GB172690A - Improvements in or relating to machines for measuring, gauging, or the like - Google Patents

Abstract

172,690. Wickman, A. E. Aug. 12, 1920. Surface and outline gauges.-In an apparatus for gauging gear wheels &c., the wheel is clamped ori a rotary mandrel 4 and its teeth are felt in succession by a spherical-ended contact-member 1 connected with a dial-gauge 5. The member 1 is secured to a blade spring mounting 2, an extension of which bears against the plunger 6 of the dial gauge. Also attached to the mounting is one end of a lever 19 pivoted at 20 and provided at its other ends with a damping-vane 22 immersed in viscous liquid. Parallel with this lever is a second similarly-damped multiplying lever connected with it by a pointed strut 26 and a pair of tension springs attached to stirrups 28 pivotally bearing on the levers. One end of the second lever is formed as a pointer to show on a scale and lateral displacement of the contact-member. The contact-member is readilv removable for replacement by one of different shape, and during such operation the lever 19 may be held stationary by a plunger 50 raised to engage a hole 49 by manipulation of a lever 51. The above-mentioned parts are mounted on a sliding frame moved by a rack and pinion so as to adjust the position of the contact-member with respect to the work. The mandrel is rotated by means of a worm and worm-wheel 33. The worm is carried by a shaft 34 turned by means of a micrometer head 35 with removable scale, and is adjustable laterally to take up wear by the provision of inclined surfaces between its supporting frame 41 and the base on which this frame is slidably movable. To carry out a test, the wheel is clamped on the mandrel and the parts adjusted so that the contact-member bears evenly between and against neighbouring teeth, this being shown by a zero reading of the multiplying lever. The dial gauge is now read and the mandrel is rotated to bring the next tooth space into position to be felt, the correctness of such position being indicated again by a nil reading of the lever. Any variation in radius of the pitch circle will now be indicated by the dial gauge, and the pitch will also be given by the micrometer head 35. In a modification, Fig. 7, adapted for testing bevel and helical gears, the mandrel 4 can be tilted by being slid along an arcuate-graduated arm 52 which is revoluble about a vertical pivot 56. The mandrel and its supporting parts are carried by a frame member 58 vertically adjustable on the frame 59.