clutch when a load signal from an engine load detecting is equal to or higher than a preset value, and for disengaging the clutch when the signal is higher than the preset value. After the second clutch control is operated when a difference between an engine speed and a clutch output shaft speed becomes equal to or lower than a predetermined value, the clutch is fully engaged by a third clutch control.

Abstract: A multiple speed transmission, specifically for motor vehicles, comprises a main shaft 24 and two auxiliary shaft 24.sub.1 and 24.sub.2. Arranged on these shafts are several gear wheel groups of which three gear wheels each are constantly in mesh. Arranged on the main shaft 24, for shifting the gears, are sliding sleeves 24.sub.3, 24.sub.4, 24.sub.5, 24.sub.6 of which one each can be coupled to one of the gear wheels (by use of an operating cylinder) in interlocking fashion. To create synchronism on the sliding sleeve to be engaged, either an accelerating device 33 or a retarding device 36 acts on one of the auxiliary shafts, depending on shifting direction. Contingent upon reaching synchronism on the respective sliding sleeve, a mircoprocessor controls the servoagent supply to the respective operating cylinder.

Abstract: A shift gear, specifically for motor vehicles, has a main shaft (9) and an auxiliary shaft (8). Arranged on these shafts are several gear groups (56), (7); (14), (15); (16), (17), with two gears each being constantly in mesh. For shifting the gears, sliding sleeves (12), (13) are arranged on the main shaft (9), one of these sleeves at a time being positively couplable to one of the gears (56), (14), (16). To synchronize the sliding sleeve to be engaged, either a retarding device (20) or an accelerating device (46), (50) acts on the main shaft (9), depending on the direction of shift. A planetary gear train (50), which may be part of said accelerating device, has a gear component (22) which can be retarded by means of a friction brake (24) and forms a clutch device for interrupting the flow of power from an engine (51) to an output shaft (27). Serving also the starting, the clutch device is arranged on the transmission output.

Abstract: A vehicular transmission shift control system is provided for effecting automatic shifting between a group of sequentially related forward gear ratios provided by the transmission that includes a logic member (16) operative to receive and process an engine speed signal (22) and a gear ratio position signal (30) and to provide an output control signal (33) to a shift actuator (34) that is operative to enable automatic shifting between the sequentially related forward gear ratios whenever the lowest sequentially related forward gear ratios of the group is manually engaged by an operator of the vehicle.

Abstract: A gearshift range preconditioning system includes a gearshift device which, when manually-operated to effect a gear-change, initiates a signal to an electronic logic circuit which is coupled to the vehicle to receive vehicle-operating characteristics such as speed and engine RPMs. The electronic logic circuit evaluates this change request and the received operating characteristics in relation to predetermined optimum operating characteristics associated with optimum neutral gear ranges. The electronic logic unit then generates a neutral gear signal which is transmitted to a solenoid-valve-controlled neutral gear cylinder to effect operation of the vehicle transmission into the neutral position best suited for the specific vehicle-operating characteristics. An auxiliary range cylinder can effect selection of active gear positions between a high and a low state to achieve a doubling of possible active gear positions.

Abstract: A shift control system for a material handling implement including a transmission having a plurality of selectively electrically-operated hydraulic clutches is disclosed. The system includes a manually positionable gear selector which provides electrical signals respectively corresponding to actuation of the transmission's hydraulic clutches. Notably, the system includes acceleration sensing means arranged to sense acceleration of the implement along its longitudinal axis, with the acceleration sensing means operatively connected with the electrical controls which interface the gear selector and the electro-hydraulic valves which operate the hydraulic clutches. By this system, acceleration on the implement, either negative or positive, created during upshifting of the transmission is monitored, and the sequential operation of the hydraulic clutches for the next-requested shift automatically adjusted responsively to the sensed acceleration for facilitating smooth shifting of the transmission.

