DE10349668A1 - Process for transporting printed sheets of different format lengths comprises fixing a front and a rear sheet holder on a single revolving traction mechanism of the machine a different distance apart during transport of the printed sheets - Google Patents

Abstract

Process for transporting a printed sheet of a first format length held at its front end by a front sheet holder (113) and at its rear end by a rear sheet holder (114) and a printed sheet of a second format length held at its front end by the front sheet holder and at its rear end by the rear sheet holder in a machine (100) processing printed sheets (112) comprises fixing the two sheet holders on a single revolving traction mechanism (103) of the machine a different distance apart (119) during transport of the printed sheet of the first format length than during transport of the printed sheet of the second format length. Independent claims are also included for: (1) Process for changing the format of a machine transporting printed sheets of different format length; (2) Sheet transport device for transporting printed sheets in a machine; (3) Sheet delivery device; and (4) Sheet-fed printing press.

Description

The present invention relates referring to a method of transporting one at its front bow end through a front bow holder and at the same time on its rear Sheet end held by a printing sheet sheet held by a rear sheet holder a first format length and one at its front bow end through the front bow holder and at the same time at its rear end of the arch through the rear Sheet holder of a second format length held in one the printing material sheets processing machine, according to the preamble of claim 1. Des Furthermore, the invention relates to a with this transport method Process related to format change essential to the application one at its front bow end through a front bow holder and at the same time at the rear end of the arch by a rear Sheet holder of a first format length and one at its front bow end through the front bow holder and at the same time at its rear bow end through the rear bow holder held sheet of printing material transporting a second format length Machine, according to the preamble of claim 3. Finally relates the present invention also relates to one for carrying out the Both methods suitable sheet transport device for transporting of printing material sheets in a machine, with a front bow holder for holding one front bow end and a rear bow holder for holding one rear end of one of the printing material sheets, in which the front Bow holder and the rear bow holder together a pair of bow holders form and attached to one and the same rotating traction device are, according to the preamble of claim 4.

The transport and format changeover procedures corresponding to the process types mentioned at the beginning work in the DE-PS 1 260 482 . DE 42 18 421 A1 and DE 100 14 417 A1 described sheet printing machines. In none of the sheet printing machines described in the three documents mentioned are the front sheet holder and the rear sheet holder attached to one and the same rotating traction means. Rather, it is characteristic of each of these sheet printing machines that the front sheet holder is attached to a different traction device than the rear sheet holder both on the drive side and on the operating side. In these sheet-fed printing machines, the front sheet holder is therefore attached to a first pair of traction means and the rear sheet holder is attached to a second pair of traction means. For a better understanding it should be mentioned at this point that the traction means pairs in particular are chain pairs and the bow holders are gripper bridges. The three documents mentioned prove that it has been a long-established method, for the purpose of changing the format of the respective sheet-fed printing machine, to phase-adjust the two pairs of traction means relative to one another or at least the pair of traction means carrying the rear bow holders relative to the pair of traction means carrying the front bow holders make. This common procedure according to z. B. rotated by the second traction means, that is the one chain, wrapped sprockets relative to the sprockets wrapped by the first traction means and thereby the rear sheet holder is adjusted by the format setting difference to be corrected towards the front sheet holder or away from the latter. The disadvantage of this format changeover method is that it requires that the front sheet holder is attached to a traction device other than the rear sheet holder. The method corresponding to the prior art can therefore only be carried out with a sheet-fed printing machine comprising two pairs of traction means.

The method corresponding to the prior art cannot be carried out by means of a sheet transport device in which the front sheet holder and the rear sheet holder are attached to one and the same traction means as in the case of the US 1,613,445 described sheet transport device, which corresponds to the type of device mentioned above, is the case. In the sheet transport device described in the last-mentioned US patent, it is a decisive disadvantage that no sheet of printing material of different size lengths can be transported by means of this sheet transport device. In the case of the last-mentioned sheet transport device, the front sheet holder and the rear sheet holder are designed as gripper bridges, which are fixedly attached to one and the same traction means, here a chain, at an invariable distance (holder distance) for each machine side (drive side, operating side). With the sheet transport device, only printing material sheets of a single format length can be transported.

