Heidelberger Druckmaschinen Ag

Lothar Stadler

Willi Jeschke

Gerhard Pollich

Andreas Fricke

Heiner Luxem

Hans-Jurgen Bernau

Gripper control for a cyclically rockingly driven pregripper for single-sheet feeding in a sheet-fed printing press, the pregripper being disposed at a free end of a rocker lever, which is swivelable about a rocker shaft fixed to a frame of the printing press, and having at least one sheet gripper forcibly movable by cams about an articulated shaft disposed parallel to the rocker shaft, for closing and opening the sheet gripper when the sheet is taken over and transferred, respectively, one of the cams being revolvable a single revolution, and another of the cams being disposed on a locally stationarily swivelable roller lever carrying a cam roller engaging with the one cam, the other cam being swivelable cyclically in the position thereof, the position of the cams determining the closing time and opening time of the gripper, includes an indexing mechanism for fixing the other cam on the locally stationarily swivelable roller lever, the other cam having a first gripper-closing cam region and a first gripper-opening cam region, the first gripper-closing cam region having a second gripper-opening cam region, the one cam revolvable a single revolution having a second gripper-closing cam region operatively associated with the second gripper-opening cam region for compensation.

Gripper control for a cyclically rockingly driven pregripper for

Device for avoiding registration errors at an oscillating pregripper of a sheet-processing machine includes a gripper bar deflectable in synchronism with the machine so that a respective sheet being processed therein undergoes stretching in a trailing region of the sheet. The gripper bar, in a middle region thereof, is guided and driven in a flexurally bending-resistant manner. A feeder cylinder carries thrust pads at both sides thereof for deflecting the gripper bar at the ends thereof in a sheet travel direction before a respective transfer of a sheet at the feeder cylinder, and for maintaining the deflection until sheet transfer has been completed.

Device for avoiding registration errors in a sheet-processing machine

Pregripper of a sheet-fed printing press includes a drive unit for pivotally driving a pregripper bar secured to a pregripper support device, the drive unit having main and auxiliary cam elements disposed on a drive shaft so as to be fixed against rotation relative thereto, and cam follower members cooperatively engaging with the cam elements so as to produce a movement of the pregripper bar, the pregripper support device engaging the pregripper bar approximately centrally for introducing a force to produce the pivoting movement.

Pregripper of sheet-fed printing press

An adjusting device has a pneumatically operating piston-cylinder unit pressurizable in an operating function thereof for actuating adjusting elements in a printing press. The piston-cylinder unit includes a cylinder housing formed with a cylinder chamber, a piston displaceable in the cylinder chamber, and an electromagnet for applying an activated holding force to the piston, the piston being subjectible pneumatically to a prepressurizing force in the cylinder chamber opposite to and less than the activated holding force.

Adjusting device with a pneumatic cylinder in a printing press

A device for securing a flexible printing plate under tension on a plate cylinder is used in combination with the plate cylinder which has an axially extending channel with side walls formed therein. There is a tensioning rail operatively associated with each end of the printing plate. Each tensioning rail is braceable against one of the side walls of the axially extending channel formed in the plate cylinder for tensioning the printing plate. The device includes one of the tensioning rails operatively associated with at least one of the ends of the printing plate which is one-piece and has a central clamping member disposed at a middle region thereof for clamping a center of the one plate end. Respective tensioning strips are disposed at end regions of the tensioning rail. Each tensioning strip is mounted for axial movement on the tensioning rail and has an edge clamping member mounted thereon for clamping an edge of the one plate end. A selectively rotatable cam member is mounted on the tensioning rail and acts on the tensioning strip to produce selective axial movement of the tensioning strip in order to selectively stretch or compress the one plate end.

Device for tensioning a flexible printing plate on a plate cylinder of a

Bending device for offset printing plates having a support plate formed with a head portion, a respective bending bar pivotally mounted at opposite ends of the head portion for bending respective ends of a printing plate disposed on the head portion, a lowerable down-holder member for holding a printing plate down against the head portion, and a positioning device for bending the printing-plate ends in-register to given printing-plate dimensions, includes adjusting means disposed parallel to the support plate between the opposite ends of the support-plate head portion, the adjusting means being movable into a plane wherein a printing plate is disposed on the head portion, so as to deflect at least part of the printing plate out of the plane.

Growing community of inventors

Eppelheim, Germany

Lothar Stadler