Abstract: A drive arrangement for folding blades in sheet-processing machines with a pair of folding rollers to support the sheet material to be folded and a folding blade movable in the direction toward the sheet material includes a linear motor with a secondary part movable along the stationary part of the motor. A transmission device coupled with the secondary part of the motor and connected to the folding blade is provided to effect the reciprocating movement of the folding blade to and from the material to be folded.

Abstract: The invention is a drive system for folding blades for the folding of flat material, preferably paper, in folding devices working by the principle of blade folding, consisting of one or several universal joints interposed between the drive and output shafts of the folding-blade drive. Universal joints may be used so that the shafts are in different planes and the angle of intersection of the shafts is greater than zero. The irregularity of the angular velocity achieved will cause an extreme displacement of the point of return, so that the folding blade will contact the sheet with a small velocity and will then be considerably accelerated to reach the velocity of the folding rollers prevailing at the moment of transferring the sheet to be folded to the folding rollers. The drive and output shafts may also be telescopic shafts.

Abstract: A rotary folder has a folding cylinder provided on its periphery with a plurality of grippers open and closable by radial displacement of respective cam followers. A pack of different release cams is axially displaceable adjacent the cylinder through positions in each of which a respective one of the cams is aligned with the cam followers. Mechanism is provided for pulling the followers radially away from the cams during adjustment, and for rotating the cams themselves for fine adjustment of the closing position in accordance with paper thickness.

Abstract: The method comprises the steps of feeding from a stack of sheets to be printed the first sheet on a feedboard, aligning the leading edge of the sheet with a preliminary stop line whereby the sheet is brought to a rest position, sucking from below the preliminary aligned sheet and removing the preliminary stop line, forwarding the preliminary aligned and positively coupled sheet in feeding direction to a second stop line and relieving the suction whereby the leading edge of the sheet is finally aligned and a successive sheet is fed to the first stop line or the preliminary alignment of its leading edge, laterally adjusting the register of the first sheet abutting against the second stop line, removing the second stop line and advancing the first sheet into the press.

Abstract: An operator safety device includes a plurality of covers for covering parts of a machine to protect an operator against contact with these parts when the machine is in operation. At least some of the covers are movable between a closed position where the covers do not cover these parts and the latter are readily accessible and constitute a danger of accidents. A switch is operable for shutting down the machine when at least one of the covers moves from the closed into the open position. A linkage connects the covers with the switch for actuating the latter whenever at least one of the covers moves from the closed into the open position.

Abstract: The method comprises the steps of feeding from a stack of sheets to be printed the first sheet on a feedboard, aligning the leading edge of the sheet with a preliminary stop line whereby the sheet is brought to a rest position, sucking from below the preliminarily aligned sheet and removing the preliminary stop line, forwarding the preliminarily aligned and positively coupled sheet in feeding direction to a second stop line and relieving the suction whereby the leading edge of the sheet is finally aligned and a successive sheet is fed to the first stop line or the preliminary alignment of its leading edge, laterally adjusting the register of the first sheet abutting against the second stop line, removing the second stop line and advancing the first sheet into the press.

Abstract: A detecting capacitive structure undergoes changes in capacitance value depending upon whether it is detecting, in the sheet transport path of a printing machine, a normal or single sheet, an absent sheet, or a double or stuck-together sheet, so that corrective action can be initiated, such as the skipping of a printing cycle. The detecting capacitive structure and also a reference capacitive structure constitute the capacitances of two RC circuit stages to which an input signal is applied and then removed. The variations with respect to time of the output signals from the two RC circuit stages are then compared, both during application of the input signal and subsequent to removal of the input signal. This comparison of time responses of the two RC circuit stages serves as the basis of the detection.

Abstract: The friction bearing for supporting a journal of a cylinder of a printing press includes a bearing sleeve supported in a tubular bearing block and being manufactured with conventional machining tolerances. To minimize the radial play of the bearing, at least three axially directed cylindrical bores are provided in the annular face of the bearing sleeve and extend in the axial direction. Tapering pins are driven into respective bores to expand on discrete locations the bearing surface of the sleeve, thus minimizing the gap between the supporting bearing surfaces and the periphery of the journal. The remaining gap is larger in size than the adjusted gap and serves for conducting oil into the bearing.

Abstract: A sheet feeding unit includes a stack elevator which raises the top of a supported stack of sheets to infeed height. A sensor senses the position of the top sheets of the stack, to ascertain whether these exhibit improper left or right offset. Depending upon the magnitude and size of the sensed offset, the stack elevator is correctively shifted, to minimize offset at the top of the stack. Although the sensor is located to only one side of the stack, not at both sides of the stack, it is capable of sensing offset in both left and right directions. When the elevator is lowered, for the laying in of a fresh stack, it is automatically brought to a centered position.

Abstract: Grippers pull the leading ends of sheets along a sheet transport path, and a guidance structure facilitates sheet travel. The guidance structure comprises a plurality of longitudinally extending guide bars provided with suction openings, the ribs spaced apart transverse to the sheet-transport direction. Intermediate the bars are large-surface-area plates having suction openings. When guiding sheets printed on only one side, the intermediate suction plates are at about the same level as the longitudinally extending guide bars, and the entire face of the sheet is engaged, with the help of suction force. When guiding sheets printed on both sides, the imtermediate suction plates all drop down out of contact with the sheet, leaving only the spaced apart and narrow longitudinal guide bars to engage the sheet. The guide bars are furthermore transversely shiftable, so that they can be brought into engagement with parts of the sheets bearing no printing.

