Abstract:
A sheet intercept mechanism for temporarily retaining sheets released by the take-off grippers above a delivery pile at the output of a sheet fed printing press. The mechanism includes a horizontal support member and a clamping member normally in open position but having means for closing to capture the edge of a dropped sheet. A horizontal actuator coupled to the support member advances it to a sheet receiving position above the edge of the pile. Triggering means are provided coupled to the take-off grippers for closing the clamping member phased with the release of a sheet so that the clamping member clamps the dropped sheet preventing it, and any subsequently dropped sheet, from dropping upon the pile so as to permit the pile to be removed and a new pile board inserted. The triggering means is disabled as long as the horizontal support is in its retracted position and enabled only when the support is in sheet receiving position. Means are included for energizing the actuator for return of the support into its retracted position accompanied by stripping of the retained sheets so that they are free to drop upon the inserted pile board and for opening the clamping member in readiness for a new retention cycle.
Abstract:
A printing machine plate cylinder having a plate tensioning slide rail adjustably mounted within a hollow of the cylinder. The slide rail is supported by a plurality of roller ring modules which stably support the slide rail and permit easy and exact movement of the slide rail in any direction in the adjusting plane.
Abstract:
A printing machine plate cylinder having a plate tensioning slide rail adjustably mounted within a hollow of the cylinder. The slide rail is supported by a plurality of roller ring modules which stably support the slide rail and permit easy and exact movement of the slide rail in any direction in the adjusting plane.
Abstract:
A gripper finger for a gripper spindle in a sheet-fed printing press includes first and second components. The first component has a gripper finger extension which contacts a gripper finger support at a transfer point. The first and second components cooperate to form an enclosure angle for enclosing the gripper spindle, with the first component contributing a maximum of 180 degrees to the enclosure angle and the second component supplementing the enclosure angle. The second component is fastened to the gripper spindle. A first compression spring is disposed between the ends of the first and second for exerting an adjustable, first spring force approximately in a direction of the transfer point. An adjustment screw is threadably engaged with one of the components and has a tip which lies against the supporting plane of the other component for exerting a screw force approximately in a direction of the transfer point. The first spring force and the screw force combine to form a resultant force in the direction of a line connecting the center point of the gripper spindle and the transfer point. A second compression spring clamped between the first component and the gripper spindle urges the first component against the gripper finger with a force greater than the first spring force and in a direction which essentially coincides with the direction of the resultant force.
Abstract:
A job strip encoding printing process data is disposed on an indicia-free zone of an associated printing plate. The printing process data include process control data, press presetting data and organization data for the entire print order using the associated printing plate. Preferably, all of the important printing adjustments are computer controlled and the printing machine includes a scanner for automatically reading the job strip when the printing plate is clamped onto the plate cylinder of the printing machine. The job strip is not integral with the printing plate so that the printing process data are easily changed. The job strip, however, is attached to the printing plate and therefore the printing process data and associated printing plates are not mixed up in the print shop. The job strip is elongated and aligned parallel and adjacent to a longitudinal edge portion of the printing plate which is clamped to the plate cylinder. The job strip is circumferentially displaced from but located close to the area of the printing plate which is capable of printing and which engages the blanket cylinder, so that the inking rollers roll over the job strip during printing to keep it clean for scanning.
Abstract:
The invention relates to an inking mechanism for letterpress and offset printing machines comprising a vibrator having a plurality of discs which are disposed side by side and which are adapted to reciprocate individually and independently of one another between a duct roller and a transfer roller, and the width of each of which corresponds to a specific inking zone. The disc each consist of a middle part and an outer ring with a covering and are disposed side by side without gaps on a stationary carrier tube. Each middle part is mounted movably on the carrier tubes and has a circular outer periphery on which the outer ring is rotatably mounted and a drive for the individual movement of the middle part is provided inside each disc.
Abstract:
A pile changing device for a printing press delivery mechanism which includes a first conveyor for delivering sheets from the press seriatim to a piling space, the sheets being accumulated on a pile board in the form of a skid. A track extends from the piling space to a second conveyor. A fork lift mechanism is provided having a carriage which is shiftable on the track. Control means, which is automatically triggered when the skid becomes full, causes the fork lift mechanism to remove the skid from the piling space and to deposit it on the second conveyor. Upon removal of the full skid from the piling space the control means causes feeding of an empty skid via a third conveyor from a skid magazine into a precise sheet-receiving position. an auxiliary pile board is interposed on the path of the delivered sheets during the brief interval when there is no skid in sheet-receiving position. In the preferred embodiment of the invention the fork, in addition to its shifting movement, undergoes lifting, lowering and rotational movement in effecting transfer of the full skid.
Abstract:
An arrangement for securing impression as well as skew adjustment of one cylinder relative to another in a printing press. One of the cylinders has a bearing assembly occupying a cylindrical opening in the press frame. The bearing assembly includes a cylinder bearing having parallel planar support surfaces on opposite sides. An annular eccentric guide bearing has a cylindrical outer surface which is fitted into the cylindrical opening in the frame. The guide bearing is provided with opposed parallel way surfaces perpendicular to the plane containing the axes of the cylinders for slidably receiving and supporting the cylinder bearing. A first adjustment is provided for rockably positioning the guide bearing. The cylindrical opening in the frame has an axis which is offset, in a direction parallel to the way surfaces, from the axis of the cylinder bearing so that as the guide bearing is rockably adjusted the first cylinder is moved toward and away from the second cylinder thereby to vary the degree of impression. A second adjusting means is interposed between the cylinder bearing and the frame for positioning the cylinder bearing along the way surfaces thereby to adjustably skew the first cylinder with respect to the second. In the preferred form of the invention the parallel way surfaces are defined by a diametrical open-ended slot formed in the guide bearing.
Abstract:
An apparatus for varnishing a sheet being fed from a sheet fed printing press into a delivery unit, the sheet being conveyed by an endless loop conveyor made up of a pair of laterally spaced conveyor chains. Cross members extend between the chains at regular intervals carrying grippers for the leading edge of successive sheets. The chains are guided to form a delivery run and a return run spaced apart and generally parallel to one another. An applicator cylinder is journalled between the runs having an axial length which is shorter than the lateral spacing between the chains. A plate cylinder journalled in the frame outside of the return run is in rolling engagement with the applicator cylinder for supplying a varnish film thereto. A backing cylinder journalled in the frame outside of the delivery run is in rolling engagement with the applicator cylinder. The circumference of the cylinders equals the spacing between successive cross members and grippers. The applicator, plate, and backing cylinders have respective longitudinal grooves sufficiently large to provide free passage for the cross members and associated grippers. The cylinders are driven synchronously with the conveyor chains so that a sheet passing on the grippers is engaged between the applicator and backing cylinders for application of varnish to the sheet. The conveyor speed is less than the press speed in a predetermined ratio. The cylinders have a diameter less than the diameter of the cylinders in the associated press unit in the same ratio.
Abstract:
An ink fountain formed of a trough and fountain roller, the trough having a recess along its presented edge which defines a ledge surface. A metering bar of durable resilient plastic, and which is of "L" cross section, has a first leg which occupies the recess and a second leg which overlaps, and is sealed to, the bottom of the trough, with the corner of the metering bar defining a gap. Adjusting keys are spaced along the metering bar, each key having a rotatable stem carrying an eccentric at its tip. The first leg of the metering bar has a groove of constant width extending along its inner surface, parallel to the fountain roller, in which all of the eccentrics are snugly received for localized adjustment of the gap, positively in both directions. A resilient sealing strip interposed between the ledge surface and the metering bar seals the second leg of the metering bar with respect to the frame.