Rotary vise for an electrolytic grinding machine

861,039. Couplings between relatively movable conducting parts; removing metal by electrolysis. HAMMOND MACHINERY BUILDERS Inc. July 13, 1959, No. 24068/59. Classes 38 (1) and 41. An apparatus for holding and positioning a workpiece 161 with respect to a. grinding wheel 15 in an electrolytic grinder comprises a frame 11, 13, a workpiece-engaging means, e.g. a collet 16 and holding device 17, rotatably supported on the frame, and an electrically conductive, annular element, e.g. a slip ring 137, resiliently urged at 141 into slidable contact with the collet 16, so that electric potential can be applied therefrom to the collet 16 and holder 17 in any position thereof with respect to the frame. The frame portion 11 is adjustable transversely of a fixed plate 21 and carries a cradle 34 angularly adjustable about a horizontal axis in the plane of the paper on releasing bolts 46, 47. The frame portion 13 is angularly adjustable through a maximum angle of, e.g., 30 degrees, about a vertical axis on the cradle 34, and carries through bearings 69, 70 the collet 16 which is rotatable about a vertical axis 155, the collet 16 supporting the adjustable workholding device'17 or. the work itself, Fig. 9 (not shown). Rotation of the collet 16 is by a shaft 78 and ring gear 76 on a sleeve 72 keyed to a housing 67 for the collet, axial movement of the collet 16 being ensured by its threaded engagement with a collar 117, rotational movement of which is prevented by manual operation of a spring-pressed pin, Fig. 7 (not shown). The collet comprises a sleeve 113 slotted at 114 which is flared at its top, as is the housing 67, whereby upward movement of the collet acts to open the bore 116 of the collet and downward movement to close it. A spring-urged collar 103 engages notches 99 in a skirt 97 secured to the housing 67 to locate the collet 16. Electrical connection to the collet 16 is via leads 143, 144 connected to the slip ring 137, and collar 117. A spring-urged cap 173, which engages the work or a post 157 on the holder 17, acts to eject the work, or holder 17, on raising the collet 16. The bearing 70 is vertically adjustable by a screw 88.