Patent GB-703887-A (GB)
Title: Improvements in or relating to machines for printing or coating fabrics
IPC: B41F15/40
Filed: 1952-02-08
Abstract: 703,887. Stencilling machines. BARROS, A. J. C. DE O. Feb. 8, 1952 [Dec. 29, 1951], No. 3439/52. Class 100 (2). [Also in Group VIII] A machine for printing fabrics comprises a pressure cylinder 1, Fig. 1, and a plurality of printing cylinders 2, 3, 4, the surfaces of which are formed by a screen permeable to colouring agent in zones corresponding to the pattern to be reproduced, the colour being fed from the inside. In operation the fabric A fed from a roll 9 is passed over various guide rollers 10-14 and passed round the cylinder 1. A blanket strip B is unwound from a roll 17 and passed round the cylinder 1 under the fabric A. The surface of the pressure cylinder is somewhat resilient, of rubber or the like. Figs. 3 and 6 show sections at right angles through one of the printing cylinders 2, 3 or 4 which comprise a pair of end plates 20, 21 mounted on shafts 30 and having clamped thereto by band clips 24 the ends of a cylindrical screen 22 consisting of a gauze, e.g. of metal, silk, nylon or glass. The end plates 20, 21 are mounted on ball bearings on sleeves 29 threadedly engaged with the shafts 30 and rotatable by handles 35 to move the plates axially so that the screen can be tensioned and also accurately located axially. The shafts 30 are fixed in slidable blocks 32 adjustable by screws 8 to move the printing cylinder towards or away from the pressure cylinder. The printing cylinder is driven by frictional contact with the pressure cylinder and by gear wheels 36 carried on the shaft 80 thereof meshing with gear wheels 26 mounted on bosses projecting from the end plates 20, 21. Angular adjustment of the printing cylinder is effected by screwed spindles 27 on the gear wheels 26 engaging worm gears 39 on the end plates. Inside the screen is a vat or tank 50 receiving the colouring agent and mounted on the ends of shafts 30, rollers 60, 65 rotating inside the vat transferring ink to the inside surface of the screen. The roller 60 is driven by spindle 61 connected to a variable speed chain gear 62, 63, 64 and the roller 65 is free and carried on brackets 68 mounted on the ends of shafts 30. Ink is fed by gravity or as shown in Fig. 3 by compressed air from a reservoir through the left hand shaft 30, via openings 49 to a trough 58 under the vat. The trough 58 is separate from the vat but communicates with it by distributing holes 59. Each printing cylinder 2, 3, 4 may be supplied with ink of a different colour for multicolour printing. In a modification, Fig. 7, each cylinder is adapted to print in a number of different colours by being partitioned by a series of discs 69 threadedly engaged on a continuous shaft 30. Each compartment is supplied with colour through pipes 78 &c. passing through a bore in the shaft 30. Rollers 77 mounted on brackets 72 on each side of each compartment force ink through the screen as before. The roller 60 is dispensed with in this arrangement, the colour level being such that the rollers dip. In modifications the colour may be sprayed against the inside of the screen in an atomized form. The stencil may be permeable all over, having no parts blocked off, the process then amounting to a dyeing or coating process. The stencil may be formed of a hollow cylinder of metal or plastic having parts of the walls cut away in the shape of the pattern to be reproduced, a cylindrical gauze lying inside the cylinder allowing ink to pass through for printing on to the fabric. Electric or hydraulic means may be provided to replace manual operation of the screws 8 and adjust the pressure. These means may be automatically controlled to increase the pressure as the speed of operation increases. A stroboscopic device may be provided to check the pattern as it leaves the machine. Specification 246,794, [Class 100 (ii)], is referred to.