GB642904A - A machine for hollow grinding scissors, razors, boning and similar knives - Google Patents

Abstract

642,904. Hollow-grinding. LAYCOCK, E. G., LAYCOCK, C., LAYCOCK, D., and LAYCOCK, F. March 30, 1948, No. 8896/47. [Class 60] A machine for hollow-grinding scissors, razors, boning and similar knives having a cup-shaped grinding wheel 12 with an externally-coned, operative, face is provided with means for presenting the work 25 to the wheel and traversing it longitudinally in its own plane and always in the same direction while it is in contact with the wheel. The work is mounted on a holder 19 pivoted at 20, 21 on a slide 18 displaceable along an inclined face on a frame 16 adapted to slide in a trough 11. The inclined face is parallel with the operative face of the wheel and the inclination of the holder with respect to its slide may be varied by a pivoted screw adjustment 22. The slide 18 is connected by links 27, 28 with a shaft 29 provided with two cams 30, 32 and connected through a lost-motion device comprising a pin 34 and a fork 33 with a hand-lever 31. The two cams alternately actuate levers 40, 41 adapted to bear on opposite ends of a cam member 39 freely mounted on a shaft 34a which fixedly carries a complementary cam member 45. The shaft 34a is provided with a hand-wheel 46 and is in screw-threaded engagement with the trough 11. A spring mounted on this shaft is constrained at one end by a flange 37 and at the other by the frame 16. Rotation of the hand-wheel advances the frame 16 to compensate for wheel wear. In operation, the lever 31 is moved towards the grinding wheel to cause the cam 32 to separate the cam members 39, 45 which advance the frame 16 towards the grinding wheel against the load imposed by the spring. The work is now in contact with the grinding wheel and the lever 31 is moved back until the pin 34 rotates the shaft 29 to cause the slide 18 to ascend the inclined face of the frame 16. When the work has been completely traversed across the wheel, the cam 32 releases the lever 41 while the cam 30 actuates the lever 40 to restore the cam members and the frame 16 to their original positions, the slide 18 gravitating to an adjustable stop. To impart "set" to the work, the holder 19 is provided with an arm 48 slidably secured to a roller 49 which is free to slide and rotate in a cylindrical guide 50 adjustably clamped to the frame 16. The guide 50 is inclined to the workholder so that the latter turns on its pivots during the grinding operation. The workholder may be fitted with a work support 24 which is adapted for angular adjustment in its own plane.