Global Patent Index - EP 1098800 A1

EP 1098800 A1 2001-05-16 - MASTER CYLINDER COMPRISING IMPROVED EMERGENCY BRAKING CHARACTERISTICS FOR A HYDRAULIC VEHICLE BRAKE SYSTEM

Title (en)

MASTER CYLINDER COMPRISING IMPROVED EMERGENCY BRAKING CHARACTERISTICS FOR A HYDRAULIC VEHICLE BRAKE SYSTEM

Title (de)

HAUPTZYLINDER MIT VERBESSERTEN NOTBREMSEIGENSCHAFTEN FÜR EINE HYDRAULISCHE FAHRZEUGBREMSANLAGE

Title (fr)

MAITRE-CYLINDRE PRESENTANT DES CARACTERISTIQUES DE FREINAGE AMELIOREES, DESTINE A UN SYSTEME DE FREINAGE HYDRAULIQUE DE VEHICULE

Publication

EP 1098800 A1 (DE)

Application

EP 99938302 A

Priority

  • DE 19834193 A
  • EP 9905174 W

Abstract (en)

[origin: DE19834193C1] The invention relates to a master cylinder (10) for a hydraulic vehicle brake system comprising a housing (34) and a boring (36) which is arranged therein. A hollow cylindrical primary piston (38) which acts upon a pressure chamber (40) is guided in said boring in a sealing and axially displaceable manner. An axially displaceable, hollow cylindrical auxiliary piston (42) is accommodated in the primary piston (38). An actuating piston (46) which projects into said auxiliary piston can be actuated by an input element (24), is guided in the auxiliary piston (42) in a sealing and displaceable manner, and, at least during braking, is pretensioned away from the auxiliary piston by a spring. The actuating piston (46) comprises a first hydraulically active diameter (D1), and the auxiliary piston (42) comprises a second hydraulically active diameter (D2). The auxiliary piston (42) couples with the actuating piston (46) in a rigid manner after a determined distance against the spring-loaded pretension thereof is surpassed. In order to realize a brake assistance function, a shift piston (58) arranged in the primary piston (38). Said shift piston is pretensioned by a spring in the direction toward the pressure chamber (40) and can be axially displaced with regard to the auxiliary piston (42). The spring-loaded pretension of the shift piston (58) corresponds to a predetermined pressure level in the pressure chamber (40). After said pressure level is exceeded, the shift piston (58) moves with regard to the auxiliary piston (42) against the spring-loaded pretension, whereby a valve (68) closes the fluid connection between the second hydraulically active diameter (D2) of the auxiliary piston (42) and the pressure chamber (40).

IPC 1-7 (main, further and additional classification)

B60T 13/573; B60T 13/565

IPC 8 full level (invention and additional information)

B60T 8/00 (2006.01); B60T 8/32 (2006.01); B60T 13/565 (2006.01); B60T 13/573 (2006.01)

CPC (invention and additional information)

B60T 8/3275 (2013.01); B60T 13/565 (2013.01); B60T 13/573 (2013.01)

Citation (search report)

See references of WO 0006436A1

Designated contracting state (EPC)

AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

EPO simple patent family

DE 19834193 C1 19990930; EP 1098800 A1 20010516; JP 2002521273 A 20020716; US 2001004833 A1 20010628; WO 0006436 A1 20000210

INPADOC legal status


2003-05-02 [18W] APPLICATION WITHDRAWN

- Effective date: 20030306

2001-05-16 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 20010117

2001-05-16 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A1

- Designated State(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE