GB859341A - Improvements in or relating to drives for the electrode in electro-erosively operating machine tools - Google Patents

Abstract

859,341. Removing metal by electro-erosion. AGIE AKTIENGESELLSCHAFT FUR INDUSTRIELLE ELEKTRONIK. July 4, 1958 [July 5, 1957], No. 21561/58. Class 83 (4). An electro-erosion apparatus has an electrode 4 connected to a rotatable driving shaft 7 and fed axially by means 60, Fig. 3, meshing with a rotatable threaded spindle 8, the shaft 7 and spindle 8 being selectively connectible together by change-speed gearing 27 and also to either a first driving source 14 or a second driving source 43. The apparatus comprises a yoke 1 mounted for vertical and lateral displacement. The electrode 4 which may consist of a number of grinding discs 4a, Fig. 3, is adjustably clamped in a holder 57 formed on the shaft 7 which is rotatably mounted within a sleeve 50 connected by bridge 6 with a second parallel sleeve 60; both sleeves are mounted for axial movement on ball-bearings 52, 62. Shaft 7 carries a clutch member 9 which may be selectively coupled to a pulley 10a for high-speed driving by a motor 14 or to a gear 18. Spindle 8 carries a clutch member 10 which may be selectively coupled to a pulley 15 for drive by the motor 14 or to a gear 19. Gears 18, 19 engage intermediate gear 20 and are driven through gears 21, 23, 24 from shaft 43. The latter is connected to the planet carrier 42, Fig. 2, of a differential gear whose sun gears 36, 37 are driven respectively by a variable-speed motor 30, which may be controlled automatically by conditions in the spark gap, and a constant or variable speed motor 31 whereby the speed and direction of rotation of shaft 43 may be changed by varying the speed of one or both motors 30, 31. Shafts 7, 8 also have extensions 25, 26 connected through clutches 100, 101 with a change-speed gearbox 27 whereby the shafts 7, 8 may be rotated together at a constant ratio for co-ordinating the electrode rotation and the feed, especially when cutting threads or spiral grooves. The electrode may be fed without being rotated, especially when used for cutting dies, and is then locked by a clamping means 102 which is itself mounted for enabling adjustment of the electrode about its axis.