Apparatus for performing actuations or operations in a printing press

Information

  • Patent Grant
  • 6227112
  • Patent Number
    6,227,112
  • Date Filed
    Thursday, July 30, 1998
    26 years ago
  • Date Issued
    Tuesday, May 8, 2001
    23 years ago
Abstract
An apparatus for performing successively performable actuations in a printing press includes a pressure converter having an actuator formed with actuator surfaces which are successively able to be acted upon stepwise by pressure fluid; and a printing press in combination with the apparatus. Successively performed actuations in a printing press include switching or controlling, coupling, adjusting and tensioning operations, wherein machine or press parts are moved and/or held in a given position. Such actuations may be necessary in various devices of the printing press, a defined sequence of actuations having to be adhered to, depending upon the functions of the individual devices and to assure disruption-free cooperation of the devices. The actuations often require a transmission of comparatively strong forces to devices located at various places in the printing press which in terms of structural space are quite restricted. Pneumatic and hydraulic systems are therefore used for these purposes.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The invention relates to an apparatus for performing actuations or operations in a printing press.




By the term actuations or operations there is meant, for example, switching or controlling, coupling, adjusting and tensioning operations, wherein machine or press parts are moved and/or held in a given position. Such actuations may be necessary in various devices of the printing press, a defined sequence of actuations having to be adhered to, depending upon the functions of the individual devices and to assure disruption-free cooperation of the devices. The actuations often require a transmission of comparatively strong forces to devices located at various places in the printing press which in terms of structural space are quite restricted. Pneumatic and hydraulic systems are therefore used for these purposes.




In the published German Patent Document DE 44 01 684 A1 and U.S. Pat. No. 5,588,363, a method for performing successive work steps in a printing press by the application of a pressure medium in various pressure stages upon actuators preloaded in the opposite direction is proposed. Also proposed therein is an apparatus for performing the foregoing method which has a piston-cylinder unit with a differential piston. One piston face of the differential piston can be subjected in a cylinder chamber to a pressure medium of a first pressure medium system with a pressure stage regulation, and another piston face acts in another cylinder chamber on a pressure medium of a second pressure medium system which, in turn, acts upon the actuators.




An unfavorable aspect of this heretofore known method and device is that, in addition to the piston-cylinder unit, pressure stage regulation is required, for example, in the form of a switchable or controllable pressure regulator or pressure limiter, which is all the more complicated, the greater the number of work steps that have to be performed in succession. Another disadvantage is that the piston-cylinder unit produces relatively little output power relative to the structural size thereof, that is, if a low pressure is applied to the cylinder input side, a high pressure on the cylinder output side cannot be generated by the pressure conversion performed there. The preloading magnitude of the actuator which is preloaded with a maximal force can therefore be only comparatively slight, especially if the actuators are intended to be of small structural dimensions. On the one hand, actuations to be performed with great force, such as fastening cylinder coverings, can be achieved only at the cost of the disadvantage of a piston-cylinder unit with a large piston face that occupies a great deal of space in the radial direction. On the other hand, this complicates the adaptation to one another of the forces that preload the actuators and in terms of the pressure stage regulation, especially when a great number of switching operations on the part of the adjusting cylinders must be performed successively. Because there is only a slight difference between the minimal and maximal preloading of the adjusting cylinders, only a limited number of adjusting cylinders can be switched or controlled in succession, because assurance must be provided that any partial relief of the adjusting cylinders of a higher pressure stage is so slight that a switching operation cannot yet take place when the switching of the adjusting cylinders of a lower pressure stage is already occurring.




In the German Patent Document DE 39 25 110 A1, a cylinder of the tandem cylinder type is proposed which produces increased power without any increase in the dimensions or operating pressure thereof. The tandem cylinder is formed of a housing with openings acting alternatively as inlets or outlets for the pressure fluid, a central column; and a member in the form of an inverted beaker. The housing forms a first expansion chamber wherein a piston with a first annular, pressure-absorbing face reciprocates. The column extends upwardly from the bottom of the housing, the piston being disposed on the open end of the member. The inner surface of the cap of the member acts as a second pressure-absorbing face, and the interior of the member acts as a second expansion chamber.




An unfavorable aspect thereof is that, with this tandem cylinder, only two pressure stages can be achieved, and the construction principle of the tandem cylinder, which is formed of individual parts that are complicated to produce, entails a major production expense.




The brochure entitled “Leibfried Antriebseinheiten Anlagentechnik Schrift (“Leibfried Drive Units Installation Technology”) 7501175.05.03.093” published by the firm Leibfried Maschinenbau GmbH discloses a compressed air cylinder, type LMZT, of the tandem construction type in a bidirectional version. This tandem cylinder has two conventional piston-cylinder units disposed in alignment with one another in the axial direction of the cylinders, which form a common housing encompassing two expansion chambers that are subjectible to the application of pressure. One adjusting piston is disposed in each expansion chamber, and one adjusting piston rod, when pressure is imposed on the adjusting piston disposed thereon, acts to transmit force to the other adjusting piston rod. When pressure is imposed simultaneously in both expansion chambers, an increased output of power is achieved, and installation of the tandem cylinder in an apparatus in the radial direction requires only little installation space.




This tandem cylinder has the same disadvantages as those of the type of tandem cylinder described hereinbefore with respect to the aforementioned published German Patent Document DE 39 25 110 A1.




SUMMARY OF THE INVENTION




Based upon the foregoing prior art and the inadequacies of previous embodiments, it is accordingly an object of the invention to provide an apparatus for performing actuations in a printing press, with which, without a complicated, additional pressure stage regulation, a very large number of successively occurring actuations can be realized in a relatively simple manner.




With the foregoing and other objects in view, there is provided, in accordance with one aspect of the invention, an apparatus for performing successively performable actuations in a printing press, comprising a pressure converter including an actuator formed with actuator surfaces which are successively able to be acted upon stepwise by pressure fluid. In accordance with another feature of the invention, the apparatus for performing actuations in a printing press include a control unit for remotely controlling a valve with which the pressure converter communicates.




In accordance with a further feature of the invention, the pressure converter communicates with two piston-cylinder units actuatable stepwise in succession.




In accordance with an added feature of the invention, the pressure converter has two expansion chambers connected to a first pressure fluid system, the expansion chambers being successively suppliable with a pressure fluid present in the first pressure fluid system.




In accordance with an additional feature of the invention, the apparatus includes a second pressure fluid system, and the pressure converter has a third expansion chamber communicating with the piston-cylinder units via the second pressure fluid system.




