Patent GB-855697-A (GB)
Title: Improvements in automatic printing machines for fabrics, papers and the like
IPC: B41F15/42
Filed: 1958-12-08
Abstract: 855,697. Screen-printing machines. MASSON, C. Dec. 8, 1958 [Dec. 16, 1957], No. 39405/58. Class 100(2) In a printing machine comprising a printing table 1 whereon fabric or paper 2 to be printed is stretched, stencil frames 3 hinged for pivotal movement relative to the table and reciprocable squeegees 4 associated with the stencil frames, the stencil frames are raised and lowered in unison by a mechanism disposed above the table, the squeegees being actuated in unison by another mechanism also disposed above the table. A frame 5 secured to the ceiling 6 or framework above the table 1 by a bracket 7 consists of two parallel tubes each carrying an electric motor 8, 9. The motors drive shafts 10, 11 mounted in the tubes and the shafts drive, through worms 14, 15 and worm wheels 16, 17 shafts 18, 19 rotatably mounted in gear casings 12, 13 at the ends of the parallel tubes. The shafts 18, 19 carry discs 20, 21 respectively in each of which is formed a pair of diametrically opposed notches 20a, Fig. 3. Bell-crank levers 22, 23 pivotally mounted on the casings 12, 13 carry rollers 24 which engage the peripheries of the discs 20, 21. The levers 22, 23 carry lateral lugs which, when the rollers 24 rest on the unnotched portions of the discs 20, 21, close switches 30, 31 in the circuits of the motors 8, 9, but which allow the switches to open when the rollers 24 come to rest in the notches 20a. When the rollers are in the latter position the motors may be restarted by pulling on strings 32, 33 attached to the bell-crank levers 22, 23 whereby the lateral lugs thereon close the switches 30, 31. As the motors rotate the shafts 18, 19 the unnotched portions of the discs 20, 21 engage the rollers 24 and hold the switches closed for half a revolution of the shafts i.e. until the rollers 24 engage in the other of each pair of notches 20a. A rod 38 mounted in a carriage 36 slidable in guides 37 on the casing 12 and in similar carriages slidable on brackets secured to the ceiling 6, is connected to one edge of each of the stencil frames 3 by strings or the like 39. A cam 34 on the shaft 18 engages a follower 35 on the carriage 36. Rotation of the shaft 18 through half a revolution from the Fig. 2 position causes the cam 34 to assume the Fig. 3 position wherein the rod 38 is raised and the frames 3 are thereby hinged upwards from the table 1 about their pivots 40. A squeegee 4, Fig. 2, comprising blades 4a which operate alternately at successive strokes of the squeegee, co-operates with each stencil frame and is mounted on a carriage 49 which reciprocates on rollers 50 along parallel tracks 41. The carriages 49 are connected by links 48 to arms 47 rigidly mounted on a shaft 46. Another arm 45 on the shaft 46 is connected by a link 44 to a crank-pin carried by the shaft 19. Half a revolution of the shaft 19 causes the arms 47 to oscillate in one direction and the subsequent half revolution causes them to oscillate in the other direction, the squeegees 4 heing thus caused to traverse the frames 3 in both directions and effect printing on the fabric or paper 2 on the table 1. The several stencils in the frames 3 may be used for printing in different colours if a multi-coloured design is used. When the squeegees are in the Fig. 2 position after printing, the shaft 18 is rotated through half a revolution so as to raise the frames 3, the squeegee carriages 49 pivoting upwards about the rollers 50, and the web of fabric or paper 2 is advanced so as to position it for receiving further designs or portions of design. The shaft 18 is then rotated through a further half revolution and the frames are lowered: with the parts in this position printing is again effected by a complete revolution of the shaft 19.