| 摘要 |
1,149,682. Abrasive tool. HAMMOND MACHINERY BUILDERS Inc. 28 June, 1967 [12 Aug., 1966], No. 29928/67. Heading B3D. [Also in Division C7] Electrolytic grinding apparatus comprises a disc D mounted on a flange 26 having a hub 22 which is secured to and rotated by a shaft 12. The disc comprises a backing sheet 25, an adhesive layer 27, non- conductive abrasive grains 29 embedded in the adhesive and an electrically conductive layer 28 with the abrasive grains protruding beyond the conductive layer. There may be adhesive 30 between the disc and the flange. Current for electrolytic grinding is supplied through the shaft 12 to the conductive layer 28 of the disc. As shown in Fig. 2 a screw 33 and cap 32 secure together the disc D, flange 26 and shaft 12 and also serve as the current supply means to the conductive layer 28 of the disc. A key 24, pin 41 and locking washer 43 prevent relative rotation between the parts. Alternative methods of securing the parts together and of supplying current from the shaft 12 to the conductive layer of the disc are illustrated in Figs. 6 and 7 (not shown). The hub may be of conductive or non-conductive materials. The backing sheet 25 of the disc D may be of paper, cotton, linen, nylon or wire cloth. The conductive layer 28 may be of metal foil or be of metal applied by spraying, vacuum metallizing or electroplating. If, while making the disc, the abrasive grains become covered by the metal, portions of the metal are removed, e.g. mechanically or electrolytically. The adhesive layer 27 may be of phenolic resin and the abrasive grains 29 may be of diamond bort or aluminium oxide. The apparatus may be oscillated during grinding. |
