by means of klinkengesperres with controlled schaltklinke acting feed device for the werkzeugschlitten on machine tools, in particular grinding machines

摘要

147,679. Norton Co., (Assignees of Wilcox, J. S., Turner, A., and Dunbar, H. W.). June 28, 1915, [Convention date]. Driving and feed devices.-The crossfeeding mechanism of grinding - machines, is so arranged that the feed-pawl of the ratchet-gearing performs its idle stroke out of contact with the ratchetwheel. The mechanism comprises a feed screw driven through gearing 24, 25 by a ratchet-wheel 22 mounted on a fixed stud 23 and moved by means of a feed-pawl 34. This pawl is operated, through a link 36, by a crank-pin 21 carried by a disk 20 connected to a pinion 18 in engagement with a rack 17, which is connected to a sleeve 16 adjustable on the curved part 15 on a lever 13 pivoted at 14 and adapted to be engaged by dogs 11, 12 carried by the reciprocating work-carriage 10. On a sleeve 30, fixed to the machine frame and concentric with the ratchet-wheel 22, is rotatably mounted .an arm 29, frictional resistance to the angular movement of which is provided by means of a friction disk or spring washer 31 and a nut 33. The other end of the arm 29 carries a stud 35 forming a pivot for the feed-pawl 34 on which is mounted a tooth 37. The stud 35 also supports a cam 38 having two inclined flat faces adapted to be engaged by a spring-pressed plunger 39 slid- .ably mounted in the pawl 34 and normally engaging the right-hand face of the cam. With the parts in the position shown in Fig. 5, movement of the carriage 10 to bring the dog 11 into contact with the lever 13 moves the rack 17 to the left, and this rotates the crank-pin 21 along the dotted-line path to position 21a. During the downward movement of the crank-pin, the link 36 rotates the pawl about the stud 35, the frictional resistance preventing rotation of the arm 29, until the tooth 37 engages the teeth of the ratchet-wheel; further movement of the crank-pin causes rotation of the arm and the ratchet-wheel, whereby the grinding-wheel is fed forwards. As the crank-pin passes its lowest point, the link 36 moves the pawl to lift the tooth out of engagement with the ratchet-wheel until the plunger 39 engages the cam 38, when the arm moves upwardly and the parts are restored to the original position. The automatic feed may be cut out by moving the pawl to bring the plunger 39 into engagement with the left-hand face of the cam. Manual feeding is brought about by means of a handle 50 carried by a lever 51 loosely mounted on the stud 23; the lever also carries a shield 53 projecting over the teeth of the ratchet-wheel to limit the feed. The Specification as open to inspection under Sect. 91 (3) (a) comprises also a positive stop for the cross-feed during manual operation thereof. This comprises a part 54 on the lever shaped as shown in dotted lines in Fig. 3, and having a radially-formed end 55 with a stud 56 therein adapted to engage respectively with the end of the pawl and a recess 58 therein. This subjectmatter is not described in the Specification as accepted.