Patent GB-712131-A (GB)
Title: Improvements in or relating to silk screen printing machines
IPC: B41F15/08
Filed: 1951-11-01
Abstract: 712,131. Printing-machines. DUBUTT, L. G. Nov. 1, 1951 [Jan. 2, 1951], No. 25599/51. Class 100 (2) Printing on curved surfaces; stencilling machines.-A machine for printing through a silk screen on articles such as bottles, having cylindrical or conical surfaces comprises, in the form of Figs. 1, 2, a base 1 having an upright 2 providing horizontal arms 3, 4. On arm 3 is pivoted at 5 a frame 6 connected by horizontal pins 7 to a second frame 8 carrying the silk screen 12 which is thereby movable in a horizontal plane. A fixed scraper blade 15 is mounted on an arm 14 pivoted at 13 to the arm 4 and bears on the upper side of the screen to force the ink through during the printing process. An inclined plate 20 fixed to the base 1 has slidably guided thereon by rollers 22 a plate 21 carrying pedestals 33, 34. In pedestal 33 is mounted a spring loaded rod 40 carrying a rotatable conical head 43 for engagement, e.g. in the mouth of the bottle 38. Pedestal 34 provides a bearing for a spindle 35 having, at one end, a cup 37 to receive the bottom of the bottle and, at the other, a disc 36 from the face of which projects an eccentric finger 50. Mounted on a bracket 24 fixed to plate 20 is a pulley wheel 26 having a notch in which the finger 50 may be engaged to couple the disc 36 to the pulley and cause rotation of the bottle. The pulley is driven so that the speed of the surface of the bottle is equal to the speed of the coacting part of the screen by means of a cable 26a wrapped round the pulley 26 and connected to the ends 31 of the frame 8. A lever 45 pivoted to pedestal 34 has one end 45a adapted to engage the outside surface of cup 37 under the action of spring 46 and another end 45b formed with a catch-shaped end 47 adapted to snap over a fixed roller 48. A cross piece 9 on the frame 8 is formed at each side with cam or ramp surfaces 17 on which the arm 14 carrying the scraper rests so that at the end of the movement of the screen the scraper is lifted out of contact therewith. Similar surfaces 18 on the underside of the cross-piece 9 engage a part of the fixed arm 4 to cause the screen to be lifted bodily at the end of its movement. In operation the bottle 38 is mounted between the cup 37 and cone 43, the support plate 21 being in its lowermost position. Where it is desired to print in more than one colour a mark on the bottle may be accurately aligned with a mark on the cup 37 in each printing operation. In the lowermost position of the support plate 21 the disc 36 is separated from and uncoupled from the pulley 26 and the cup 37 is locked by the engagement of the spring loaded lever 45. When a bottle is mounted, the support is displaced to the right (as seen in Fig. 1) to the printing position where the conical surface of the bottle lies under the screen. The support plate 21 is retained in this position by the engagement between the catch 47 and roller 48, the lever being tilted thereby to release cup 37. Displacement of the screen from one extreme position to the other first causes the screen to drop into contact with the conical surface of the bottle and the scraper to move to operative position. After the printing operation the plate 21 is displaced downwardly (to the left as seen in Fig. 1) and the printed bottle removed. In the form of Fig. 5, adapted to print on flagons having only one curved surface, the screen 109 is mounted on a carriage 107 running by rollers 106, 110 on parallel guide rails 105 supported on pillars 103. The scraper 114 is pivotally carried on an arm 113 by bracket 111 and has means to lift it out of engagement with the screen at the ends of the travel of the screen. A rack 121 carried on the underside of the carriage meshes with a gear wheel 120 having bearing in a sleeve 117 carried on a pedestal 115. The flagon 128 or the like to be printed, which is held between blades 129, is turned by a spindle 124 slidably keyed in a bore in the gear wheel 120. The spindle 124 is slidden axially to bring the flagon to the printing station under the screen 109. In another form the support for the article to be printed, e.g. a tumbler is pivotally arranged in an opening in a plate which carries a series of such supports, the machine being adapted to print automatically on a succession of tumblers carried on the plate which is rotated in steps to bring each in turn under the screen. A cam controls the coupling of the driving pulley to a tumblersupporting cup and a lever locking said cup. Another cam causes lifting of the support to bring the tumbler into printing contact with the screen. In the form of Fig. 12 a series of support plates 311 are carried by arms 310 pivoted to a series of rods 307 mounted on a head 308 which is rotated in steps to bring each tumbler in turn into engagement with the printing means. The driving pulley 350, which is driven by movement of the screen through a cable 351, is carried on a bracket 343 having an arm 344 cooperating with a cam 346 to move the pulley towards the position in which it is coupled with disc 335 fast on a spindle with the tumbler mounting cup 334. A downwardly extending projection on the plate 311 engages a cam operated member displaced when at the printing station to lift the plate 311 and bring the tumbler mounted thereon into contact with the screen. Means are provided for locking the tumbler carrying cup against rotation until the bracket 343 moves to coupling position. Spring-loaded tumbler retaining means 320 is displaced by means of cam 329 to facilitate removal of printed tumblers and insertion of tumblers for printing, the tumblers being carried, when released, on yokes 353.