Abstract: A device for automatic actuation of a friction clutch in the transmission line of a motor vehicle between an internal combustion engine and a change-speed gear, including a setting drive system for positioning a clutch releaser of the friction clutch in dependence upon an ideal-position signal, an engine rotation rate sensor which generates an engine rotation rate signal corresponding to the rotation rate of the internal combustion engine, a sensor device generating a gear rotation rate signal corresponding to the input rotation rate of the change-speed gear, and a control system responding to the engine rotation rate sensor and controlling the setting drive system for the engagement and disengagement of the clutch, the control system, for the engagement of the clutch in the starting of the motor vehicle, generates the ideal position signal according to a predetermined characteristic in dependence upon the engine rotation rate signal, and increases the ideal-position signal, in dependence upon the engine rota

Abstract: For the automatic actuation of a friction clutch arranged in the torque transmission path between an engine and a change-speed gearbox of a motor vehicle an actuating element of the clutch is coupled to a controllable drive device which moves the actuating element between a clutch-release position, in which the clutch is completely released, and a clutch engagement position in which the clutch is completely engaged. The position of the actuating element in the slipping range between a position of commencing torque transmission and the engaged position is adjusted by a program control, which responds to the engine rotation rate and controls the clutch engagement operation of the drive device, according to a position characteristic provided by means of a first function generator, in starting, as a function of the engine rotation rate. The program control comprises a second function generator controlling the position of the actuating element independently of the first function generator.

Abstract: The controllable drive for a movable releaser of a friction clutch which couples a transmission of a motor vehicle with its internal combustion engine comprises an electric motor and a force-transmission device converting the rotating movement of a drive-output shaft of the electric motor into the actuating movement of the releaser. In the force path of the force-transmission device there is arranged a hydraulic servo-unit, but preferably a suction-pneumatic servo-unit, which transfers the movement of its input element into a proportional movement of its output element and transmits the force exerted upon the input element in boosted form to the output element. In the force transmission in the disengagement direction, the input element abuts on the output element directly or through a likewise movable additional element of the servo-unit, in order to be able to disengage the clutch even when the internal combustion engine is stopped. By reason of the servo-unit the electric motor can be of smaller dimensions.

Abstract: A controllable drive device moves an actuator of a motor vehicle friction clutch between a disengaged position and an engaged position. The drive device adjusts the position of the actuator in the slippage area of the clutch between a position at which torque conversion begins and the engaged position in response to a program control that operates on the basis of an engine's rotating speed and controls the drive device according to a characteristic determined by an engine's speed dependent function generator.

Abstract: A system for automatic actuation of the clutch of a motor vehicle wherein a pneumatic cylinder operates a normally engaged clutch to disengage the clutch when fluid pressure is applied to the pneumatic cylinder. A valve system operated through a control system vents the pneumatic cylinder to effect engagement of the clutch and applies fluid pressure from a fluid pressure source to disengage the clutch. The control system is responsive to the position of a clutch activating element interposed between the clutch and the pneumatic cylinder as well as to the speed of the motor of the motor vehicle. Additionally, sensors responsive to the operating condition of a manually shiftable transmission also operate to control the fluid pressure condition of the pneumatic cylinder to determine actuation of the clutch.

Abstract: In the disclosed device, a square wave generator drives a network composed of a parallel resonant circuit in series with a series resonant circuit. The resonant frequency of the parallel resonant circuit is substantially equal to the fundamental frequency of the square wave voltage generator and lower than the resonant frequency of the series resonant circuit. The resonant frequency of the series resonant circuit is lower than the frequency of the third harmonic of the square wave voltage generator. A load coupleable to the parallel resonant circuit has a complex impedance which shifts the current at the fundamental frequency about 30.degree. relative to the fundamental square wave voltage.

Abstract: Disclosed is a cooking vessel for use with an induction heating appliance. The vessel bottom is formed at least partly of a non-magnetic conductive layer which, when coupled to a coil of the appliance, detunes the appliance's resonant circuit. The layer has a thickness of less than about 0.2 mm when the resistivity of the layer is less than 0.035.times. 10.sup.-6 .OMEGA.m, and a thickness greater than 0.2 mm when the resistivity is higher than about 0.035.times.10.sup.-6 .OMEGA.m.

Abstract: Gear shifting in an automotive vehicle with internal combustion engine, particularly a motorcycle, is facilitated by a mechanism which automatically inactivates the ignition circuit in response to operation of a speed or gear shifting member, and again activates the ignition circuit with a predetermined delay after inactivating.

Abstract: A magnetic field for coupling to a load is produced by means of apparatus having first and second amplifiers operating in phase opposition and connected to a first oscillating circuit for generating a first oscillating voltage of predetermined fundamental frequency, an inductor producing the magnetic field being an element of the first oscillating circuit. A second oscillating circuit connected to the first circuit furnishes a second oscillating voltage having a frequency corresponding to the third harmonic of the fundamental frequency and includes a coil positioned relative to the load in such a manner that substantially no energy is transferred from the coil to the load.