GB653751A - A spool having means for retaining fixed to its core a perforated photographic film - Google Patents

Abstract

653,751. Photographic and kinematographic film spools. DUCATI-SOC. SCIENTIFICA RADIO BREVETTI DUCATI. Feb. 27, 1948, No. 6162. Convention date, Nov. 12, 1946. [Classes 97 (i) and 98 (i)] A film spool of the kind in which perforated film is attached to the spool core by engaging the perforations upon teeth extending outwards from the outer surface of the core is characterized in that the film is retained on the teeth by a strip or spring carried by the core and partially surrounding it. In an alternative construction the teeth are formed on and extend inwardly from the inner surface of the strip. As shown a preferably resilient strip 4 partially surrounds the spool core 1 and is prevented from rotating about it in one direction by a stop 2. Teeth as 3, 3<SP>1</SP>, are formed in the outer surface of the core or the inner face of the strip and engage in the film-feed perforations 6 as the film is pushed between the core and the strip, return movement of the film being prevented by the vertical face of the sawtooth profile of the teeth engaging the back edge of the perforations. To remove the stump of film held on the spool after cutting off the free portion of the film the strip 4, (Fig. 2) is rotated anticlockwise and the stump of film freed so that the spool may be used again. In the alternative construction, Fig. 3, having teeth formed on the inner face of the strip, the strip is rotated until it and the film stump have passed completely over the inclined face of the stop 2, the film is pressed down into the space between the strip and the core, and is then removed from beneath the end of the strip opposite to that under which it was inserted originally.