CH371319A - Machine intended for drilling hard materials - Google Patents

Description

  

  Machine intended for drilling hard materials The present invention relates to a machine intended for drilling hard materials according to the claim of the main patent, that is to say comprising a spindle carrying at its end a drill formed by a section of metal wire and a motor driving this spindle at high speed, said section forming part of a long metal wire extending inside the spindle, a clamp for axially holding the wire, a movable stopper capable of '' be placed in front of the drill and means exerting an axial action on the wire,

   the whole so that by bringing said stopper in the axis of the spindle and by opening the clamp the wire advances until its end comes into contact with the stopper which puts it back in length.



  This machine is characterized according to the invention in that the clamp comprises balls arranged symmetrically around the wire in a conical trough that the spindle presents, a clamping member forcing these balls against elastic return means between the walls of the cup and the surface of the wire, so as to clamp this wire and hold the latter in position, the clamp control device comprising means making it possible to release the balls from said member.



  The single figure of the drawing represents in section and by way of example an embodiment of a detail of the object of the invention.



  The drawing shows in section the lower end of a spindle 1 fixed to the headstock of a machine not shown but described in the main patent No 369002 and in which is mounted a clamp 2 intended to clamp a drill 3 in a determined position.



  The lower end of this spindle is sub-divided into two housings 4 and 5 by plates 6, 7 and 8 driven into corresponding housings. The plates 6 and 7 are of similar shape but of different diameter and each have a cylindrical guide 9.



  The plate 8 has in its central part a frustoconical recess 10 closed by a cap 11 fixed to this plate by embossing its edges. 12 is a cylindrical socket placed in the spindle, the bottom of which, in contact with the plate 7, has in its central part a frustoconical recess 13 identical to that of the plate 8.



  Balls 14 are placed in the recesses 10 and 13 and disposed symmetrically around the drill 3. Their diameter is greater than the smallest diameter of the recesses so as to be easily wedged between the surface of these recesses and the drill against springs 15 and 15a arranged on the cap 11 respectively on the plate 7.



       The force necessary to wedge the balls in the recesses 10 and 13 and to position the drill is delivered by a device comprising springs 16 and 16a arranged around the guides 9. These springs act on the bottom of intermediate bushings 17 and 17a arranged. on balls 14 and 14a.



  The guides 9, the plate 7 and the bushes 17 and 17a are crossed symmetrically by cylindrical openings of identical axis to the spindle, all of these openings forming a continuous passage for the drill 3.



  All the elements contained in the head of the spindle are held in place by a stopper 18 placed above the plate 6 and whose axial positioning is ensured by a bayonet 19 engaged in an annular groove 20 of the spindle.



  The spindle also has a shoulder 21 against which rests a spring 22 stretched between this shoulder and a sleeve 23 sliding on the spindle. This sleeve is flared at its upper part so as to provide a bearing surface, for example for a tool intended to push the sleeve upwards against the spring 22. Rods 24 are fixed to this sleeve perpendicular to its surface and extend inside openings 25 made in the pin and openings 26 made on the side surface of the sockets 17 and 17a.



  By moving the sleeve upwards, these rods raise the bushes 17 and 17a in their course so as to release the balls 13 and 13a from the action of the springs 16 and 16a. These balls are then driven upwards from the recesses 10 and 13 by the springs 15 and 15a thus freeing the drill from their grip, which drill, under the action of means, recovers in length by abutting against an advanced stop for this purpose.

 

Claims (1)

CLAIM Machine intended for drilling hard materials comprising a spindle leaving at its end a drill formed by a section of metal wire and a motor driving this spindle at high speed, said section forming part of a long metal wire extending to the end. 'inside the spindle, a gripper for axially holding the wire, a device for controlling this gripper, a movable stop capable of being placed in front of the drill, and means exerting an axial action on the wire, all in such a way that by bringing said stopper in the axis of the spindle and turning the clamp, the wire advances until its end comes into contact with the stopper, which puts it back in length, characterized in that the clamp comprises balls arranged symmetrically around the wire in at least one frustoconical cup presented by the spindle, a clamping device forcing these balls, against elastic return means, (15, 15a) between the walls of the cup and the surface of the wire so as to clamp this wire and to hold the latter in position, the clamp control device comprising means making it possible to release the balls from the action of said member. SUB-CLAIMS 1. Machine according to claim, characterized in that said clamping device comprises a bush resting on the balls and elastic means acting on the bush. 2. Machine according to claim and sub-claim 1, characterized in that the gripper control device comprises a cylindrical sleeve slidable on the spindle against the return means, this sleeve having rods whose end is engaged in the corresponding housings of the socket. 3. Machine according to claim, characterized in that the clamp clamps the wire in at least two different points of this wire.