Patent GB-407926-A (GB)
Title: Improvements relating to cinematograph apparatus
IPC: G03B1/50
Filed: 1932-06-21
Abstract: 407,926. Kinematograph apparatus. COMMUNITY SERVICE, Ltd., 1, Montague Street, Russell Square, London, and FOSTER, W. D., 4, Wilsey Square, Ridgewood, New Jersey, U.S.A. June 21, 1932, No. 17576. [Class 97 (i).] Kinematograph apparatus for handling films having image bearing areas of different size and/or differently spaced feed perforations has an interchangeable film gate or part thereof which is provided with means adapted to associate with and alter toothed film feeding means permanently mounted on the apparatus so that the film feed is adjusted to correspond with the gate in use. In the form shown in Fig. 1, the intermittent film feeding means comprises claws 27 on a plate 20 slidably mounted by straps 21, 22 on a plate 15. The latter has at one end an open slot 16 embracing a screw 14 on the support 10 and is provided with an aperture through which the driving shaft 12 passes. The plate 20 is moved in and out to cause the claws 27 to engage the film by a cam 25 permanently mounted on the shaft 12 and working in an opening in the plate 20. The plate 15 is oscillated about the screw 14 to effect longitudinal movement of the film by a cam 18 which is detachably mounted on the shaft 12 in set position by co-operating key and key way 73, 74<1>. A bracket 55, Fig. 4, carries both a film gate 47, pivotally mounted by means of a stub shaft 48 supporting the gate between the window 52 and aperture 75 for the feed claws, and a cam 18, rotatably mounted on a depending lug 56. Thus, when the bracket 55 is fixed by a screw 60 to the support 10 a cam 18 corresponding to the gate 47 is applied to the shaft 12 to effect appropriate oscillation of the plate 15. The pivotally supported gate section 47 is held against a fixed gate section 40 by a spring urged plate 80 slidably mounted on the support 10 and having an extension 83 with a notch 84 which engages an edge of the gate section 47. A pin 91 enables the plate 80 to be moved against the tension of the spring 86 so that the gate may be opened to permit insertion of the film. A screw 88 enables the tension of the spring 86 to be adjusted. A plate 30 may be slidably mounted on the support 10 and moved by a cam on the shaft 12 2 to insert a retaining claw in the film perforations when the claws 27 are not operating. The lower part 41 of the fixed gate section is yieldingly mounted on screws 42 biassed by a spring 44 and may be longitudinally split so that one part may be depressed by a cam formation on the gate for narrow films to form an appropriate film track. In a modification, Figs. 6 and 7, the film feeding means comprises a sprocket 125 provided with teeth 126 for engaging a wide film and teeth 128, 129, in an annular groove 127 for engaging narrow film. The sprocket 125 is fixed on a shaft 130 carrying two freely rotatable, spaced, star wheels 132, 142 and an intermediate clutch member 137 rotating with the shaft 130 but axially movable thereon. The star wheels 132, 142 have differently spaced teeth so that a rotation appropriate to the film being used may be given to the sprocket 125 and are driven respectively by cam wheels 150, 151. The clutch member 137 has teeth 136, 136<1>, adapted to engage teeth 135, 135<1> on the star wheels 132, 142 respectively and is axially moved to bring one or other star wheel into engagement with the shaft 130 by links 162, 167 in accordance with the position of a pivoted lever 165, which is spring urged normally to hold the clutch member in neutral position. The interchangeable film gate 102 which preferably carries the appropriate lens 110 is attached to the support 100 by lugs 103 inserted in straps 101 and is provided with a projection 171 which contacts with and moves the lever 165 to cause the appropriate star wheel to drive the sprocket 125 at a rate corresponding to the size of film for which the gate is designed. A gate section 122 is mounted by hinges 116 on the gate section 102. According to the Provisional Specification the film gate and film feed mechanism may be formed as a single unit which is interchangeable to suit films of different sizes. Specification 255,496, [Class 97 (i)], is referred to.