Patent GB-774411-A (GB)
Title: Improvements in or relating to machine-tools with mechanical and hydraulic cross-slide feed devices
IPC: B24B47/20
Filed: 1954-07-20
Abstract: 774,411. Grinding. GAUB, H., [trading as JUNG SCHLEIFMASCHINEN H. GAUB]. July 20, 1954 [Dec. 10, 1953; Jan. 20, 1954], No. 21188/54. Class 60 A grinding machine has both mechanical and hydraulic feed devices for the crossslide. An internal grinding machine comprises a rotating workpiece carrier 4, e.g. a chuck, the housing 3 of which is secured to a carriage 2 movable backwards and forwards on a machine frame 1; the housing 3 carries a trueing device 5. The carriage 2 is reciprocated hydraulically, reversal being effected automatically by a lever 7 actuated by dogs 6 on the carriage 2 so as to operate a distributing valve. A grinding wheel 11 and its driving motor 12 are carried by a cross-slide 9 movable on a guide 8. The cross-slide 9 is connected by a link 18 to one end of a lever 17; a spring 19 takes up play in the connections. The lever 17 is pivoted on the central portion 50 of a pin, the portion 50 being eccentric to the outer pin portions 50a, 50b which are coaxial with each other and journalled in bosses 52 of the guide 8. A lever 48 is fixed by key 49 to the portion 50; one end 48b of the lever 48 is connected to a spring 48c anchored to the guide 8; the other end 48a of the lever 48 is connected by a link 47 to a block 55 adjustably mounted on a pivoted lever 46, the end of the lever 46 being connected by a link 45 to the piston rod 44 of a piston 43 working in a cylinder 42. The position of the block 55 on the lever 46 is adjusted by a screw shaft 56 carrying a worm wheel 57 in mesh with a worm 58 operated by a shaft 60 carrying a handwheel; the position of the block 55 is shown by a scale 62. The supply of pressure 'oil to the cylinder 42 is preferably so controlled that the cross-slide 9 is moved forwardly rapidly until the grinding wheel contacts the work, after which the movement is at a slower rate; the return movement is at high speed. The mechanical feed device comprises a spindle 14 threaded at one end to engage a nut 15 connected to a slide 15<SP>1</SP> in turn connected by a link 16 to the other end of the lever 17. A handwheel 20, having a graduated ring, is mounted for free rotation on the end of the spindle 14 and can be connected, by means of a setscrew 21, to a driving disc 22 keyed on the spindle. Automatic feed is operated by a dog 23 on the carriage 2 which, when the carriage is extended to the truing position, actuates a rod 24 driving the spindle 14 through pawl and ratchet gearing. A rod 25 on the end of rod 24 actuates a bell-crank lever 27 having a pawl 28 driving a ratchet wheel 29. Coaxially connected to the latter is a gear-. wheel. 30 meshing with gear wheel 31 freely rotatable on the spindle 14. One arm 27a of the bell-crank lever 27 is connected by rod 32 to a bell-crank lever 33 the free arm 33a of which rests against a stop 34, by adjustment of which the feed can be varied. The bell-crank lever 33 is rigidly connected to a shaft carrying a press-button 35 for manual operation; to permit this, the rod 25 has a longitudinal recess 25a. The gearwheel 31 has an internal taper against which a cone 36 slidable on the spindle can be pressed by a push rod 37 connected to the cone by a cross pin 38 and moved, against the action of a spring 40, by a knob 39 threaded on the free end of the spindle 14.