Abstract: A differential housing support assembly includes a pivot pin which projects from an end of the housing and is pivotally received in an annual ring of a support bracket which is bolted to a vehicle frame member. A cover plate is bolted to an end fact of the ring and includes a central portion which is directly engageable with an end of the pivot pin. Free play between the pivot pin and the cover plate is adjusted by controlling the number of annular shims placed between the annular ring and the cover plate.

Abstract: A front transaxle for an all-wheel drive motor vehicle wherein the housing of an interaxle differential is operatively connected to a shiftable transmission and, via a tubular shaft, drives one bevel gear of an angle drive. The other angle drive bevel gear is operatively connected to a longitudinal propeller shaft for driving the rear axle. One front wheel drive shaft extends from the interaxle differential through the tubular shaft. The housing of the angle drive is connected by a flanged joint to the transmission outer housing. The arrangement permits the differential and angle drive subassemblies to be manufactured and tested at different locations while preventing the mixing of lubricants between the two subassemblies upon their assembly into the transaxle.

Abstract: A four-wheel drive vehicle has a front wheel side having a front wheel set, a rear wheel side having a rear wheel set, an engine having an output shaft extending in a transverse direction of a vehicular body, a transmission having an input shaft connected to the output shaft of the engine and an output shaft connected through a transmission mechanism to the input shaft such as to extend in a transverse direction of the vehicular body, a rotating member connected to the output shaft of the transmission, a front differential gear, a first output member connected between the rotating member and one of the wheel sets for transmitting power to one of the wheel sets through the front differential gear, a second output member coaxial with the first output member, a rear wheel propeller mechanism between the second output member and the other wheel set, and operative to convert the rotation of the second output member into rotation about an axis perpendicular to the axis of rotation of the second output member for dr

Abstract: A drive system for a four-wheel drive motor vehicle, in particular an agricultural tractor, includes a gradually lockable differential for the front wheels, a gradually lockable differential for the rear wheels, and a gradually lockable center differential in the drive to the front and rear differential gears. The degree of locking of the respective differentials is controlled by a control circuit based upon their relative rotational speeds, the steering angle and the temperature in the center differential. In an alternative embodiment, brakes on each wheel and on the shafts connecting the center differential to the front and rear differential are used to supplement or replace the differential locks.

Abstract: A viscous shear coupling has housing and hub parts (20 and 22) with interleaved sets of plates (35, 36, 37), the set of plates carried by the housing part being in two sub-sets (35 and 36), the plates (36) of one sub-set being rotationally fast with the housing part and the plates (35) of the other sub-set being capable of limited relative rotation to the housing part and the plates of the other sub-set; plates of the first set carry projections (50, 52) so that upon said relative rotation the spacing of the plates is varied thus to control the torque transmitted by the coupling.

Abstract: To the end of eliminating the problems arising from substantially rigid connection between a front wheel set and a rear wheel set in a four-wheel drive vehicle, there is provided a power transmission system in which a speed-dependent power transmission device is provided between the front wheel set and the rear wheel set so that both the wheel sets are substantially rigidly connected to each other in a low speed range and rotational power is transmitted only from the front wheel set to the rear wheel set in a high speed range.

Abstract: A drive force distribution control system in a four-wheel drive motor vehicle for distributing drive forces from an engine of the motor vehicle to first and second wheels of the motor vehicle includes drive force distributing means for distributing and transmitting the drive forces to the first and second wheels, first speed detecting means for detecting a rotational speed (Nf) of the first wheel, second speed detecting means for detecting a rotational speed (Nr) of the second wheel, torque detecting means for detecting a torque (Tr) transmitted to the second wheel, and control means for controlling the drive force distributing means.

Abstract: A disconnectable transmission assembly comprising a coupling member within which is rotatably mounted in bearings a viscous coupling having a housing member and a hub which respectively carry interleaved plates. The coupling member and the housing member are connectable and disconnectable by means of a deformable sleeve which closes a chamber formed in the housing member and which can be supplied by fluid under pressure from a cylinder by movement of a piston. Deformation of the sleeve, which is connected to the housing member, engages the bore of the coupling member thus connecting the housing member and the coupling member for rotation. When the chamber is de-pressurized there is a running clearance between the sleeve and the coupling member.

