摘要:
In an apparatus for adapting the pressing force of a control roller on a control can in a sheet-processing machine by a torsion spring, the apparatus either changes the effective spring length or the spring stiffness as a function of the rotational speed of the sheet-processing machine. The spring can be a torsion spring rod with an actuator setting the spring force by changing the prestress. A stiffening element can be connected to the torsion spring rod and set the spring force by changing the spring stiffness of the torsion spring rod.
摘要:
In an apparatus for clamping and releasing a gearwheel rim with respect to a main gearwheel that bears the gearwheel rim, a clamping apparatus includes an axially guided, displaceable clamping plate clamping the gearwheel rim between the plate and the main gearwheel. Antifatigue bolts are used for such a purpose. The bolts are expanded by an actuator for releasing the clamped gearwheel rim to an extent that cancels the clamping action.
摘要:
In a device for reducing the frictional force between a guiding or carrying element for sheets in a sheet-processing machine, in particular rotary printing machines, guiding and carrying elements acted upon by throttled blowing air include a sheet surface, orifices fluidically connected to a hollow interior, and a throttle disposed in the hollow interior. The elements are to be connected to an air source for blowing air out through the orifices and for generating an air cushion between a sheet and the sheet surface. Each of the orifices is preceded by the throttle with respect to a direction of air from the air source.
摘要:
A method of varying a drum profile of a vario drum for transporting printing material sheets, in which shell segments of the vario drum are pivoted inward and outward. Sheet supporting elements assigned to the shell segments are reversibly deformed by pivoting the shell segments. A vario drum suitable for implementing the method and a machine containing the vario drum for processing printing material sheets contain the shell segments and the associated sheet supporting elements.
摘要:
An apparatus for guiding and transferring a sheet in a printing machine from a first cylinder to a gripper of a second cylinder in which the apparatus has a guide device for a holding element, which is held outside the first and second cylinder. In this way, the design of the guide apparatus can be independent of the first and second cylinders. In addition, a longer time period is available for gripping, tensioning and transferring the sheet. The apparatus can be used both in a recto printing machine and in a turner device in recto and verso printing.
摘要:
A guiding device in a machine for processing sheets of printing material includes unthrottled air nozzles for contact-free guidance of the sheets, and throttled air nozzles arranged at locations which are prone to contact by the sheets; and a machine for processing sheets of printing material and a sheet-fed rotary printing machine, respectively, having the guiding device.
摘要:
A device for locking, with respect to a first power transmission element, a further power transmission element that is lockable in a rotational position thereof, provides for the first and the further power transmission element to have a common working chamber with a variable volume to which a pressure medium can be applied, it being possible for the pressure medium in the working chamber to be solidified by applying an electric voltage or a magnetic force field thereto.
摘要:
In a device for guiding sheets in a sheet-fed apparatus, preferably, a rotary printing press, sheet guide elements that are charged with blasted air are disposed at the sheet guide cylinder, and the air blast nozzles include a combination of conventional free jet nozzles and throttled nozzles, which are independently charged with different pressure levels.
摘要:
An apparatus and a method for changing printing plates in sheet-fed rotary printing presses include a plurality of printing units and plate cylinders being coupled to one another mechanically in the printing units during a printing operation. At the beginning of a plate change, the plate cylinders are coupled to one another mechanically and are driven jointly by a main drive motor. After an old printing plate has been conveyed out, each plate cylinder is decoupled from the common mechanical connection and is driven by a separate drive motor.
摘要:
A reversing or turning assembly of a sheet-processing machine includes an impression cylinder having a circumferential surface for transporting sheets thereon for printing the sheets in a printing nip associated with the impression cylinder. Gripper devices are provided for gripping the printed sheets at a respective trailing edge thereof and for lifting the gripped sheets off the impression cylinder for reversing the gripped sheets. The circumferential surface of the impression cylinder is formed with recesses in a region thereof occupied by the trailing edge of the sheets, for permitting the gripper devices to penetrate or dip into the recesses to grip the sheet trailing edge. The recesses have a position being variable in circumferential direction of the circumferential surface of the impression cylinder for adapting to different sheet formats.