US 4,284,222 AGranted

Pressing roller for use in sheet-advancing arrangements

AssigneeVEB Polygraph Druckmaschinewerke Leipzig

InventorDietrich Hank

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Abstract

A pressing roller is used in a sheet-advancing arrangement to press the advancing sheet material against a driven roller to control the friction between the driven roller and the sheet material and thereby reduce, if not entirely eliminate, any slippage between the driven roller and the sheet material. Two levers pivotally mount the pressing roller on a housing which, in turn, is detachably mounted on a support, the housing being extremely flat and bounding a chamber which has an open end. A diaphragm deflectably spans and sealingly closes the open end of the chamber and urges the pressing roller and thus the sheet material against the driven roller with a force proportionate to the pressure prevailing in the chamber of the housing. Each of two springs is connected to one of the levers and to the housing and moves the pressing roller away from the driven roller when the pressure in the chamber drops below a predetermined value.

Claims7

Dependent claims

In an arrangement for advancing sheet material, a combination comprising a support;

two rollers;
means for mounting said rollers on said support for rotation and for movement of at least one of said rollers into and out of an operating position in which said rollers confine the advancing sheet material between themselves;
means for biasing said one roller out of said operating position;
means for controlling the friction between at least the other of said rollers and the advancing sheet material, including a housing mounted on said support and bounding a chamber having an open end, a diaphragm deflectably spanning and sealingly closing said open end of said chamber;
means for transforming a deflection of said diaphragm into the movement of said one roller into said operating position;
and means for varying the pressure in said chamber to thereby deflect said diaphragm and urge said one roller against said biasing means and thus the advancing sheet material confined between said rollers against said other roller with a force proportionate to the pressure in said chamber.

3 more elements

Dependencies are inferred from the claim text.