Detailed designs for an improved photographic cassette, which pre-tensions

摘要

The film is rolled onto the rotating spool core (26) which is inside, and held by, the cassette shell (11). A first and second flange (7,28) fasten to the ends of the core, locating the roll. The ring-shaped lip (27b,28c) moulded integrally with the flanges, projects towards, and contacts the outermost winding, preventing looseness in the roll. The flanges are pressure injection moulded from plastic resin. Its temperature of thermal deformation is -80 deg C at a loading of 18.6 kg/cm2; the elastic modulus in bending is 13,000-30,000 kg/cm2; the surface hardness is - 80 on the Rockwell R scale, and it has high flowability for injection moulding. The flanges outer diameter is - 15 mm; thickness is = 0.3 mm and projecting area is -100 mm2. Their contour is essentially circular. In addition to the cassette described, the method of making a flange for ruse with it, is also claimed.