Patent GB-613262-A (GB)
Title: Machine for finish cutting gear teeth and analogous curved elements
IPC: B23F21/28
Filed: 1946-06-13
Abstract: 613,262. Gear-cutting. FELLOWS GEAR SHAPER CO. June 13, 1946, No. 17796. Convention date, July 25, 1945. [Class 83 (iii)] [Also in Group XXXIV] A machine for cutting the faces of gear teeth &c. comprises a reciprocating cutter having a cutting-edge transverse to the directions of its reciprocative movement, means for supporting and rolling a work-piece along a plane which is transverse to the path of said cutting-edge and means for adjusting the cutter so as to locate its path at various inclinations to the rolling plane. The cutter c, Fig. 11, may have a crenelated cutting-edge b for finishing gear shaving cutters or a straight cutting edge for use with plain or helical spur gears. The cutter-head 10, Fig. 9, is pivotally mounted on a ram 11 which is reciprocated by an adjustable lever arm 14, Fig. 1, actuated by an adjustable connecting-rod 19 driven by an adjustable crank 20 on an independently driven shaft. The cutter c, Fig. 9, is mounted on a block 96 by means of a bolt 95 passing through a slot 119. The block 96 is adjustably mounted on the cylindrical surface 97 of a table 98 rotatable about a pivot 103 by a worm 108. The pivot 103 is carried on a base 102 which provides a circular bearing for the table 98 by means of clamp shoes 115 mounted in guides in the head 10. The ram 11 reciprocates in a housing 12, Fig. 1, which is angularly adjustable on circular guides 84 by a screw 91. The axes of the guides 84 and of the cylindrical surfaces of the blocks 96 and 102 are parallel to the rolling-plane, thus providing means in conjunction with the pivot 103, for adjusting the cutter to provide clearance at the cutting- edge and to accommodate the edge of the cutter to helical teeth of all practical helix angles. To provide for work-pieces of different diameters the housing 12 is adjustable longitudinally by a rack and pinion. The head 10, Figs. 5, 9, is provided at its lower end with a cam surface 133 which is pressed by a spring-plunger 136 against a wedge block 134 carried on a sliding rod 137 which is gripped frictionally at its lower end by spring-pressed, recessed blocks 139. Thus, on the upward stroke of the plunger, the cutter head is forced against a shoulder 141 and, on the downward stroke, the plunger 136 is urged forward to swing the head and relieve the cutter. The work-piece W is mounted on a shaft 28 rotating in bearings 29, 30 in a carriage 31 which is reciprocated along guides 32 by means of a screw 45. The screw 45 is rotated by a feed motor 35, Fig. 12, driving a worm-wheel 39 which is rotatably mounted on a shaft 40 and which carries a clutch plate 41 meshing with a similar plate 42 splined on the shaft 40, thus rotating a pinion 43, crown wheel 44 and hence the screw 45. At the end of the feed-stroke a dog 163, Fig. 1, on the carriage trips a switch 160 on the bed which cuts out the motor 35, disengages the clutch 42 by a solenoid 62 and lever arms 64 and closes the circuit of a motor 46 which drives the shaft 40 direct in a direction to reverse the carriage. At the end of the return stroke a limit switch 161 is operated and the feed motor is again set in operation, after a suitable interval to allow for indexing the work. The shaft 40 also rotates the workpiece W through the gear train 50, 51, 52, 53, 55, 57, 59, 60 and a worm 48 and worm-wheel 49. The work is indexed manually by a plunger 56 mounted on the wheel 55 which engages a dividing-head 54 carried on the wheel 53. The gears 50-53 may be changed so that the speed of the worm 48 may be adjusted when the pitch-circles of the wheel 49 and work-piece differ. The carriage may be manually adjusted by a shaft 72 carrying a pinion 73 which is pushed into engagement with teeth on the periphery of the crown-wheel 44. Adjustments for wear. The screw 45, Fig. 7, runs in two nuts, one of which, 142, is fixed, and the other, 143, may be rotated and clamped to take up slackness. The shaft 28 is forced against its bearing 29 by means of a torque shoe 147 which is pressed against the shaft by a spring 156 bearing on an arm 151 (see Group XXXIV). The worm 48 is carried in a bearing bracket 481 which may be adjusted vertically to take up back-lash in the wheel 49.