To solve the problems arising from the entire prior art explained above, neither DE 32 20 805 A1 , wherein a sheet transport device is described without a front sheet holder, nor the DE 42 41 789 A1 , wherein a sheet transport device is described without rear sheet holder to make a contribution. With regard to the present invention, the two last-mentioned laid-open publications merely embody further prior art.

Therefore, the object of the invention underlying, further methods of transporting both ends held sheet of printing material in a machine and for format change of this machine and a suitable one for performing the procedures Sheet transport device for the Creating machine.

This object is achieved by a Transport process with the features of claim 1, a format conversion process with the features of claim 3 and a sheet transport device solved with the features of claim 4.

The method according to the invention for transportation one at its front bow end by a front bow holder and at the same time at its rear bow end by a rear bow holder held substrate sheet of a first format length and one at its front bow end through the front bow holder and at the same time at its rear end of the arch through the rear Sheet holder of a second format length held in one the printing material sheets processing machine is characterized in that the two Bow holder on one and the same rotating traction device of the machine while the transport of the printing material sheet having the first format length at a different holder distance from each other than during the transport of the second format length Substrate sheet are held in attachment.

For example, using the front Bow holder and the rear bow holder, which together form a pair of bow holders form, first a first substrate and then a second Substrate sheet transported, the format length of the first sheet of substrate larger than the format length of the second substrate sheet. Therefore there is between the front bow holder and the rear bow holder at the given here Example during a large distance between the holders for the transport of the first printing material sheet, the to the format length of the first printing material sheet is coordinated, and during the Transport of the second sheet of printing material a small holder distance, the to the format length of the second substrate sheet is coordinated. It is essential that for the Transport of the first printing material sheet and transport of the second Printing material sheet one and the same pair of sheet holders for holding on both ends of the respective substrate sheet is used. Is essential continue that the front bow holder on the same traction mechanism how the rear bow holder is attached, both during the Transport of the first printing material sheet as well as during the Transport of the second substrate sheet.

An advantage of the transport method according to the invention is that for its implementation only a single pair of traction means, which consists of the traction means already mentioned and another traction means is formed, and no further traction means pair is required. The transport method according to the invention can So be carried out by means of a bow boom that only a single pair of chains, one chain on the operator side and the other chain the drive side of the sheet boom is arranged.

An advantageous development of the The transport procedure has the content that the rear bow holder while of the continuous circulation of the traction device automatically and periodically detached from the traction device and then again on the traction device is attached. This coupling and uncoupling of the rear bow holder to and from the traction device takes place both during the transport of the first Printing material sheet with the first format length as well as during the Transport of the second substrate sheet with the second format length. there the first substrate sheet can be processed in the Machine to be part of a first sheet stack that is made from Bedruckstoffbögen exists, each of which has the first format length, and can second sheet of substrate before it is processed in the machine be part of a second sheet stack, which consists of printing material sheets, each of which has the second format length. For example can they Bedruckstoffbögen of the first stack of sheets of long printing material sheets and the printing material sheets of the second sheet stack be short sheets of printing material. The one described here Development of the transport method according to the invention can the rear bow holder during the passage of the long sheets of printing material through the machine and repeatedly uncoupled and coupled from and to the traction means be, the rear bow holder at its for the purpose of Transporting the long coupling sheets to the traction mechanism every time at a great distance from the front Bow holder is attached to the traction device. As a result, the same can rear bow holder during of the z. B. the transport of the long printing material sheets as a follow-up order The machine also transports the short sheets of printing material mechanically and repeatedly uncoupled and coupled from and to the traction means be, which takes place for the purpose of transporting the short sheets of printing material Couplings of the rear bow holder to the traction device of the rear Bow holder each time at the same shorter distance to the front bow holder is attached to the traction device.

The method according to the invention for changing the format of a one at its front sheet end by a front sheet holder and simultaneously at its rear sheet end by ei NEN rear sheet holder holding printing material sheet of a first format length and a printing material sheet of a second format length held at its front sheet end by the front sheet holder and simultaneously at its rear sheet end by the rear sheet holder is characterized in that, depending on a length difference existing between the two format lengths a holder spacing in which the two bow holders are held fastened to one another on one and the same rotating traction means is changed.