In accordance with yet another feature of the invention, a first one of the piston-cylinder units is actuatable by a first actuating force, and a second one of the two piston-cylinder units is actuatable by a second actuating force having a different magnitude from that of the first actuating force.




In accordance with yet a further feature of the invention, the piston of the first piston-cylinder unit is preloaded with a first force different in magnitude from that of a second force with which the piston of the second piston-cylinder unit is preloaded.




In accordance with yet an added feature of the invention, a first spring for bringing the first force to bear is assigned to the first piston, and a second spring for bringing the second force to bear is assigned to the second piston.




In accordance with yet an additional feature of the invention, the first piston has a first piston face different in size from a second piston face of the second piston.




In accordance with still another feature of the invention, the first pressure fluid present in the first pressure fluid system has at least one characteristic different from that of a second pressure fluid present in the second pressure fluid system.




In accordance with still a further feature of the invention, the first pressure fluid system is embodied as a pneumatic pressure fluid system, and the second pressure fluid system is embodied as an hydraulic pressure fluid system.




In accordance with still an added feature of the invention, the pressure converter includes a housing formed with a partition, and the actuator is embodied as an adjusting piston rod carrying a first adjusting piston and a second adjusting piston, so that the partition and the second adjusting piston define an expansion chamber.




In accordance with still an additional feature of the invention, the first adjusting piston defines an expansion chamber formed with a vent opening.




In accordance with another feature of the invention, the pressure converter is embodied as a component-containing modular system for varying the number of expansion chambers therein during assembly of the pressure converter.




In accordance with a further feature of the invention, the modular system contains at least one component type that includes identically embodied components.




In accordance with an added feature of the invention, the modular system contains three different component types including a first component type embodied as a partition, a second component type embodied as an intermediate element, and a third component type embodied as an adjusting piston.




In accordance with an additional feature of the invention, the partition has a pressure fluid connection with a thread, the connection being formed of two bores opening into one another.




In accordance with yet another feature of the invention, the actuator is returnable in one direction of motion by the action of the forces for preloading the pistons.




In accordance with yet a further feature of the invention, the actuator is returnable by a restoring spring for reinforcing the return.




In accordance with yet an added feature of the invention, the actuator is returnable by an application of pressure fluid on at least one surface of the actuator.




In accordance with an additional feature of the invention, the apparatus includes a valve with which the pressure converter communicates, and the first pressure fluid is controllingly feedable into at least one of the expansion chambers via the valve.




In accordance with yet another feature of the invention, the valve is embodied as a multiway valve having various control positions and flow paths for feeding pressure fluid to both expansion chambers.




In accordance with yet a further feature of the invention, the pneumatic pressure fluid system is connected to a compressed air source for supplying compressed air to the printing press for a plurality of other functions.




In accordance with yet an added feature of the invention, the actuator is constructed for directly actuating another part of the printing press.




In accordance with yet an additional feature of the invention, the pressure converter has a pressure fluid conduit connecting at least two of the expansion chambers for supplying the at least two expansion chambers with the pressure fluid via a single common pressure fluid connection.




In accordance with still another feature of the invention, the apparatus includes a device for starting and stopping sheet turning in a sheet-fed printing press.




In accordance with another aspect of the invention, there is provided, in a printing press, in combination, an apparatus for performing successively performable actuations therein, comprising a pressure converter including an actuator formed with actuator surfaces which are successively able to be acted upon stepwise by pressure fluid.




With the apparatus according to the invention, the output pressure or output force of the pressure converter can be adjusted in stages, and a constant input pressure can be employed. With the constant input pressure, an actuator can be acted upon in such a manner that the input pressure can act selectively on different-sized portions of the face of the actuator.




The actuator may also additionally be acted upon by input pressures of various magnitudes.




The “effectiveness” of an actuator face or piston face is intended, in the context of this invention, to mean the cooperation of the pressure-absorbing face with a pressure fluid, and the term “piston-cylinder unit”, going beyond a so-called adjusting cylinder, is understood to mean a device with a component that may be acted upon by pressure fluid and thereby movable, preferably displaceable.




The actuator is constructed so as to be movable, in particular, movable by an application of pressure fluid and, for example, is rotatable. Preferably the actuator may be embodied so as to be displaceable, for example, as a displaceable unit made up of two adjusting pistons and one adjusting piston rod. Tandem cylinders, often called multi-power cylinders, with two or more adjusting pistons on two or more separate but cooperating adjusting piston rods, (the term actuator, in this case, being understood to mean a plurality of cooperating actuators) and preferably tandem cylinders with one or more adjusting pistons on a single common adjusting piston rod can be employed in accordance with the invention. The latter type of tandem cylinder may also have a stationary adjusting piston rod with adjusting pistons which, for example, is fixed to the machine frame; in that case, the actuator is formed by a tandem cylinder housing that is displaceable on the adjusting piston rod or on the adjusting piston.




The first expansion chamber of the pressure converter may be formed by a face belonging to the actuator, such as the pressure-absorbing face of a first adjusting piston, and a housing of the pressure converter, for example, in the form of a cylinder jacket. A second expansion chamber may communicate with switchable piston-cylinder units. A further expansion chamber, hereinafter called the third expansion chamber, may be formed by a face belonging to the actuator and by the housing and a partition. The partition may be embodied in the housing, for example, if the housing is formed in a single pouring, and it can belong to the housing, for example, if the housing is composed of various structural components. A multi-partite housing may, for example, be in the form of two piston-cylinder units of conventional type, disposed in alignment one after the other in the direction of the cylinder axis, with a single common adjusting piston rod connecting the adjusting pistons. Thereat, the end-face housing wall of one cylinder, through which the adjusting piston rod may be passed, forms a partition that defines the third expansion chamber formed in the cylinder. The end-face housing wall of the other cylinder in that case forms a further partition that defines a fourth expansion chamber formed in the other cylinder. The term partition will be used hereinafter both to mean two adjoining or two spaced-apart partitions and for a preferable embodiment in the form of a single partition.




When a first pressure fluid is fed via a first pressure fluid system to the first and/or third expansion chamber, the actuator can be moved, for example, by being displaced or slid, in such a manner that an actuator face active in the second expansion chamber exerts a force relative to the size of the actuator face and thus exerts a pressure on a second pressure fluid carried in a second pressure fluid system. If the pressure fluid fed or applied to the first and/or third expansion chamber is interrupted, the actuator face can absorb the pressure exerted by the second pressure fluid and generated by the forces preloading the piston-cylinder units, so that, in this manner, the actuator can be returned indirectly via the pressure fluid. Restoring springs may also be provided, in addition, for returning the actuator directly.




