Abstract: In a hydraulic torque converter having a torus of flatness ratio (L/H) within the range 0.82-0.9, the outer and inner contours of the turbine in a meridional plane through the axis of the turbine each comprises a combination of a plurality of circular arcs, wherein the ratios between the radii of the circular arcs constituting said outer contour is substantially less than 2, and the ratios between the radii of the circular arcs constituting said inner contour is substantially less than 2.As a result, fluid flows through the turbine stably without being biased, increasing the velocity of relative flow along the turbine blade, and raising the normal speed ratio at which the absolute flow is in the direction of no impact, enabling a higher stall torque ratio without reduction in efficiency.

Abstract: A belt driven continuously variable transmission unit which converts the rotation of the input member by continuously variable ratios, and a gear unit such as a planetary gear unit to which the output torque from said continuously variable transmission unit and torque from said input member transmitted through a transfer unit is fed and delivered to the output member, are provided. A clutch and arresting member, such as a brake and one-way clutch are provided on the input path to said gear unit from said transfer unit. When the arresting member is actuated to low speed mode, the gear unit functions as a reduction mechanism, whereas when the arresting member is engaged to high speed mode, the gear unit functions as a split-drive mechanism which combines the output torque from said continuously variable transmission unit with the torque transmitted through said transfer unit.

Abstract: A four-wheel drive vehicle having a front- and rear-wheel engaging mechanism designed to enable differential limiting means provided between the front and rear wheels to be controlled over the range from the direct coupling position to the disengaged position through the slip region by the control of the degree of engagement. The vehicle is provided with engaging means for driving the front- and rear-wheel engaging mechanism at a set degree of engagement, wheel acceleration detecting means, reference acceleration detecting means, and control means for controlling the engaging means by setting a degree of engagement on the basis of the result of a comparison between the detected acceleration of rotation of the wheels and the detected reference acceleration.

Abstract: Provided is a power transmission device for four-wheel drive vehicles of both the full-time type and part-time types, wherein a wet multiple-disc clutch is mounted in a ring gear covering the front-wheel differential gear and arranged coaxially with the differential gear. The wet multiple-disc type clutch is engaged by means of a hydraulic actuator in which a plurality of pistons are arranged in series. Hydraulic pressure is fed into oil chambers formed by the pistons through individual or common oil passages. The wet multiple-clutch constitutes a differential motion limiting device for stopping or limiting the differential motion of a center differential gear for the full-time four wheel drive, or constitutes a rear wheel drive switching unit for engaging and disengaging the power transmission between the ring gear mount casing and the transfer unit.

Abstract: In an automatic transmission equipped with a lock-up clutch (6) capable of transmitting engine power to the automatic transmission (1) directly or via a torque converter (2), the automatic transmission has sensors (11, 12) for detecting an input rotational speed and an output rotational speed of the transmission, a control system including a shift start determination step (66) for judging start of a shift by comparing a ratio of the input rotational speed to the output rotational speed with a gear ratio prevailing prior to a shift and a shift end determination step (68) for judging end of a shift by comparing the ratio of the input rotational speed to the output rotational speed with a gear ratio prevailing after a shift, and a lock-up solenoid (10) responsive to output signals from the shift start determination step and shift end determination step for releasing the lock-up clutch (6) during a shift.

Abstract: A transmission control device according to the present invention comprises a main transmission having a torque converting device provided with a direct clutch for effecting engagement and disengagement of the input member with output member of a torque converting portion; a sub transmission having a speed change mechanism; a drive-mode detecting means for detecting the drive mode of the speed change mechanism of the sub transmission; and a controller for controlling the lock-up characteristics of the direct clutch by means of the output of the drive mode detecting means.

Abstract: A hydraulic control device of an automatic transmission for a vehicle utilizes a shift valve for shifting at a high speed stage to prevent creeping and provide a hill-stop mechanism. The shift valve for shifting at the high speed stage has a port open to a forward clutch hydraulic servo, a port communicating with a brake hydraulic servo, and a port receiving modulator pressure from a modulator valve. A solenoid valve controlling the shift valve is in turn controlled by signals issued when the vehicle stops and begins to travel, and the modulator valve is controlled by a linear solenoid throttle valve. The modulator pressure is applied to the forward clutch hydraulic servo, and line pressure is applied to the brake hydraulic servo when the vehicle stops. Line pressure is applied to the forward clutch hydraulic servo and line pressure to the brake hydraulic servo is drained when the vehicle runs.