The format changeover method according to the invention it is therefore peculiar that after the printing of the printing material sheet having the first format length and before transporting the printing material sheet having the second format length the holder distance is varied. Preferably the holder spacing corrected by a measure when changing the format, which is approx the length difference corresponds to that which determines the holder spacing between the two Media sheets exist. The correction measure of the Distance between the brackets does not necessarily have to be exactly this difference in length correspond. reasons for one in practice tolerable deviation of the correction measure from the length difference can a chain division of the traction means or a sag of the substrate sheet. The chain pitch is important if the traction device is a chain is, the chain links, z. B. chain pin, in chain link are arranged at a fixed distance from each other. The of Chain link to chain link existing distances could be a stepless variation oppose the holder spacing and only gradually Allow correction. The chain division would give discrete correction measures, which are practicable, but do not absolutely match the format length differences. In certain applications, it can be tolerable or even beneficial that the respective sheet of printing material held by the two Bow holders are not stretched taut but instead between slack in the two bow holders. Such an arch sag is capable of a deviation of the correction dimension of the Holder distance from the length difference of format lengths balance within certain limits, so for this reason too the correction measure and the difference in length not to be in a 1: 1 ratio need. The format changeover method according to the invention lies the surprising Based on the knowledge that the phase adjustment corresponding to the prior art at least one traction device for the purpose of continuously changing the format is not necessary at all and instead a gradual change of the holder spacing is often more effective.

The change in the holder distance can be done manually, semi-automatically or automatically. The automatic execution is particularly advantageous in the case in which the traction means while of change of the holder spacing continues to circulate without, however, during this Circulation by means of the front bow holder and the rear bow holder to transport any sheet of substrate.

At this point, attention is drawn to this made that, of course, within the scope of the present invention heard that variant which one before the format changeover at a certain holder spacing rear bow holder attached to the traction device by the front bow holder for the purpose of format change by another rear sheet holder, z. B. a cached reserve sheet holder or one before the format change also attached to the traction device rear bow holder one another pair of bow holders of the traction device, is replaced, wherein the original rear bow holder replacing new rear bow holder into one different holder spacing than the original rear bow holder is attached to the traction mechanism. In other words, includes the invention also includes the variant based on the regrouping or - Formation of the bow holder pair or several attached to the traction device pairs of bow holders attached to the traction means.

The sheet transport device according to the invention for transporting printing material sheets in a machine with a front bow holder for holding a front bow end and a rear bow holder for holding a rear bow end one of the substrate sheets, which sheet transport device the front sheet holder and the rear bow holder together form a pair of bow holders and are attached to one and the same rotating traction means characterized in that the machine has at least one positioning device for positioning the rear sheet holder in different lengths of format Bedruckstoffbögen dependent and different sizes holder intervals includes relative to the front bow holder.

This sheet transport device is particularly good to carry out the inventive method suitable.

The positioning device can be a conversion device for manual conversion of the sheet transport device used for the format changeover. For example, this retrofitting device can be a coupling which enables the operator of the machine to decouple the rear bow holder from the traction means by releasing the coupling and to reconnect it to the traction means at another point when the traction means is at a standstill. The positioning device can also be an auxiliary device which facilitates manual handling of the rear sheet holder. The auxiliary device can e.g. B. be a lifting device by means of which the operator rear bow holder when it is coupled and uncoupled to the traction device and away from the latter. The positioning device can ultimately also be an automatic handling device for handling the rear sheet holder during its repositioning relative to the front sheet holder for the purpose of changing the format.

Below are some in the dependent claims mentioned advantageous developments of the sheet transport device according to the invention briefly explained.

