Patent · US Expired

Security locking system

US4113291A · kind A · utility

38Cited by
12References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 14, 1977
Grant dateSep 12, 1978
Priority date
Expiry dateMar 14, 1997

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T292/31
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A combination door handle and security locking system in which the conventional door latch is actuated by turning the five-sided head of an operating shaft with a special socket wrench. A hinge plate having a slot for a padlock bail and a flat index tab on its inner surface is rotated to cover the operating shaft head. The tab must fit against one side of the operating shaft head to allow the hinge plate to be fully closed so that a padlock can be inserted in the bail. The latching mechanism is designed so that this tab will fit against one side of the operating head when the door is fully latched, to thus prevent rotation of the latching mechanism. The free end of the hinge plate has an offset portion which serves both as a sleet hood for the padlock and as a handle for opening the door.

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