The feeding of pressure fluid to the first and third expansion chambers can be controlled in a simple manner by shutoff valves assigned to the pressure fluid feed lines, the valves, for example, being in the form of stopcocks or slide valves. Remote control of individual valves or of a multiposition valve is especially advantageous.




The order in which the first and third expansion chambers are acted upon by pressure can be selected in various ways. What is essential is that first one of the expansion chambers is acted upon, so that the actuator in a first pressure stage moves a first distance counter to the action of the forces preloading the piston-cylinder units, the actuator, for example, being displaced. After that, a further expansion chamber can be acted upon by the first pressure fluid, so that in a second pressure stage the actuator is moved a further distance counter to the action of the preloading forces. Depending upon the magnitude of the preloading forces and upon the size of the piston face, a first piston-cylinder unit switches on in the first pressure stage, and a second piston-cylinder unit switches on in the second pressure stage.




The cross-sectional shape of the actuator and of the housing of the pressure converter and also of the switchable piston-cylinder units may be constructed axially symmetrically or circularly, which is advantageous from a production standpoint, but may also have a polygonal construction, for example. The adjusting piston or pistons forming the actuator or belonging to the piston-cylinder units may be embodied as differential pistons.




Precisely the same gaseous or liquid pressure fluid may be carried in the first and second pressure fluid system communicating with the pressure converter. It is equally possible for a hydraulic oil of a given nature to be carried in the first pressure fluid system, for example, and some other kind of hydraulic oil, in terms of its composition or its rheological properties, to be carried in the second pressure fluid system, so that the pressure converter acts as a pressure medium converter from one hydraulic medium to another. The pressure converter may also act as a pressure medium converter from gas to gas, liquid to gas, or preferably gas to liquid.




The apparatus according to the invention can be employed for various kinds of actuations in a printing press, for example, as will be described in further detail in an exemplary embodiment, to actuate a device for switching a sheet turning on and off or for actuating a clamping and tensioning device in printing presses. A clamping and tensioning device for printing plates actuatable by the apparatus of the invention is described and shown in the published German Patent Document DE 44 01 684 A1. Devices in other machines which process material to be printed can also be actuated with the apparatus of the invention.




Other features which are considered as characteristic for the invention are set forth in the appended claims.




Although the invention is illustrated and described herein as embodied in an apparatus for performing actuations in a printing press, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.




The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein:











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a diagrammatic and schematic view of an apparatus according to the invention for successively performing actuations in a printing press;





FIG. 2

is a diagrammatic and schematic view, in section, of a device for turning on and off, i.e., starting and stopping sheet turning on one side of the printing press;





FIG. 3

is an enlarged fragmentary diagrammatic and schematic view, in section, of

FIG. 1

showing a different advantageous embodiment of a pressure converter of the apparatus according to the invention, which has identical components;





FIG. 4

is a reduced side elevational view of the pressure converter shown in

FIG. 3

; and





FIG. 5

is a diagrammatic cross-sectional view of another different pressure converter which is provided with a rotatable actuator.











DESCRIPTION OF THE PREFERRED EMBODIMENTS




Referring now to the drawings and, first, particularly to

FIG. 1

thereof, there is shown therein an apparatus for successively performing actuations or operations in a printing press, the apparatus having a pressure converter


103


which includes at least one actuator


101


and a housing


102


which has a first expansion chamber


105


connected to a first pressure fluid system


107


, and a second expansion chamber


109


connected to a second pressure fluid system


111


, a first actuator face


104


being operative in the first expansion chamber


105


, and a second actuator face


108


being operative in the second expansion chamber


109


, the apparatus further having at least one first piston-cylinder unit


118


,


218


, including a first piston


113


,


213


preloaded with a first force represented by the arrow


115


,


215


and being formed with a first piston face


112


,


212


that is operative in a first cylinder chamber


117


,


217


of a first cylinder


116


,


216


, the first cylinder chamber


117


,


217


being connected to the second pressure fluid system


111


, and the apparatus also having at least one second piston-cylinder unit


125


,


225


, including a second piston


120


,


220


preloaded with a second force represented by the arrow


122


,


222


and being formed with a second piston face


119


,


219


that is operative in a second cylinder chamber


124


,


224


of a second cylinder


123


,


223


, the second cylinder chamber being connected to the second pressure fluid system


111


. The apparatus according to the invention is distinguished in that the pressure converter


103


has a third expansion chamber


129


connected to the first pressure fluid system


107


and defined by a third actuator face


130


operative therein, and in that a pressure fluid


106


guided in the first pressure fluid system


107


can be conducted either to only one of the expansion chambers


105


,


129


at a time or to both expansion chambers


105


,


129


simultaneously, so that the actuator


101


, by successively effected and staggered application, respectively, of the pressure fluid


106


on the actuator faces


104


,


108


, is displaceable in stages, and the piston-cylinder units


118


,


125


and


218


,


225


are switchable or controllable in succession and in staggered manner, respectively.




The actuator


101


includes a first adjusting piston


136


and a second adjusting piston


137


, which are secured to an adjusting piston rod


138


by retaining rings


149


. The housing


102


, formed as a casting, for example, is in the shape of a circular cylinder and includes a partition


135


having a bore


179


, through which the adjusting piston rod


138


extends, as well as end-face walls


181


formed with bores


180


through which the adjusting piston rod


138


can extend.




This embodiment is especially advantageous if an actuation, such as a clamping


159


, is to be effected directly, i.e., not via the second pressure fluid system


111


, by the force exerted by the adjusting piston rod


138


of the pressure converter


103


. The clamping may be effected by two components which are to be held in frictional locking engagement, such as coupling halves, or by two components


160


and


161


, such as clamping jaws or claws, and a component


182


, such as a printing plate, to be clamped between them in a printing plate clamping and tensioning device. Provision may also be made for undoing or releasing, in this manner, any clamping effected by a spring force.




Either both or one of the end-face walls


181


may also be formed without bores


180


, so that in the absence of the adjusting piston shaft ends protruding beyond the actuator faces


104


,


108


, the actuator faces


104


,


108


are operative over the entire surface thereof in the first and/or second expansion chamber


105


;


109


.




