Patent ID: 6098537
Filing Date: 2000-08-08
Classification: B41L

Abstract:
A stencil printer comprising a printing drum having a perforated construction in a circumferential portion thereof excluding two annular edge portions at opposite ends of a cylindrical configuration and a stencil sheet leading end mounting bar portion extending between the two annular edge portions along a generatrix of the cylindrical configuration, an inking roller provided inside the printing drum to supply ink to the perforated circumferential portion of the printing drum from the inside thereof, and a back press roller having a cylindrical outer configuration and a print sheet leading end holding clamp in an outer circumferential surface thereof along a generatrix thereof such that a part of the cylindrical outer configuration thereof is provided by the print sheet leading end holding clamp at an outer surface thereof when the clamp is in a closed position, the printing drum and the back press roller being arranged close and in parallel to one another to be rotated mutually in opposite rotational directions, so as to apply a stencil printing onto a print sheet transferred through a nip region between the printing drum and the back press roller with a leading end thereof being held by the clamp, the stencil printing being formed by the ink supplied from the inking roller to flow across the perforated portion of the printing drum and a perforated stencil sheet wrapped around the printing drum, wherein a portion of the outer circumferential surface of the back press roller in an area thereof adjacent to rear and opposite side edges of the outer surface of the clamp as viewed in a direction of movement of the outer circumferential surface of the back press roller due to the rotation thereof is provided by a circumferential wall member at an outer surface thereof conforming to the cylindrical outer configuration of the back press roller, the circumferential wall member being connected to the back press roller to be movable relative thereto and to the clamp, so as to be closely adjacent to the rear and opposite side edges of the outer surface of the clamp in operation with the outer surface thereof aligning to the outer surface of the clamp along the cylindrical outer configuration of the back press roller and biased rearward relative to the clamp as viewed in the direction of the movement of the outer circumferential surface of the back press roller when the clamp is opened from the closed position.