Patent · US Expired

Hydraulic door closer construction

US4394787A · kind A · utility

15Cited by
14References
5Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 27, 1978
Grant dateJul 26, 1983
Priority date
Expiry dateJul 27, 1998

Classification

  • Technology area (CPC E)Fixed Constructions
  • CPC primaryE05Y2900/132
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A hydraulic door closer is provided with a fluid seal for its output shaft, the seal comprising multiple O-rings disposed side-by-side in an elongated annular chamber.

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