Damping of the actuator


101


in the terminal positions may be provided. This damping may be either singly adjustable in its action, that is, in only one terminal position, or doubly, or nonadjustable. Seals


148


, such as plastic rings guided in grooves, may as shown be provided on the bores


179


,


180


of the housing


102


that guide the adjusting piston rod


138


and on the partition


135


as well as on the seat of the adjusting pistons


136


,


137


on the adjusting piston rod


138


and at the sealing face between the adjusting pistons


136


,


137


and the inside surface of the housing, so that it is possible to prevent an escape of pressure fluid out of the housing or to prevent pressure fluid from spilling over from one expansion chamber to the other. This can also be achieved by an appropriate accuracy in terms of fit and surface of the joined-together parts guided in one another.




The first expansion chamber


105


can be supplied with the first pressure fluid


106


carried in the first pressure fluid system


107


via a first pressure fluid connection


144


introduced into the housing, and the third expansion chamber


129


can be supplied with the same pressure fluid via a second pressure fluid connection


145


. A third pressure fluid connection


146


connects the second expansion chamber


109


to the second pressure fluid system


111


. A vent opening


147


enables the aeration and ventilation


162


of the fourth expansion chamber


152


.




The restoration of the actuator


101


in a second direction of actuator motion


132


can be effected by the action of the forces


115


,


122


,


215


,


222


; by an additional restoring spring


150


; or by a pressure fluid application


163


to the fourth expansion chamber


152


; as well as by a combination of a plurality of these options. The forces


115


,


122


,


215


,


222


which preload the pistons


113


,


120


,


213


,


220


may, as shown, be brought to bear by springs


133


,


134


,


233


,


234


, or by elastic properties of components such as components to be clamped.




The restoring spring


150


may also be disposed in the interior of the pressure converter


103


, and the springs


133


,


134


,


233


,


234


may be disposed in the interior of the piston-cylinder units


118


,


125


,


218


,


225


, for example, being mounted on the piston rods. Instead of the helical springs


133


,


134


,


233


,


234


shown as compression springs, other types of springs may also be employed, such as leaf springs, cup springs, tension springs and torsion springs, or gas pressure elements, as well as other springs that exert a corresponding force


115


,


122


,


215


,


222


upon the pistons


130


,


120


,


213


,


220


.




The pressure fluid source


143


feeding the first pressure fluid


106


into the first pressure fluid system


107


may be embodied as a compressor, when a pneumatic first pressure fluid system


107


is present, and as a hydraulic pump in the case of a hydraulic first pressure fluid system


107


. Instead of the pressure fluid source


143


embodied as a hydraulic pump in

FIG. 1

, a pneumatic pressure fluid source is used in a preferred embodiment. Other versions of the pressure fluid source


143


are also possible, for example, in the form of hydraulic or pneumatic reservoirs. It is useful to use a central pneumatic pressure fluid source that is present in any printing press for performing other functions, such as for guiding printed sheets with blown air. The pressure fluid source


143


may include a pressure adjuster or a pressure regulator


164


. However, in contrast with the prior art, this pressure regulator is not used to switch various pressure stages of the first pressure fluid system but rather to adjust a desired value, for example, in an infinitely graduated manner, or to regulate an actual pressure to a nominal or setpoint value. The pressure prevailing in the first pressure fluid system


107


is of such value that when a given number of expansion chambers are acted upon by the first pressure fluid


106


, a given number of piston-cylinder units is switched. For the embodiment of the invention shown in

FIG. 1

, the pressure may, for example, be so great that by or after action on the first and third expansion chambers


105


and


129


, all the piston-cylinder units


118


,


125


,


218


and


225


shown have been switched counter to the action of the preloaded forces


115


,


122


,


215


and


222


. The view shown, wherein the piston-cylinder units are presented in different switching positions, is helpful for the sake of a more-detailed explanation to be made hereinafter regarding the switching of the piston-cylinder units


118


,


125


,


218


and


225


.




The first pressure fluid system


107


may be embodied as a closed pressure fluid system or preferably as an open pressure fluid system. In the hydraulic first pressure fluid system


107


shown, a return flow of the first pressure fluid


106


into a pressure fluid reservoir


153


is contemplated.




The second pressure fluid system


111


is embodied according to the invention as a closed pressure fluid system; that is, the hollow chamber formed by the second expansion chamber


109


, the lines or conduits of the second pressure fluid system


111


, and the cylinder chambers


111


,


124


,


217


,


224


, is filled with a given quantity of the second pressure fluid


110


. An hydraulic second pressure fluid


110


advantageously has a relatively low compressibility in comparison with a pneumatic pressure fluid, making this second pressure fluid quasi-incompressible. Thus, the piston-cylinder units


118


,


125


,


218


,


225


to be switched on are switched on without delay via the second pressure fluid


110


upon actuation of the pressure converter


103


. An additional advantage associated with this is that, given the practical absence of a significant compression of the second pressure fluid


110


associated with the first transmission by the second pressure fluid


110


, very short reciprocating motions of the actuator


101


of the pressure converter


103


can be realized. The structural size of the pressure converter


103


can thus be kept small.




The first pressure fluid system


107


may preferably be embodied as a low-pressure system, and the second pressure fluid system


111


as a high-pressure system; that is, if a low pressure is applied to the first pressure fluid system


107


, a higher pressure prevails in the second pressure fluid system


111


, at least in certain pressure stages. In the embodiment of the invention shown in

FIG. 1

, the first, second and third actuator faces


104


,


108


,


130


are all the same size. Upon the imposition or application of pressure solely in the first expansion chamber


105


in accordance with a first pressure stage, and disregarding the restoring spring


105


, an action which is acceptable in this example, the same pressures would prevail in the first and second pressure fluid systems


107


,


111


, or in other words a pressure conversion ratio of the input to the output of 1:1 would prevail. If pressure is additionally imposed on or applied in the second expansion chamber


129


in a second pressure stage, then the pressure applied in the first pressure fluid system


107


would be maintained unchanged, while the pressure prevailing in the second pressure fluid system


111


would rise to twice that value, resulting in a pressure conversion ratio of 1:2. Provision may also be made, even in the first pressure stage, or in all the pressure stages, for a higher pressure to prevail in the second pressure fluid system


111


than in the first pressure fluid system


107


. This may be attained, for example, by an effective first actuator face


104


that is larger than the effective second actuator face


108


, as is similarly shown in the aforementioned published German Patent Document DE 44 01 684 A1 for a differential piston, which has a larger piston face on the inlet side, functionally similar to the first actuator face


104


, and a smaller piston face on the outlet side, functionally similar to the second actuator face


108


. In this manner, high preloading forces


115


,


122


,


215


,


222


can be overcome. In addition, provision may also be made for the first pressure fluid system


107


to be embodied as a high-pressure system, and the second pressure fluid system


111


as a low-pressure system.