Continuing education, both with regard to a automatically as well as with regard to one carried out by the operator detachment and attaching the rear bow holder from and to the traction means advantageous is characterized in that the positioning device and others such as a first connection point, a second connection point and are a coupling element that the first connection point continues as the second connection point away from the front bow holder is arranged on the traction means that the coupling element on the rear Bow holder arranged and with each of the two connection points is designed to be compatible, so that the rear bow holder over the Coupling element optionally to form a large holder distance in the first connection point and to form a small holder distance can be coupled to the traction means in the second connection point. The first connection point, the second connection point and both with the first connection point as well as the second connection point Coupling elements designed to be compatible are those positioning devices those for positioning the rear bow holder in the different from the Dependent sheet formats holder intervals serve. The connection points can z. B. extended Be a chain pin if the traction mechanism is a chain. The coupling element can be a bolt pliers, a connector, a sliding bolt, a Pair of sliding latches or a spring latch of a snap fastening his. In the latter case, the coupling element forms together with each for the required bracket distance selected one of the connection points Snap connection. For example, the coupling element forms together a snap connection with the first connection point, if the rear one Bow holder over the coupling element to form the large holder distance in the first connection point is connected to the traction device, and forms the coupling element together with the second connection point other snap connection when the rear bow holder over the Coupling element to form the small holder distance in the second Connection point is connected to the traction device.

Another advanced training course is characterized by the fact that a strand of the traction device and an intermediate store to temporarily store the rear sheet holder together a first Determine the circuit in which the rear bow holder and rear Bow holders circulate further pairs of bow holders, and that that Traction means determines a second circuit in which the front Bow holder and front bow holder of the other bow holder pairs circulate. The circulation of the front bow holder in the second Circulation results from having the front bow holder together circulate with the traction device because the front bow holder is permanent remain attached to the traction device. In contrast, the rear bow holder during of the continuous circulation of the traction device automatically and periodically successively detached from the traction means in the buffer cached and then automatically back on the traction device attached.

Another advanced training course is characterized in that the positioning device is a connecting spring is about which the rear bow holder is elastically connected to the traction means is. This training enables the setting of different holder distances or the format change serving adjustments of the rear bow holder relative to the front Bow holder while which the rear bow holder remains attached to the traction device. The rear bow holder therefore needs to be changed to the front Bow holder related holder distance not to be detached from the traction device. The connecting spring is preferably a leaf spring or it is instead of the connecting spring, a plurality of such connecting springs, z. B. a series of spring bands, intended.

It is particularly beneficial to have one Sheet printing machine with the sheet transport device according to the invention equip. The sheet transport device can be part of a Sheet delivery of the sheet printing machine.

More functional and constructive particularly advantageous developments of the method according to the invention and device result from the following description preferred embodiments and the associated one Drawing.

In this shows:

1 and 8th a first sheet transport device ( 1 ) and a second sheet transport device ( 8th ), each with a traction device and bow holder,

2 a loading device of the first sheet transport device,

3 a first embodiment of an unloading device of the first sheet transport device,

4 a second embodiment of the unloading device,

5 to 7 various coupling elements Ment types that are provided for locking the sheet holder of the first sheet transport device with its traction means but also suitable for locking the sheet holder of the second sheet transport device with its pulling means,

9 a detailed view of one of the sheet holder of the second sheet transport device,

10 to 12 a coupling element type, which is used to lock the bow holder ( 9 ) the second sheet transport device is provided with its pulling means but is also suitable for locking the sheet holder of the first sheet transport device with its pulling means,

13 a third sheet transport device with a traction means and sheet holders,

14 an elastic or spring-loaded connection of two sheet holders of the third sheet transport device to one another and

15 and 16 an operating device of the third sheet transport device.

In 1 is a machine that processes printing material 100 shown in a section. The machine 100 is a rotary printing press printing on the printing material sheet with at least one printing unit, which comprises a printing form cylinder and an impression cylinder, e.g. B. with an offset printing unit or a flexographic printing unit. The section shows a sheet transport device 101 the machine 100 , The sheet transport device 101 is a sheet delivery, which successively the printing material sheets to a delivery stack 102 stacked up.

The sheet transport device 101 includes a self-contained or endless traction device 103 which is around a drive wheel 104 and a deflection wheel 105 rotates in a direction of rotation indicated by an arrow symbol. The traction device 103 is a chain, especially a bush or preferably roller chain with chain pin 160 and link plates 161 (see. 6 to 8th ) and the drive wheel 104 and the deflection wheel 105 are therefore sprockets.

The term "traction means" is used in technical language and also in a multi-link (e.g. chain) or flexible (e.g. belt) machine element.

