GB704137A - Improvements in means for driving the printing cylinders of a printing machine - Google Patents

Abstract

704,137. Printing machines; cylinder adjustments. DECK, J. P., and RAPP, A. May 12, 1952 [Feb. 19, 1952], No. 11927/52. Class 100 (2). [Also in Group XXIV] In a printing machine of the kind comprising a central impression cylinder 11, Figs. 1, 2 and a series of printing cylinders 15 distributed on the periphery thereof, a driving wheel 16, coaxial with the central cylinder 11, has a series of double helical teeth, and a pair of pinions 59, 64, Fig. 3, are engaged respectively with the sides 18, 19 of wheel 16 ; the pinions form part of a transmission unit 30 for each printing cylinder and are displaceable towards and away'from each other to advance or retard a printing cylinder in relation to the others. The impression cylinder 11 is freely mounted on a shaft 12 extending between a pair of frames 10. Mounted on an extension 17 of shaft 12 are the driving wheel 16 and an angularly adjustable disc 20 on which is carried a number of transmission units 30 connecting the driving wheel 16 to pinions 28 on the shafts 27 of each printing cylinder. Each transmission unit comprises a casing 31, Fig. 3, mounted on a boss 20a formed on the disc 20, the boss being formed with a cavity 35 to receive a crown 43. A series of fixed gear teeth 41 are formed on the inside of the rim of the cavity 35. The crown 43 is also formed with a series of internal teeth 42 adjacent the fixed teeth 41 but different in number and an epicyclic gear 39 rotated on a carrier 38 driven by motor 33 engages both sets of teeth 41, 42. The crown is thereby driven as the motor rotates, through a very low gear-ratio. The crown has an external screwed surface engaged with a screwed socket formed in an abutment 52 slidable but not rotatable in the casing 31. An internally screw-threaded socket 45 of opposite hand is engaged with a screwed plug 47 secured to a shaft 48 fixed at its other end to the other abutment 50 also slidable but not rotatable. in the casing 31. A sleeve 54, rotatable and slidable on the shaft 48, carries one of the pinions 59 and bears against the abutment 52 through a thrust bearing 55. The other pinion 64 is slidable but not rotatable on the sleeve 54 and bears against the abutment 50 through a thrust bearing 63. The sleeve 54 also carries a pinion 56 meshing with the driving pinion 28 of the printing cylinder. The slope of the two tooth parts 18, 19 of the double helical gears are such that the driving pressure forces the pinions 59, 64 apart and into engagement with the abutments. Rotation of the crown in one direction causes the pinions to close together and advance relative to the driving wheel 16. Rotation in the opposite direction has the reverse effect. The motor 33 is adapted to run in either direction and to stop immediately it is de-energized. The disc 20 carrying the transmission units is rotatable by the handle 26 of a worm gear 24, 25. By changing the augular position of the disc the driving wheels 56 of the transmission units may be engaged with driving wheels 28 of any size. By this means the size of the printing cylinders may be changed without modifying the machine.