Moving microfilm print mechanism - has printing roller with rotary support wheel with automatically variable support radius

摘要

The printing mechanism is for use in a machine for printing continuously moving microfilm strip. It has a printing roller bearing against a guide surface of the documents to be printed, and lifted clear of this surface as desired. Intermediate support rollers may be incorporated. The printing roller (13) turns with support wheel (12) bearing against the guide surface (2), the working radius of this wheel being adjustable. A system is provided (14-17) to alter the radius automatically, dependent on whether or not items (1) are present near the printing mechanism. The support wheel can have an elastic tyre whose periphery may be increased by exertion of a force.