The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 29, 1983
Filed:
Jan. 12, 1982
Rainer Sudbeck, Duisburg, DE;
Pierburg GmbH & Co. KG, Neuss, DE;
Abstract
A piston pump, for use for example for operating auxiliary mechanisms in motor vehicles, has a piston 1 which is reciprocated in a cylinder 2 by an eccentric 20 and a return spring 18. The cylinder 2 has an outlet valve 23, and inlet openings 4 in its side wall. Instead of moving the piston 1 so far downwards in the suction stroke of the pump that the piston head 6 L is below the inlet openings 4 to allow fluid to flow into the pump chamber 10, the piston is provided with a peripheral groove 13 and openings 11 in its side wall. The openings 11 lead to a recess 17 in the piston head and hence to the pump chamber 10. The groove 13 moves into communication with the inlet openings 4 at two separate times in each to and fro movement of the piston, that is in each pumping cycle, so that the fluid being pumped can only flow into the pump chamber from the inlet openings 4 during these two times. This arrangement provides a more accurate control of the pump output in dependence upon its speed than does the prior arrangement in which the pump chamber 10 is in direct communication with the inlet openings 4 when the piston is at bottom dead-center.