GB533246A - Improvements in grinding or abrading machines - Google Patents

Abstract

533,246. Grinding hard metals. NAGY, A. Oct. 21, 1939, No. 28403. [Class 60] A machine particularly for grinding hard metals in the manner described in Specification 521,697, comprises a work support 26 mounted within a tank containing grinding liquid, a rotary grinding wheel which is reciprocated in its own plane past the work, the tank being intermittently and adjustably fed towards the grinding wheel to control the depth of cut. The tank 13 is mounted on a bracket 81 slidable in vertical guides on a standard 11 under the control of a lead screw 83 which may be operated either automatically or, for setting purposes, from a handle 82. The tank is fitted with a detachable cover 16 having a front slot 17 of sufficient size to permit reciprocation of the grinding-wheel and vertical feed of the tank. The cover is latched in position by means 25. The work consisting of a hard metal bar 14, Fig. 7, brazed to a shank 15, is secured in its support 26, which is of channel form, by screws 27, Fig. 6. The support has a ball connection 28 with a socket 29 secured in the tank so that the work may be held in a substantially vertical position at the required angle, the tool shank being accommodated in a deep recess 33 in the tank. The grinding wheel consisting of a carrier wheel which picks up hard grinding granules from liquid-in the tank as described in Specification 521,697, is driven from a motor 35 and is mounted on a slide 38 carried by a second slide 40 and adjustable axially of the grinding wheel by a handle 41. The slide 40 is itself carried on a slide 42 and is adjustable in the plane of the grinding wheel by a handle 43. The slide 42 is carried on a member 45 which is angularly adjustable on the standard 10 this adjustment being indicated by a scale. The adjustment by the handle 43 serves to determine the limits of the automatic stroke of the grinding wheel. For the automatic movement, a second electric motor 51 drives through gearing 52-56 a vertical shaft 46 carrying an upper cam 57 co-acting with a roller 62 on a bridge piece 61 secured to the hollow interior of slide 42. The slide is returned by springs 63. A second cam 58 on the shaft 46 acts through adjustable lever mechanism 68- 70 on a pawl which feeds a ratchet wheel on a shaft 76 to impart vertical feed to the tank and work, the amount of the feed being adjustable through the levers 70, 74. The feed movements are timed to occur during the return movement of the grinding wheel. The shaft 76 drives a worm wheel 84 which may be connected by a dog clutch member 89 to the lead screw 83. The clutch may be dis-engaged when the height of the tank is to be adjusted by the handle 82. A scale 92 is provided to indicate the total amount of feed.