Abstract: An electro-hydraulic control system is intended for the kind of automatic power transmission which comprises at least three forward gear ratios and in which ratio changes are effected under power by releasing one clutch interconnecting the transmission input and output through one engaged gearset simultaneously with engaging another clutch interconnecting the input and output through another engaged gearset. The control system comprises hydraulic gear actuators each for engaging and disengaging a separate gearset. Electro-hydraulic valves control the supply of hydraulic fluid to the actuators in response to ratio selection signals derived in an electronic control. One set of electro-hydraulic valve states is arranged to engage first and second gearsets while a second set of electro-hydraulic valve states is arranged to engage both second and third gearsets.

Abstract: A motor drive device for an operation of a camera such as film winding, etc. with a motor is arranged to detect the rotating speed of the motor and to shift, according to the rotating speed thus detected, the reduction ratio of a driving force transmitting gear train of a drive mechanism for transmitting the driving force of the motor to a load, so that the load can be adequately driven.

Abstract: Pressure-medium actuated shifting arrangement for a gear transmission, primarily for a multispeed transmission, in which the speed selection lever performs a movement in accordance with a double H shifting configuration. Within the reach of the driver, in a shift console another transmission shaft is mounted, which is displaced by the speed selection lever for path selection and twisted for gear shifting. The transmission shaft has also cams and valves cooperating with a pressure-medium source over the selection cylinder and shift cylinder mounted to the gear box which actuate a gear-shift-lever shaft, whereby not only the desired shift couplings are put into effect, but also feedback information about the shifting situation in the transmission perceptible by the driver is conveyed.

Abstract: On an input and an output shafts of the transmission, there are provided a plurality of gear pairs which have different reduction ratios. One of the gears of the gear pair having the smallest reduction ratio is operably connected with the input shaft through a multi-disk clutch, and the torque transmitted from the input shaft to the gear can be controlled by adjusting the thrusting force applied to the clutch. When the selection of the gear pair is changed, the gear pair under operation at present is brought into the neutral condition and, at the same time, the thrusting force of the clutch is increased. Thereby, the torque of the input shaft is transmitted to the output shaft through the clutch and a rotational synchronism of the input and output shafts is advanced by adjusting the thrusting force. When the rotational synchronism is completed, the gear pair to be selected is brought under the operation.

Abstract: A method is described for controlling a vehicle transmission mechanism which incorporates several selectively engagable power transmission systems each being selectively individually connectable between a first member and a second member for transmitting rotational power between them, with each such power transmission system including a clutching mechanism which can be selectively controlled either to freewheel in both rotational directions or to provide direct transmission of rotational power in one rotational direction only and to freewheel in the other rotational direction.

Abstract: An automatic transmission shift control system is provided for work vehicles, such as front-end loaders, which permits automatic shifting between first and second gears in response to vehicle speed but which inhibits downshift for a predetermined time interval after initiating reversal of the vehicle. A speed signal generator produces shift point signals at predetermined speed values and a speed logic circuit responds to the shift point signal for producing respective upshift and downshift signals. An inhibit circuit produces an inhibit signal in response to a reversing signal. The speed logic circuit is responsive to the inhibit signal for delaying the change from an upshift control signal to a downshift control signal for a time interval corresponding to the duration of the inhibit signal. The inhibit circuit is disabled when the speed decision logic circuit produces a downshift signal so that an upshift of the transmission may occur during reversal.

Abstract: An actuation system for a transmission synchronizer, including a first member and a second member, the second member being pressed against the first member for synchronization of two relatively rotating elements, includes a variable pressure type actuator which selectively presses the second member against the first member, with a pressing force which is controllable to vary over a range so as to press the second member against the first member at a lower pressure in the initial phase of synchronization and at a substantially increased pressure at the end of synchronization.

Abstract: An aircraft secondary power system having a selectively operable power source for drive of accessories and for starting of a jet engine. The system includes a clutch which is engaged when the power source is to start the engine. At a predetermined engine speed, the engine takes over the drive of the accessories through the clutch and, at a selected higher speed of the engine, the clutch is disengaged to cause the drive of the accessories from the engine at a lower drive ratio whereby the accessories are driven at a lower speed relative to the speed of the engine.

