Patent GB-947717-A (GB)
Title: Improvements in or relating to devices and methods for producing photocopies
IPC: G03B27/30
Filed: 1960-09-01
Abstract: 947, 717. Photocopying apparatus. W. ZINDLER, [trading as LUMOPRINT ZINDLER KOMM. GES]. Sept. 1, 1960 [Sept. 9, 1959], No. 30203/60. Heading G2A. In contact printing apparatus the original and negative are moved together through a printing zone and then separated, the original being guided out of the apparatus back through the inlet, and the negative guided to a developer section together with a positive sheet. In the form shown, a slot arrangement comprises an inlet slot 16 for the negative sheet, an inlet slot 17 for the original, an outlet slot 18 for the original, and an inlet slot 19 for the positive sheet. The original and negative sheets are guided together, in contact, round a roller 25, against which they are pressed by a curved transparent plate 26, pivoted at 27 and spring-loaded as at 28. The light source 30 is backed by a movable reflector 31, which can be rotated by means of a disc 32 which projects through the housing 1; thus by altering the position of the reflector, the illumination can be adjusted. The roller 25 is mounted on a driven shaft 47, and is formed in two parts separated by a slot (Fig. 4, not shown). In this slot is mounted a swinging element 51, formed asymmetrically so as to have a counterweight effect; thus when swinging freely under its own weight, it always moves so that a projecting part 52 occupies a predetermined position, which is the position shown in Fig. 1. At the tip of the projection 52 is mounted a tongue 53 in a pivoted support 54. The support is acted on by an eccentrically placed spring 55 so as to lift the tongue away from the periphery of the roller 25. In the normal position of Fig. 1, the tongue 53 just engages in an abutment 57 at the inner end of the guide 21 which separates entry slots 16, 17, thus forming in effect a continuation of this guide. A negative sheet is not inserted through slot 16, and an original through slot 17. The negative passes above tongue 53, but the original is below it, so that as soon as the latter reaches the pivot 54, the tongue, and hence the whole swinging segment 51 is pushed round on the shaft 47. As the sheets pass beneath the plate 26,the exposure is made As they pass from beneath the plate, the end of which is bent back, as at 58 (Fig. 2), this bent back portion allows the spring-biased tongue 53 to be lifted away from the roller 25 (position of Fig. 2). This lifts the negative sheet away from the original the positive sheet then proceeding between guide plates 34, 36 to a developing section, while, with continued rotation of roller 25,the original passes, guided by another plate 35, to the outlet slot 18, this slot being bounded by plates 22, 23. As the original leaves roller 25 to pass between plates 22, 23, tongue 53 is lifted fully away from the roller, the end of plate 22 having a recess 59 for this purpose (position of Fig. 3). The segment 51 now swings under its own weight, independently of the roller rotation, from the Fig. 3 position into the Fig. 1 position, the tongue 53 engaging once more in the abutment at the end of guide plate 21. The tongue 53 can carry an identification or other marking, which will then appear on each print. At the same time as the negative and original sheets are fed into the apparatus, a positive sheet is fed in through slot 19. This arrives at the developer section 5 at the same time as the negative sheet, the two passing through the developing fluid held in the bath 38, and finally between squeezing rollers 8 to leave the apparatus through a slot 3. Above the bath 38 is a replenishment drum 41 containing developing fluid, and having two small openings 42, 43, which supply fluid to the bath, and determine the liquid level therein. The drum 41 is rotatably and removably mounted in the main housing 1, and has a tightly closable filling vent. Alternatively it can be filled through openings 42,43.