The traction device 103 forms together with the drive wheel 104 and the deflection wheel 105 a first traction mechanism. A second traction mechanism comprises (chain) wheels that are connected to the drive wheel 104 and the deflection wheel 105 arranged coaxially and over waves 106 . 107 are non-rotatably connected, and also an endless traction means, the same (chain) length as the traction means 103 has and rotates in parallel and synchronously with the latter. The two traction mechanism transmissions are thus essentially identical to one another and in the axial direction of the four wheels, ie in the image plane of the 1 vertical direction, staggered. The two traction mechanism gearboxes together form a chain conveyor, especially a chain gripper delivery.

The traction device 103 are pairs of bow holders 109 . 110 . 111 assigned the holding of the printing material sheets during which by means of the traction means 103 carried out by a cylinder equipped with at least one gripper system for holding the substrate sheet 108 , e.g. B. a counter pressure cylinder or a transfer drum, to the delivery stack 102 serve. Each of the bow holder pairs 109 . 110 . 111 holds one substrate sheet each 112 fixed at both ends and includes a front bow holder 113 for holding a leading end of the bow in the circumferential direction and a rear bow holder 1l4 for simultaneously holding a trailing sheet end of the printing material sheet 112 , The bow holder 113 . 114 are considered to be relative to the direction of rotation of the traction device 103 perpendicular and parallel to each other longitudinally extending trusses, each with its one end to the traction means 103 and is attached or attachable with its other end to the traction means of the second traction mechanism transmission. Each of the bow holders 113 . 114 is with in a relative to the sheet leading edge and the sheet trailing edge of the sheet of printed material held 112 parallel row arranged sheet holding elements occupied.

These sheet holding elements could be suction nozzles, so that each or at least one, e.g. B. the rear, the two bow holder 113 . 114 would form a suction rod.

In fact, however, the sheet holding elements are designed as grippers for clamping the sheet leading edge or the sheet trailing edge, so that at least one, e.g. B. the front, or preferably each of the two bow holders 113 . 114 is designed as a so-called gripper bridge. In 1 are all sheet holders of the sheet transport device 101 shown only schematically, with all front bow holder 113 with a dot symbol and all rear bow holders 114 are marked with a cross symbol. Each of the rear sheet holders passes through in printing operation 114 an orbit of the traction device 103 only incomplete. Each of the rear bow holders runs 114 only along one in a coupling point 115 beginning and a decoupling point 116 ending section of the orbit. This section is located in the area of a lower run of the traction device 103 , In contrast to the rear bow holders 114 the front sheet holders 113 move in printing operation along the entire orbit, which is thus from the front sheet holders 113 is completely run through. One from an upper run of the traction mechanism 103 certain, previously not mentioned section of the orbit is only from the front bow holders 113 , but not from the rear bow holders 114 run through.

The coupling point 115 is from a loading facility 117 determines which the rear Bo genhalter 114 in a holder distance that depends on the respective format length of the substrate sheets to be transported 119 from or relative to the front bow holders 113 to the traction device 103 automatically connects. The one between the front bow holder 113 and the rear bow holder 114 of the respective pair of bow holders 109 . 110 . 111 existing holder spacing 119 can be done by the machine operator 100 varied and adjusted to the latter, so that the loading device 117 the rear bow holder 114 when processing short printing material sheets closer to the front sheet holder 113 and further away from the front sheet holders when processing long printing material sheets 113 to the traction device 103 docks. The holder spacing 119 is so while the machine is running 100 and with continuous traction means 103 varied.

The decoupling point 116 is from one of the loading facilities 117 in the direction of rotation of the traction device 103 downstream unloading device 118 given which the rear bow holder 114 from the traction device 103 automatically decouples or unloads after the respective rear bow holder 114 in his at times with the traction device 103 connected state its between the disconnect point 115 and the decoupling point 116 has passed through the lying transport path. The loading device 117 and the unloader 118 are between one for temporarily storing the rear sheet holder 114 serving buffer or buffer 120 and the traction device 103 arranged.

The loading device 117 and the unloader 118 could each be considered a translator of the rear bow holder 114 between the cache 120 and the traction device 103 from the former to the latter and back and forth swiveling arm and are actually each designed as a circulation system, specifically as a loading wheel or a loading drum.

