Automatic parking brake
AssigneeRobert Bosch GmbH
InventorsJoerg Haffelder, Dieter Blattert, Guenther Hertlein, Frank Baehrle-Miller
Life of this patent
Estimating the term…
Abstract
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.
Claims21
1-19. (canceled)
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.
A method for actuating an automatic parking brake, having a brake piston and a spring-loaded auxiliary piston that is connected to a spindle device via a threaded connection the method comprising the following steps:
- actuating the spindle device, until the spindle device contacts the brake piston;
- building up a hydraulic pressure in a hydraulic chamber disposed between the brake piston and the auxiliary piston, when the spindle device contacts the brake piston, in order by means of the brake piston to shift the parking brake into a locked state, and in order to move the auxiliary piston, connected to the spindle device, in an opposite direction, whereupon the spindle device is spaced apart from the brake piston;
- actuating the spindle device again, until the spindle device again contacts the brake piston and the position of the brake piston is mechanically fixed via the spindle device and the auxiliary piston;
- and
- reducing the hydraulic pressure in the hydraulic chamber.
Dependencies are inferred from the claim text.