Abstract: An automatic transmission having a one-way brake in which an outer race is fixed to a rotational member of a planetary gear unit or to a transaxle case and, conversely, an inner race is fixed to the transaxle case or the rotational member of the planetary gear unit, characterized in that the rotational member is provided with an oil infeed plate co-rotatable therewith. Oil dispersed from the input shaft of the transmission is introduced to the one-way brake by pressure produced by the centrifugal force of the rotating oil infeed plate. Thus, burn-out of the one-way clutch is prevented since the clutch is sufficiently lubricated at the time of overrun.

Abstract: An automatic transmission for F.F. (front engine-front drive) type motor vehicles, in which a hydraulic torque converter and an auxiliary transmission mechanism are successively coupled with an output shaft of a transversely mounted internal combustion engine with its rotational axis disposed widthwise of the vehicle, and the rotational axis of a main transmission mechanism is disposed parallel with the rotational axis of the auxiliary transmission mechanism, the input shaft of the main transmission mechanism being rotationally coupled with the output shaft of the auxiliary transmission mechanism. The output shaft of the main transmission mechanism is rotationally coupled with a differential gear device which has its output shafts rotationally coupled with front wheel axle shafts. The auxiliary transmission gear mechanism constitutes an overdrive or an underdrive (reducing) mechanism.

Abstract: A selecting valve is provided, which is switched by different signals sent out when the vehicle is stopped or when the vehicle is to start to move. The selecting valve is connected to a hydraulic servo unit for a forward clutch which is engaged to transmit torque when the vehicle is to move forward, and is supplied with line pressure and a control pressure provided by an electronically operated regulating valve, such as an electronically controlled throttle valve. The regulated control pressure from the electronically operated regulating valve is supplied to the hydraulic servo unit for the forward clutch when the vehicle is stopped, while line pressure is supplied when the vehicle is to move, thus preventing creeping and shift shock at starts. Since the selecting valve is provided with a port leading to the hydraulic servo unit for a brake which restricts vehicle movement, the brake can be applied when the vehicle is stopped and released when moved, thus providing hill-holding capability.

Abstract: In accordance with the invention, the mounting position of a throttle opening sensor is adjusted in such a manner that the output voltage of the sensor attains a value a value of V.sub.100 at a throttle opening of 100%. When execution of the system program starts, V.sub.0 is stored in memory as initialized voltage data at a throttle opening of 0%. A throttle opening .theta..alpha. corresponding to sensed voltage data V.alpha. is calculated in an arithmetic unit in accordance with the following equation: ##EQU1## The throttle opening - output voltage characteristic may change due to an error in mounting the throttle opening sensor, a change in the length of the throttle cable caused by a temperature variation, or a change in resistance value caused by aging. If such is the case and a voltage V'.sub.0 greater than the previously stored voltage V.sub.O prevailing at the throttle opening of 0% is sensed, then V'.sub.0 is stored in memory as new voltage data corresponding to the throttle opening of 0%.

Abstract: A strainer is mounted in an oil passage within a valve body constituting the hydraulic control unit of an automatic transmission. The strainer includes a frame (4) fitted into the oil passage, a reticulate member (5) secured to the frame (4) so as to form a barrier across the oil passage, and a permanent magnet (8) secured by press-fitting or by bonding to frame at a position ahead of the reticulate member (5) in terms of the direction of working oil flow. Foreign matter contained in the working oil is removed by the reticulate member (5) while extremely small contaminants exhibiting a magnetic property, such as ferrous chips, that cannot be removed by the reticulate member (5) are removed by the magnet (8).

Abstract: An endless transmission belt is formed of a plurality of symmetrical V blocks. Each V block comprises upper and lower portions disposed approximately parallel to each other, and two pillar portions connecting the upper and lower portions. The block includes side openings on both sides, and a center opening between the pillar portions. The upper and lower portions have wavy configurations, so that the upper and lower portions have flexibility against the force applied from sheaves to the V block.

Abstract: Under idle condition of a vehicle, control valve 90 is "left half position", line pressure modulated by throttle valve 41 is applied to clutch hydraulic servo C.sub.1 through ports .delta., .mu.; and the clutch is held just under connection, line pressure is applied to brake hydraulic servo B.sub.1 through shift valve 52 being under low speed condition;in case of high speed running, shift valve 52 is "left half position", so that line pressure is not applied to brake hydraulic servo B.sub.1 ;when a vehicle starting, control valve 90 becomes "right half position", then, line pressure is applied to clutch hydraulic servo C.sub.1 through ports .alpha., .mu. and port .beta. is drained;in case of high speed coasting, control valve becomes "left half position", line presure is not applied to clutch hydraulic servo C.sub.1 ;in case of speed higher than certain level, if a manual valve being shifted to R range, control valve 90 becomes "left half position" and ports .epsilon., .eta.

