GB544687A - Improvements in or relating to feeding devices for grinding machines - Google Patents

Abstract

544,687. Grinding. AKTIEBOLAGET SVENSKA KULLAGERFABRIKEN. Dec. 11, 1940, No. 17569. Convention date, Dec. 13, 1939. [Class 60] In a grinding machine comprising a pivoted or reciprocating periodically-movable head for the work or tool, and means for feeding the tool relatively to the work, the feeding-means is driven by the head in such a manner that the speed is varied in accordance with the variations in the speed of the head. The arrangement reduces the feed at the ends of the stroke of the head, thereby causing the tool to make a more uniform cut, and preventing excessive pressure between the work and tool. The mechanism shown in Fig. 2 is included in a machine for grinding spherical bearing-rollers, and comprises an oscillating head 4 carrying cross-slides carrying the work in position for engaging a grinding-wheel on a slide which is advanced by a feed-screw 54. The head is oscillated by means of ropes 27 which are connected to a pulley 28 on the head and to crank-pins 25, 26 on a shaft 24 geared to a driving-shaft 21, the shafts being mounted in a pivoted casing 29 which is connected to a spring for tensioning the ropes. The feed-screw 54 is geared to a shaft 34 provided with pulleys 33, 37 engaging a rope 32 which is secured at the ends to the head, and passes over tension-pulleys 35, 36. The pulleys 33, 37 are provided with free-wheels so arranged that the cord transmits uni-directional movement to the shaft 34, and consequently to the feed-screw, the speed of the latter varying in accordance with that of the head. The mechanism may be provided with the automatic stop-device described in Specification 529,449 for stopping feed when the work has been ground to the required dimension. The stop-device comprises a gauging-finger for closing the circuit of a solenoid 57 and thereby permitting a lever 59 to release a clutch 62 in the train of gearing between the shaft 34 and feed-screw 54. The mechanism shown in Figs 7 and 8 is included in a machine for grinding the interior of a ball-race 70 by means of a grinding- wheel 75 carried by a slide 76 on a head 75 which oscillates on a vertical pivot 4. The feedscrew 78 for the slide 76 is now provided with a ratchet-wheel 89 co-operating with pawls 87, 88 on slides 86, 83 which are guided by a casing 84 on the head. The slides are inter-geared by a pinion, and the slide 83 is provided with a roller 82 co-operating with a stationary, inclined track 81. During oscillation of the head, the slides are reciprocated in opposite directions, the pawls are alternately effective, and unidirectional movement is imparted to the feedscrew, the speed of the latter varying in accordance with that of the head.