Patent GB-570741-A (GB)
Title: Improvements in or relating to a photographic film spool cassette
IPC: G03B19/04
Filed: 1944-02-01
Abstract: 570,741. Photographic roll - film cassettes. KODAK, Ltd., and NAGEL, H. Feb. 1, 1944, No. 1873. [Class 98 (i)] A film spool cassette comprises two concentric sleeves fitting one within the other and capable of partial rotation relatively to each other to bring film exit slots therein into and out of registration with each other, the inner sleeve being provided with means which during relative rotation of the sleeves to open the slots engages the outer convolution of film on a film spool inserted in the cassette and delivers the leading end of the film .through the registering slots until at or near the end of such partial rotation the means becomes disengaged from the film. As shown, the cassette comprises two sleeves 1, 2 with film exit slots 3, 4. The sleeve 1 is open at one end and secured at the other to the flange 5 of a knurled head 6. The sleeve 2 is open at both ends and fits over the sleeve 1, which is rotatable between the two extreme positions in one of which the slots 3, 4 register and in the other the wall of sleeve 2 closes the slot 3. The movement is limited by the pin 7 projecting from sleeve 2 into the slot 8 in sleeve 1. A film spool is inserted into the cassette, the slots being in registration and the leading end of the film protruding therethrough, and the end cap 13 is applied, the spool being located by bosses on the end cap 13 and the knurled head 6. The cassette is rendered light-tight by turning the head 6, a tooth 16 on sleeve 1 engaging a perforation in the protruding end of the film and winding this end back into the cassette to become located between the sleeves 1 and 2. The flange 5 carries two pins 18 cooperating with slots 22 in a camera body 19 to form a bayonet locking device, a notch 23 being provided to permit passage of the pin 7 into a fixed guideway 24 preventing rotation of the sleeve 2. On rotation of the head 6 the bayonet lock becomes operative, the slots 3, 4 are brought into register, and the film is fed out by tooth 16 between an exposure frame and a spring-pressed presser plate having a slot coinciding with one row of film perforations. Towards the end of the partial rotation the tooth 16 disengages from the perforation and is received in a notch 28 in the film slot 4. The film is fed through the exposure gate by a claw slidable in the back wall of the camera by a button guided in a slot rendered light-tight by a cover strip secured to the button and of such length that one complete movement feeds an exposure frame. In the return movement the claw clicks over the perforations and is retained out of engagement therewith by a cam surface. The exposed film coils into a film-receiving chamber, and is finally rewound into the cassette by a rewind member 34 ha.ving a key extending through the cap 13 to engage a web inside the projecting end of the film spool core. An additional looking device may be provided on the cassette to prevent relative rotation of the sleeves prior to insertion of the cassette in the camera, which device may be rendered inoperative on insertion or locking of the cassette in the camera. The cassette may be of metal or wholly or partly of plastic material. The inner sleeve may be only a segment, and the knurled head may be replaced by an end disc to which a driving member carried by the camera body may be connected after insertion of the cassette in the camera. Specification 372,398 is referred to.