Abstract: A gripper opening/closing apparatus in a sheet-fed rotary printing press, the apparatus having a broadside printing cam and a perfecting cam which are commonly brought into contact with cam followers, and which are adjacent to each other to be coaxial with an impression cylinder, and the apparatus being arranged such that, in a broadside printing mode, grippers of the impression cylinder are opened/closed by the broadside printing cam to cause reversing grippers of a reversing cylinder to grip a leading end of a printed sheet gripped by the grippers of the impression cylinder, and that, in a perfecting mode, the grippers of the impression cylinder is opened/closed by the perfecting cam and the broadside printing cam to cause the reversing grippers of the reversing cylinder to grip a trailing end of the printed sheet gripped by the grippers of the impression cylinder, wherein a central angle of the impression cylinder which is formed between a sheet gripping position where the grippers of the impression cylind

Abstract: A gripper mechanism for printing press folding machines or other sheet handling equipment comprises a rigid holder mounted on a pivot shaft and a resilient gripper finger, fixed to the holder, which pivots into engagement with an angled clamping surface. The geometry of the gripper finger relative to the holder is such that the rigid holder and resilient finger act as a linkage which, upon application of counterforce by the clamping surface, imparts a radial component of force to the gripper tip equal and opposite to the radial component of counterforce, thereby producing non-sliding engagement of a sheet of paper positioned between the clamping surface and said tip.

Abstract: An apparatus for printing the back, or "verso", side of a sheet being fed from a sheet-fed printing press into a delivery unit, the sheets 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 and carry grippers for gripping the leading edge of a sheet. The chains are guided so that they form a delivery run and a return run spaced apart and generally parallel to one another. An impression cylinder is journalled between the runs having an axial length which is shorter than the lateral spacing between the chains. A blanket cylinder is journalled outside of the delivery run in rolling engagement with the impression cylinder. A plate cylinder having inking and dampening systems is in rolling engagement with the blanket cylinder. The impression and blanket cylinders have mating longitudinal grooves of a size sufficient to provide free passage for the cross members and grippers.

Abstract: To permit axial excursion of the gripper spindle (2) with respect to the shaft (6) of a transfer drum or printing cylinder upon bend-through of the shaft, a spindle axial alignment element (13) is located approximately centrally of the gripper spindle (2) which is axially maintained in position by being engaged, at both axial sides, by guide rollers (14, 15) secured to the shaft (2). Thus, the gripper spindle is axially aligned with respect to the shaft essentially at the center thereof. The axial alignment element (13) in form of a plate between the rollers (14, 15) is shorter by a distance (d) than the radial distance between the shaft (6) and the gripper spindle (2) to permit radial excursion of the shaft (6) which occurs particularly at high printing speeds, thereby preventing transfer of forces on the gripper spindle (2) upon bend-through of the shaft (6).

Abstract: Paper gripper improvement in a printing press of the type having a frame, a large paper carrying impression cylinder drum mounted on the frame and a plurality of retractable printing stations mounted on the frame and spaced around the drum. Each gripper has a stationary finger and a second finger reciprocatable with respect to the stationary finger. A cam is connected to operate the reciprocatable finger to grip the paper as it is fed onto the drum. To detect a missing paper, an electrical circuit is completed by contact between the stationary finger and the reciprocatable finger in the absence of a paper between them insulating them from each other, whereby the need for photo-cells or other detectors to detect missing papers is eliminated. The inking rollers are driven separately from the drum to facilitate retracting the printing stations in the event of a missing paper.

Abstract: A driving mechanism for groups of operating elements arranged in a rotary sheet guiding cylinder of a sheet-fed printing machine includes a pair of control shafts arranged in the guiding cylinder parallel to its axis of rotation and being driven by transmission gears arranged in the cylinder, two sets of cams, each supported on an assigned control shaft for activating a group of operating elements in a selected operational mode of the machine, and clutch means provided between the transmission gears and the shafts and operated from one point to actuate one control shaft and deactivate the other control shaft.