Abstract: A rotary printing machine has at least two successive printing stations. A self-contained aggregate is located between these printing stations and can be inserted and removed from between them as a unit. The aggregate has a transfer roller which receives sheets from one of the printing stations, one or more heaters for heating the sheets on the transfer roller, and a reversing roller which receives sheets from the transfer roller, selectively reverses them and furnishes them to the other of the printing stations.

Abstract: An elongated array of partially overlapping sheets advances to a printing machine and, prior to entering the same the individual sheets of the array, one after another, are aligned both along their front edges and along one of their lateral edges. This is accomplished by first displacing the respective sheet transversely of the array so that a lateral marginal portion adjacent to the one lateral edge becomes exposed, after or during alignment along the front edge, and by subsequently engaging the exposed lateral marginal portion of the respective sheet and displacing the latter a further distance only transversely of the array into a position in which the one lateral edge is aligned. Subsequently to the alignment along both of the above-mentioned edges, the respective sheet may be partially returned by a given distance prior or during feeding of the sheet into the printing machine.

Abstract: A pair of parallel blanket rollers have their ends received in respective eccentrics themselves received in respective spaced-apart holes in a support frame. A pair of plate cylinders each tangentially contacting a respective blanket cylinder are similarly received in respective eccentrics also received in respective holes in the machine support. Each of the holes receiving an eccentric for a respective cylinder is of greater diameter than the respective cylinder so that the cylinders can be mounted in the machine frame by slipping them axially through these holes. A web to be printed is passed between the two blanket cylinders for simultaneous printing on both sides. The plate cylinder to one side of the web being printed and the blanket cylinder to the opposite side lie in one plane and the other two cylinders lie in another plane parallel to but spaced horizontally from the first-mentioned plane.

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: The sheet-presenting unit presents received sheets to the printing instrumentality of the machine. The sheet-feeding unit feeds sheets to the sheet-presenting unit. The two units have activators which can be enabled and disenabled. The operator of the machine initiates a start signal. A sheet detector generates missing-sheet, skew-sheet and muliplee-sheet signals, indicating the condition of the sheet at the sheet-presenting unit. Enablement stages determine whether the activators for the feeding and presenting units are to be enabled or not. When the activators are enabled, the start signal is automatically extinguished. A logic circuit receives the start signal and the signals from the sheet detector. The logic circuit has pre-start-up and post-start-up modes of operation, corresponding to generation and termination of the start signal.

Abstract: A printing machine operates at a variable speed, and includes a rotary reference component. Activation and deactivation of positioning units for printing cylinders and other functional units for the printing machine is performed in synchronization with the rotation of the rotary reference component. The positioning units exhibit dead times in their response to applied activating or deactivating signals. The duration of each such dead time expressed in terms of the extent of angular movement of the rotary reference component varies in dependence upon printing machine operating speed, tending to produce improper synchronization between activation and deactivation of positioning units, on the one hand, and machine operation, on the other hand.

Abstract: A web is being pulled off a supply roll nearing exhaustion. As the supply roll becomes exhausted, the web being pulled off is severed, and the trailing end of the severed web is glued to the periphery of a fresh web supply roll. Before the severing and gluing operation occurs, the peripheral speed of the fresh web supply roll must be brought up to coincidence with the travel speed of the web being pulled. An accelerator roller driven by a motor rolls upon the fresh supply roll, accelerating it up to speed. When the fresh roll reaches the predetermined speed, the severing and gluing unit is enabled for subsequent synchronized activation. The acceleration of the fresh roll is monitored indirectly by a transducer coupled to the accelerator roller. When the desired speed is reached, a time delay is allowed to elapse before the motor is shut off, causing the desired speed to be exceeded. As the fresh roll then decelerates it again reaches this speed.

Abstract: The printing cylinders or other functional units of a printing machine are engaged and disengaged by positioning units. When a positioning unit receives an activating signal, its response thereto includes a dead time or delay time. Because the activation of the positioning units proceeds in dependence upon the angular position of a rotary reference component of the printing machine, and all operations are synchronized in terms of angular positions and angular spans, the dead time of the positioning units, when expressed in angular units, is a function of the operating speed of the printing machine. If the operating speed is variable, proper angular synchronization tends to be lost. The invention includes a clocked control unit clocked in angular synchronism with machine operation and determining when positioning units are to be activated and time-delay stages which introduce compensatory time delays into the application of activating signals to the positioning units.

Abstract: A paper web is continuously moved by rotary drive rollers through a series of printing machines having pairs of printing rollers movable between inoperative and printing positions, and controlled and operated so that successive web sections are imprinted by the correlated printing machines only once whereby a plurality of type areas representing printed pages are printed on both sides of each web section in a predetermined pattern. After cutting of the web sections into sheets, and after collecting and folding the sheets, consecutive printed pages follow each other in a folded book.

Abstract: A printing machine has a plurality of printing stations which print images on both major surfaces of each sheet passing through the printing machine. A reversing arrangement turns the respective sheet between two of the printing stations so that the major surface of the respective sheet having a fresh image thereon faces downwardly. A support arrangement is provided which supports this sheet during its advancement to the next following printing station, and includes a blow casing having upwardly oriented passages through which air issues in upward direction to create an air cushion between the respective sheet and the blow casing for supporting the respective sheet during its advancement. An elongated bracket is arranged upwardly of the blow casing and supports a region of the respective sheet which is devoid of the image, during the advancement of the sheet in a path portion located upwardly of the blow casing.