GB736494A - Improvements in machines for flame cutting gears, sprockets and like toothed members - Google Patents

Abstract

736,494. Dividing by fusion. DALIN, D. Nov. 22, 1951, No. 27457/51. Class 83 (4). A machine for flame-cutting gears, sprockets, &c., comprises a blank support, a cutting torch, means mounting the support and torch for relative motion along a path traversing the path of movement of a blank on the support, drive means to effect cyclical relative movement of the torch and support, further drive means to continuously move the blank support and synchronizing means connecting the two drive means so that teeth are cut in the blank. In an embodiment a machine comprises a table 6 on which are rails 12 forming tracks for rollers 10 on a carriage 9. Vertically rotating rollers on the carriage engage the insides of the rails 12 to ensure straight rolling for the carriage 9. Adjustably mounted in guides 19 on the carriage 9 is a bracket 14 with an upstanding bridge 21 on which is mounted a vertically adjustable oxy-acetylene torch 23 and valve gear 28. A slot 33 in the carriage 9 encloses a spindle 34 on which a blank 35 to be cut is secured. The carriage 9 is reciprocated on the rails 12 by a cam 43 on a shaft 44 acting through pantograph linkage 47. The linkage 47 comprises a lever 48 pivoted at 51 to the table 6 at one end and carrying a cam follower device at the other. The follower device comprises a pair of discs 54 carrying various sized rotatable followers and is arranged to be pegged to the lever 48 with a desired follower contacting the cam 43. A further lever 49 is pivoted to the side of the table remote from the pivot 51 and its other end is connected to a tension spring 61. The levers 48, 49 are connected by a link 50 adjustable on the levers. The linkage 47 is connected to the carriage 9 by a link 47<SP>1</SP>. A shaft 63 which drives the shaft 44 through worm gearing is driven from a motor 68 through gearing 67, belt 65 and a pulley 64 fixed to the shaft 63. A shaft 71 which drives the spindle 34 through worm gearing is driven from the shaft 63 through adjustable gearing A, BA, BC, C. The shafts 34 and 44 are thus driven synchronously. To obtain substantially constant relative speed between the cutting torch 23 and the blank 35 a device to accelerate the shafts 34, 44 when the carriage 9 is at the beginning and end of its stroke and to de-accelerate them in the middle of the stroke is provided. This comprises a two-lobe cam 86 fixed to the shaft 44 and operates through a lever 87 and rod 91 to adjust the gearing 67 and thus the speed of the drive shaft 63. A secondary support 37<SP>1</SP> for smaller gears is provided in which case the torch is attached to another lug 22 on the bridge 21. In operation the blank 35 is fixed to the shaft 34, the bracket 15 is fixed relatively to the carriage 9, the link 50 is adjusted on the levers 48, 49, a cam follower is brought against the cam 43 and the motor 68 is started. The blank 35 is rotated and the torch 23 is reciprocated relatively to the rails 12 to cut teeth in the blank 35. Teeth may be cut on the inner or outer periphery of a gear.