Patent GB-525114-A (GB)
Title: Improvements in or relating to apparatus for processing photographic film or other strip material
IPC: G03D3/13
Filed: 1939-03-15
Abstract: 525,114. Apparatus for processing photographic film or other strip material. KODAK, Ltd. March 15, 1939, No. 8330. Convention date, March 15, 1938. [Class 98 (ii)] [Also in Group XIII] Apparatus for processing photographic film or other strip material comprises a single means for driving a plurality of independent drive shafts carrying driving pulleys by which the strip is continuously advanced in a series of loops which are formed about the driving pulleys and about idler pulleys carried by associated floating shafts, each of which controls means by which the drive imparted to each drive shaft may be independently varied. In the apparatus shown, the film is fed from a reel 11 through a take-up device 12 over a positivelydriven feed-roll 13 to tanks 14 containing the treating liquids, in which it passes in helical loops over rollers 32 on upper drive shafts 30 and lower idler shafts 31. The rollers, which preferably carry a pair of rubber tyres which engage the edges of the film are loosely mounted on the shafts, the upper rollers being driven by friction from the shafts 30. The shafts 30 are driven by a floating belt 43, which is pressed by rollers 66 into engagement with pulleys 42 connected to the shafts 30 by sprocket and chain gears 40. The pressure exerted by each roller 66, and hence the slip of the belt on the pulley 42 which determines the speed at which the shaft 30 is driven, is controlled by the position of the preceding floating shaft 31, which is mounted on a floater 53 carrying rollers 52 moving on vertical rails 51. Variations in speed of the film due to stretching cause vertical movements of the floater, which are communicated to the roller 66 by a rod 56 and levers 57, 60, so varying its pressure on the belt and causing a compensating change in the speed at which the shaft 30 is driven. In order to thread the film, the whole of the mechanism is raised from the compartments 14 by an hydraulic hoist 45, which carries a girder 44 on which are mounted castings 35 carrying the shafts 30 and the angle-iron frames 51 in which the floaters 53 are mounted. To permit this, the belt 43 has a pair of loops 125 passing under pulleys 126 on a weighted vertically-movable slide 127, Fig. 2. In machines having a long wet section the internal mechanism may be in two parts each carried on a hoist, the driving belt having loops similar to the loops 125 between the two parts, or a separate driving belt being employed for each, in order that the two parts may be raised independently. From the wet section 14 the film passes to a drying section 15 past an air squeegee 73. Here it passes over upper and lower rollers 32 similarly mounted to those in the wet section, the driving shafts 30 carrying pulleys 42, Fig. 2, on which the floating belt 43 is pressed by rollers controlled by the floater carrying the preceding floating shaft 31, as in the wet section. The drive to the first of the shafts 30 in the section 15 is controlled by the last floater in the section 14 by mechanism somewhat similar to that shown in Fig. 5. In the reserve section 16 of the apparatus the film passes round pulleys on a lower shaft 30a, the drive to which is controlled by the last floater in the section 15 by similar mechanism, and pulleys on a counterbalanced floating shaft 31a. The film is finally wound on a roll 17 supported and driven by a roller 99 on a shaft 110 driven from the floating power belt 43 at a speed controlled by the floater shaft 31a through the mechanism shown in Fig. 2. This comprises a pressure roller 116 mounted on a lever 117 which is operated through a, rod 120 by a block 122 carried by the floater shaft 31a, to cause the roller to press the belt more or less firmly on to the driving pulley 115. The partitions 28 in the wet section are notched at the top in order that the film may pass from one compartment to the next beneath the liquid. Where adjacent compartments contain different liquids, the notch is closed by a filler-piece and the film passed up between elevated squeegee rollers 143.