Patent GB-812909-A (GB)
Title: New or improved photographic printing and developing apparatus
Inventor: SANDERSON THOMAS EDWARD FRANCI
IPC: G03B27/30
Filed: 1954-12-09
Abstract: 812,909. Photographic printing and developing apparatus. COPYCAT Ltd., [formerly COPYCAT ASSOCIATED (MARKETING) Ltd.]. March 9, 1956 [Dec. 9, 1954], No. 27650/54. Class 98(2) An automatically operating apparatus has as chief features an intermittently operable feeding device to advance a web of photosensitive material to a printing position where it is clamped against a master for exposure and then released for further advancement to a cutting device where the exposed length is severed and finally passed through the developer. The apparatus may be set to repeat these operations for a preselected number of times. As shown by way of example a cabinet 1 has flat table top 2 with central portion as glass sheet 3 (Fig. 3), under which are fluorescent lamps 4. Shutter flaps 5 (Fig. 2) under the table top 2 are operated with a cover or head 6 hinged to the cabinet 7 as further described below. Photopaper from a reel (Fig. 4, not shown), in casing 9 at the front of the apparatus passes across the glass sheet 3 steD by step to an assembly of a pair of feed rolls of which the upper one 10 only is shown, guillotine 11, and developer unit 12, which assembly is movably supported on guides 24 for adjustment in position in accordance with the length of the steps by which the paper is advanced, a length variable as by replacement of rolls 10 by others of different diameter. The feed rolls and guillotine are driven through clutches by belt 26, gearing 27, belt 28 and a tandem pair of chains housed in casings 29, 30 from a main motor (not shown) housed in the lower part of cabinet 1; and the developer unit 12 is driven by a separate motor 25. The negative or master to be printed is laid between a pair of flexible transparent sheets comprising a carrier 21 beneath the glass sheet 3, and guides 22 operated by a handle 23 are provided for shift or change of the master. The main motor also drives through belt 38 a hydraulic pump mounted within oil reservoir 39 to deliver oil through pipe 40 to cylinder 41 for moving ram 44 and hence operating arm 45 secured to the head 6 to move the latter upwards and so allow free movement of the carrier 21 and the printing paper and also, with aid of side bars 46 of a rocking frame pivotally supported at 47 to swing shutter flaps 5 downwardly to a closed position. The reverse movement, opening of the shutter flaps to the (exposure) positions shown, is initiated on operation of the guillotine to sever an exposed length of paper which operation is caused to give a pull on the tension member of a Bowden cable leading to a port in a hydraulic timing cylinder (Fig. 5, not shown) in communication with the delivery pipe of the hydraulic pump, resulting in release of oil from cylinder 41 with lowering of ram 44 and the head 6 for the next exposure. For repetitive operation the piston of the timing cylinder, after the appropriate period of exposure which may be controlled by a needle valve in such cylinder, is caused to cover the port and so restore the pressure in cylinder 41. The developing apparatus shown comprises a single pair of driven rollers of which the upper one 96, Fig. 1, may be of sponge rubber, and the lower dips into a bath of developing liquid which is automatically replenished from reservoir 95, the upper roller 96 being wetted from the lower one during the intervals between the passage of successive sheets from the guillotine to the rollers.