GB878899A - Improvements in printing machines - Google Patents

Abstract

878,899. Printing-machines. GERICKE, E. May 6, 1959 [Oct. 31, 1958], No. 15515/59. Class 100(2) [Also in Group XXIV] A lithographic printing machine, particularly a rotary offset printing machine, in which the input shaft of the machine can be coupled by a dog clutch either to a power drive or a manual drive is characterized in that a slip coupling is interposed between a driven pulley and the input shaft of the machine. As shown, the input shaft 5, Fig. 3, is driven by a pulley 4 housing a friction clutch comprising friction liners 6, 6a, urged together by springs 7 on adjustable screws 8 to engage a coupling disc 3 having teeth engageable with teeth 23 on a slidable clutch member 2 keyed to the shaft 5 by a key 22 as shown in Fig. 4. In this position, the pulley 4 is operatively connected to the shaft 5 for power drive. The member 2 is moved towards pulley 4 by a sleeve 19, Fig. 4, rotatably mounted on shaft 5, the sleeve 19 being moved towards the pulley 4 by a cap 1 of a hand crank 9 and in the opposite direction by a spring 10. The sleeve 19 is retained in its right hand position by a locking lever 21 engaging a step 25 on sleeve 19, the sleeve 19 being released upon a 45 degrees rotation of the hand crank 9, thereby causing spring 10 to press member 2, sleeve 19, and cap 1 outwardly until the lever 21 engages a middle step 26. The teeth on the disc 3 and member 2 are disengaged in this position to stop the machine, while the pulley continues to be driven. Upon 90 degrees further rotation of the crank 9 the lever 21 is released from step 26, thereby causing spring 10 to push member 2 further outwards until teeth 24 thereon engage teeth 27 on the crank 9 for transmitting manual drive.