The cache 120 is the unloading device 118 and the loading device 117 interposed and transports the rear bow holder from the former to the latter 114 which during this transport on a rotating storage element 121 the cache 120 sit. The storage element 121 is a traction device, especially a chain, and just like the previously mentioned traction device 103 provided in duplicate, namely once on the so-called operating side of the printing press and another time on the so-called drive side.

Instead of the traction means, a rotating storage wheel or a rotating storage drum for temporarily storing the rear sheet holder could also be used 114 Find use. Likewise, instead of the rotating storage element 121 an immobile and unloading device 118 to the loading facility 117 inclined storage element, e.g. B. a correspondingly sloping storage rail or an inclined storage slot, on which inclined storage element, the rear sheet holder 114 under the action of gravity to the loading device 117 would slip or roll.

The traction device 103 and the memory element shown 121 run in the same direction to each other, namely with regard to 1 each clockwise. The rear bow holder 114 sit positively on the traction mechanism 103 , with which they are locked during transport, and only sit frictionally on the storage element 121 on which the rear bow holder 114 are only slidably attached and clamped during their transport.

Each of the rear bow holders 114 is in a first step by means of the loading device 117 from the cache 120 removed and with the traction device 103 connected, in a second step by means of the traction means 103 from the loading device 117 to the unloading device 118 transported there, the rear bow holder 114 the rear end of the front bow holder at the same time at its front end 113 held substrate sheet 112 stops in a third step by means of the unloading device 118 from the traction device 103 removed and on the clipboard 120 put on and in a fourth step by means of the buffer 120 back to the loading facility 1 promoted l7. The front sheet holders circulate during printing 113 in a different circuit than the rear bow holder 114 whose circulation through the loading device 117 , the traction device 103 and more precisely, its lower run, the unloading facility 118 and the storage element 121 and more precisely, whose upper run is formed in the order mentioned.

The storage element 121 moves to the one sitting loosely on the latter and a traffic jam 122 forming rear bow holders 114 continuously over. Those stuck in traffic 122 parked rear bow holder 114 waiting in a queue, so to speak, from a separation device 123 one by one from the traffic jam 122 to be removed. Simultaneously with or shortly after by the separating device 123 removal of the respective bow holder 114 from that of the loading device 117 facing end of the traffic jam 122 adds the storage element 121 to the traffic jam 122 at that of the unloading device 118 end facing one of the bow holders 114 so that the traffic volume, ie the number of traffic in traffic 122 bow holder 114 , is kept constant or only by the amount of a single sheet holder 114 fluctuates. The separation device 123 is the cache 121 and the loading device 117 interposed and passes the rear bow holder from the former to the latter 114 ,

Out 2 , in which the separation device 123 and the loading device 117 are shown in more detail, it can be seen that the separating device 123 a cam or star wheel 124 for individually removing the sheet holder 114 from the traffic jam 122 and a transfer drum 125 for also transferring the separated sheet holders individually 114 to the loading facility 117 includes.

The star wheel 124 , in its place another and z. B. a reciprocating separator could be used, has a cam, z. B. teeth or transport pins, and circumferential contour formed between these gaps. The star wheel 124 rotates with respect to the transfer drum 125 and the loading device 117 in the opposite direction of rotation.

The transfer drum 125 and the loading device 117 rotate in the same direction of rotation. The transfer drum 125 and the loading device 117 are each with a receiving compartment 126, 127 for receiving the sheet holder 114 fitted. The respective recording compartment 126 . 127 has an essentially secant bottom and an essentially radial wall. Out of the floor and into the respective storage compartment 126 . 127 a spring bolt projects into it 128 . 129 , which serves the respective bow holder 114 to fix when this in the receiving compartment 126 . 127 sitting. These spring bolts 128 . 129 are each by a stationary control curve against the force of a return spring of the respective spring bolt 128 . 129 in a recess in the in the receiving compartment 126 . 127 seated bow holder 114 held. Out of the wall and into the storage compartment 126 . 127 A conical index and positioning pin, which therefore acts to center the last-mentioned bow holder, projects into it 130 . 131 whose longitudinal axis is perpendicular to the parallel longitudinal axes of the transfer drum 125 and the loading device 117 and also perpendicular to the longitudinal axis of the respective spring bolt 128 . 129 is aligned.