Abstract: A system for detecting a slip for four wheels of a four-wheel drive motor vehicle has a speed difference detector for detecting the difference between the front-wheel speed and the rear-wheel speed and for producing a speed difference signal when the difference is larger than a predetermined value. A wheel acceleration calculator is provided for calculating wheel acceleration, and a vehicle body acceleration detector is provided for detecting vehicle body acceleration. When the difference of the wheel acceleration from the vehicle body acceleration is larger than a predetermined value, and when the speed difference signal is not generated, which means that there is no difference between the front and rear wheel speed, a four-wheel slip signal is generated.

Abstract: An operating system used in a vehicle equipped with a part-time four-wheel drive comprises; a center-differential shiftable between at least a two-wheel drive mode and a four-wheel differential-locked drive mode; a free-wheeling device with a clutch mechanism incorporated in an output shaft of an axle differential associated with wheels which are rendered non-driven when the vehicle is traveling in the two-wheel drive mode and adapted to connect and disconnect the transmission of driving power between the axle differential and the non-driven wheel; a drive mode selecting member operated by a driver in the driver's compartment to select a desired driving mode of operation of the center-differential; and a shift control device which sequentially shifts the center-differential responding to an operation of the drive mode selecting member.

Abstract: A planetary transmission having a centrifugal brake is connected into a vehicle drive line and, when there is a rotational speed difference between an input shaft and an output shaft, transmits torque to the output shaft. Due to a special mounting of the input shaft and the output shaft of the planetary transmission, the occurring forces and torques are transmitted effectively, in which the case the parts of the planetary transmission can be manufactured in a cost-effective way and are easy to assemble.

Abstract: A power transmission apparatus for a four-wheel drive vehicle has a first rotary shaft for transmitting drive force to front wheels of the vehicle, a second rotary shaft for transmitting drive force to rear wheels of the vehicle, and a hydraulic pump connecting the first and second rotary shafts and driven by a difference in rotational speed between the first and second rotary shafts to deliver hydraulic oil in an amount depending on the difference in rotational speed. A suction passage and a delivery passage is changed over in dependence on relative rotational direction of the first and second rotary shafts. An expansion chamber communicates with the suction passages and delivery through a restriction to temporarily suppress an increase in pressure of hydraulic oil delivered from the hydraulic pump, thereby suppressing transmission of a drive force by the hydraulic pump when the variation in relative rotation speed between the first and second rotary shafts is small.

Abstract: A planetary sub-transmission for a vehicle has a planetary gear unit with a carrier member fixedly mounted on an output shaft, a sun gear mounted on the output shaft for rotation, and a ring gear fixedly supported by the sub-transmission case. A remotely operable shift member supported by an input shaft for axial movement selectively couples the input shaft to the output shaft, either directly or through the sun gear of the planetary unit, to shift the sub-transmission between high speed and low speed drive ranges.

Abstract: A motor vehicle drive system including a transmission having an output gear connected with an idle gear which is provided rotatably on an input member of a front inter-wheel differential gear mechanism which is provided in the front axle assembly. A transfer shaft is provided adjacent to the front axle assembly and has two or more inter-axle differential gear mechanisms which are of different torque split ratios. A selecting mechanism is provided for selectively connecting one of the inter-axle differential gear mechanisms with the idle gear to establish a desired torque split ratio between the front and rear wheels.

Abstract: A viscous shear coupling includes a housing and a hub, the hub with and housing having interleaved plates and the housing containing viscous liquid. A screw pump is provided to pump the viscous liquid into and out of the portion of the housing containing the plates thus to vary the torque transmission of the coupling. The viscous coupling may be used in a motor vehicle driveline to provide a viscous transmission.

