Patent · US Expired

Locking device

US3977222A · kind A · utility

7Cited by
5References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 22, 1975
Grant dateAug 31, 1976
Priority date
Expiry dateAug 22, 1995

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T70/7424
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

An improvement in a locking device of the type having a series of reference combinations arranged serially upon a tape. A combination is entered into the system by a set of push buttons. The combination entered is compared with the reference combination. If both combinations are complementary, the system can be unlocked. The improvement prevents the unauthorized ascertainment of the combination needed to release the device. An isolation or restraining bar acts as a buffer between an internal gate and a set of tumbler levers. When an actuator knob is turned to unlock the system, the tumbler levers normally will engage with the gate when the combination push buttons are not set to the proper combination. The combination then becomes ascertainable, because the tumbler levers that require actuation, transmit movement to the push buttons when contacted by the gate. The isolation or restraining bar prevents the gate from engaging with the tumbler bars, thus preventing unauthorized ascertainment of the combination required to release the locking device.

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