Abstract: A hydrodynamic-mechanical vehicle drive wherein an engine drives the primary portion of an input clutch whose secondary portion can receive torque with varying degrees of slip and rotates the pump of a counter-rotating hydrodynamic torque converter, either directly or through the medium of a differential. The turbine of the converter is adjacent to the inlet side of the pump and drives the input shaft of a reversing gearing which utilizes a friction clutch to drive the take-off shaft forwardly and a friction brake to drive the take-off shaft in reverse. The turbine and the pump rotate in the same direction during hydrodynamic braking and the pump is then rotated at a speed which depends on the degree of slip of primary portion of the input clutch relative to the secondary portion.

Abstract: A multiple-transmission-ratio transmission arrangement includes at least first and second transmission-ratio-establishing units, for example brake bands and/or clutches, having hydraulically activated and unactivated states and operative in the hydraulically activated state for establishing respective first and second transmission ratios. An arrangement for changing the transmission ratio of the transmission arrangement comprises, in combination, a source of hydraulic activating fluid and conduits connected to the source and to the hydraulically activatable transmission-ratio-establishing units. Electrically controllable valves in the conduits are operative for alternately permitting and preventing the supply of hydraulic activating fluid to the transmission-ratio-establishing units.

Abstract: A hydrodynamic coupling wherein the radially outermost region of the working circuit communicates with one or more radially inwardly extending channels defined by a casing which surrounds the impeller or runner element or by the casing and one of these elements. The casing has one or more openings located radially inwardly of the normal liquid level in the working circuit and in the channel or channels. These openings discharge working fluid which flows in the channel or channels radially inwardly in response to abrupt rise of fluid pressure in the working circuit as a result of abrupt change in RPM, particularly sudden acceleration of the impeller element. The outflowing fluid reduces the magnitude of transmitted torque, and the upper limit of such torque is determined by the distance between the radially outermost portion(s) of the opening(s) and the common axis of the impeller and runner elements.

Abstract: The transmission arrangement includes first and second hydraulically activatable units. When the first and second units are activated and unactivated, respectively, the arrangement exhibits a first transmission ratio. When the first and second units are unactivated and activated, respectively, the arrangement exhibits a second transmission ratio. Electrically controllable first and second valves each connect an associated unit to a source of hydraulic fluid. A transmission-ratio changeover is effected by causing the valves to undergo opposite changes of energization state. Each valve has its own time-delay stage. Upon receipt of a signal commanding a transmission-ratio changeover, each time-delay stage delays the initiation of the change of energization state of the associated valve by a respective time-delay interval.

Abstract: A hydrodynamic brake system for the wheel of a vehicle, particularly for the non-driven wheel of a trailer, forms an integral unit which is installed within the confines of the wheel rim at one side of the hub. The stator of the brake system is mounted on the non-rotating axle for the wheel, and the rotor of the brake system is connected with a reservoir for a supply of hydraulic brake fluid and is rotated by the hub and/or rim. The reservoir is connected by discrete feeding and evacuating conduits with a toroidal working chamber which is defined by the stator and rotor, and a portion of the reservoir is exposed to the surrounding atmosphere so as to promote the cooling of brake fluid therein.

Abstract: A torque-delivering vehicle drive system having a friction clutch actuated by a pressurized medium, a hydrodynamic working circuit including a pump wheel and a turbine wheel, operatively connected to the friction clutch and a device including an operating lever for adjusting pressure and/or rate of flow of the pressurized medium to the friction clutch including a regulating device for maintaining the torque delivered by the vehicle drive system at a constant value corresponding to a given position of the operating lever, and means for supplying to the regulating device a measured quantity that is a function of a difference in working fluid pressure producible by the pump wheel of the hydrodynamic working circuit.