Patent GB-508638-A (GB)
Title: Improvements in or relating to machine tools for example shapers and gear shapers
IPC: B23F5/16
Filed: 1938-10-29
Abstract: 508,638. Gear-cutting. SYKES, W. E. Oct. 29, 1938, No. 31328. [Class 83 (iii)] A gear-shaper or other machine tool having a tool-holder which reciprocates in a cutterhead which is itself movable bodily in fixed guides to relieve the tool on its return strokes, has the tool-holder pivoted at one end to connecting-rod which can pivot about its other end in the direction of the cutter-head movement. The frame 30 and pedestal 31 are of narrow construction to facilitate the arrangement and supervision of a battery of machines and the pedestal is closed at the base by a door which gives access to the timing-gears. A gear housing at the head of the machine encloses a driving shaft 40 driven by V-belts from a motor 44. The shaft 40 is connected by bevel gearing to a shaft 53a geared to a crank shaft 83 carrying an adjustable crank-pin 88 having roller bearings for the end of a connecting-rod 90. The shaft 40 is also connected through a clutch 59, operable from an external handle 75, to a shaft 58a which operates the generating rotations of the, cutter and blank and the blank in-feed. The lower end of the-rod 90 is bifurcated to receive a cross-pin 98 carrying an eccentric 99 having a bearing in the head of a .stud 97, the eccentric being rotatable in order to adjust the stud. A guide 100 rigidly secured at 105 to the cutter spindle 104, receives the outer races 'of multiple ballbearings 106 the inner races being secured to the stem 107 of the stud 97. The spindle 104 is supported in a bearing 112 in the head 113 carried by a bracket secured to'the pedestal. A bushing 115 secured to the head is spaced from the guide 100 by a flanged sleeve 116 which is secured to the hub of the worm-wheel 120 by which generating rotation is imparted to the work, the guide rotating around the stud 107 without interfering with the axial movement imparted by the stud. Two-part keys 121 are secured to the sleeve 116 and engage key-ways in the guide 100. These keyways may be helical and coact with corresponding keys when helical gears are to be cut. The worm-wheel 120 is driven by a worm on a shaft 126 connected through a gear 158 shaft 157, change gears 156 and bevel gears 154 to the shaft 58a. The bracket 114 has a box-shaped bearing for an extension 135 of the cutter-head. A cam member 140 has bearings in the sides of this extension and is engaged by a cam 145 on a shaft driven from the main shaft 40. The cam 145 makes one rotation for each rotation of the crankshaft. During the cutting stroke springs move the cam to the right and move the cutter head outwards to operative position against a stop 151 but for the return stroke a rise on the cam moves the cam-bar to the left and withdraws the cutter-head from the work to relieve the cutter. A branch train from the shaft 157 is connected through change-gears 156a and gear 163 to a work-driving shaft 150 carrying a splined worm 174 engaging a wormwheel 175 on the work-spindle 180 carrying a table 177 on which the work is mounted. Alternatively the blanks may be mounted on an arbor 179. The work-spindle is mounted on a saddle which may be fed towards the tools in the manner described in Specification 508,639. The upper end of the work may be supported on a tailstock similar to that described in the above-mentioned Specification. The cutter may consist of two aligned sections 280, 281 the stroke being somewhat longer than the distance between the sections.