Patent GB-147681-A (GB)
Title: Improvements in or relating to grinding machines
IPC: B24B47/04
Filed: 1920-07-08
Abstract: 147,681. Norton Co., (Assignees of Wilcox, J. S.). Oct. 24, 1916, [Convention date]. Driving and feed devices.-The cross-feeding mechanism of grinding-machines is arranged so that the feed may be automatic both when the table of the machine is being reciprocated and when stationary. The feed-shaft 25, Figs. 1 and 2, is actuated through gearing 23, 24 by a ratchetwheel 20 rotatably mounted on a shaft 21 and engaged by a feed-pawl 27 pivotally mounted on an arm 29 rotatable about the axis of the ratchetwheel. The pawl has an arm 27a connected by a link 30, Figs. 1 and 8, to a crank-pin 50, and pivoted to the arm 29 is a throw-off plate 31, Fig. 3, adapted to be held in either of the positions shown by a spring 33; when in the position shown in dotted lines, it holds the pawl away from the ratchet-wheel. The feed may be manually operated by means of a handle 40, Fig. 1, carried by an arm 41 adapted to be locked to the shaft 21 and wheel 20 by a nut 22. On this arm is a shoulder 44 adapted, when the arm is rotated in a clockwise direction, to engage a lug 45 on the plate 31 and lift it. On the arm 27a of the pawl is a surface 27b adapted to engage a surface 31<a> on the plate 31 when the link 30, moving upwards on the idle stroke, moves the pawl about its pivot on the arm 29; after engagement of the surfaces 27b and 31a, the arm 29 is rotated and carries the pawl backwards, in readiness for a new feeding stroke, while out of contact with the ratchet-wheel. The crank-pin 50 is adjustably mounted on a crank-disk 52 secured to a shaft 53, and on the shaft is slidably keyed a clutch-member 54. A pinion 55 loosely mounted on the shaft is engaged by a circular rack 56 slidable on a rod 57 and pressed by springs 58 interposed between its ends and the ends of a voke 59 also slidable, on ball bearings, on the rod. The circular rack is moved by means of a segmental gear 70<a> carried by the arm 70 of the feed lever, the other arm of which is engaged by dogs on the reciprocating table: movement of the rack rotates the pinion 55. The clutch-member 54 has at its right-hand end, Fig. 8, two projections adapted to engage with projections on the pinion 55 in one angular position of this only, and at its left-hand end projections adapted to engage projections on a bevelpinion 80 loosely mounted on the shaft 53 and in engagement with a continuously rotating bevelgear 81. The clutch-member 54 is moved to engage the pinion 55 or the pinion 80 by means of an arm 83 carried by a sleeve 84 slidable on a rotatable shaft 85 and moved thereon by the engagement of a pin on the shaft with a spiral groove 86 in the sleeve; springs 88, 89 yieldingly position the shaft longitudinally. The shaft is. supported at its outer end in the hub 90 of a handle 91 having a cross-pin 94 engaging a slot in the end of the shaft. In operation, when the table is reciprocating, the clutch 54 is moved to engage the pinion 55, the crank-pin 50 being then moved by the oscillations of the lever 70. When the table is stationary, the clutch-member 54 is moved to engage the bevel-pinion 80, the crankpin then being rotated by the bevel-gear 81.