Patent GB-651310-A (GB)
Title: Improvements relating to the printing and embossing of paper, fabric or other webs
IPC: B41F1/10
Filed: 1948-06-02
Abstract: 651,310. Printing, stencilling and embossing machines. BENNETT, C. D. June 2, 1948, No. 14882. [Class 100 (ii)] In a stencilling, platen printing, or embossing machine employing a movable impression surface in the form of an intermittently - driven polygonal drum adapted to feed a paper &c. web through the machine and co-operating with a flat printing &c. surface movable normal to each flat impression surface on the drum in turn, movable web-gripping means are carried by the drum for holding an area of the web during the printing &c. upon that impression surface which faces the printing &c. surface and for holding the web against longitudinal and lateral movement relatively to the drum during the intermittent rotary movements of the drum. In the stencilling-machine shown, the impression bed comprises a rotatable octagonal drum 1, Fig. 5, having mounted at each opposite edge of each flat portion a set of grippers, e.g. 313, adapted to grip a web 5 to hold it during stencilling and, when the drum rotates, to feed the web from a roll 7, Fig. 1, and over a table 6 between guides 8. Certain grippers, including those in printing position, are rendered inoperative by cam means 16 actuating rods 14 adapted to swing the grippers about their pivots against the action of springs 17. Each gripper comprises a thin metal plate which is slit to provide a series of resilient fingers. Guide rods 21 are arranged on each side of the actuating rod 14. The stencil screen 23, Fig. 9, of fine mesh wire or fine textile fabric, is detachably carried below an opening in a platen 24 which is raised and lowered by rods 65 operated by cams on shafts 31, 63. Paint or ink is forced through the screen by means of a reciprocating rubber &c. squeegee 87, Fig. 9, mounted in a holder on a bar having stub axles 90 engaging in carrier discs 91 which are oscillatable against springs within circular recesses in pivoted rockers 92 mounted resiliently on the platen 24. The squeegee and rocker assembly is reciprocated along guides 95 in the platen by pins thereon engaging within slots in the upper ends of rockers 59 which are actuated by levers 58, 56, 55 from a crank disc 52. Plungers 98 in the rockers 92 resiliently lock the discs 91 within the rockers, and are released towards the end of each stroke of the squeegee assembly by the engagement of adjustable ramps 101 with heads 99 on the plungers. At a further point near the end of the stroke, pegs 115 on the rockers 92 engage pegs 116 fixed on the platen to oscillate the rockers and their carrier discs 91, and thereby raise the holder and squeegee away from the stencil. At the same time, the squeegee holder is engaged by an adjustable contact 118, Fig. 1, which reverses the inclination of the squeegee ready for the return stroke; a spring-controlled snap-joint on the holder facilitates this reversal. The driving and timing mechanism of the machine is derived from a main shaft 25, Fig. 1, through a clutch shaft 30, a lay-shaft 31, and system of gears. A clutch sleeve 45 (not shown) operated by a." wobble " cam 69 on the shaft 30, a fork 70 and links 71, 74 control the timing, the rotation of the drum 1, the lifting of the platen 24, and reciprocation of the squeegee. The drum 1 is registered in each impression position by cam-operated rods adapted to engage ratchet-wheels secured to the shaft 100 of the drum; the drum is also braked by a flexible strap engaging a brake drum on the shaft 100. Embossing can be effected by omitting the squeegee assembly and operating means, and substitutng a relief embossing block or plate for the stencil. For printing, a printing-plate replaces the stencil, and the rockers 59 for traversing the squeegee assembly are utilized for reciprocating an inking roller over the printing-plate.