Patent · US Expired

Master cylinder piston with floating sealing ring recuperation valve

US4866938A · kind A · utility

2Cited by
14References
25Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 22, 1988
Grant dateSep 19, 1989
Priority date
Expiry dateJan 22, 2008

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB60T11/16
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

A hydraulic master cylinder piston carries a circumferential seal ring which allows recuperation flow valving. The floating seal has a reinforcing metal girdle which prevents radial expansion and axial crushing. The seal material resists extrusion and has an outer radius slightly greater than the radius of the circumferential girdle. A forward slotted bearing ring maintains the piston in alignment with the bore. During piston return, recuperation occurs through a path comprising the radial clearance between piston and floating seal ring and at least one slot or groove in the bearing ring. Upon full piston return, the seal is withdrawn from the master cylinder working chamber into a larger diameter bore communicating with the reservoir and thus allows relatively free make-up flow.

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