Patent · US Expired

Apparatus and method of determining torque, presenting digital torque readout and automatic cycling and termination of wrench operation

US4864903A · kind A · utility

22Cited by
3References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 29, 1988
Grant dateSep 12, 1989
Priority date
Expiry dateJun 29, 2008

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG05D17/02
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

Apparatus and a method are presented for determining the torque load applied to a fastening element by a fluid powered wrench, and displaying a digital readout of the torque. The operating pressure of the wrench, after compensation for the temperature of the pressure transducer, is converted to a torque measurement by a programmed microprocessor and the torque value is displayed on a digital readout. The system is useable with and adjusts for wrenches of several sizes by an input selector switch connected to the microprocessor. Apparatus and method are also presented for automatic cycling of a ratcheting hydraulic powered wrench and automatic termination of the tightening process when a predetermined torque has been delivered to the fastening element.

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