| 摘要 |
A device for the lateral and longitudinal positioning of sheets on the feed table of a printing press, with the leading edge of the sheet engaging a set of front stops and the lateral edge of the sheet in contact with a side guide, enabling accurate registered pick up by a transfer cylinder or the like. Cooperating laterally swingable wiper members are provided both above and below the sheet having friction shoes for wiping the sheet in the direction of the side guide. The friction shoes are connected to the respective wiper members in such a way as to provide freedom of relative movement at right angles to the direction of wipe so that the sheet may move against the front stops at the same time that is being wiped toward the side guide. In the preferred embodiment of the invention the wiper members are in the form of synchronously rotated arms timed so that the arms engage the sheet as the sheet approaches the front stops, and the friction shoes are in the form of rollers interposed at the ends of the arms, freely rotatable about axes which extend in the direction of wiping movement, so that the sheet may complete its movement against the front stops, with accommodating rotation of the rollers, as it is being urged by the rollers toward the side guide. In an alternative embodiment the friction shoes are stiffly secured to the wiping members in the wiping direction but supported with light resilient force in the direction of movement of the sheet so as to permit final movement of the sheet simultaneously in the two directions. |
