Abstract: A multiple-speed automatic transmission for automotive vehicles able to produce three underdrive speed ratios, a near direct ratio, and two overdrive ratios. A kinematic arrangement includes three simple planetary gear units (48, 50, 52). One of these produces an underdrive output drivably connected to components of the other gear units, two friction clutches (118, 122), three friction brakes (124, 126, 140), an overrunning coupling (82), a final drive gearset (94), a differential mechanism (102), a chain drive mechanism (30) for transmitting power from the turbine (16) of a torque converter (10) to the input shaft, which drives elements of the planetary gear units.

Abstract: A control system for a continuously variable sheave drive having a driving sheave assembly (124) and a driven sheave assembly (126) connected drivably by a torque transfer belt or chain (144), each sheave assembly being comprised of a pair of friction drive sheave portions (128/130 and 178/180) that are axially adjustable, one with respect to the other, to establish varying pitch radii, each sheave assembly having a fluid pressure operated servo with a pressure chamber (164/212) supplied with control pressure from a pressure source, distribution of control pressure to one servo assembly effecting a pitch radius adjustment thereby changing the overall drive ratio, control pressure distribution to the other sheave assembly resulting in a clamping force, and valve means for limiting the rate of delivery of pressurized fluid to the ratio controlling sheave assembly (124) so that control pressure will not fall below a desired value.

Abstract: An automatic transmission for an automotive vehicle includes first and second simple planetary gear units, certain of whose elements are continually interconnected and certain others are releasably connected through operation of friction elements and one-way couplings. The input shaft of the transmission is adapted to drive elements of the planetary gear units through an underdrive gearset and an overdrive gearset. The various speed ratios result by either underdriving or overdriving an element of the planetary gear unit or both underdriving one element and overdriving another element. Several parallel torque delivery paths include a series arrangement of the overrunning coupling in parallel with a friction element. This arrangement permits engine braking during coast conditions when the coupling overruns. The overdrive gearset is available to produce a speed ratio without involving the planetary gear units.

Abstract: An automatic transmission for an automotive vehicle includes first and second simple planetary gear units, certain of whose elements are continually interconnected and certain others are releasably connected through operation of friction elements and one-way couplings. The input shaft of the transmission is adapted to drive elements of the planetary gear units through an underdrive gearset and an overdrive gearset. The various speed ratios result by either underdriving or overdriving an element of the planetary gear unit or both underdriving one element and overdriving another element. Several parallel torque delivery paths include a series arrangement of the overrunning coupling in parallel with a friction element This arrangement permits engine braking during coast conditions when the coupling overruns. The overdrive gearset is available to produce a speed ratio without involving the planetary gear units.

Abstract: A continually variable transmission includes a fluid coupling having an impeller driven from a power source and connected to the input sheave of a fixed speed ratio change drive mechanism, and an impeller connected to the input sheave of a variable speed ratio belt drive mechanism. A coupling bypass clutch mechanically connects the impeller and the turbine. A compound planetary gear set has its sun gear driven from the output sheave of the variable drive mechanism and its ring gear connected to the output sheave of the fixed ratio mechanism, which is mounted on a one-way clutch and selectively drives the ring gear through a low mode clutch. One planet pinion set is continuously engaged with the ring gear, a second planet pinion set is continuously engaged with the first planet pinion set and with the ring gear. A pinion carrier rotatably supports both pinion sets and its connectable through a high mode clutch to the output of the variable belt mechanism.

Abstract: In a continually variable belt-driven transmission, a system for actuating and controlling the operation of the forward clutch and reverse clutch includes a source of hydraulic pressure regulated at line pressure, an accumulator control valve, a line and belt load control solenoid and solenoid-actuated valve, an accumulator, a decel disconnect solenoid-operated valve and a manual valve. The line and belt-load control valve regulates a pressure signal applied to the accumulator control valve whose output pressure develops, on the piston of the accumulator, a force that adds to a spring force tending to purge the accumulator and add that flow to the flow through an orifice directed through the manual valve to the selected clutch.

Abstract: In an automotive automatic transmission, a torque converter lockup control system includes a main regulator valve connected to the discharge of a hydraulic pump for supplying converter feed pressure between the plates of the lockup clutch in accordance with the magnitude of line control pressure produced as a result of a line control pressure command applied to the windings of a solenoid-operated valve in response to a computer command signal. A converter cooler circuit includes a relief valve that opens at a relatively low pressure and communicates through a clutch control valve to the torque converter casing in accordance with the magnitude of lockup clutch control pressure produced by a solenoid-operated lockup clutch control valve. A converter regulator valve regulates converter feed pressure by opening the connection to the relief valve as lockup clutch pressure rises.

Abstract: An infinitely variable belt drive having a pair of belt clamping servos and a ratio control servo, a high pressure source connected to a common high pressure feed circuit for the clamping servos, a ratio control servo, a low pressure source that is independent of the high pressure source, and a high pressure accumulator and pressure amplifier system that is adapted to supply the clamping servos with a high pressure with minimal high pressure fluid flow.

Abstract: In a belt driven continually variable transmission, the drive ratio is changed by varying the radial position of the drive belt by moving displaceable sheaves of a pulley assembly. A system for actuating the displaceable sheaves includes a ratio control valve supplied with pressurized fluid and connected to a source of ratio control pressure produced by a solenoid actuated valve. An orifice located between the ratio control valve and the hydraulic cylinder in which the displaceable sheave is located has feedback lines located on opposite sides of the orifice. Pressure in the feedback lines produces a differential force on the ratio control valve tending to increase the flow rate to the cylinder when the pressure drop across the orifice decreases.

Abstract: A control circuit for an automatic power transmission mechanism for use with an internal combustion engine in a vehicle driveline including fluid pressure operated clutches and brakes that are applied selectively to effect various ratio changes, a forward clutch being applied to effect a forward driving mode and being released to effect a neutral condition, and a clutch pressure regulator valve assembly for controlling distribution of actuating pressure to the forward clutch whereby the clutch pressure is regulated at a threshold value to effect minimum frictional engagement during coasting operation of the vehicle and during engine idling wherein provision is made for quickly increasing the pressure in the forward clutch to establish a maximum torque capacity when the coasting and idling mode is interrupted at the onset of driving torque delivery through the driveline thereby effecting a smooth transition from the coasting and idling condition to the driving mode.