Abstract: Camless drive of an oscillating pregripper feeder for a sheet-fed rotary printing machine having a feed table, an impression cylinder and an oscillating pregripper feeder disposed between the feed table and the impression cylinder, the camless drive including a seven-bar linkage transmission system, the bars of which are articulatingly connected to one another solely by pivot joints, two cranks connected to the transmission system and revolvable at the same angular velocity for driving the transmission system, one of the linkages forming at least part of a pregripper of the oscillating pregripper feeder, the one linkage being disposed directly behind one of the cranks, the oscillating pregripper feeder having means for gripping a sheet to be printed which lies on the feed table, and the seven-bar linkage transmission system being actuatable by the cranks for transporting the gripped sheet along a given path directly to the impression cylinder.

Abstract: Continuously rotatable advance gripper drum assembly for sheet-fed rotary printing machines having an advance gripper drum and a gripper bridge movable relative to the drum includes a crank-driven linkage transmission device disposed on and rotatable with the drum and operatively connected to the gripper bridge for moving the gripper bridge.

Abstract: A rotary printing machine for printing several colors on continuously fed sheets comprises a cylinder for driving a web disposed at the web inlet in the printing machine and coupled to a speed variator.A rotary cutting device is disposed downstream of the web driving cylinder, and means are provided for rotating said rotary cutting device at constant speed. The printing machine also comprises a drum provided on its periphery with regularly distributed grippers, normally closed by springs and of which the opening is controlled by fixed opening ramps.This drum forms a single large-diameter impression cylinder in contact, at different points of its periphery, with the blanket cylinders of the different printing units. This impression cylinder is mounted to rotate about a horizontal and transverse axis on a support frame mounted for horizontal and longitudinal slide, and means are provided for causing the support frame to slide towards and away from the blanket cylinders of the various printing units.

Abstract: A sheet gripper for a sheet-fed rotary printing machine is disclosed. The sheet gripper is secured directly to the oscillating gripper shaft of the impression cylinder of the printing machine and includes a gripper finger having a gripper tip, a gripper base, and a connecting gripper side. A hinge joint assembly between the sheet gripper and gripper shaft is formed by a shoulder on the gripper and a notch on the shaft. Alternatively, the shoulder may be provided on the shaft and the notch formed in the gripper. The gripper is secured to the shaft and is biased toward the shaft by suitable springs or the like. An adjustment assembly is provided to adjust the distance between the gripper tip and an abutment surface on the cylinder.

Abstract: A clamp for holding a flexible sheet on a rotary carrier tightens the grip on, and pulls, the sheet upon rotation of the carrier, as a result of centrifugal forces generated on two weights attached to two cooperating arms within the clamp. The magnitude of the grip-tightening force is dependent upon the mass of a grip-tightening weight attached to the clamp. The magnitude of the sheet-pulling force is dependent upon the mass of a sheet-pulling weight attached to the clamp. The clamp faces are mounted for concurrent movement along the periphery of the carrier to prevent tearing or other damage to the sheet when it is pulled as the carrier is rotated.

Abstract: A system for duplicating images on copy sheets utilizing an impression cylinder. The system provides for transfer of an image to one side of each sheet, and the sheet may then be reversed to locate the sheet on the impression cylinder, trailing edge first. The reversing is in synchronism with a second image whereby this second image may be transferred to the opposite side of each sheet. The impression cylinder is provided with a first gripper for engaging the leading edge of each sheet when the sheet is first fed to the impression cylinder. A second gripper is provided on the impression cylinder for engaging the trailing edge of each sheet, and this second gripper turns around to achieve the reversing action after application of the first image. The first gripper is externally mounted and is movable relative to the impression cylinder whereby the relative positions of the grippers can be changed so that different size sheets can be duplexed.

