GB366548A - Improvements in or relating to centerless grinders - Google Patents

Abstract

366,548. Centreless grinding. CINCINNATI GRINDERS, Inc., 3058, South Street, Cincinnati, Ohio, U.S.A.-(Assignees of Harrison, R. E. W.; 5860, Wayside Avenue, and Hopkins, C. W. ; 4339, Rose Hill Lane, both in Cincinnati, Ohio. U.S.A.) Sept. 24, 1930, No. 28599. Convention date, Sept. 27, 1929. Addition to 366,005. [Class 60.] Gauges; guides and rests.-In a centreless grinding-machine of the "infeed" type, means are provided for gauging the work-pieces whilst they are in the grinding throat, and in cases where the work is over size, for actuating means to give additional infeed to the regulating- wheel. The machine comprises a bed 15 upon which are mounted a grinding-wheel 16 and a slide 17 carrying a work-rest bracket 18 and a second slide 19 supporting a regulating-wheel 21 ; the slides may be clamped together by a clamp 30. In order to advance the regulating- wheel to position it relatively to the work, a nut 23 is mounted rotatably in the slide 19 to engage a screw 24 rotatable by a hand-wheel 29 and mounted rotatably in a block 25 slidable in a housing 27 supported by the bed. The block is movable to feed the regulating-wheel, to grind the work to size, by a bell-crank lever 32 moved by a cam 35 driven by a motor 37; a fine adjustment of the regulating-wheel is brought about by worm-gearing 38 on the nut 23 operated by a hand-wheel 43 on a spindle 40. The spindle 40 also carries a ratchet wheel 44 operated by a pawl 45 carried by a gear 46, which is moved by rack teeth on a piston 52 in a fluid pressure cylinder 53 and movable under the control of a valve 57 operated in one direction by a solenoid 58, and in the other direction by a spring 59. The work is supported by a rest 22 on the bracket 18, and secured to the bracket 18 is a housing 62 having pivoted therein a lever 63 with a feeler 64 bevelled at 65 and pressed by a spring 66 to engage the work ; the lever carries an electrical contact 68 adapted to engage a contact 70 in the circuit of the solenoid 58. The cam 35 also is adapted to actuate a circuit-breaker 75 in the same circuit when the regulating-wheel is being given a dwell by the cam for finish grinding. If the work is to size, the feeler 64 falls sufficiently to open the contacts 68, 70, so that the solenoid is not energized ; if, however, the work is over size owing to wear of the wheels, the solenoid is energized and actuates the valve 57 to cause the piston 52 to give an additional feed to the regulating-wheel. The stroke of the piston is adjusted by screws 60 ; the pawl 45 is lifted, on the reverse stroke of the piston, by a screw 49 which engages a bevel 50 on the pawl.