A New Sprocket for Theatrical 35mm Projection Equipment, Designed to Limit Film Damage
An answer to the problem of premature film damage in theatrical exhibitions is found in a new sprocket-tooth shape. Torn film often occurs when heavy film tension causes the sprocket tooth to deform the driven edge of the perforation. Lateral film movement causes the tooth to cut into the perforation corners. A redesign of the projector sprocket must take into consideration the importance of handling films with CS perforations as well as the standard KS perforation. The new VKF (Very-Kind-to-Film) sprocket design follows standard center-to-center dimensions, but involves an increase in overall tooth width and adds a radius at all tooth corners so that no sharp edges can contact the perforation, and there is no opportunity for the tooth to contact the corners of the perforation. The design will accommodate either KS or CS perforations. The VKF sprocket is an attempt to make the possibility of film damage less likely, to reduce wasteful film loss, to limit the time spent on film repair, and to make screen presentation more pleasing to the patron.
- Print ISSN
- 0036-1682
- Published
- 1979-02
- Content type
- Original Research
- DOI
- 10.5594/J10446