Motor vehicle anti-lock hydraulic brake system reciprocating piston pump

• Main Authors: EHRLICH, JOACHIM, 87437 KEMPTEN, DE, HELLEBRANDT, MICHAEL, 87545 BURGBERG, DE, WEH, ANDREAS, 87471 DURACH, DE, SCHLITZKUS, MICHAEL, 87463 DIETMANNSRIED, DE, SIEGEL, HEINZ, 70435 STUTTGART, DE, FLUCK, TOBIAS, 87509 IMMENSTADT, DE, MERKLEIN, DIETER, 87435 KEMPTEN, DE
• Format: Patent
• Language: English; German
• Published: 04.02.1999
• Edition: 6
• Subjects: ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; BLASTING; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; HEATING; LIGHTING; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OFVEHICLES; POSITIVE DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS; TRANSPORTING; VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES; VEHICLES IN GENERAL; WEAPONS

The piston (40) is of composite construction and has an e.g. metal or ceramic core (42), located in an injection-moulded plastic sleeve (44) with a peripheral lip (82) which bears against the cylinder wall and provides a seal. The pump (12) has a piston which reciprocates in a bushing (10) and is driven by an eccentric (50), which runs against the exposed end (46) of the core. The core is made by a process which generates no swarf, e.g. extrusion or cold forming. The sleeve has an integral non-return valve (62), and can have an internal shoulder to retain the core. A tapered bung (84) can be inserted between the piston return spring (48) and the tapered inner wall (86) of the lip to press the lip against the bushing. Several alternative arrangements are described.