Abstract: A four-wheel-drive vehicle in which the brakes are individually controlled to prevent locking. According to the invention, during anti-locking brake, the torque transmitted between the front and rear wheels is reduced, either by disconnecting the inter-axle transmission or switching to a loosely coupled viscous coupling.

Abstract: A drive line assembly and mounting arrangement for converting a front engine front wheel drive vehicle to an on-demand four wheel drive system. The vehicle rear axle is adapted to be selectively driven by means of a viscous fluid coupling positioned intermediate a forward angled universal-joint drive line assembly and a rear torque tube enclosed longitudinal propeller shaft assembly. An overrunning clutch is rigidly connected intermediate a forwardly extending neck portion of the rear axle drive housing and the torque tube defines a composite torque tube structure. The overrunning clutch is adapted to be locked for a transmission of torque during normal driving. The rear axle drive housing is sprung from the frame by a pair of transversely aligned isolation mounts while the composite torque tube is resiliently secured by a bracket support adjacent its forward end.

Abstract: A four wheel drive vehicle with brakes equipped for respective wheels on front and rear axles, in which an anti-lock control device is provided to control the braking pressure applied to the brakes so as to reduce the pressure when an associated wheel is about to be locked. The antilock control of the braking pressure for the wheels on the front axle and the control of the braking pressure for the wheels on the rear axle are conducted individually and reduction of the braking pressure for the rear wheels is effected more intensely than reduction of the pressure for the front wheels.

Abstract: In a driving apparatus for a four-wheel drive vehicle in accordance with the present invention, a multiple disc clutch is incorporated between a front wheel driving system and a rear wheel driving system, a hydraulic chamber is formed in a fixed casing supporting rotatably a front differential case in the front wheel driving system and a clutch piston is disposed in the hydraulic chamber. Bearings are disposed between the clutch piston and the front differential case in order to enable them to rotate relatively. Hydraulic pressure generated from hydraulic pressure generation means disposed outside each driving system is caused to act on the clutch piston so that the multiple disc clutch is operated by the press force of the clutch piston through the front differential case and the differential operation of the front and rear wheel is restricted in accordance with the operation force of the multiple disc clutch.

Abstract: For improving the load-change behavior of a four-wheel drive motor vehicle when driving through curves, the vehicle is provided with a longitudinal clutch continuously controllable and with a lockable differential continuously controllable in its locking action. The activation of the longitudinal clutch takes place in the first instance in dependence on velocity whereas the activation of the lockable differential is undertaken in the first instance in two stages dependent on power output whereby a velocity-dependent characteristic can additionally be super-imposed on this power output dependent control.

Abstract: A differential (10) for use with dual wheel assemblies (12) includes pinion gears (34) commonly engaged with opposing pairs of bevel gears (36, 38) but at different drive ratios in order to effect differential drive between the dual wheel assemblies, as well as between the wheels in each assembly, so that all four wheels are positively driven independently.

Abstract: A transfer case operating apparatus for shifting a part-time four-wheel transfer case of a vehicle having a transfer gear assembly and a center-differential gear assembly, with their associated gear shift devices. The operating apparatus comprises a power drive actuator coupled to one of the shift devices; a mechanical actuator directly coupled to the other; a shift control device operated by a driver in the driver's compartment of the vehicle shift the transfer case between at least two-wheel high-speed drive mode; four-wheel, differential-free drive mode; and four wheel, differential-locked, low-speed drive mode; and a mechanism for, when the shift control device is operated to shift one gear assembly associated to the power drive actuator, disconnecting the mechanical actuator from the shift control device so as not to shift the other gear assembly. The mechanism works with different operating forces for causing the power drive and mechanical actuators.

Abstract: A power transmission apparatus for a vehicle which is used for a four-wheel drive vehicle driving both the front and rear wheels by a driving force from an engine, in which a discharge amount of a hydraulic pump provided between a front wheel drive shaft and a rear wheel drive shaft to generate hydraulic pressure by a rotation speed difference between the two rotary shafts is desirably adjusted by a remote-controllable variable throttle valve provided on the way of a discharge oil passage extending from the hydraulic pump, so that a simple hydraulic circuit is used to make the coupling of two rotary shafts freely adjustable from loose condition to tight condition.

Abstract: A center differential offering a full-time two axle dirve system. The center differential includes a planetary gear set defining a first drive path which provides an effective torque split ration to the front axle of the vehichle which is several percent less than the minimum dynamic weight ratio on the front axle assembly. The center differential further includes a bidirectional clutch mechanism defining a second drive path for connecting the driving input to the front drive axle assembly with a drive ratio several percent more than the rear axle ratio. The effective torque split and drive ratios are selected as a function of vehicle weight distributionand tire data for a specific vehicle so as to effect a controlled transfer of torque between the first and second drive paths and before the affected axle assembly reaches its traction limit in any mode of operation.

Abstract: A drive power transmission device includes: a first shaft for receiving drive power transmitted from a drive source; a second shaft having a coupling shaft portion at a front end thereof; a coupling housing comprising a cover body having a front portion operatively coupled to a rear end of the first shaft and a rear portion including a central bearing portion in which a distal end of the coupling shaft portion is rotatably supported, and a tubular member having a front open end in which an outer circumference of the cover body is fitted and a rear boss end having a central through hole in which a proximal portion of the coupling shaft portion is rotatably supported, the cover body, the boss end, the coupling shaft portion, and the tubular member jointly defining a cylindrical fluid chamber filled with a fluid; a viscous shear coupling mechanism disposed in the fluid chamber for transmitting the drive power from the first shaft through the fluid to the second shaft; and a centrifugal clutch mechanism disposed

Abstract: To the end of eliminating the problems arising from substantially rigid connection between a front wheel set and a rear wheel set in a four-wheel drive vehicle, there is provided a power transmission system in which a torque-dependent power transmission device is provided between the front wheel set and the rear wheel set so that both the wheel sets are substantially rigidly connected to each other in a low torque range and rotational power is transmitted only from the front wheel set to the rear wheel set in a high torque range. The power transmission device of this kind can be conveniently formed by a parallel combination of a one-way clutch and a torque limiter.

Abstract: The invention relates to a coupling assembly which is controllable to vary the amount of torque transmitted by the assembly. The latter comprises a housing (2, 70) and hub carrying sets (12, 26, 97, 98, 99) of interleaved plates, the housing being filled with a viscous liquid. Means (4, 29; 23, 24, 25, 51) externally of the housing is provided rapidly and repeatedly to increase and decrease pressure applied to the liquid in the housing. Application of such pressure causes the plates of the two sets to come into contact and release of the pressure allows the plates to move apart.

Abstract: A power transmission system for a four-wheel drive vehicle has an automatic transmission for transmitting power of an engine to main driving wheels and a transfer clutch for transmitting the power to auxiliary driving wheels. First and second vehicle speed sensors are provided for sensing vehicle speed dependent on the main driving wheels and the auxiliary driving wheels, respectively. A two-wheel drive switch is provided for producing a two-wheel drive signal. The automatic transmission uses an output signal of the first vehicle speed sensor as data representing driving conditions of the vehicle. In response to the two-wheel drive signal, the transfer clutch is disengaged and an output signal of the second vehicle speed sensor is selected as vehicle speed.

Abstract: A vehicular four-wheel drive system which includes: an oil pump adapted to be actuated by the relative rotations of a first rotating shaft connected to front wheels and a second rotating shaft connected to rear wheels for discharging pressure oil; a hydraulic clutch having a cylinder chamber communicating with the discharge passage of the oil pump; an electromagnetic throttle valve for controlling the discharge pressure of the oil pump; and a control mechanism for changing the throttle opening of the electromagnetic valve in accordance with the running situation of the vehicle.