Also shown in

FIG. 1

is a multiway valve


139


, which can be actuated by a remotely controllable actuating device, such as an electromagnet


151


. The multiway valve


189


includes the switching positions U through Z, and each switching position


140


includes flow courses a through d. A flow course


156


may be provided in the form of an open flow course


157


or a closed flow course


158


or a non-illustrated throttling flow course in the respective switching position


140


. A spring that returns the multiway valve


139


from the switching positions


140


and a retainer, such as a detent that keeps the multiway valve


139


in switching positions


140


, may be provided. The Remotely-controllable actuating device


151


is controlled by a control unit


142


, which is preferably embodied in the form of an electrical control unit with a microprocessor, in accordance with other actuations and processes in the printing press or on the periphery of the printing press, which are controlled by the control unit


142


. In the illustrated switching position U, an application solely of the first pressure fluid


106


into the first expansion chamber


105


is contemplated; this fluid can take the flow course a, while the flow courses b, c and d are blocked. In the switching position V, an application is effected solely into the third expansion chamber


120


via the open flow course b. The switching position U or the switching position V may correspond to a first stage, in which the actuator


101


, by the application of pressure fluid to the first actuator face


104


or the third actuator face


130


, is displaced out of the basic position for a first stroke course distance in a first direction


132


of actuator motion, and in which a first pressure stage is applied to the second pressure fluid


110


as a result of the displacement and action of the second actuator face


108


in the second expansion chamber


109


. Any volume of air that may be displaced positively out of the fourth expansion chamber


152


by this actuator displacement can escape via the vent opening


147


. The second pressure fluid


110


has a force-transmitting effect and exerts a force, which can assume the magnitude of a switching force


183


,


184


,


283


,


284


, on the piston faces


112


,


119


,


212


,


219


.




In the exemplary embodiment shown, the first piston face


112


of the first piston-cylinder unit


118


is larger than the second piston face


119


of the second piston-cylinder unit


125


, and the forces


115


,


122


which preload the pistons


113


,


120


are of equal magnitude, assuming that the types of springs


133


,


134


are identical. The pressure of the second pressure fluid


110


acts upon the first piston face


112


of the first piston-cylinder unit


118


and upon the second piston face


119


of the second piston-cylinder unit


125


. The lesser switching force


183


, in this pressure stage, switches the first piston-cylinder unit


118


, first, by displacing the first piston


113


in a second direction of piston motion


126


, counter to the action of the first force


115


, over a defined travel distance until it meets a stop, for example. This also effects a partial relief of the second piston


120


of the second piston-cylinder unit


126


. The partial relief is so slight, however, that no switching operation occurs yet; that is, the second piston


120


is virtually not displaced or not adequately displaced counter to the action of the second force


122


. In this partial relief, the function of the partially relieved piston-cylinder unit can still be either fully operative, an example being the clamping of two coupling halves in frictional engagement with one another, or not yet established, an example being the release of the coupling halves. This can depend upon whether the clamping or release, for example, is effected by the preloading spring.




Once the actuation of the first piston-cylinder unit


118


in a first stage corresponding to one of the switch positions U or V has been performed, then in a second stage in a switch position W the first and third expansion chambers


105


,


129


can be jointly acted upon by the first pressure fluid


106


via the pressure fluid feed line


154


. In this process, the actuator


101


is displaced farther, over a second stroke distance, in the first actuator motion direction


131


, and a higher pressure than in the first pressure stage can be imposed upon the second pressure fluid


110


, so that the second switching force


184


resulting therefrom assumes a sufficient magnitude for complete relief of the second piston


120


, and the second piston-cylinder unit


125


is switched, in that the second piston


120


is displaced a given distance in a second direction of piston motion


121


, counter to the action of the second force


122


.




In certain applications, such as clamping


159


or in the case of piston-cylinder units


118


,


125


with very stiff counteracting springs


133


,


134


, for example, the stroke distances of the actuator


101


may be so short that in the individual pressure stages practically only an increase or decrease in the effective clamping forces or in the forces acting upon the pistons


113


,


120


is perceptible.




The magnitude of the switching forces


183


,


184


,


283


,


284


required for the switching is determined by the magnitude of the forces


114


,


122


,


215


,


222


preloading the pistons


113


,


120


,


213


,


220


and by the size of the piston faces


112


,


119


,


212


,


219


. It will now be shown, in terms of further piston-cylinder units


218


,


225


illustrated in

FIG. 1

, how a successively effected switching can also be achieved by a different preloading of the first piston


213


and the second piston


220


. The first piston


213


is preloaded by a first spring


233


, which brings to bear a greater first force


215


and requires a greater switching force


282


for the switching than does the second spring


234


that preloads the second piston


220


and requires a lesser switching force


284


. Thus, in the switch position U or V of the multiway valve


139


, switching of the second piston-cylinder unit


225


can be accomplished first, followed by switching of the first piston-cylinder unit


218


, as well, in the second switch position W.




It is readily apparent that a combination of the two different embodiments is also possible; that is, the first and second piston-cylinder units can differ from one another both in having piston faces of different areas and in having preloading forces of different magnitudes. In this way, assuming suitable adaptation or adjustment, both successive and simultaneous switching of the first and second piston-cylinder units can be achieved. For example, the piston-cylinder unit


118


can be switched or actuated jointly with the piston-cylinder unit


225


in a first stage, and in a subsequent second stage, the piston-cylinder unit


125


can be switched or actuated jointly with the piston-cylinder unit


218


.




The imposition or application of the first pressure fluid


106


into the expansion chambers


105


,


129


can be undone successively as well, by moving the multiway valve


139


from the switch position W to one of the switch positions X or Y. In the switch position X, for example, the imposition or application into the first expansion chamber


105


via the open flow course a is maintained, while the imposition or application into the third expansion chamber


129


is undone by the blocked flow course b. One or more piston-cylinder units


125


,


218


that were switched in the second stage now switch back again, before one or more other piston-cylinder units


118


,


225


subsequently switch back again as well. The piston-cylinder units


118


,


225


are partially loaded again in this process. However, the pistons


113


,


220


are not yet returned to the original outset position thereof and, thus, no switching takes place. The preloading forces


122


,


215


now act, by displacing the pistons


120


,


213


in a first direction of piston motion


121


,


214


, upon the actuator


101


via the second pressure fluid


110


, thereby returning the actuator in a second actuator motion direction


131


.




