Patent · US Expired

Automatic fastening machine with brushless electric motor for drill spindle drive

US4720897A · kind A · utility

21Cited by
11References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 30, 1985
Grant dateJan 26, 1988
Priority date
Expiry dateAug 30, 2005

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T409/309352
  • WIPO fieldMachine tools
  • WIPO sectorMechanical engineering

Abstract

In an automatic fastening machine comprising a frame, drilling assembly carried by the frame for drilling a fastener receiving hole in a workpiece and an arrangement carried by the frame for installing a fastener in the hole drilled in the workpiece, the drilling assembly comprising a drill spindle having an axis of rotation and a drilling tool at one end thereof and rotatably mounted in a ram movable on the machine frame toward and away from the workpiece, the improvement of a brushless synchronous a.c. servomotor including an output shaft having an axis of rotation and an arrangement for connecting the motor directly to the drill spindle with the axis of rotation of the motor shaft coincident with the axis of rotation of the drill spindle. There is also provided a fan on the frame and positioned to direct cooling air onto the motor. There is further provided a heat sensor embedded in the motor winding and a readout operatively connected to the heat sensor for providing an indication of motor winding temperature.

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