Patent GB-500287-A (GB)
Title: Improvements in or relating to the application of colours or the like to various surfaces
IPC: B05B13/02
Filed: 1937-07-02
Abstract: 500,287. Stencils and stencilling - apparatus. ROCKWARE GLASS SYNDICATE, Ltd., MURGATROYD, J. B., and GREGORY, J. G. July 2,1937, Nos. 18450/37 and 13834 /38. [Class 100 (ii)] A non-rotary stencil of the type comprising a porous screen having portions blocked out is employed for applying designs, and colour is caused to pass through the stencil on to the surface by applying simultaneously over the whole area of the stencil either suction to one side thereof or air pressure direct to the colour on the other side or both. In the case of a curved article such as a bottle, a curved stencil is used which is supported on a box disposed within a easing to which a vacuum is applied' and which has means associated therewith adapted to engage the article to form a vacuumtight seal therewith. A stencil 1 is secured to the underside of a colour box 3, Fig. 1, pivoted at 9 and pressed downwardly by springs 12. The box 3 may be divided into compartments 6 for multi-colour work, and a heating resistance 5 may be provided to maintain the ink in a fluid condition: A transfer sheet to be printed is laid on a porous support consisting of a sheet of sponge rubber or layers of linen &c. 14 resting on gauze arranged on a perforated plate covering a recess 18 in a table 13 which is rocked about the pivot 9 by means of a piston 26 in a cylinder 27; the table may be heated by a resistance 21. On depressing a treadle 29, a piston valve 28 is raised whereby compressed air is admitted to the cylinder 27 to raise the table 13 and bring the paper into contact with the stencil. A disc 33 fixed to the piston actuates a valve 34 to admit compressed air to a cylinder 36 to actuate a piston valve 36 to connect the recess 18 with a vacuum whereby ink is sucked through the stencil on to the paper. On return of the piston 26 to normal position, the disc 33 actuates a valve 35 to admit compressed air to the other side of the valve to return it to normal position. Compressed air may be applied to the top side of the stencil via a port 7. Fig. 3 shows apparatus for printing on bottles or other curved articles. A curved stencil 54 is secured across the bottom of a colour-box 53 carried by a casing 51 provided with a rubber &c. rim 52 having air-tight engagement with the article. The outer space of the casing is connected by a pipe 55 with a vacuum whereby the stencil, which is normally spaced slightly from the article, is sucked down on to it and colour is sucked through the stencil. Compressed air may be supplied to the top of the stencil via a pipe 56 in which case the colour box has a detachable cover 57. Fig. 5 shows apparatus in which the table 13 is stationary and the stencil is raised and lowered about the pivot 9 by connection with the piston 26. Compressed air is admitted to a cylinder 81 pivoted at 63 and counterbalanced by a weight 79 to move a piston 65 to the left whereby rollers 74 on a carriage 67 travel over the edges of the stencil as it is lowered on to the paper. On the return movement, the rollers apply line pressure so that the stencil is stripped evenly off the sheet. The rollers are raised by cams near the end of the return stroke.