| 摘要 |
1381521 Film cartridges GAF CORP 6 Jan 1972 [8 Jan 1971] 538/72 Heading G2X The inner face of the end wall of a roll film cartridge has a number of radial ridges 12 extending outwards from the centre, and also a number of concentric circular ridges. These bear against the edge of the rolled-up film and have a braking effect which prevents the film from clockspringing or jamming as it unrolls. A number of transverse ridge-like members 20 are also provided round the inner periphery 16 of the cartridge wall, which further help to control the unwinding of the film roll. |
