Roll film camera for different film sizes - has interchangeable backs carrying film spools and counter mechanisms

摘要

The rear cover for a camera which can be used with roll films of various types, providing for the use of films with difficult film thickness guide channels, and different frame counting rates. A separate interchangeable back is provided for each specific type of roll film. Each film back has on its inner side a pair of film spool holders (2, 3) with a winder engagement slot (7), together with a spring-loaded pressure plate (9). It may also carry a control cam to assure the proper engagement wiht the counter mechanism and display.