Patent · US Expired

Impact type clamping apparatus

US5366026A · kind A · utility

45Cited by
11References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 27, 1993
Grant dateNov 22, 1994
Priority date
Expiry dateAug 27, 2013

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB25B23/1405
  • WIPO fieldMachine tools
  • WIPO sectorMechanical engineering

Abstract

In an impact type clamping apparatus including a motor unit for generating a pulsatory driving torque, a main spindle driven by said pulsatory driving torque to rotate a fastening member, a detecting unit for detecting a pulsatory torque applied to the main spindle, a calculating circuit for calculating a clamping force in accordance with a peak value of the pulsatory torque, and a control unit for stopping the operation of said motor unit when the calculated clamping force exceeds a desired clamping force, said clamping force is calculated not only from the peak value of the pulsatory torque but also from an increasing coefficient which represents a relationship between the peak value of the pulsatory torque and an increment of the clamping force. The increasing coefficient is gradually decreased in accordance with the increase in the clamping force, so that the clamping force can be calculated very accurately and the fastening member can be clamped with an actual clamping force which is very close to the desired clamping force.

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