Patent · US Expired

Door control device

US4937914A · kind A · utility

8Cited by
7References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 30, 1989
Grant dateJul 3, 1990
Priority date
Expiry dateMar 30, 2009

Classification

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

Abstract

The piston of a door control device is assembled from a channel and cups welded on to opposite ends of the channel. A valve assembly is mounted in one of the cups. Rollers extend between opposite sides of the channel and co-operate with teeth on a rotatable member to which a control arm is secured.

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