GB904149A - Improvements in or relating to photographic processing - Google Patents

Abstract

904,149. Feeding webs. LANGHAM THOMPSON Ltd., J., and PRUDENCE, M. B. Sept. 29, 1960 [Sept. 3, 1959], No. 30092/59. Class 100 (1). [Also in Group XX] In a film or like strip feeding arrangement, the film is inserted through the apparatus in contact with feeding devices in an unlooped condition, and means are provided for rendering the feed devices effective sequentially, and for successively forming loops in the said strip. Fig. 1 represents diagrammatically a number of successive processing tanks, sections 1 and 2 representing a development stage, section 3 a fixing stage, and section 4 a washing stage. The film is advanced through the apparatus by a number of drive sprockets 11-14, and is initially laid across the sprockets as indicated by the line FL1. Between sprockets 11 and 12 is a fixed undriven roller 16. Above each section is a weighted roller 31-34, which is allowed to rest on the top of the film, as shown. First, sprocket 11 only is driven, in consequence of which the weighted rollers 31, 32 descend to form two loops in the film, one on each side of roller 16. The descent is arrested when the rollers have reached a lower position 31<SP>11</SP>, 32<SP>11</SP>, so that the film is now looped down twice into the developing tank. Sprocket 12 is now also set into rotation, so that the film now feeds into section 3. Weighted roller 33 thus can now descend to form another downward loop into the section 3 (fixing) 'tank. Similarly, on causing sprocket 13 to operate, roller 34 forms a loop into the section 4 tank (washing). Sprocket 14 then comes into operation, and the film thereafter feeds at a uniform speed through the apparatus. Sprocket 11 is driven directly from a motor, and this drive is transmitted to the other sprockets by a chain 22. The drive only becomes operative on sprockets 12, 13, 14, however, when a clutch mechanism is actuated. Each sprocket has its own clutch 30, 31, 32, respectively, operated by a solenoid B, C, D. A cam mechanism (Fig. 2, not shown), is arranged to actuate three microswitches in succession, at predetermined time intervals, to bring drive sprockets 12, 13, 14 into a successive operation at the required times. Fig. 3 (not shown), is a suitable circuit for carrying out the sequence of operations automatically.