Abstract: A differential gear includes two rotatable cases, pinions disposed rotatably in each of the cases, first and second side gears meshing with the pinions and disposed rotatably in each of the cases, a first shaft supported rotatably about a co-axis of the cases and extending from the second side gear in the first case to the first side gear in the second case, a second shaft supported rotatably about the co-axis and extending from the first side gear in the first case, a third shaft supported rotatably about the co-axis and extending from the second side gear in the second case, a driven gear provided in the first shaft and a first drive gear for rotating the driven gear to give driving force to the shafts. First and second worm wheels respectively fixed to the first and second cases, first and second worms respectively meshing with the first and second worm wheels and at least one electric motor for rotating the first and second worms are provided.

Abstract: A pair of planetary gear devices and a viscous coupling are provided in a power transmitting system. The viscous coupling operates to transmit power of an engine in accordance with the difference between speeds of an input member and output member thereof. One of the members of one of the planetary gear devices is operatively connected to a front drive shaft through the viscous coupling and another member of the other planetary gear device is operatively connected to a rear drive shaft. A pair of change-over coupling devices are provided to selectively lock the planetary gear devices and the viscous coupling.

Abstract: A differential gear includes a rotatable case, pinions rotatably disposed in the case, a pair of side gears meshing with the pinions and disposed in the case, a first shaft supported rotatably about a rotary axis of the case and extending from one of side gears, a second shaft supported rotatably about the axis and extending from the other side gear in the opposite direction to the first shaft, a first driven gear provided in one of the first and second shafts, a first drive gear for rotating the driven gear to transmit driving force to the first and second shafts. A worm wheel fixed to the case, a worm meshing with the worm wheel and an electric motor are provided. The motor is controlled by a control device so as to maintain the difference between numbers of revolutions of the first and second shafts within a predetermined range.

Abstract: A motor vehicle comprises at least two driven axles (2, 5). One (5) of said axles can be disconnected from the prime mover (1). In order to prevent a swerving of the vehicle without a need for interrupting the transmission of power to one (5) of the driven axles (2, 5) during each braking operation, the vehicle is provided with a sensor (6) for measuring the angular acceleration of its yawing movement. In response to a rise of the angular acceleration to a predetermined value the sensor (8) causes a clutch control means (15) to disconnect one driven axle (5) from the prime mover (1), or operates means for effecting a pressure drop in the brake system.

Abstract: Control for the automatic locking of the transfer transmission of a motor vehicle equipped with a multi-axle drive, having a wheel slip control system for the wheels of one axle and having an electronic unit that carries out a comparison of a quantity determined from the steering angle and the rotational speed difference of the wheels of the other axle that characterizes the moving condition of the motor vehicle with a limit value assigned to the steering angle and the driving speed. Control signal for the lock of the transfer transmission is generated when a control signal of the wheel slip control system is present or the quantity characterizing the moving condition of the motor vehicle exceeds the limit value.

Abstract: A vehicle (10) disclosed incorporates an improved drivetrain (18) for providing full time four wheel driving. The drivetrain (18) includes an engine (20) driving a transmission (22) including multiple gear paths (28) and a differential (30) located within a single oil bath (36) defined by a housing (34) of the transmission. Front and rear outputs (38,40) of the transmission (22) respectively drive front and rear axles (42,44) through associated front and rear differentials (46,48) to provide the full time four wheel driving. In the preferred construction, front and rear driveshafts (50,52) extend between the transmission outputs (33,40) and the front and rear differentials (46,48 ) to provide the driving. It is also possible for the transmission (22) to incorporate a viscous clutch (54) for limiting interaxle differential rotation in order to prevent one axle from spinning when one of its wheels loses traction.

Abstract: A four-wheel drive vehicle has a laterally disposed engine, a transmission, and a planetary gear device for transmitting power of an engine to front and rear wheels of the vehicle. The planetary gear device is provided at a position between the engine and the transmission.

Abstract: An oil hydraulic clutch having opposite disks is provided in a power transmitting system. One of disks is operatively connected to one of side gears of the central differential through a gear train and the other of the disks is operatively connected to the other side gear of the central differential through another gear train, whereby torque is transmitted to front and rear wheels in a distribution ratio.

