Patent GB-190301959-A (GB)
Title: Improvements in and connected with Machines for Cutting Gear Teeth.
Inventor: JUSTICE PHILIP MIDDLETON
Filed: 1903-01-27
Granted: 1903-04-09
Abstract: 1959. Justice, P. M., [Soc. des Etablissements Malicet et Blin]. Jan. 27. Milling; planing; dividing-apparatus. - Relates to improvements in the type of gear - cutting machine described in Specification No. 23,968, A.D. 1898, which states that the machine may be used for grinding the teeth of wheels. Only one cam shaft 27 is used, which is driven directly from a worm shaft, driven as before by chain gearing from the pulley shaft 21. The cam 28 for raising the carrier 29 supporting the hollow work spindle 42 is placed under the centre of gravity of the carrier, and engages a block 30 on which is a track 33 for a roller on the carrier. In place of a vertical adjustment of the carrier, the cutter spindle 112 and its driving-mechanism are carried by a bracket, vertically adjustable by a screw. The cutter 111 is adjusted in the direction of its axis as described in the prior Specification. The work spindle is mounted in bearings 35, 36 on the carrier, and has an arbor 41 to which it is clamped by a ring 43, the front end of the arbor being supported by a steady rest 38. One bearing has a friction block 37 to check the movement of the spindle during indexing. The blank 39 is placed in position by unclamping and partially withdrawing the arbor, and is held against a shoulder 45 on the arbor by spacing-collars 47 and a nut 46. The pattern consists of a single tooth 40 adjustable in a radial slot 53 in a segment 49 secured to a hub 48 on the work spindle, so as to be adjustable round the apex of the blank, thus allowing one pattern to be used for different sizes of teeth and different bevel angles. The index-wheel 54, with an adjustable notched ring 56, is mounted on the work spindle which is locked to the pattern during cutting by a spring latch 58 on an arm 57 on the hub 48 engaging the index-wheel. The latch is disengaged as the carrier descends by the engagement of a pin 63, on a slide 62 to which the latch is connected, with a fixed stop 64. The pivotal connection between the latch and the slide allows the index-ring 56 to be easily changed. The weight 66, for imparting a rotative tendency to the work spindle as the side of the tooth is being finisbed, is carried by an arm which can be turned to rest on one of two stops as in the prior Specification, but the weight is supported, except during the side cutting of the tooth, by a horizontal arm 73 pivoted on a plunger 72 raised by a cam 71, so that the position at which the weight is left unsupported may be varied without changing the cam by tilting the arm. The mechanism for imparting a horizontal oscillation to the carrier and work consists of a heavy vertical slide 78 controlled by a cam 77 and connected by links 79 to the slotted ends 81, Fig. 4, of bell-crank levers 80, which may be separately connected by links 82 and ball projections 84 to the carrier, to impart to it an oscillation to suit the side of the tooth being cut, the amount being varied by adjusting the pivots of the links 79 in the ends 81 of the levers 80. The index-wheel is actuated by a set of differentially-arranged pawls 96, with which engage ratchet teeth on the wheel when the carrier is in its lowest position. The pawls are carried by a block 94 moving in a segmental track 95 and operated by links and levers from a cam 86, the traverse of the block being adjustable to suit the index-ring in use. The guide 97, with which the pattern cooperates, is arranged as in the former machine, but is mounted on an arm 98, which is radially and angularly adjustable with respect to one of the clamping-bolts 99 to suit the position of the pattern. The end of the arm is formed as a split clamp to receive a stud 104, with a head in which the guide can move in the direction of its length, the guide being balanced by a spring and provided with antifriction rollers, so that it may be slightly drawn out as it is moved round the pattern to avoid rubbing on and consequent wear of the pattern. A stop-motion, for stopping the machine when one side of every tooth has been cut, consists of a ratchet-wheel 126 operated one tooth at each revolution of the cam shaft 27 by a pin 121 and detent 125 and provided with a pin 128 for operating a lever 130 connected to the belt shifter. The carrier may be raised by hand to enable the blank to be accurately set, the raising being effected by turning a handle 131 connected by gearing to a cam 134 bearing on the upper end of a rod 135 pivoted to a lever 136 which engages the lower end of the carrier spindle. The operation of the machine is substantially the same as that of the former machine.