Patent · US Expired

Entry lock

US3955322A · kind A · utility

9Cited by
7References
4Claims
0Family size

Inventor

Key dates

Filing dateJul 2, 1973
Grant dateMay 11, 1976
Priority date
Expiry dateJul 2, 1993

Classification

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

Abstract

An entry lock for controlled ingress and egress for confined areas such as live animal growing and holding pens is disclosed. The entry lock includes a door opening, first and second doors spaced apart from each other and adapted to swing together about a common axis positioned at a side of the door opening into alternate register with the door opening, and a third door hingedly attached approximate the outside edge of the first or second door and latched approximate the outside edge of the other of the first or second doors forming a confined area or enclosure large enough to accomodate a human. The enclosure is formed by the third door in conjunction with the first and second doors. The structure prevents ingress and egress through the door opening when the first and second doors are swung together into alternate register with the door opening.

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