GB817354A - Improvements relating to printing press drives - Google Patents

Abstract

817,354. Clutches; clutches combined with brakes. REYROLLE & CO. Ltd.. A. Nov. 11, 1955, No. 32370/5.5. Class 80 (2). [Also in Group XVI] A rotary printing press drive comprises a main motor coupled to the press shaft to drive the press at printing speed and a separate inching motor coupled to the main motor shaft through an overrunning coupling to drive the press forwardly for inching, and independently operable locking means which when operated, causes the inching motor drive, when reversed, to be coupled to the press shaft for reversing the press. As shown, a shaft 10, Fig. 1, which forms the shaft of the main motor (not shown) or is coupled thereto is supported in bearings 11 carried by a support 12. A ratchet wheel 13 is secured to the support 12 and engaged by spring- pressed pawls 27 carried by the cage 18 of a differential gear. Two driving pinions 14 and 15 carried by shafts 10 and 21 respectively mesh with planetary pinions 16 and 17 carried by the cage. The shaft 21 carries a wormwheel 25 meshing with a worm 24. Brake shoes 30 engage a surface 29 on the cage 18 and are actuated to effect braking of the cage by a solenoid 32. When it is necessary to " inch " the press in the forward direction the inching motor, not shown, is energized and thus rotates the pinion 16 counterclockwise; the cage 18 is prevented from rotating counterclockwise by the pawls 27 engaging the ratchet wheel 13 and so causes the pinions 16 and 17 to drive the pinion 14 and shaft 10 clockwise. When it is necessary to drive the press at printing speed the main motor is energized, thus causing the pinion 14 to rotate clockwise faster than the pinion 15, thereby rotating the cage 18 clockwise since the worm drive 24, 25 is not reversible. The pawls 27 are raised, by centrifugal force, from the wheel 13 when the main motor attains a predetermined speed. The brake shoes 30 can slow the press or hold it at rest. When the press is to be reversed the shoes 30 are applied, by energization of the solenoid 32, thus holding the cage stationary. The pinion 14 is then driven counterclockwise through the pinions 15, 16, 17 by the inching motor being driven in reverse. In another embodiment, Fig. 3, the shaft 10 is coupled to the main motor and press while the shaft 21 is driven by the inching motor through a non- reversible worm gear, not shown. The shaft 10 carries a wheel 30 which carry pawls 31 engaging a ratchet wheel 52 secured to a flange 33 on the shaft 21. The pawls 31 and ratchet wheel 52 transmit the drive from the inching motor to the shaft 10 for inching the press and permits the shaft 10, when driven by the main motor, to overrun the inching motor, thus accelerating the press to printing speed. To reverse the press at inching speed, the shafts 10 and 21 are connected by a friction clutch comprising clutch plates 38 and 39 carried by the flange 33 and an annular plate 36 on the wheel 30. The clutch is released, upon energization of a solenoid, by levers 42 actuated by rods 44 secured to a slidable sleeve 46 actuated through a lever 47 connected to the solenoid armature. In a modification, the clutch may be engaged by electromagnets secured to the rotating parts and energized through slip rings. In both the embodiments described with reference to Figs. 1 and 2, and 3, the solenoids 32 and 48 respectively may be replaced by hydraulic cylinders.