Patent ID: 7267206

Claim:
Parking or emergency brake device, particularly for a motor vehicle, comprising a controlled actuating device ( 10 ) which exerts a determined mechanical force on a brake operating member to immobilize the vehicle, in which the actuating device ( 10 ) is being supplied with a pressurized fluid, comprises: a cylinder ( 12 , 22 ) in which there slides a piston ( 14 ) which axially delimits a front hydraulic pressure chamber ( 16 ) to exert said determined mechanical force on the brake operating member over an actuating travel of the piston, and valve means ( 18 ) which selectively cause the front hydraulic pressure chamber ( 16 ) to be placed in communication with a pressurized hydraulic fluid supply port ( 20 ) to establish a hydraulic actuating pressure in the front pressure chamber ( 16 ), characterized in that the valve means ( 18 ) is interposed between the piston ( 14 ) and the cylinder ( 12 ), to control an axial movement of the piston ( 14 ) over a control travel prior to said actuating travel, said valve means ( 18 ) comprise primary ( 50 ) and secondary ( 52 ) sealing means which are arranged axially respectively in front of and behind the pressurized fluid supply port ( 20 ) to isolate the front hydraulic pressure chamber ( 16 ) from the supply port ( 20 ) when the piston ( 14 ) is in a forward position of rest, characterized in that a control means ( 58 ) for a translation control of the piston ( 14 ) over the prior control travel corresponds to an axial movement of the piston ( 14 ) in the cylinder ( 12 , 22 ) between: said forward position of rest, towards which the piston ( 14 ) is elastically returned and in which the valve means ( 18 ) isolate the front hydraulic pressure chamber ( 16 ) in a sealed manner from the supply port ( 20 ), and an intermediate position in which the front pressure chamber ( 16 ) is supplied with pressurized hydraulic fluid, said control means ( 58 ) controlling the axial movement of the piston ( 14 ) comprise drive means ( 54 ), consisting of an electric motor ( 68 ), which actuates movement-transmission means ( 66 ) allowing a rotational movement of the motor ( 68 ) to be converted into translational movement of the piston ( 14 ).