Patent GB-328275-A (GB)
Title: Improvements in and relating to duplicating with the aid of stencils
IPC: B41L13/10
Filed: 1928-12-20
Abstract: 328,275. Creed, G. E., and Gestetner, Ltd., D. Dec. 20, 1928. Stencils and apparatus; inking -apparatus; stencil-printing.-A stencil heading adapted to facilitate securing stencils, stencil sheets, porous sheets, and the like on a duplicating-machine is provided with one or more tongues, flaps, or the equivalent, the free ends of which are directed or are adapted to be directed towards the stencil &c., and, when so directed, are adapted by their displacement away from or out of the plane of the stencil &c. to co-operate with stencil fastening means on the machine in securing or assisting in securing the stencil &c. in position thereon. As shown, a series of tongues 4, Fig. 1, is formed in the heading 3 of a stencil 2 by means of V-shaped incisions 5, and similar tongues 11 are provided in the heading 10 of a porous sheet 9, Fig. 2, to be interposed between the stencil and the inking-devices of the machine. Recesses 6, 13 are provided to avoid distortion of the material when the tongues are bent up, and recesses 7, 14, in the headings 3, 10 respectively coincide with the tongues 11, 4 when the headings are placed together for fixing in the machine; incidentally, these recesses assist in guiding the headings into correct position in the fastening-means. In a modification, Fig. 12, the tongues are formed by bending V-shaped projections 51 about the lines 52, slots 53 being provided to allow the elevations 22 described below to engage the tongues. The stencil fastening means consists, as shown, of a clip extending the width of the inking-devices and comprises a lower member 15, Figs. 7 and 8, to which is pivoted at 17 an upper member 16 provided with a finger piece 19 for opening the clip against the action of a spring 18. On the member 15 is a series of elevations 22, which, as the heading 3 or 10 is pushed up into the clip, engage and bend up the tongues 4 or 11, so that when the stencil &c. is pulled back the tongues engage and are guided into correct position by V- shaped recesses 20 stamped in the end of the member 16, the forward ends 21 of the recesses forming abutments for the ends of the tongues. A pin 3 is provided in the lower member of the stencil fastening clip to prevent the stencil being inserted wrong side out, a corner of the heading being cut away at 30a, Fig. 1, to avoid this pin when the heading is correctly inserted. The heading 24, Figs. 5 and 7, of the usual silk carrier 25 arranged between the inking-devices and the stencil &c. sheets is also fixed in the clip 15, 16, and is provided with a slot 29 clear the pin and with projections 27 engaging apertures in the member 15. The elevations 22 may be on the heading 24 instead of on the member 15. Where the fastening-means is applied to a duplicator of the type comprising inking-rollers 42, 43, Figs. 8 and 9, connected by driving bands 37, the clip is fixed to the usual ink-proof protector sheet 31, which is fixed to a bar 32 carrying slides 33 provided with holes to engage pins 36 on the bands 37, the ends of springs 40 fixed to a bar 26 on the free end of the silk carrier 25 being looped over the outer ends of the slides so that the springs pull the carrier taut. The duplicator may, alternatively, be of the type comprising a perforated drum, the clip being fixed thereto in, known manner. Specifications 328,194 and 328,195 are referred to.