Abstract: A four wheel drive vehicle comprising an engine, a transmission connected to the engine, a front wheel drive line, a rear wheel drive line, and an automatic switch mechanism for operatively connecting the front wheel and rear wheel drive lines to the transmission to selectively provides a two wheel drive mode and a four wheel drive mode. The front wheel drive line and the rear wheel drive lines are constructed such that front wheels are driven at a lower speed than rear wheels. The automatic switch mechanism includes an input portion connected to the transmission, a first output portion connected to the front wheel drive line, a second output portion connected to the rear wheel drive line, and a clutch for connecting the first and second output portions to the input portion. The clutch is operable to disconnect the first output portion from the input portion upon receipt of a torque exceeding a predetermined value.

Abstract: A four wheel drive vehicle comprising dirigible front wheels and nondirigible rear wheels. Drive of an engine is transmitted to the front and rear wheels through a propelling drive transmission for producing at least two, high and low, speeds, a front wheel change speed mechanism, and a rear wheel change speed mechanism. The front and rear wheel change speed mechanisms are controlled by a control device to produce a high speed state with the front wheels accelerated when a steering angle of the front wheels exceeds a predetermined angle and the propelling drive transmission is in a low speed position, to produce a low speed state with the front wheels accelerated when the steering angle of the front wheels exceeds the predetermined angle and the propelling drive transmission is in a high speed position, and to produce a standard state in which the front and rear wheels are driven at the same speed when the steering angle of the front wheels is below the predetermined angle.

Abstract: A power transmission system for a four-wheel drive vehicle has, for the front and rear wheels, a driving power transmitting system for transmitting the output of a transmission with a forward overrunning clutch and a reverse overrunning clutch. Either or both of the overrunning clutches are engaged with a sleeve of a selecting device. An outer race of each overrunning clutch has outer toothings on the periphery thereof and the sleeve has inner toothings. Each inner toothing of the selecting device has chamfers on both axial ends thereof, and each outer toothing has a chamfer on an end opposing the inner toothing. Opposed chamfers of the inner and outer toothings have an angle so that a component in a free rotational direction of the outer toothing is produced by the engagement of the chamfer of the inner toothing.

Abstract: A two-wheel/four-wheel automatic change-over device in an automobile transfer apparatus is disclosed. In the transfer apparatus in which driving forces are transmitted directly from a transmission to front two wheels or rear two wheels and also transmitted through a wet-type multiple disc clutch to the other two wheels, the two-wheel/four-wheel change-over device has a change-over control unit for changing over from two-wheel drive to four-wheel drive. This unit automatically effects an engagement and a release of a wet-type multiple disc clutch in response to a signal of high speed travelling, a signal of slope travelling, a signal of quick acceleration travelling, a slip signal obtained from a relation between a real car speed and rotation of the wheels and a signal of a selector switch. In such a constitution, the wet-type multiple disc clutch is usually hydraulic-controlled so that it is differentiable in time of the four-wheel travelling.

Abstract: A four wheel drive vehicle including a front inter-wheel differential gear between front drive axles, a rear inter-wheel differential gear between rear drive axles and an inter-axle differential gear between the front and rear drive axles. The vehicle has a transmission arranged with its output axis transversely of the vehicle. The inter-axle differential gear includes two planetary gear sets which are mounted on one of the front drive axles and provided with clutches so that the planetary gear sets are selectively brought into an operative position.

Abstract: A brake control system for a vehicle provided with a four-wheel drive mechanism and an antiskid brake system for controlling the braking effort upon application of the brakes to prevent locking of the wheels comprises a brake application sensor for detecting application of the brakes over a predetermined level to such a degree that can lead to locking of the wheels, and a releasing mechanism which releases the driving connection between the front wheel driving system and the rear wheel driving system of the four-wheel drive mechanism when the brake application sensor detects application of the brakes over the predetermined level.

