Patent GB-562502-A (GB)
Title: Improvements in and relating to mirror-script duplicators
IPC: B41L11/00
Filed: 1942-09-01
Abstract: 562,502. Copying documents. ANDERSON, A., and WRIGHT, A. J. J. Sept. 1, 1942,No. 9860/41. [Class 100 (ii)] A rotary mirror-script duplicator is provided with a master clip adjustable lengthwise of the drum and adapted to be coupled to a carriage movable lengthwise of the drum on stationary guides. Preferably also the drum carries a fixed master clip so that sheets may be printed with matter on a master sheet carried thereby and with variable matter from the master sheet carried by the adjustable clip. The fixed master clip comprises a fixed plate 19, Figs. 2 and 5, and spring gripping fingers 20, and the movable master clip, a plate 22 and similar fingers 23. The plate 22 is slidable on a guide bar 26, Figs. 2 and 3, and has secured thereto a rack 29 engaged by a pawl 30 on a slidable pawl plate 31, the feed movement of which is effected against the action of a returning spring 33 by means of a slidable rod 34 engaging at one end with a flange 31a on the plate 31 and at the other end with a bell crank 36 rocked by a finger lever 37 on the machine frame. To adjust the throw of the pawl plate 31, the rod 34 may be positioned further from or nearer to the axis of the bell crank 36 and for this purpose the guides 35 for the rod are carried by parallel levers 39 urged by a spring 40 in a direction to give maximum throw to the plate 31, the movement however being limited by the engagement of the guide-carrying member with the end of a rod 43 carried by a block 41 mounted for adjustment along a fixed, rack 42. The block carries a locating pawl 44 to engage the rack and a detent pawl 45 to engage the rack 29, a common spring 47 urging the pawls to operative position. In the initial position of the parts, as shown in Fig. 3, the pawls 45, 30 engage stops to disconnect them from the rack 29 so that the clip plate 22 can be drawn to the left-hand end of the drum 4, as shown in Fig. 3, in which position the master sheet carried thereby is entirely beneath the master sheet carried by the fixed clip plate 19. The impression roller 10, which, as shown, is about half the length of the drum 4, is mounted in a carriage 7 adjustable along the drum on guides 3. A lever 15 pivoted to the carriage 7 and serving, by engagement with a rack 17, to lock the carriage in adjusted position, has a forked upper end 50, which, when the lever is moved to unlock the carriage, embraces the block 41 and lifts the pawl 44 out of engagement with the rack 42 so that movement of the roller 10 along the drum 4 is accompanied by a movement of the movable master sheet clip plate 22, due to the engagement with the rack 29 of the pawl 45 so that a predetermined part of the movable master sheet is exposed at the side of the fixed master sheet so that composite prints from the two sheets may be made. The same movement of the block 41 also sets the rod 34 so that a subsequent operation of the bell crank 36 advances the movable master sheet to an extent equal to the amount exposed by the movement of the block 41. Instead of a short movable impression roller, a roller extending the full length of the drum may be employed, masks being used to cover those parts of the masters from which no impressions are desired.