Improvements in or relating to rotary indexing or dividing tables

摘要

843,189. Indexing. CENTEC MACHINE TOOLS Ltd., [formerly CENTRAL TOOL & EQUIPMENT CO. Ltd.]. May 15, 1958 [Feb. 22, 1957], No. 6066/57. Class 83 (3). In an indexing mechanism for the table 14 of a machine tool, an axially movable member 30 holds the table stationary after each indexing operation. The table is rotatable on a hollow post 16 supported by a flange and nut arrangement 17, 19, from a plate 22 attached to the bed 11. An indexing sleeve 24 attached to the table has upper and lower clutch teeth 27, 28, for engagement respectively with teeth on the member 30 and on a driving ring 40. A steel diaphragm 32 is attached by screws 33 to member 30, and by a ring 34 to a bearing plate 13 on the bed, and springs 38 in the plate act downwardly on the diaphragm, tending to engage clutch teeth 27, 31, and disengage clutch teeth 28, 41. A spacing ring 43 with a needle bearing is arranged between sleeve 24 and ring 40, and a similar ring 44 between ring 40 and an annular piston 45, which is operated to shift the ring 40 and member 30 against the influence of springs 38. Instead of the springs 38, the diaphragm may be operated pneumatically, and the piston 45 may be replaced by spring means. Gear teeth 42 on the ring 40 are engaged by opposed racks 68, 69, operated respectively by pistons 62, 63, piston 63 indexing the table, and the piston 62 operating to return piston 63 while clutch teeth 28, 41 are disengaged. Operation.-Air is admitted to cylinder 46 to engage teeth 28, 41, and the building up of air pressure operates a valve (not shown) which supplies air to cylinder 61 and exhausts cylinder 60. At the end of an indexing step, the end of rack 69 engages a plunger 80 contacting a rocker 84 operating a control valve 53 which releases the pressure behind piston 45, permiting springs 38 to disengage the clutch teeth 28, 41. Piston 62 is then operated to return.the racks, until a dog 70 on rack 68 contacts an adjustable stop 71. The position of the stop, which is accessible through a slot 72 covered by a removable panel 74, determines the retracted position of rack 69, and thus the travel of the rack, and angle of rotation of the table.