Abstract: A lithographic sheet-fed press having an impression cylinder with a gap formed in the surface thereof and having a cooperating blanket cylinder having bearers at its ends. A pair of auxiliary short bearer members bridge the gap in the impression cylinder, presenting arcuate edges for engagement with the bearers on the blanket cylinder, the bearer members are arranged at such radial height that when the blanket cylinder rolls into the region of the gap the force of printing pressure between the cylinders is taken over by the auxiliary bearer members to maintain the transaxial pressure between the cylinders substantially constant throughout the revolution thereby avoiding the cyclical impact accompanying sudden build-up of printing pressure at the end of the gap.

Abstract: The basic press structure includes a printing couple consisting of a lower printing cylinder, having a single work area, and a large printing cylinder, having an effective diameter which is a whole multiple, greater than one, of the effective diameter of the lower printing cylinder, and has a number (equal to the whole multiple) of work areas, in each of which one of a variety of the especially constructed removable and interchangeable segments may be mounted. One of a variety of different printing surfaces may be carried in each of the various work areas on the cylinders of the printing couple, in a wide range of combinations. The printing couple is mounted in a frame structure constructed so as to provide a plurality of module mounting positions, at each of which one of a variety of printing modules may be mounted in cooperative relationship with the large printing cylinder.

Abstract: Transfer drum for a sheet-fed rotary printing press includes a pair of spaced support discs mountable on a shaft of the printing press, a drum shell peripherally secured to the support discs and having an outer surface, a blanket reinforced with fabric plies and tautly covering the outer surface, the fabric plies being subjected to tensile force acting in a given direction, the blanket having two ends, and means for securing the ends of the blanket to the drum shell, the fabric plies being elastic in the given direction of action of the tensile force.

Abstract: A sheet advancing cylinder in an offset printing machine, has a sheet gripping system arranged in its interior. The system includes a rocking member rigidly connected to a first gripper for moving the latter between two terminal positions in a slot formed in the jacket of the cylinder. The movement of the rocking member is such that in the first terminal position the first gripper is flush with the jacket periphery, in an intermediate position it is above the periphery and in the second terminal position it is below the periphery.

Abstract: Sheets are displaced from a supply to a continuously rotating receiver drum in a printing machine by means of a transfer drum having at least two angularly spaced grippers. The drum carrying the gripper is rotated at a relatively slow speed, and each of the grippers can be angularly displaced on the transfer drum and relative to the other gripper. Thus each gripper is accelerated after it picks up a sheet at the pickup station so that when it reaches a transfer station where it passes the sheet off to the receiver drum it is moving at the same speed as the receiver drum. Thereafter each gripper is uniformly decelerated so that when it has returned to the pickup station it is moving at the same speed as the sheet thereat.

Abstract: A rotary printing machine including an impression cylinder which has at least two grippers for gripping the forward edge of a sheet of paper for drawing the paper onto the same at each appropriate instant in each cycle of operation of the machine, the grippers being movable circumferentially of the impression cylinder and retainable in a different position which is stationary relative to the impression cylinder, to vary the relative position of the sheet of paper on the cylinder while the cylinder is rotating.

Abstract: In a printing mechanism, the leading edge of a sheet of paper is fed onto the printing surface of a cylindrical drum and is clamped thereto. A gear is rotatively attached to the drum, and a sensor controlled gear segment clutch, which is mounted for rotation independently of the drum, controls the clamping and rotational movement of a clamp for clamping the trailing edge of the sheet of paper. The sensor senses when the trailing edge of the sheet passes thereby and activates the gear segment clutch which rotates toward the gear attached to the drum and engages it. The rotational movement of the gear segment clutch results in the closing of the trailing edge clamp onto the trailing end of the sheet of paper. The gear attached to the drum rotates the gear segment clutch and it in turn rotates the trailing edge paper clamp which now rotates the drum. Consequently, the above described printing mechanism can clamp both ends of variable length paper onto a cylinder and rotate it for a print operation.