GB748362A - Silk screen printing machines - Google Patents

Abstract

748,362. Stencilling; printing-processes. DUBUIT, L. G. July 24, 1953 [July 25, 1952; Oct. 4, 1952; June 16, 1953], No. 20666/53. Class 100 (2). Apparatus for printing on objects having a non-planar (e.g. convex) surface comprises a frame to hold the object, and an off-set, resiliently deformable transfer pad consisting of a resilient block of sponge rubber or the like secured on a rigid backing plate and adapted to receive an impression of a stencil design on a silk screen, the object being pressed against the pad so that the surface of the pad is deformed to conform with the surface of the object and transfer the design thereto. The offset transfer pad is of sponge rubber 1, Fig. 3, mounted in a rigid frame 2, on which pad is secured a rubber sheet 3 to receive the printing. The article to be printed, such as a capsule 4 of polyvinyl chloride or other plastic material is held by its edges between plates 7, 8 and lowered on to the pad, both the pad and the article becoming deformed, so as to obtain satisfactory printing contact. Several articles 4 can be clamped between plates 7, 8, Fig. 7, the plates being pivoted on a rod 10, Figs. 7 and 8, whence by means of a handle 15, the articles can be printed on both sides by means of two pads 1, 1a. Printing on the pad is performed by means of a silk screen 39, Fig. 4, and squeegee 40. The pad 87 is supported on a carriage 86. A vertical shaft 84 is rotated from a powerdriven pulley 82 through a clutch 79. The shaft 84 reciprocates the carriage 86 through interrupted gears 37, 35 and a crank 31. The squeegee 40 is supported on a tube 44 slidable on a rod 43 pivoted on trunnions 45. The tube 44 and squeegee are reciprocated by a crank 55 actuated by the shaft 84 through interrupted gears 59, 58. The shaft 84 also carries a cam 50 which co-operates with a cam roller 49 to oscillate the rod 43 and raise and lower the squeegee, and the arrangement is such that the squeegee is in contact with the screen only during its rightward stroke. In another form, three pads are carried spaced at 120 degrees on a rotary table, which is rotated intermittently through 120 degrees from the shaft 84 by means including a Geneva cross having six branches, and a gear train.