Patent ID: 6471027
Filing Date: 2002-10-29
Classification: F16H,Y10T

Abstract:
A parking brake for an automatic transmission of a motor vehicle in which, upon an actuation signal triggered via a control device, a pawl one of engages and disengages a parking gear on a shaft of the automatic transmission for one of blocking and releasing the automatic transmission, the pawl engaging the parking gear as a result of displacement of a spring accumulator (3) and the pawl disengaging the parking gear by hydraulic pressure supplied to the spring accumulator (3) and inducing prestressing of a spring of the spring accumulator (3), and the pawl being held in a disengaged state by the hydraulic pressure and an electromagnet (5);the electromagnet (5), when supplied with current, actuates a locking system (13) to maintains a previously pressure-loaded position of the spring accumulator (3), the electromagnet (5) has a relatively high power consumption when the electromagnet (5) is actuated and the locking system is initially loaded while the electromagnet (5) has a relatively lower power consumption, following initial loading, when the electromagnet (5) is maintaining the locking system in a loaded state until the electromagnet (5) is switched off and, thereafter, the locking system (13) is released and the parking brake (18) is actuated via the spring accumulator (3) and the pawl (15) engages the parking gear (16).