The volume of first pressure fluid


106


positively displaced by the return of the actuator


101


from the third expansion chamber


129


can be delivered to a pressure fluid reservoir


153


through the open flow course d and via outgoing pressure fluid lines


155


. Compressed air acting as the first pressure fluid


106


can simply be vented.




From the switch position X or Y, the multiway valve


139


can be set into the switch position Z. In the latter position, because the flow courses a and b are blocked, the pressure imposed on both the first and the third expansion chambers


105


,


129


is undone. In the switch position Z, one or more previously first partially re-loaded piston-cylinder units


118


,


225


can be switched completely back again, and consequently a further displacement of the actuator


101


in the second actuator motion direction


132


back into the outset position thereof can be effected. The volume of first pressure fluid


106


positively displaced in the process out of the last expansion chamber to be relieved of the pressure which is imposed can be fed back into the pressure fluid reservoir


153


by way of a second flow course c or d that is now open as well, an example being the flow course c. The flow course c or d, in this example, the course d, that was open in the previous switch position X or Y now remains open, so that the volume of pressure fluid, now having been positively displaced even more, can be diverted out of the outer expansion chamber that in the previous stage was the first to be relieved of the pressure which was imposed. It is understood that the expansion chambers


105


,


129


can be supplied jointly and simultaneously with the pressure fluid


105


, so that a major force is immediately operative, if a previous switch position X or Y is skipped, and the switch position W is activated immediately.




The displaceable multiway valve


139


illustrated in

FIG. 1

is shown only diagrammatically and schematically. A practical version assures tightness of the parts movable relative to one another. Check valves may also be disposed in the first pressure fluid system


107


or in the multiway valve


139


, thus simplifying the construction of the multiway valve


139


and requiring fewer flow courses per switching position, because one flow course can act as an open flow course in one direction and simultaneously as a closed flow course in the other direction.




Another exemplary application of the features of the invention is shown in FIG.


2


. This exemplary application is shown in vertical section through a storage drum


13


, a turning or inversion drum


14


, and an impression cylinder


15


which, for recto/verso printing, are rotatably supported or journalled on both sides of a printing press in a respective side wall


16


thereof. The storage drum


13


is formed of two segments


17


and


18


which are adjustable in the circumferential direction relative to one another; bearings


19


for a gripper shaft


20


are located on the segment


17


, and grippers


21


for the front edge of the sheet are disposed on the gripper shaft. The segment


18


, which is rotatable relative to the segment


17


about a common pivot axis, has suction devices


22


for the trailing edge of the sheet being guided on the circumference of the storage drum


13


. The printing cylinder


15


, the turning drum


14


, and the storage drum


13


having twice the diameter of the standard printing-unit cylinders are all driven by the train of wheels of a toothed wheel gear mechanism. Beginning at a gear wheel


23


of a preceding transport drum, the drive of the storage drum


13


is effected by a gear wheel


24


; the drive of the turning drum


14


is effected by a toothed ring (gearwheel)


25


and a gearwheel


26


; and the drive of the printing cylinder


15


is effected by a gearwheel


27


. The gearwheels


24


,


26


and


27


are each disposed solidly on ends of the respective storage drum


13


, turning drum


14


and impression cylinder


15


, those ends being journalled in the side wall


16


.




The segments


17


and


18


are joined to one another by a clamping device. In this clamping device, the short arm of a clamping lever


28


presses the adjustable segment


18


against a countersupport


31


secured to the shaft end of the storage drum


13


by a securing ring


29


and screws


30


. The clamping lever


28


is supported with a cam


32


on a flat or planar face


33


of the segment


17


. The cam


32


is disposed off-center, so that the clamping lever


28


has one short lever arm and one long lever arm. The inner end of a thrust rod


34


that is guided axially displaceably and coaxially in the storage drum and extends out therefrom at an end face thereof is directed towards an end of the long lever arm. This thrust rod


34


is loaded by a spring


37


, which is braced at one end against a bridge


35


and at the other end against a thrust rod flange


36


, in such a way that the segments


17


and


18


of the storage drum are joined firmly to one another by frictional engagement as a consequence of the lever ratio of the clamping lever


28


. The resultant clamping of the segments


17


and


18


can be undone with the aid of a hydraulic piston-cylinder unit


12


.


1


which, when pressurized, presses the piston of the work cylinder thereof against a stop ring


38


secured to the thrust rod


34


, so that the spring


37


is compressed and the clamping between the two segments


17


and


18


is undone. Via the line


11


, the piston-cylinder unit


12


.


1


communicates with the symbolically represented pressure converter


1


. The relative adjustment of the segments


17


and


18


is performed manually or by machine. For gripper control, a roller lever


39


is secured to the gripper shaft


20


; a cam roller


40


is rotatably supported or journalled on a free end of the roller lever


39


and rolls along a cam


41


disposed on an adjustable toothed rack segment


42


. The rack segment


42


is clamped to the side wall


16


by a clamping piece


43


that is disposed on the inner end of a bolt


44


that, in turn, is axially displaceably guided in the side wall


16


. In the clamping direction, the bolt


45


is loaded by a spring


45


which, in turn, is braced at one end against the side wall


16


and at the other end against a flange ring


46


on the bolt


44


. To undo this clamped connection, a piston-cylinder unit


12


.


2


is disposed between the bolt


44


and a bracket


47


secured to the side wall


16


; its piston and work cylinder are braced against the bolt


44


on one side and against the bracket


47


on the other. This piston-cylinder unit


12


.


2


likewise communicates through a line


11


with the hydraulic pressure system of the pressure converter


1


. Once the clamping has been undone, the rack segment


42


is angularly adjusted in a conventional manner, either by hand or automatically via an adjusting shaft, not shown in the drawing, whereon a pinion engaging the teeth is disposed and which is supported in the side wall


16


.




