Patent · US Expired

Drop-bolt door lock assembly

US4688409A · kind A · utility

32Cited by
14References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 6, 1986
Grant dateAug 25, 1987
Priority date
Expiry dateJun 6, 2006

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T70/8568
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A high security drop-bolt lock assembly for a door includes a cylinder lock carried by a guard plate positionable on the outside of the door with the cylinder lock within the door, and a drop-bolt assembly on the inside of the door. The drop-bolt assembly is connected to protected studs extending from the guard plate to make a strong unitary construction extremely difficult to defeat and protecting the cylinder lock behind the guard plate and within the door.

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