Patent GB-512015-A (GB)
Title: Improvements in or relating to chamfering machines for shaping the ends of gear teeth
IPC: B23F19/10
Filed: 1938-12-22
Abstract: 512,015. Chamfering toothed gears. CIMATOOL CO. Dec. 22, 1938, No. 37297. Convention date, Dec. 29, 1937. [Class 83 (iii)] A machine for chamfering the teeth of gears by means of a rotary cutter comprises means operated by a common driving member intermittently rotating the work carrier and for axially moving said carrier in timed relation to its rotational movements. In some cases the work may have uniform instead of intermittent rotation. The machine is duplex and comprises frame sections 11, 12 carrying similar work supports 14, 14<1> and similar cutter heads 13, 13<1>, the head 13 carrying a pencil type cutter 17 and the head 13' a hollow mill 17'. The cutter 17 is driven by a motor 22 and is supported in a housing 21 which is vertically adjustable between side walls of a slide 24 movable axially of the cutter along another slide 25 moving on the frame 12. Vertical adiustment of the housing is obtained by operation of a shaft 26 geared to three nuts 33 coacting with threaded posts secured to the housing. The housing is clamped after adjustment by bolts 41. Axial adjustment of the slide 24 is effected by a screw shaft 45. The slide 25 is moved to and from its working position by a hydraulic cylinder 55, the advanced working position of the cutter being determined by the engagement of the end of the cylinder with the piston. The work-support includes a slide 69 sliding on the frame along guides 71, The slide 68 carries a vertical pivot pin 66 on which the work housing is mounted so that it can be set over as shown at 14<1>, Fig. 1. The gear blank is mounted on an arbor 80 carried in bearings 90, 91 in a member 92. The arbor carries an abutment plate 82 having a positioning-finger 81, the work W being secured by a plate 87 on a rod 84 operated by a fluid-pressure cylinder 85. The arbor is driven from a motor through belt gearing, shaft 100, worm gearing 103, shaft 108, worm gearing 118, and spur gearing 96. The worm wheel 103 is adjustably secured to its shaft through a pin 113. The worm wheels 118, 119 are easily replaceable to vary the speed of the work arbor. The work is moved in an axial direction in timed relation with its rotation. For thus purpose the shaft 108 carries a cam 126 engaging a roller on a pivoted arm 145 acting through a slide block on a part 149 of the arbor support 92. The roller is kept against the cam by means of a spring 156 acting through a lever 152. The support 92 moves on guide surfaces 159 and a wedge member 161 may be adjusted by a screw to take up wear. To supply lubricant to the machine, an oil pump 168 is operated by an eccentric strap 182 on the shaft 108 and delivers into a supply line connected to branch passages such as 176, 177, 179 and 180. The cutter is first positioned by the fluid-pressure cylinder 85 and the work is then rotated and moved axially so that the cutter forms the tooth ends with the required chamfer, after which the cutter head is withdrawn and the work replaced. When a hollow mill is used the worm gearing 118 is replaced by cam gearing which holds the work stationary during the cutting operation and then quickly imparts an indexing movement thereto. The cam 126, is also replaced by one which causes the work to be fed axially while it is held against rotation and withdrawn while the work is indexed to the next tooTh.