Paper guide wheel
OwnerNorman H. Kemp, James R. Kempinventors
Life of this patent
Estimating the term…
Abstract
A paper guide wheel for printing presses is formed to include an outer surface eccentric with respect to the axis of rotation of the wheel so as to form an air gap between the outer surface of the wheel and the paper as the paper is drawn thereover during movement through the press. The air gap gradually narrows as the wheel turns, allowing the freshly inked surface of the paper to gently nest against the outer surface at a point removed from the leading edge of the paper. The outer surface has a slightly convex contour in the axial direction to avoid marking of the paper by contact with the axial extremes of the outer surface. Foam material may be provided on the wheel rim to assist in supporting the paper without marking the freshly inked image.
Claims16
A paper guide wheel for a printing press which includes gripper means for pulling sheet paper through the press, said guide wheel comprising:
- a hub portion for supporting the wheel on a shaft driven by the press;
- a rim portion supported by the hub portion and having an outer surface for supporting the paper as it is pulled around the wheel;
- and
- edges defining an opening extending from the rim portion inward toward the hub portion for receiving the gripper means, said edges including leading and trailing edges where the opening interrupts the outer surface of the rim portion, wherein substantially the entire outer surface is not concentric with the axis of rotation such that the leading edge is closer to the axis of rotation than the trailing edge and the distance between the axis of rotation and the outer surface increases gradually and uniformly while travelling along the outer surface in the direction from the leading edge toward the trailing edge.
The method of reversing the direction of a sheet of paper moving through a printing press comprising the steps of:
- providing a rotating guide wheel adjacent an impression cylinder;
- pulling the paper sheet in a first direction around the impression cylinder until the leading edge of the paper sheet reaches a transfer point between the impression cylinder and the guide wheel;
- pulling the paper sheet in a second direction opposite in rotation to the first direction and around the guide wheel at the same rotational speed as the guide wheel;
- and
- while pulling the paper sheet in the second direction, moving the paper-supporting surface of the guide wheel gradually closer to the transfer point from a position slightly separated from the transfer point until the leading edge has moved a substantial distance around the guide wheel.
The method of transporting paper sheets in a printing press comprising the steps of:
- providing a guide wheel having a circular surface for supporting the paper sheets;
- eccentrically rotating the guide wheel to cause the distance separating the circular surface from a transfer point to decrease from a maximum separation distance to a minimum separation distance with each successive rotation of the guide wheel;
- bringing the leading edge of a paper sheet to the transfer point at a time when the circular surface is spaced from the transfer point sufficiently to avoid contact with the paper sheet;
- and
- pulling the leading edge of the paper sheet at least part way around the guide wheel while the separation distance is decreasing to cause a portion of the paper sheet substantially removed from the leading edge to gently nest against the approaching circular surface in the vicinity of the transfer point.
Dependencies are inferred from the claim text.