ES336154A1 - Improvements in or relating to portable screw-threading die driving machines - Google Patents

Abstract

A portable screwing die head comprises a tooldriving member 13, Fig. 2, in which a die or an extension die-holder is located, drive input spindles 14-17, Figs. 1, 3, for driving member 13 at different speeds via a worm and wheel drive 18, 19 and a clamp having arms 97, 98, Fig. 4, for clamping the workpiece. The drive is supplied to any of the socket-ends 23-27 of spindles 14-17, manually, or by a portable electric drill, and each spindle 15-17 transmits the drive to spindle 14 by gearing. Member 13 has an internal cross-section as shown in either Fig. 3 or Fig. 5, and is held in an aluminium alloy frame 11 by a wire-race ball-bearing 12, Fig. 2. The arms 97, 98, Fig. 4, have jaws 107, 108, for clamping a pipe 59 to be screwed, and are pivoted about a pin 56 by a screw 99 having opposite hand screw threads 100, 101 actuated by a handle 106. A nylon brake band 73, Fig. 1, is wrapped on pin 56 and acts on a nut 60 screwed on to member 13. The die head is connected to a base 86, Fig. 10, by legs 84, 85. A method of plotting the shape of jaws 107, 108, is described. The arms 97, 98 may pivot about separate pivots (561), (5611), Fig. 14 (not shown), or the pivots may be replaced by cam faces (134), (135), Fig. 14A (not shown). Reference has been directed by the Comptroller to Specifications 998,001, 998,002 and 998,003.