GB491610A - Improvements in or relating to grinding and polishing machines for hard materials - Google Patents

Abstract

491,610. Grinding &c. marble &c. SPEED SURFACES, Ltd. (Brendel, G. F.) April 19, 1937, No. 11173. [Class 60] A machine for grinding and polishing the surface of hard material, for example, granite, porphyry, marble, glass, steel, &c., comprises a shaft a rotating in a bearing o and having at its lower end a disc c on which are mounted split bearings e, which receive trunnions e of tubular bearings f, the bearings e being clamped by screws g to hold the bearings in any desired angular position. Rotatable in the bearings f are spindles h, each carrying at its lower end a plate i to which is fixed a grinding-stone j, each spindle also having at its upper end a crank arm k provided with a roller l running in a cam groove in a part m secured by bolts p to a member n fixed to the part o ; by adjustment of the bolts in slots q the eccentricity of the part m in relation to the shaft a may be adjusted. In operation, as the shaft a is rotated, carrying round the stones j, the spindles h and the stones are oscillated to an extent determined by the eccentricity of the part m ; the inclination of the spindles also may be adjusted, according to the hardness of the material undergoing treatment. A lever engaging trunnions s on the part o may be used to lift the apparatus or to apply pressure to the stones j.