Patent · US Expired

Piston pump with rolling membrane

US4773305A · kind A · utility

19Cited by
8References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 19, 1987
Grant dateSep 27, 1988
Priority date
Expiry dateJun 19, 2007

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S277/91
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A piston pump having a flexible rolling membrane which seals the piston from the cylinder wherein the piston is designed to include an upper portion which is spaced inwardly from the cylinder wall so as to form a cavity which communicates through channels and seals carried by the lower portion of the piston in such a manner that the lower portion of the flexible membrane is depressed between the upper portion of the piston face and the cylinder walls during an intake stroke as the cavity is subjected to a decreased pressure and which decreased pressure is removed from the membrane during a discharge stroke of the piston. In the preferred embodiment, the membrane is secured to the upper surface of the piston by a cup-shaped element which protects the membrane from materials within the cylinder.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.