Patent GB-259172-A (GB)
Title: Improvements in or relating to rotary stencil duplicating machines
IPC: B41L13/04
Filed: 1925-12-23
Abstract: 259,172. Dick Co., A. B., (Assignees of Brasseur, E. J.). Oct. 3, 1925, [Convention date]. Stencilling; inking-apparatus.-A rotary stencil duplicating-machine is provided with improved inking-apparatus, including improved means for attaching an ink-pad over the usual perforated diaphragm, and with improved means for securing and adjusting a stencil in position on the pad. Figs. 1, 3, and 6 show views of the drum, and Fig. 10 shows the ink-pad. A closed compartment 5, Figs. 1 and 3, is provided behind a diaphragm 3, and within this compartment is an open ink-trough 6 suspended from a shaft 7 about which the stencil drum rotates. The trough 6 is rocked to pour a supply of ink on to the diaphragm by means of a handle 12 adapted to be pushed inwardly and coupled to the shaft 7, this mechanism being similar to that described in Specification 243,071. To ensure a leak-proof mounting of the cylinder on the shaft 7, a stuffing-box is provided at one end consisting of a sleeve 110 passing through one side 112 of the compartment 5, packing 113 between the sleeve and the shaft, an inner sleeve, and a screw-cap 115, which bears against the outer end of the sleeve and thus exerts pressure on the packing. At the opposite end the cylinder rotates about a shaft 117 fixed to a support 8 by means of a. screw 118, which, to facilitate removal of the cylinder, has a lug adapted to be moved into and out of a groove 120 in the shaft 117. An ink-pad 10, Fig. 10, is provided consisting of a sheet of fabric attached at each end to a metal strip 14 by twice folding the edge of the strip on to itself with the end of the pad in between, each strip being identical so that the pad may be reversed end for end when worn. Perforations 17 in the strips 14 engage prongs 21 on a cross-bar 20, Fig. 3, at the leading end, offset portions 18 being provided to guide the perforations on to the prongs; at the trailing end the pad is passed partly around a rod 22 and the plate 14 engages behind the rod and beneath a selected pair of hooks 24 on pivoted members 23 provided at each side of the drum. The ink-pad is clamped at each end between a stencil 11 and the diaphragm in the manner described below. The leading end 25 off the stencil 11 has the usual perforations, and these are passed over hooks 26, Fig. 6, on a plate 27 extending across the drum, the plate 27 being slidably mounted on a bar 33 and fixed to arms 30 carrying adjusting-screws 34, which engage threaded holes in plates 35 fixed to the bar 33, whereby each end of the stencil may be independently adjusted, pointers on the arms 30 and lines marked on the plates 35 indicating the relative positions of the ends. The leading ends of both the stencil and the ink-pad are clamped against a bevelled edge on the diaphragm by means of a curved plate 48 carried by arms 46 pivoted at 45, the arms 46 being rocked for clamping purposes by hand-operated toggle levers 53, Fig. 3. Also carried by the arms 46 is a bent plate 61, which forces the stencil home on to the hooks 26 before clamping is effected. The pivot 45 is carried by an arm 41 pivoted at 40 and fixed by a clamping screw 43 in such a position that the edge of the plate 48 is slightly higher than the stencil so that the plate receives the shock of the impression roller; incidentally, the edge of the plate presents a knife edge for tearing off the stencil backing sheet. At the trailing end the stencil and ink-pad are clamped against the diaphragm by means of a curved plate 75, Fig. 3, which is mounted on a pivot 82 and is actuated by toggle links 86. The plate 75 is guided in its movement by arms 79 pivoted at 81. Adjacent to the arms 79 and dogs 78, which are mounted on the pivot 82 and engage the rod 22, whereby the latter forms a pivot about which the plate 75 tilts in its final clamping movement. One of the dogs 78 carries a pin riding against a fixed guide and, in the withdrawn position of the plate, engaging a recess in the guide, a spring 90 holding the parts in this position. The clamping arrangements may be in the form of removable units, the flanges of an ordinary duplicator being cut away to receive the units, and the parts filled in with inserts 102, 103, Fig. 1, which may carry the fixed guide and also the usual crank button 106, Fig. 6, for coupling to an automatic drive. Pivotally mounted between the arms 46, Fig. 6, and arranged to rock about a bolt 68 are two fingers which engage between the stencil and the sheet to be printed to facilitate the action of the usual ejecting pins.