Abstract: An automatic mechanical change gear transmission system (10) is provided. The transmisssion (12) is a splitter type comprising a main section (48) connected in series with a blocked splitter type auxiliary section (50). The auxiliary section blockers (172) and clutch members (164) are provided with ramps (218, 220, 222, 224) which will tend to align the blockers and ramps in a nonblocking condition under the influence of biasing spring (178) if the main section is in neutral. A control unit (38) receives input signals and commands transmission shifts in a sequence including shifting the main section into neutral and shifting the auxiliary section to a new ratio during each shift procedure.

Abstract: A multiple clutch type transmission including a plurality of input shafts, a plurality of clutch devices for releasably and alternately connecting respective ones of said input shafts with an engine output shaft. Each of the input shafts has two driving gears mounted thereon to rotate therewith, a countershaft having freely rotatable driven gears which are in meshing engagement with respective ones of the driving gears on the input shafts, connecting hubs provided on the countershaft for axial sliding movements for selectively connecting the driven gears with the countershaft, clutch actuators for controlling said clutch devices so that selected one of the input shafts is connected through selected one of the clutch devices with the engine output shaft.

Abstract: First and second clutch devices releasably and alternately connect respective transmission input shafts with an engine output shaft. The input shafts are connected through respective sets of transmission gears with a transmission output element. In a gear shift up operation, one of the clutch devices, which has not been in driving engagement, is brought into partial engagement with a first engaging speed for a first period of time, while the second clutch device remains in driving engagement, so that there is a certain period of time overlap wherein both clutch devices are in engagement simultaneously. After the second clutch device has been disengaged, the engagement speed of the first clutch device is decreased to a lower speed and then again increased to a higher speed.

Abstract: A multiple clutch type transmission including a plurality of input shafts, a plurality of clutch devices for releasably and alternately connecting respective ones of the input shafts with an engine output shaft, each of said input shafts being associated with at least one set of transmission gears for connecting the input shaft associate therewith to an output element of the transmission, means for controlling the clutch devices so that selected one of the input shaft is connected through selected one of the clutch devices with the engine output shaft and through selected set of the transmission gears with the output element.

Abstract: Disclosed is an automatic control system for a powershift, preselect transmission (10) including a plurality of power paths (36, 38) alternately connectable between input (12) and output (20) shafts by first engaging selected ones of synchronizer clutches (42, 74, 84) associated with each of a plurality speed ratio gears (44, 46, 76, 78, 80) in each path and then alternately engaging a powershift clutch (48, 82) associated with each path. The control system includes a hydraulic logic system (118) which may be electronic and a hydraulic and shift valve system which may be electrically controlled should the logic be electronic. The control system preselects ratio gears in a nondriving path and then alternately engages the powershift clutches to switch driving connections from one path to the other. The logic system includes an improved reverse sequence valve (132) and improved shift valves (124, 126, 128).

Abstract: Disclosed is an automatic control system for a powershift, preselect transmission (10) including a plurality of power paths (36, 38) alternately connectable between input (12) and output (20) shafts by first engaging selected ones of synchronizer clutches (42, 74, 84) associated with each of a plurality speed ratio gears (44, 46, 76, 78, 80) in each path and then alternately engaging a powershift clutch (48, 82) associated with each path. The control system includes a hydraulic logic system (118) which may be electronic and a hydraulic and shift valve system which may be electrically controlled should the logic be electronic. The control system preselects ratio gears in a nondriving path and then alternately engages the powershift clutches to switch driving connections from one path to the other. The logic system includes an improved reverse sequence valve (132) and improved shift valves (124, 126, 128).

Abstract: A transmission incorporating a continuously variable ratio unit connected to further gearing, such that a plurality of regimes are available with synchronous shifting between regimes, is controlled such that to avoid hunting between regimes when the transmission is running at or around the synchronous ratio, regime and ratio changing beyond the synchronous ratio is inhibited until the optimum ratio for the prevailing operating conditions differs from the synchronous by a predetermined value.

