Patent GB-874048-A (GB)
Title: Improvements relating to testers for bevel gears and similar toothed parts
Filed: 1959-06-12
Abstract: 874,048. Gauging toothed gears. GLEASON WORKS. June 12, 1959 [June 17, 1958], No. 20244/59. Class 106 (2). A tester for bevel gears G comprises a frame 21, a spindle 22 for the test part G rotatable in the frame, indexing means 37 and 39 (Fig. 4, not shown), for periodically advancing the spindle 22 to effect approximate tooth-to-tooth indexing of the gear G and then freeing the spindle for rotation, a positioning finger 61 adapted to complete the indexing by moving into engagement with a tooth space of the gear G, and means for effecting movement of the finger 61 in time with the indexing movement. A motor 45 drives a shaft 48 and, through bevel gearing 49 and a vertical shaft (not shown), an arm 37 connected to an adjustable crank-pin assembly on this latter shaft and to a further shaft 35, thus causing oscillatory movement of the shaft 35 during rotation of the shaft 48. The shaft 35 is connected to the spindle 22 by an electromagnetic clutch 34, which is arranged to engage during forward movement of the shaft 35 and disengage during reverse movement. Thus the gear G is rotated through approximately one tooth spacing during a half-revolution of the shaft 48 and is free to turn during the second half of the revolution. Adjustment of the position of the crank-pin allows this indexing movement to approximate to the tooth spacing of the gear G. The finger 61 is supported by a head 62 universally adjustably mounted on a rod 63 slidable vertically in the frame 21 under the action of a cam 66. When the clutch 34 is released, the rod 63 which has previously been raised by the action of the cam 66 falls under gravity following the cam until stopped by a collar 70 resting on a shoulder 80 provided on the frame 21. This movement allows the finger 61 to drop into the gap between two teeth of the gear G, being urged against one face a by a spring-supported contact 101, thus completing the indexing movement. A probe 103 is pivotally supported in the head 62 and variations in the distance between corresponding faces a, a<SP>1</SP> of adjacent teeth which cause movement of this probe can be read from a dial indicator (not shown). This probe can be adjusted along the line 11-11 (Fig. 10) so that the indicator reads zero when the tooth-to-tooth distance is correct. In order to measure the other faces of the gear teeth the finger 61 is pivotable about its axis, means being provided to lock it in any required position. A second probe 105 having a spherical head and only able to move between guides 128 and vertically, operates a second dial indicator 104 to show differences in composite eccentricity of the gear teeth when it rests between two teeth with its surface touching both of them. Means are also provided for recording the readings of the indicators, the recording pens being operated by cams 137, 138 after the gear has been indexed, a short period being allowed for settlement of the parts. The operation proceeds automatically, alternately indexing the gear and recording the measurements until a counter, operated by a cam 139 on the shaft 48, stops the machine when all the teeth have been measured.