Patent GB-393823-A (GB)
Title: Improvements in and relating to the production of worm gear
IPC: B23F13/04
Filed: 1932-09-30
Abstract: 393,823. Gauging toothed gears. KLINGELNBERG, G. A., KLINGELNBERG, M., KLINGELNBERG, R. G., KLINGELNBERG, W. H., and KLINGELNBERG, H. W., (trading as KLINGELNBERG SÍHNE, W. F.), 56, Berghauserstrasse, Remscheid, Berghausen, Germany. Sept. 30, 1932, No. 27226. Convention date, June 3. [Class 106 (ii).] In the production of worm and worm-wheel gearing, the screw hob used for cutting the worm wheel is gauged at each stage of its wear to ascertain the flank angle, tooth thickness, pitch cylinder diameter, and lead by measuring devices mounted on the machine for grinding the conjugate worm. The hob F is mounted for gauging between centres on the wormgrinding machine in place of the worm blank S, and subsequently the grinding machine is set up to conform with the hob measurements, the work being tested from time to time until its basic dimensions conform with those of the hob. One form of measuring device consists of a plate 1 carrying a housing 2 rotatable about a horizontal axis perpendicular to the work axis. A sleeve 3 may rotate within the housing about a vertical axis 4 and receives a tube 5 which is axially adjustable in the sleeve by means of gearing 6 associated with an indicator 7. A hollow lever 8 mounted within the tube 5 may rock slightly about a vertical pivot 9 and the bore of this lever accommodates an axially movable spindle 10 which carries either a feeler pin 11, Fig. 2, or a tooth thickness templet 12, Fig. 3. A scale 16 enables the device to be set to the helical angle of the work. In testing a straight-sided flank 13 with the pin 11, the device is swung until a pin 18 rests against a gauge block 21 adjacent an abutment 19, the size of the gauge block being determined by trial until, when the pin 11 is moved over the flank by moving the crank 6, the reading of a dial 14 which is responsive to angular movement of the lever 8 remains constant. In the case of curved flank worm-hobs the variations of readings of the dial 14 during the movement of the pin over the flank are recorded for the subsequent grinding of the worm. Either the cutter or the gauging device may be swung over for testing the opposite tooth flank 26. For measuring the distance of a given tooth thickness from the axis, the feeler pin is replaced by the templet 12 and the sleeve 3 is set perpendicular to the cutter axis. The templet is then forced against the flanks until a dial 15 responsive to axial movements of the spindle 10 indicates a predetermined mark and the reading of the scale 7 is noted. The worm is subsequently ground until the same readings are obtained on the scale 7 and dial 15. For testing the lead or linear pitch of the hob, the tooth templet is first positioned over the end tooth 27 and the distance of the device from an indicator 24 is gauged by an interposed spacer 25. The templet is then placed over another tooth and the distance from the indicator 24 again gauged. This measurement allows the worm grinder to be set up so that the worm is ground with the same lead as the hob. In some cases the measuring device may be mounted on a baseplate independent of the grinding machine.