Patent GB-533312-A (GB)
Title: Improvements in or relating to grinding or regulating wheels for grinding machines
IPC: B24B41/04
Filed: 1939-08-10
Abstract: 533,312. Grinding rock drill hammers &c. LIDKOPINGS MEKANISKA VERKSTADS AKTIEBOLAG. Aug. 10, 1939, Nos. 23133 and 23134. Convention dates, Aug. 12, 1938 and Dec. 9, 1938. [Class 60] Wheels; trwing wheeds.-A composite grinding or regulating wheel for a grinding machine or a support for such wheel comprises a number of separate component parts movable towards or away from each other in the direction of the axis of the wheel, in combination with an operating member mounted outside the end of the spindle and coupled to the movable parts through connecting members mounted in a longitudinal bore in the spindle. A grinding wheel for grinding projecting sharp and distinct edges 2, 5 or 3, 6, Fig. 4, between different surfaces may thus be more easily initially dressed in its corresponding inwardly directed corners 7, 10 or 8, 11 between the surfaces. The wheel elements may be carried by hubs 20, 21, 22 on a cylinder 23 secured to the spindle 24. The hub 21 may be fixed on the cylinder 23 by a flange 25 and nut 26 and the hubs 20, 22 splined thereon so as to be slidable. Axial movement of the hubs 20, 22 in opposite directions may be effected by a hand-rotated rod 28 having right and left hand threaded portions 31, 32 engaging threaded bores in fourarmed crosses 33, 34 passing through slots 35 in the cylinder and spindle, and secured by members 36 to the hubs. Alternatively, the spindle 24 may contain a tube 37, Fig. 4, provided with a cross-member 39 engaging the hub 22 and slotted for the passage of a crossmember 41 engaging the hub 20 and carried by a rod 40 movable in the tube 37. The end 45 of the tube 37 and the end 46 of the rod 40 are threaded in opposite directions to engage a screwed sleeve 42 rotatably mounted in the end of the spindle 24. The elements may be set in their truing,positions by stops. Truing may be effected by a diamond tool 12 secured in a transverse slide 14 held by a spring in contact with a template 18 and carried by a longitudinally movable slide 15. The grinding wheel may consist of only two elements or may consist of more than three elements. Adjustment may be effected by screws of different pitches instead of being of opposite hand. The axial movement of the elements, in addition to being effected by hand for truing when the spindle is stationary, may also be effected automatically during a grinding operation, thus the wheel of a centreless grinding machine for grinding the cylindrical parts 113, 114, 118, Fig. 8, and the plane side faces 119, 120 and fillets 116, 117 of a rock drill hammer, may consist of a centre disc 50, Fig. 6, on a hub 57 secured to the spindle 24 and a pair of discs 51, 52 slidable on the spindle 24. The tube 37 and rod 40 carrying the cross-members 39, 41 are connected in thrust bearings 67, 69 in blocks 68, 70, which are slidable in guides respectively in the fixed housing 72 and in the blocks 68. The blocks are provided with screw threads of opposite hand engaging a threaded member 74 carrying a crown wheel 78. On the crown wheel is mounted a casing 81 for a worm 82 provided with a hand-wheel 83 for adjusting the grinding elements axially prior to truing. Axial movement of the elements during grinding to effect the grinding of the parts 116, 119 and 117, 120 is effected by angular movement of the casing 81 which is directly connected to the member 74 through the worm 82. In the form shown in Fig. 7 the regulating wheel 88 and grinding wheel 90 of a centreless grinder are carried by slides 85, 87, of which the slide 87 is moved towards and from the work at varying speeds by a rack and pinion through an arm 98 engaging a cam 96 driven by worm gear from a shaft 95 connected by gearing to a motor 92. The shaft 95 is also connected by worm gear to a shaft carrying a cam 105 which through lever 109 and link 111 oscillates the casing 81 to give the axial feed to the elements. In a modification, the cam 105 may be dispensed with, the arm 98 being replaced by a two-armed lever, the other arm of which is connected by a link to the casing 81. Friction between the tabs 56, 58 and the spindle may be reduced by axially displaceable ball bearings 65, 66 or the bushings may have longitudinal ribs to assist in driving the wheel and having intervening balls or collars. In another form the hubs and spindle may both be of square or other polygonal section and contain balls to reduce sliding friction. The work may be pressed against the rest 89 by a pressure roller.