GB831595A - Improvements in or relating to feed adjustment devices for thread-grinding machines - Google Patents

Abstract

831,595. Grinding screw threads; trueing grinding wheels. LINDNER G.m.b.H., H. Dec. 3, 1958 [Feb. 1, 1958], No. 39040/58. Addition to 829,935. Class 60. The feed adjustment device of the parent Specification in which a feed adjustment wheel 9 is provided with two rings 11, 12 graduated in opposite directions, each ring having a stop member 13, 14 and being capable of being displaced and secured in position on the wheel independently of the other to enable the stop members to permit a predetermined amount of rotation of the feed adjustment wheel in one direction to feed a grinding disc 1 into a trueing means 7, and in the opposite direction to feed the grinding disc into a workpiece 5, is modified by providing each ring 11, 12, with a fraction ring 31, 32 which is furnished with an abutment 29, 30 and driven by the feed adjustment wheel at a reduced speed whereby, irrespective of the number of revolutions of the feed adjustment wheel, the zero setting of the disc for grinding or trueing can be determined. The friction rings 31, 32, and a spacing ring 34, are frictionally held between a flange 43 on a member 42 and a second flange 44 on a gear 36 urged together by springs 46 disposed on screws 45, the spacing ring also having a slot engaged by a pin 35 connected to the member 42. The gear 36 has internal teeth engaging a gear 40 integral with a gear 39 having one tooth less than the gear 40 and engaging a gear 38 non-rotatably secured to the machine. The gears 39, 40 are mounted on a spindle 41 secured to the feed adjustment wheel 9. During rotation of the wheel 9, the rings 31, 32 rotate at a reduced rate until either projection 29 or 30, depending on the direction of rotation, engages a fixed projection 33 on the machine ; the final position of the grinding disc is determined by engagement of one or other of the stops 13, 14 on the rings 11, 12 with abutment 23 or 24 on a lever 25 movable to bring one or other of the abutments into operative position: Any further rotation of the wheel which may be necessary because of wear of the wheel automatically repositions the friction rings relative to the wheel, the graduated rings 11, 12 being repositioned by the screws 15, 16 as described in the parent Specification. A ring 55 is spring-urged into contact with the feed adjustment wheel to provide constant friction. The parts may be lubricated with grease supplied through passages 50 ... 53 from a nipple 49. In an alternative embodiment, the gears 36, 38 and rings 31, 32 are mounted on an auxiliary spindle to the side of the feed adjustment wheel.