Gripper tongs


48


, for example, constructed in a conventional manner, are disposed on a gripper shaft


49


on the turning drum


14


. Control of the gripper tongs


48


on the gripper shaft


49


of the turning drum


14


is effected by double cams


50


, preferably secured to the side wall


16


on both sides of the machine, a respective cam roller


51


rolling on each cam of the double cams


50


and moving a gripper control segment


52


. This gripper control segment


52


is secured at an end face thereof to a carriage


53


guided axially displaceably along the turning drum


14


, so that the cam roller


51


is adjustable by axial carriage motion from one cam to the other of the double cam


50


. The carriage


53


is radially clamped to the turning drum


14


by a further clamping device. To that end, a thrust rod


64


is axially movably supported coaxially in the turning drum


14


and a free end thereof is directed towards one arm of a bellcrank


55


, which is pivotably supported in the turning drum, the other arm of the bellcrank


55


engaging a tie rod


56


from below, the tie rod


56


being radially movably guided and being connected to the carriage


53


. The other end of the thrust rod


54


, which is directed outwardly at the end face thereof, passes through both a spring


57


and a thrust ring


58


. The spring


57


is braced at one end thereof against the thrust ring


58


and at the other end against a flange


59


of the thrust rod


54


. The abutment of the thrust ring


58


is formed by a plurality of clamping levers


60


and by a printing plate


61


that is firmly connected to the gearwheel


26


. The thrust ring


48


presses against the inner ends of the clamping levers


60


which, with the outer ends thereof press the gearwheel


25


against the gearwheel


26


, and cams provided in the vicinity of these outer ends are braced against the printing plate


61


. A sleeve


63


is slipped axially movably onto the outward-extending end of the thrust rod


54


, one of the end faces of which rests on the thrust ring


58


, and the other end face of which cooperates with the piston-cylinder unit


12


.


3


, which in turn is braced at the other end thereof against a flange ring secured to the free end of the thrust rod


54


. By suitably activating the piston-cylinder unit


12


.


3


, the sleeve


63


is displaced on the thrust rod


64


until it meets a shoulder


65


on the thrust rod


64


, so that the clamping action between the gearwheels


25


and


26


and of the carriage


53


on the turning drum is undone. This adjusting cylinder


12


.


3


, also communicates through a line


11


with the pressure converter


1


.




Another piston-cylinder unit


12


.


4


is secured to the outside of the side wall


16


; the piston thereof, when subjected to the pressure fluid in the adjusting cylinder, presses against the end face of the gearwheel


27


and firmly holds it thereat for the duration of the readjustment operation. The piston-cylinder unit


12


.


4


again communicates through the line


11


with the pressure converter


1


. By the action of the pressure converter


1


, upon its actuation in the first pressure stage P


1


, the piston-cylinder unit


12


.


4


is acted upon first, so that the drive of the drums in the zero position is blocked. At the same time, the piston-cylinder unit


12


.


1


can be suitably activated to undo the clamping in order to adjust the format at the storage drum. In a further pressure stage P


2


, the piston-cylinder unit


12


.


1


is then acted upon, to undo the clamping of the rack segment


42


so as to adjust the gripper opening, and at the same time the piston-cylinder unit


12


.


3


is acted upon, to undo the clamping in order to adjust the toothed ring and also the carriage of the turning drum. Once these readjustment operations have been performed, a pressure relief of the pressure converter first relieves the pressure in the piston-cylinder units


12


.


2


and


12


.


3


which are combined in the pressure stage P


2


, so that the associated clamps become operative again, before relief of the piston-cylinder units


12


.


1


and


12


.


4


is effected in the pressure stage P


1


, so that the release of the driving gearwheel


27


does not occur until after all the clamps are again operative.




A pressure monitor


87


in the line


11


of the second pressure medium system stops the press during the press readjustment, or does not allow the press to run until the line


11


is pressureless.





FIG. 3

shows an especially advantageous embodiment of the pressure converter


103


of the invention in the form of a modular system that includes components


165


,


166


,


167


. As a result of this construction, the pressure converter


103


is readily adaptable to various requirements in use, because the number of expansion chambers


172


acted upon by the pressure fluid supplied from a non-illustrated pressure fluid source, can easily be varied during assembly. For example, depending upon the intended purpose, a different adjusting piston rod


185


that carries a different number of adjusting pistons


165


can be provided. The adjusting pistons


165


may be different in construction; for example, adjusting pistons


165


of the embodiment shown may be used jointly with adjusting pistons embodied as differential pistons.




In terms of production effort and expense, a modular system that includes at least one component type having identically embodied components is advantageous. For example, an identical embodiment of the partition


166


and a different embodiment of the adjusting piston


165


and the intermediate element


167


may be contemplated. By dimensioning the intermediate element


167


and/or the adjusting pistons


165


differently, the size of the expansion chambers and the stroke length of the actuator


165


,


186


can be varied, and the partition


166


that defines the expansion chambers can essentially continue to have the same construction in all cases. In

FIG. 3

, an advantageous embodiment of the modular system shows which three component types, namely, the adjusting piston


165


, the partition


166


, and the intermediate element


167


, are provided with respectively identical components. The partitions


165


and the intermediate elements


167


can be connected to one another during assembly by a non-releasable connection, such as an adhesive bond, or by a releasable connection, such as one or more screw fastenings


168


,


169


. The pressure converter


103


may preferably have a circular-cylindrical or parallelepipedal (note

FIG. 4

) outer form and jacket surface, respectively. If the outer form is circular-cylindrical, then the intermediate elements


167


may be circular-ringshaped, and may be joined, for example, by three screw fastenings each offset 120° from one another. In the case of a parallelepipedal form, four screw fastenings


168


,


169


may be provided. The position of the components relative to one another can be assured not only by the screw fastenings, but also by position-securing elements, such as pins. Form-lockingly interengaging embodiments of the components, such as shoulderlike offsets made on a lathe, so that the components can be inserted partly into one another, can also contribute to the positional securing. In this regard, it is noted that a form-locking connection is one which connects two elements together due to the shape of the elements themselves, as opposed to a force-locking connection, which locks the elements together by force external to the elements. In the embodiment shown in

FIGS. 3 and 4

, only bores


170


in which the screws


168


are guided, are necessary. The play of the bores


170


allows for the alignment of the components in accordance with the adjusting piston rod


185


.




Sealing of the gaps formed by the faces of joined-together components can be achieved by a smooth, flat embodiment of the sealing faces, which is effected by grinding or precision turning, for example, or by seals, such as rubber washers, placed between the sealing faces


171


.




In accordance with the invention, the intermediate element


167


and the partition


165


may already form a structural unit because of how they are produced, for example, making this component in the form of a flangelike or cup-shaped turned part.




