GB1135771A - Improvements in brakes for power presses or other machines - Google Patents

Abstract

1,135,771. Clutch-brake combinations. COWLISHAW, WALKER & CO. Ltd. 14 Dec., 1965, [21 Dec., 1964]. No. 51884/64. Headings F2C and F2L. A clutch-brake comprises a plate 15 acted on by springs 16 bearing against a part 18 adjustably held against axial movement, to grip a disc 11 with loose friction inserts 12 between plate 15 and a plate 14, the plate 15 being withdrawn by air pressure acting on an annular diaphragm 22 engageable with annulus 23 fixed to part 18. The part 18 is connected to an annulus 26 secured to four extensions 27 of a gear wheel 28, the plates 14, 15 being splined at 44 to extensions 27. The gear wheel can be driven by motor 41 and can be braked by a magnetic brake 42. Each extension 27 has a plunger 32 which can be moved by air pressure into the path of abutments 37 on disc 11 whereby the extensions 27, plates 14, 15 and disc 11 are locked together. Normally the plungers are withdrawn and brake 42 applied to hold plates 14, 15, the springs acting to brake disc 11. To drive a shaft 10 and a press, the motor drives plates 14, 15 and disc 11 is either frictionally engaged for low torque or engaged by plungers 32 for positive drive. Motor 41 is supplied from a three-phase mains, Fig. 3, not shown, through a star-delta equipment; in one position of a two-pole switch, the star connection can be held so that the motor can be inched under the control of forward and reverse push buttons at a reduced output torque for tool setting, and in the other position, to effect a full pressing operation, the motor starts with the star connection and automatically changes to delta connection after a predetermined time; this latter operation can only take place if the pressing mechanism is within a certain range of topdead centre; if not the press must be inched into this range. The change to delta connection takes place by the time the motor reaches full speed.