GB783675A - Improvements in or relating to apparatus for indicating the surface finish of the face of gear teeth - Google Patents

Abstract

783,675. Gauging surface-roughness. BRITISH PETROLEUM CO., Ltd., and BARCLAY, I. DUFF-. Jan. 17, 1956, No. 1560/56. Class 106 (2). A roughness tester, particularly for gear tooth surfaces, is held at a variable radius by a pivoted arm and moved thereby along an arc about the pivot of the arm, mechanism being provided to cause the tester to traverse the surface at a controlled speed. A swinging horizontal arm 1 mounted on a vertical shaft 2 is adjustable vertically by fine-adjusting screw 5 co-operating with a clamp 4 and is given oscillatory movements by partial rotation of shaft 2 from a hand wheel 15 through an eccentric 9 and actuating lever 8. A slider 16 has an aperture containing a nut 17 loaded by springs 19, 20 on a screw 18 by means of which the slider 16 may be horizontally adjusted along the arm 1 to which it may be locked by plate 21 and screw 22. The pick-up head of the surface-roughness tester is held in a clamp at the lower, non-vertical end of an angular drop-arm 26 whose upper vertical portion is pivoted by a screw 29 to a lever 24 in turn pivoted at 23 to the slider 16. The lever 24 may be swung horizontally about the pivot 23 by a screw 25 and the lower-end of the drop arm may be moved in an arc by pivoting the drop-arm about the pivot 29 by means of a screw 28 co-operating with a pivoted lug 27. The gear to be tested is placed on a spigot 36 provided with a register 37 to fit the bore of the gear, the angle of the spigot being such that the root of the tooth under test will lie in a plane parallel to that of the traverse arc of the roughness tester. The gear is correctly located by means of a member 33 having a cross-section the same as the tooth gap and mounted for movement in a T-slot machined in a quadrant 31 at a radius corresponding to the mean radius of the ring-gear tooth gap. The depth of penetration of the member 33 into the gap is maintained constant for successive teeth by a stop 34. After setting, the gear is clamped in position by means of a clamp 38, washer 39 and nut 40, the roughness tester is adjusted into gauging position and then traversed over the tooth surface by rotating the wheel 15.