Abstract: A four-wheel drive vehicle has a front wheel side having a front wheel set, a rear wheel side having a rear wheel set, an engine having an output shaft extending in a transverse direction of a vehicular body, a transmission having an input shaft connected to the output shaft of the engine and an output shaft connected through a transmission mechanism to the input shaft such as to extend in a transverse direction of the vehicular body, a rotating member connected to the output shaft of the transmission, a front differential gear, a first output member connected between the rotating member and one of the wheel sets for transmitting power to one of the wheel sets through the front differential gear, a second output member coaxial with the first output member, a rear wheel propeller mechanism between the second output member and the other wheel set, and operative to convert the rotation of the second output member into rotation about an axis perpendicular to the axis of rotation of the second output member for dr

Abstract: A transfer case for four-wheel-drive vehicles for distribution of the power from an input shaft through a transmission route to the rear propeller shaft and the front propeller shaft is shown. The transfer case is provided with a torque detection unit for detecting the torque on the input shaft side and is equipped also, on the transmission route between the rear propeller shaft side and the front propeller shaft side, a friction clutch whose coupling force is adjusted in accordance with the variations in the values of the torque detected by the torque detection unit.

Abstract: An all-wheel limited slip differential system in the power train of the front axle and the rear axle of a motor vehicle has an intermediate planetary transmission in the direct through drive and a clutching device engageable at its planetary carrier. The planetary transmission includes an inlet ring gear that is torsionally fixed with respect to the drive shaft, and an outlet ring gear having a slightly smaller number of teeth that is disposed coaxial and adjacent to the inlet ring gear and is torsionally fixed with respect to an output shaft. The planetary transmission also has several planetary wheels engaging jointly with both ring gears, the planetary wheels connected to planetary carrier and rotating together with it.

Abstract: A control arrangement for a four-wheel drive vehicle which has at least one gear box or differential with controllable power transmission characteristics having circuitry for producing control signals in response to vehicle operating conditions and parameters. The arrangement allows for control of the distribution of torque to the respective wheels of the vehicle as a function of a selected number of parameters, such as relative or average wheel speed, engine speed, gas pedal or throttle valve angle, etc. The arrangement contemplates the simultaneous control of more than one adjustable gear box or differential as a function of commonly and/or separately sensed parameters.

Abstract: Four-wheel drive transmission device comprising at the outlet of transmission (15) a drive gear (1) driving an outer ring gear (2) which comprises an internal toothing which is the ring gear (4) of the central differential (16) whose sun gear (6) controls one of the axles (17), and whose planet carrier (18) controls the other axle, characterized in that a self-braking system is placed between the planet carrier (18) and the sun gear (16) so as to transfer automatically a portion of the energy from the axle losing adherence to the other axle.

Abstract: A motor vehicle comprises two driven axles (5, 8), which are interconnected by an interaxle coupling (10) for transmitting a torque only when the halves of the coupling (10) rotate at different speeds and by a speed-changing transmission (9) connected in series with the coupling (10). A brake system (12 to 15) is provided for braking the wheels of both axles (5, 8). In order to ensure that the wheels of the driven rear axle (8) will not block before the wheels of the driven front axle (5), a pressure-setting controller (17) is adapted to control a brake pressure regulator (16) associated with the driven rear axle (8) and is responsive to a reversal of the direction in which torque is transmitted to and from the driven rear axle (8).

Abstract: In a drive system for motor vehicles having two drive axles, one of said driven axles is driven by means comprising a liquid friction coupling. In order to permit the use of a relatively small liquid friction coupling and to permit the interdependence of the speed difference between the coupling halves of the liquid friction coupling and the torque transmission capacity to be modulated within a large range with simple means, one coupling half of the preferably controllable liquid friction coupling is held against rotation, the other coupling half is connected to one torque-transmitting member of a planetary gear train having three torque-transmitting members, another of said three torque-transmitting members is arranged to be driven by the motor, and the third of said torque-transmitting members is connected to the axles to drive the same.