GB650383A - Improvements in or relating to grinding machines - Google Patents

Abstract

650,383. Grinding-machines. CINCINNATI MILLING MACHINE CO. March 31, 1948, No. 9084. Convention date, April 12, 1947. [Class 60] [Also in Groups XXIV, XXVI and XXXIV] A grinding-machine comprises a spindle 12 journalled in a support 16, means 56 for rigidly clamping a resiliently mounted journal for one end of the spindle, an automatic balancing mechanism carried by the spindle and including hydraulically-releasable balancing elements 98, and means 62 for effecting successive releasing movements of a control device which is movable into one position for unclamping the journal, and into a second position for unclamping the balancing elements hydraulically. An assembly unit carrying the spindle 12 is mounted in a bore 14 in the machine frame 10. The spindle 12 is supported at its forward end by a bushing 77 and rocking shoes 78 carried by a sleeve 53 which is normally clamped in the bore 14 by the pin 56. The sleeve 53 is unclamped by manually turning the pinion 62 to move a cam-bar 59 against a stop 71 to release the pin 56. The sleeve 53 is then resiliently supported from the sleeve 16 by a series of rods 79 and tubes 80. The rear end of the spindle is supported to pivot about a centre 102 by spherically-seated bearings 21,22 and rocking shoes 18. A driving pulley 31 is mounted at the rear end of the spindle about the centre 102. The spindle 12 is bored at 88 to receive a piston 90 which is acted upon by a spring 92 to clamp the three balancing elements or balls 98 against a resilient washer 97. Pressure fluid is supplied by a pump P, the minimum pressure being controlled by a valve 48 and the unclamping of the sleeve 53 and the balls 98 by a valve 50. The valve 50 is actuated by a cam 51 on the end of the pinion shaft 62. Initial movement of the shaft 62 therefore releases the sleeve 53 and partially releases the valve 50; further movement depressed the stop 70 against a spring 76 allowing a spring 52 to raise the pressure in the fluid system and move the piston 90 to release the balls 98. The spindle, being rotated above its critical speed, is balanced automatically by the balls 98 which, together with the sleeve 53 are then reclamped. The pump P also serves to lubricate the shoes 78 and 18 via the tubes 80 and a passage 37 respectively. The assembly may be removed and inserted into the bore 14 in the opposite direction, the opposite end of the cam-bar 59 then being effective. A vibration indicator is provided. U.S.A. Specification 2,142,021 is referred to in the Specification as open to in spection. under Sect. 91.