Both the transfer drum 125 as well as the loading device 117 is a so-called skeleton drum composed of disk-shaped segments which are arranged offset to one another in the axial direction of the respective drum. The segments of the transfer drum 125 are in the gaps between the segments of the loading device 117 arranged and the segments of the loading device 117 run in the gaps between the segments of the transfer drum 125 , The segments of the transfer drum 125 comb, so to speak, with the segments of the loading device 117 , As a result, the positioning pin 130 the transfer drum 125 and one with this positioning pin 130 interacting positioning or centering hole in the respective bow holder 114 relative to the positioning pin 131 the loading device 117 and one with the last-mentioned positioning pin 131 interacting, further positioning or centering hole in the bow holder 114 arranged offset in the direction parallel to the drum axis. The spring bolts are also 128 and its recess in the bow holder 114 relative to the spring bolt 129 and its recess in the axially parallel direction and with respect to 2 arranged perpendicular to their image plane.

The handover of the respective bow holder 114 from the transfer drum 125 to the loading facility 117 takes place when the receiving tray 126 of the former and the storage compartment 127 of the latter overlapped with each other in the course of the drum rotation, so that the walls of the two compartments 126 . 127 lie in one and the same plane and the bottoms of the two compartments 126 . 127 also lie on a common level. During the handover of the sheet holder 114 from the storage compartment 126 in the receiving compartment 127 becomes the positioning pin due to the drum rotation 130 from the bow holder 114 pulled out and the positioning pin 131 in this bow holder 114 pushed. The two positioning pins 130 . 131 can be in the bow holder at the same time for a short moment 114 or in its centering holes. It is important that at least one of the two positioning pins at any time during the handover of the sheet holder 130 . 131 in the sheet holder to be transferred 114 intervenes. During the handover of the bow holder, it releases the spring bolt 128 steering cam, which next to the transfer drum 125 is attached to a machine frame in a rotationally fixed manner, the spring bolt 128 free so that it can be released from the bow holder by its return spring 114 is pulled out, and presses the spring pin 128 controlling, other control curve, which next to the loading device 117 is attached to the machine frame in a rotationally fixed manner, the spring bolt 128 against the action of its return spring in the bow holder 114 into it. The two spring bolts can 128 . 129 for a moment in the bow holder at the same time 114 or its locking recesses. It is important that at least one of the two spring bolts is always used during the transfer 128 . 129 in the bow holder 114 intervenes.

It is also possible to use the spring bolts 128 . 129 and to arrange the locking recesses interchanged, so that on each of the rear bow holders 114 the spring bolts 128 . 129 are arranged, and it is also possible to use the positioning pins 130 . 131 and to arrange the centering holes interchanged, so that on each of the rear bow holder 114 the positioning pins 130 . 131 are arranged, however, the in 2 arrangement variant shown the cheapest.

On the positioning pin 131 opposite side of the tray 127 is a feather loaded latch 132 pivoted, which the in the receiving compartment 127 seated bow holder 114 only releases after this bow holder 114 through the loading device 117 safely to the traction device 103 has been coupled.

In 3 is the unloading device 118 shown in a first construction variant, according to which the unloading device 118 a holder bracket 133 for carrying the rear bow holder 114 having. The holder carrier 133 is essentially identical to the transfer drum 125 and therefore includes a storage compartment 134 , one of the securing of the sheet holder 114 in the receiving compartment 134 to prevent the positioning pin from slipping in the radial direction 135 and one for securing said bow holder 114 against slipping in the tangential and axially parallel direction serving spring bolts 136 , Just like the transfer drum 125 is the holder carrier 133 assembled in a skeleton construction from support disks or segments 137, 138.

The holder carrier 133 is about a relative to an axis of rotation 139 the unloading device 118 eccentric swivel 140 as a so-called satellite on a drum base 141 stored one around the axis of rotation 139 revolving gear bridge of a multi-stage or two-stage epicyclic gear of the unloading device 118 forms. The basic drum body 141 consists of two side plates, between which the holder bracket 133 is mounted as a rotatable traverse.

