Patent GB-546569-A (GB)
Title: Improvements in or relating to machines for testing the curves of gear tooth faces and other machine elements or parts having surfaces of involute or other curvature
Filed: 1941-03-26
Abstract: 546,569. Gauging toothed gears &c. MILLER, E. W. March 26, 1941, No. 4083. Addition to 527,518. [Class 106 (ii)] Comprises a carriage support or table, a rotary work support, drive and feeler slides mounted on the table guided for movement in paths tangenital to circles concentric with the axis of the work support, and a ratio lever having arms abutting with the drive slide and feeler slide respectively, distinguished in that force-applying means are provided to maintain engagement between the feeler slide and lever and between the lever and drive slide. The support or table 11 has an upright rotatable spindle 12 accommodating a tapered centre 13 to co-operate with a centre 18 in alignment therewith carried by a bar 17 guided at 16 in a port 15 carried by the table. The slide bar 17 is formed as a rack pressed down by a pinion 20 on the axis of which is a weighted arm 22. The spindle 12 is adjusted without rotation in a sleeve 23 by a screw 27 turned by a handwheel 28. A feeler 29 adjustable vertically by rack and pinion 33, 34 is carried on a feeler slide 31. The device may be used for testing gear clusters used in automobile transmissions and by adjusting the centres and the feeler any of the gears in the groups shown may be tested. The gear may be driven by a dog 37 or this may not be necessary owing to the pressure of the weighted lever. The feeler 29 is shaped as in Fig. 10 and may be rotated about its axis and secured by a set screw so that either side of a tooth may be felt. Either of the arms 40, 41 on a collar at the base of the rack 32 may engage the plunger of the dial gauge. The spindle 12 is rotated from a handwheel 48 by worm gear 86, 44, 43. The gear 43 meshes also with a worm 49 supported by the drive slide 50 diametrically opposite the feeler slide 31. A ratio lever 51 is pivotally mounted on the table so as to transmit motion from the slide 50 to slide 31 when the former is moved to the left, Fig. 3. The lever 51 is bolted to a head on a shaft 52 parallel to the axis of the spindle 12, one arm 51a engaging a pin 54 on slide 50 and the other 51b, a pin 55 on the feeler slide. The pins are held with one side only against the lever by a weight 57 suspended by a cord 58 attached to slide 31. Normally the worm 49 acts as a rack and is held from rotation by a screw and slot clamp which allows of turning the worm to take up wear. The bracket carrying the pin 55 is adjustable on the feeler carriage in the direction of its movement. The axis of the shaft 52 is located at a distance from the axis of pin 54 equal to the radius of the pitch circle on which the worm wheel 43 coacts with the worm 49. Setting of the feeler at known distances from the axis of the worm spindle is accomplished by gauge blocks 72 between a shoulder 73 on the feeler slide base 30a and a pin 74 set on the base of the post 15. In order to ascertain the points at which errors occur, a gauge block 75 of correct thickness is placed between a pin 76 on the base and a shoulder 77 on the carriage 31. An index 78 carried by the work spindle co-operates with a scale 79 to measure the roll of the test piece. A projection on main slide 50 travels between adjustable stops to secure the same starting point for movement of all curves being the same relationship to the same base circle.