Robert Boschgmbh

Guenther Hertlein

Juergen Hachtel

Holger Sievert

Frank Baehrle-Miller

Dieter Blattert

Marc Micke

Joerg Haffelder

The present invention relates to an automatic parking brake, including a brake piston, an auxiliary piston, a hydraulic chamber disposed between the brake piston and the auxiliary piston, a spring element, for prestressing the auxiliary piston, a spindle device connected to the auxiliary piston via a threaded connection, and a drive for the spindle device, wherein in a locked state of the parking brake, the brake piston is mechanically locked via the spindle device and the spring-loaded auxiliary piston, and in a released state of the parking brake, the auxiliary piston is blocked by means of the spring element and/or by means of the spindle device.

Automatic parking brake

A method and a device for measuring the speed of a pulse-activated electric motor are described. According to this method, the motor is fully activated at time intervals to be determined for a defined measuring time by the circuit element provided for timing and, in this time, the frequency of the current ripples, which is proportional to the motor speed, is measured. A current-proportional voltage measuring device is located on the circuit element, on whose load side are located an amplifier, filters, and an evaluation circuit in the form of a comparator for determining the frequency of the current ripples flowing in a measured phase during which the motor is fully activated.

Method and device for measuring the rotational speed of a pulse-activated electric motor based on a frequency of current ripples

A method and a system for detecting the speed of a pump motor of a hydraulic pump system are provided, in which pump system a pump is driven by a pump motor to deliver hydraulic fluid into a pump reservoir. In accordance with the present invention, a pressure signal representing the fluid-delivery activity of the pump is detected, and the pressure peaks within this pressure signal identified. The speed of the pump motor is determined on the basis of the frequency or the time intervals of these pressure peaks.

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Fichtenberg, Germany

Guenther Hertlein