Patent GB-648695-A (GB)
Title: Method and apparatus for treating continuous strips of flexible material with liquids
IPC: G03D3/13
Filed: 1947-10-02
Abstract: 648,695. Coating webs. PAKO CORPORATION. Oct. 2, 1947, No. 26579. Convention date, Aug. 28, 1943. [Class 140] [Also in Groups XVI and XX] An apparatus for processing a strip of flexible material comprises a receptacle containing liquid, means for moving the leading edge of the strip substantially directly across the receptacle, means at the entrance to the receptacle for simultaneously advancing the strip in the rear of its leading edge at a greater speed than the rate of advancement of said leading edge so that a loop is formed in the liquid and means at the exit of the receptacle for withdrawing the strip at the said greater speed. In the apparatus shown, for the processing of photographic film four receptacles 110-113, Fig. 1, are provided side by side and in a frame 20 which is supported on legs 21, 22 and comprises angle members 20a interconnected at their ends by brackets, receptacle 110 contains a developer, receptacle 111 contains a short-stop solution, receptacle 112 contains a fixing solution and receptacle 113 contains wash water. The film 104 is carried in a spool mounted on brackets 101 at the front end of the frame 20 and its leading edge is passed through slots in a bar 105, Fig. 6, having projections 105b, which is slidable over projections 26b of brackets 26, Figs. 6 and 17, one of which is attached to each angle member 20a. Over the portion 26a of each bracket 26, the upper run of a chain 27 is.caused to travel, the lower run of this chain passing along a portion of a bracket 60, Fig. 17, attached to each angle member. The two chains 27 are entrained around sprockets 28, and two other sprockets, which are mounted so as to be movable along the length of the frame 20 under spring control to vary the tension in the chains, while sprockets 28 are mounted on a shaft 29, Fig. 6. This shaft carries a ratchet wheel 36 into engagement with which a pawl 38 is spring urged ; the pawl is carried by an eccentric 39, Fig. 8, on a shaft 40 which is rotated through a worm gear and belt and pulley arrangement by an electroc motor 56, Fig. 17. Thus, when motor 56 is energized, pawl 38 is given a reciprocatory motion and thereby intermittently rotates the ratchet 36 and sprocket 28 to give an intermittent movement to the chain 27. Projections 27a, Fig. 8, from this chain thereby serve to move intermittently the bar 105. Also mounted on one of the angle members 20a are brackets over portions 75, 70 on which travel the upper and lower runs of a chain 72, Fig. 6, which is entrained over a sprocket 77 on the shaft 40 and another sprocket which is adjustable under spring pressure to vary the tension in the chain. Meshing with this chain 72 are pinions on the shafts 92, Fig. 8, of rollers 93 which drive frictionally upper rollers 97 ; the respective shafts of these rollers 97 are mounted in slots provided in brackets 90, Fig. 6, which have extensions passing through openings in the angle members 20a and which are secured to the angle members by nuts on bolts which pass through elongated slots in said angle members.. The rollers 93, 97 are disposed immediately in front of each receptacle. Pivotally carried adjacent the upper end of the first receptacle 110 is a lever 120, Figs. 6 and 8, having spaced arms 120b carrying a roller 122 and arms 120d with which the bar 105 is to engage. In operation, the film spool is placed on the bracket 101 and the leading edge of the film is threaded through the slots in the bar 105 which is positioned on the guideway 26b of bracket 26. Motor 56 is energized so that shaft 40 moves continuously the chain 72 and therefore the lower rollers 93, while the reciprocatory motion of the pawl 38 imparts an intermittent movement to the ratchet wheel 36, shaft 29 and to chains 27 so that the projection 27a contacts the bar 105 and moves it along its guideway 26b. Just before reaching the rollers 93, 97 of the receptacle 110, the bar contacts the arms 120d of the lever 120 and thus raises the latter. Rollers 93, 97 are rotating at a speed greater than that of the chains 27 so the bar moves ahead of the projection 27a. Immediately afterwards, the lever 120 descends so that the roller 122 carried thereby contacts the film strip and moves it down into the developing solution. Bar 105 then moves the film strip between the next pair of rollers 93, 97 and thereafter the cycle of events is repeated with the exception that the wet film strip forms a loop in the succeeding receptacles of its own accord. The film may pass from the last receptacle into a drier.