Abstract: A rotational speed number controlling device for automatic transmissions for changing speeds by automatically changing a plurality of centrifugal clutches in response to the number of revolutions of the engine wherein a sliding piece is connected to a rotary shaft to which the rotation of a low speed side centrifugal clutch is to be transmitted so as to be able to transmit rotations and to be slidable in the axial direction in response to the driving torque so that the number of engaging rotations of a high speed side centrifugal clutch may be varied by the sliding of the above mentioned sliding piece caused in response to the driving torque. For example, in the case of a quick acceleration at the time of the second speed running in an automatic three-speed transmission, the high speed side centrifugal clutch may not be immediately engaged but the second speed state may be maintained until a sufficient acceleration and then the high speed side centrifugal clutch may be engaged.

Abstract: A four speed, constant mesh transmission includes an input and an output shaft with four pairs of driver and driven gears respectively spaced on the two shafts. A pair of gear couplings are slidably disposed on the output shaft and splined for rotation therewith. Each gear coupling is selectively moved along the shaft for engagement with one of the driven gears by means of a pair of shift forks respectively engaged with the gear couplings. The two shift forks are slidably disposed on a guide rail which extends parallel to the input and output shafts of the transmission. Each shift fork includes a solenoid lock which may be selectively engaged with the guide rail for preventing sliding movement of the shift fork with respect thereto.

Abstract: A rotary power transmission having a series of up to five gear trains and two clutches alternately engagable to provide drive paths through the gear trains in series sequence has control means including a fluid pressure source and three solenoid-operated valves to direct source fluid to two spool valves which provide discrete fluid pressure signals for engagement of gear trains two at a time in progressively over-lapping pairs, the gear trains being for eventual drive according to clutch engagement.

Abstract: Disclosed herein is a marine propulsion device including an input shaft drivingly connected to a power source, a lower unit having a rotatably mounted drive shaft extending in coaxial relation to the input shaft, a rotatably mounted propeller shaft carrying a propeller and drivingly connected to the propeller shaft, and a two-speed transmission drivingly connecting the input shaft to the drive shaft. The transmission includes a third shaft rotatably mounted in parallel relation to the input shaft and the drive shaft, a first pair of meshing gears including a first drive gear mounted on the input shaft and a first driven gear mounted on the third shaft, a second pair of meshing gears including a second drive gear mounted on the third shaft and a second driven gear mounted on the drive shaft, and a one-way overrunning clutch drivingly connecting one of the shafts to a gear mounted on the shaft when the rotational speed of the input shaft is less than a predetermined value.

Abstract: Disclosed herein is a marine propulsion device including an input shaft drivingly connected to a power source, a lower unit having a rotatably mounted drive shaft extending in coaxial relation to the input shaft, and a propeller shaft rotatably mounted in the lower unit, the propeller shaft carrying a propeller. A two-speed transmission is provided to drivingly connect the input shaft to the drive shaft, the transmission including a first drive arrangement between the input shaft and the drive shaft for selectively drivingly connecting the input shaft and the drive shaft, the first drive arrangement including a third shaft rotatably mounted in parrallel relation to the input shaft and the drive shaft, a drive gear, a driven gear mounted on the third shaft and in meshing engagement with the drive gear, and a one-way overrunning clutch drivingly connecting the input shaft and the drive shaft through the drive and driven gears when the rotational speed of the input shaft is less than a predetermined value.

Abstract: An automatic mechanical change gear transmission system (10) is provided. The transmission (12) is a splitter type comprising a main section (48) connected in series with a blocked splitter type auxiliary section (50). The auxiliary section blockers (172) and clutch members (164) are provided with ramps (218, 220, 222, 224) which will tend to align the blockers and ramps in a nonblocking condition under the influence of biasing spring (178) if the main section is in neutral. A control unit (38) receives input signals and commands transmission shifts in a sequence including shifting the main section into neutral and shifting the auxiliary section to a new ratio during each shift procedure.