An embodiment that is advantageous in terms of both production and function includes a partition


165


which has a pressure fluid connection


173


,


186


,


189


formed of two bores


174


and


175


which open into one another. This preferred embodiment makes good pressure fluid feeding feasible, even when the stroke lengths of the actuator


165


,


185


are very short. The bore


174


extending perpendicularly to the central axis of the adjusting piston rod


184


may, as shown in

FIG. 3

, be formed as a stepped bore with a thread


176


for connecting the pressure converter


103


to pressure fluid delivery lines and/or drain lines, which are not illustrated. The supply of pressure fluid to the expansion chambers may, however, also be effected via recesses


188


formed in some other manner.




Depending upon the installed position of the partition


166


and the orientation of the bore


175


, the pressure fluid connections


173


and


189


may serve for the first pressure fluid system and the pressure fluid connections


186


for the second pressure fluid system.




In at least one pressure stage, two or more expansion chambers may be acted upon by the first pressure fluid, in addition to the number of expansion chambers acted upon in the previous pressure stage. To that end, the control of pressure fluid in the first pressure fluid system may be constructed accordingly, so that a plurality of additional expansion chambers


172


per pressure stage can be supplied with the first pressure fluid, via individual pressure fluid connections


173


associated with these expansion chambers. A transverse conduit


187


which connects a plurality of expansion chambers, for example, two of them, may also be provided, so that the two expansion chambers can be supplied via a single common pressure fluid connection


189


. Furthermore, more than one expansion chamber may be connected to the second pressure fluid system.





FIG. 5

shows the application of the features according to the invention to an apparatus for performing actuations that are to be performed in succession in a printing press, the apparatus having a pressure converter


190


operating on the rotary principle. The pressure converter


190


, including rotary parts, has an actuator


198


embodied as a vane wheel which, in a housing


210


of circular-cylindrical outer contour, is supported rotatably relative to the housing. The pressure converter


190


also includes expansion chambers


192


,


196


,


197


of circular sector-like cross section, which can be acted upon by pressure fluid and are defined by actuator faces


200


,


202


,


204


operative therein and by partitions


199


. The actuator


198


is rotatable relative to the housing


210


in one rotational direction


296


by an application of pressure fluid into expansion chambers, for example, three expansion chambers


192


,


196


and


197


. The mode of operation of the apparatus that includes this pressure converter


190


may be equivalent to that of the apparatus described in conjunction with

FIG. 1

but, instead of the pressure converter


103


with a displaceable actuator


101


shown therein, the rotationally acting pressure converter


190


is integrated with the apparatus, so that the cooperation of individual components of the apparatus as described in conjunction with

FIG. 1

is applicable in the same manner to the pressure converter


190


operating on the rotary principle.



Claims
  • 1. An apparatus for performing successively performable actuations in a printing press, comprising:a pressure converter including a plurality of input-side actuators formed with actuator surfaces which are successively able to be acted upon stepwise by pressure fluid, said pressure converter communicating with two piston-cylinder units actuatable stepwise in succession, said pressure converter having two expansion chambers connected to a first pressure fluid system, said expansion chambers being successively suppliable with a pressure fluid present in said first pressure fluid system; and a second pressure fluid system; said pressure converter having a third expansion chamber communicating with said piston-cylinder units via said second pressure fluid system.
  • 2. The apparatus according to claim 1, including a control unit for remotely controlling a valve with which said pressure converter communicates.
  • 3. The apparatus according to claim 1, wherein a first one of said piston-cylinder units is actuatable by a first actuating force, and a second one of said two piston-cylinder units is actuatable by a second actuating force having a different magnitude from that of said first actuating force.
  • 4. The apparatus according to claim 3, wherein the piston of said first piston-cylinder unit is preloaded with a first force different in magnitude from that of a second force with which the piston of the second piston-cylinder unit is preloaded.
  • 5. The apparatus according to claim 4, wherein a first spring for bringing said first force to bear is assigned to the first piston, and a second spring for bringing said second force to bear is assigned to the second piston.
  • 6. The apparatus according to claim 4, wherein said first piston has a first piston face different in size from a second piston face of said second piston.
  • 7. The apparatus according to claim 1, wherein said first pressure fluid present in said first pressure fluid system has at least one characteristic different from that of a second pressure fluid present in said second pressure fluid system.
  • 8. The apparatus according to claim 7, wherein said first pressure fluid system is embodied as a pneumatic pressure fluid system, and the second pressure fluid system is embodied as an hydraulic pressure fluid system.
  • 9. The apparatus according to claim 8, wherein said pneumatic pressure fluid system is connected to a compressed air source for supplying compressed air to the printing press for a plurality of other functions.
  • 10. The apparatus according to claim 1, wherein said pressure converter includes a housing formed with a partition, and said actuator is embodied as an adjusting piston rod carrying a first adjusting piston and a second adjusting piston, so that said partition and said second adjusting piston define an expansion chamber.
  • 11. The apparatus according to claim 10, wherein said first adjusting piston defines an expansion chamber formed with a vent opening.
  • 12. The apparatus according to claim 1, wherein said actuator is returnable by a restoring spring for reinforcing the return.
  • 13. The apparatus according to claim 1, wherein said actuator is returnable by an application of pressure fluid on at least one surface of said actuator.
  • 14. The apparatus according to claim 1, including a valve with which said pressure converter communicates, and wherein said first pressure fluid is controllingly feedable into at least one of said expansion chambers via said valve.
  • 15. The apparatus according to claim 14, wherein said valve is embodied as a multiway valve having various control positions and flow paths for feeding pressure fluid to both expansion chambers.
  • 16. The apparatus according to claim 1, including a device for starting and stopping sheet turning in a sheet-fed printing press.
  • 17. In a printing press, in combination therewith, an apparatus for performing successively performable actuations therein, comprising a pressure converter including a plurality of input-side actuators formed with actuator surfaces which are successively able to be acted upon stepwise by pressure fluid, said pressure converter communicating with two piston-cylinder units actuatable stepwise in succession, said pressure converter having two expansion chambers connected to a first pressure fluid system, said expansion chambers being successively suppliable with a pressure fluid present in said first pressure fluid system; anda second pressure fluid system; said pressure converter having a third expansion chamber communicating with said piston-cylinder units via said second pressure fluid system.
Priority Claims (1)
Number Date Country Kind
197 32 821 Jul 1997 DE
US Referenced Citations (5)
Number Name Date Kind
3916931 Shaw et al. Nov 1975
4097198 Herron Jun 1978
5103866 Foster Apr 1992
5588363 Becker Dec 1996
5845678 Ishihama et al. Dec 1998