Abstract: A hydraulic control system for a four-wheel drive torque transfer mechanism for a vehicle, including an automatic transmission, a transfer mechanism having gear positions of a two-wheel drive direct-coupling mode H.sub.2, a four-wheel drive direct-coupling mode H.sub.4 and a reduced-speed four-wheel drive mode L.sub.4, and a hydraulic control circuit for controlling the transmission and the transfer mechanism. The transfer mechanism includes a reduction gear mechanism, a first output shaft, a second output shaft rotationally connectible to the first output shaft through a link mechanism, a four-wheel drive clutch for releasably coupling the first and second output shafts, a direct-coupling clutch for releasably coupling an input shaft of the reduction gear mechanism with the first output shaft, and a reduction brake for setting the reducing gear mechanism in a gear train of the reduced-speed mode.

Abstract: A hydraulic control system for a four-wheel drive torque transfer mechanism for a vehicle, including an automatic transmission, a transfer mechanism having a two-wheel drive direct-coupling gear (H.sub.2), a four-wheel drive direct-coupling gear (H.sub.4) and a reduced-speed four-wheel drive gear (L.sub.4) and a hydraulic control circuit for controlling the transmission and the transfer mechanism. The transfer mechanism includes a reduction gear mechanism, a first output shaft, a second output shaft connected to the first output shaft by means of a linkage, a four-wheel drive clutch for rotatably connecting and disconnecting the first and second output shafts, a direct-coupling clutch for connecting and disconnecting the input shaft of the reduction gear mechanism and the first output shaft and a reduction brake for shifting the reduction gear mechanism into the reduced-speed mode.

Abstract: An endless transmission belt for transmitting torque between a pair of pulleys including a plurality of pairs of first and second metallic blocks having at least one through holes in alignment with recesses formed in opposite inclined side edges of the block and an endless chain belt for holding said metallic blocks. The endless chain belt is constructed by at least three strands of link plates which are pivotally interconnected with predetermined intervals therebetween with common articulating pins. Each strand of link plates is inserted into each of through holes or holes and recesses and a pair of first and second metallic blocks is retained pivotably between a pair of adjacent pins.

Abstract: In an automatic transmission including a torque converter, the transmission mechanism is capable of performing lock-up function. The input side portion of a first clutch is coupled with the turbine of the torque converter, wherein the first clutch is in connection while the automatic transmission mechanism is in forward one, forward two and forward three speed, respectively. The input side portion of a third clutch is coupled with the impeller of the torque converter, wherein the third clutch is in cut-off during forward one and two speed and in connection during high speed stages (three speed and four speed, for instance).Thus, in low speed states (one speed and two speed), the torque is transferred through the oil flow of the torque converter, and in high speed states (three speed and four speed), the torque which is machanically coupled with the engine output shaft is transfered to the automatic transmission mechanism.

Abstract: A power transmission device for a full-time four wheel drive vehicle has a differential motion limiting device composed of a hydraulic frictional clutch such as a wet multiple disc type clutch. The friction clutch is disposed between a diff-carrier constituting a front wheel differential gear and a ring gear mount casing covering the diff-carrier and arranged coaxially with the diff-carrier. The ring gear mount casing is associated with the diff-carrier in a center differential gear, and the diff-carrier of the front wheel differential gear is associated with the left hand side gear in the center differential gear. Thus, when the friction clutch is engaged, the ring gear mount casing and the diff-carrier of the front wheel differential gear are integrally coupled with each other so that the rotation of the ring gear is transmitted directly to the front wheel differential gear, while the two elements in the center differential gear are integrally coupled with each other to lock the center differential gear.

Abstract: A hydraulic operating unit for the friction engaging apparatus of a transmission provides a hydraulic operating unit which permits the introduction of a low-pressure working fluid to permit the forceable disengagement of the hydraulic operation unit to work against the fluid which would normally urge the unit into engagement. The effective pressure-receiving area on the releasing side of a hydraulic power servo mechanism is made sufficiently large with respect to the effective pressure-receiving area on the engaging side of the servo mechanism while the piston diameter is kept small in order to save space in the construction of the servo mechanism while at the same time permitting the device to effectively disengage the friction mechanism.