Patent · US Expired

Heat sensitive locking device

US4442756A · kind A · utility

6Cited by
7References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 24, 1981
Grant dateApr 17, 1984
Priority date
Expiry dateAug 24, 2001

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T137/1819
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A temperature sensitive locking mechanism is provided for a fluid pressure actuator which will hold the shaft of the actuator in a spring compressing position until the occurrence of a pre-selected temperature in the vicinity of the actuator. Locking threads are provided on the exterior of the actuator, and a latching collet, having a plurality of peripherally spaced, internally threaded, latching arms cooperates with such threads and prevent movement of the actuator shaft by abutting a surface of a stop block which is in abutment with the actuator shaft. The radial faces of the threads are sufficiently angled so as to exert an outwardly directed camming force on the collet latching arms to permit the release of the latch under the axial forces produced by the spring bias on the actuator shaft. The collet latching arms are forcably retained in locked position by an encircling spring wire, the ends of which are connected by a fusible link. Expansion of the wire resulting from the link melting due to temperature increase causes the wire to un-coil and the above to occur.

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