The epicyclic gear includes one with the axis of rotation 139 coaxially arranged, central sun gear 142 , which is non-rotatably connected to the machine frame and is therefore stationary. Furthermore, the epicyclic gear includes a planet gear 143 which is coaxial with the swivel 140 arranged and rotatably with the holder carrier 133 is connected and instead by directly into the holder bracket 133 introduced toothing could be formed. With the sun gear 142 and the planet gear 143 there is an intermediate gear 144 in mutual meshing, which via a further swivel joint 145 on the drum body 141 is appropriate. The intermediate wheel 144 forms together with the sun gear 142 a first gear stage and together with the planet gear 143 a second gear stage of the epicyclic gear. The basic drum body 141 , the holder carrier 133 , the planet gear 143 and the idler 144 run together in a direction of rotation marked by an arrow symbol - with respect 3 counterclockwise - around sun gear 142 around. The planet gear turns 143 and with this forcibly the holder carrier 133 due to the presence of the idler gear 144 in relation to the drum base 141 opposite sense of rotation - in terms of 3 clockwise - around the swivel 140 , The wheels 142 . 143 . 144 are externally toothed and are only shown schematically based on their pitch circles. The pitch circle diameter of the planet gear 143 is essentially the same size as the pitch circle diameter of the sun gear 142 so that the gear ratio of the epicyclic gear 1 : 1 and the receiving tray 134 including the bow holder inside 114 during the pivoting movement around the swivel joint 140 and simultaneously and together with the swivel joint 140 pivoting movement about the axis of rotation 140 around the in 3 maintains the position shown relative to the horizontal.

In one on the circumference of the unloading device 118 or the flight circle of the holder carrier 133 lying and imaginary sheet delivery point offset relative to the decoupling point 116 by an approximately 90 ° central angle 146 the sheet holding elements are still in the receiving compartment 134 seated rear bow holder 114 deactivated, ie its gripper opened or suction nozzles switched off, so that the bow holder previously 114 attached printing material sheets 112 precisely on the delivery pile 102 falls or falls. The one together with the one in the sheet delivery point 146 rear bow holder to be deactivated 114 the pair of bow holders 110 forming front bow holder 113 is timed in front of the rear bow holder 114 deactivated so that first the front sheet end of the substrate sheet 112 and then the rear end of the sheet is released and the substrate sheet 112 in the period in which the substrate sheet 112 moves on due to its inertia and only through the rear bow holder 114 and no longer through the front bow holder 113 is held, braked and pulled taut in the longitudinal direction of the bow.

The decoupling point 116 and an imaginary holder drop point 147 that is on the holder carrier's flight circle 133 and in which the unloading device 118 the bow holder 114 to the cache 120 emits, are essentially diametrically opposed to each other. The holder drop point 147 is therefore relative to the sheet delivery point 146 by an approximately 90 ° and on the axis of rotation 139 related center angle and relative to the decoupling point 116 by an approximately 180 ° central angle of the unloading device 118 staggered. A scraper 148 which is the holder drop point 147 localized, bumps the bow holder 114 from the storage compartment 134 as soon as the sheet holder 114 in the course of the pivoting movement of the unloading device 118 to the scraper 148 strikes. The scraper 148 is non-rotatable, ie not with the unloading device 118 moving, and in the path of movement in the receiving compartment 134 seated bow holder 114 arranged protruding. At the moment of hitting the bow holder 114 on the scraper 148 lie the wall of the storage compartment 134 from which the positioning pin 135 protrudes, and a stop surface of the stripper 148 essentially in one and the same plane. To avoid unwanted effects, e.g. B. vibrations, of the impact of the bow holder 114 on the scraper 148 caused by impact on other machine parts is the scraper 148 with a cushion made of a shock-absorbing material 149 padded, which forms the stop surface.

The upholstery can 149 instead of the scraper 148 once on each of the rear bow holders 114 be provided, however, in contrast 3 shown assignment of the cushion 149 to the scraper 148 cost-effective. It would also be possible to use the scraper 148 with one of the cushions 149 deviating damper, e.g. B. a damping spring.

The in 3 shown wipers 148 is arranged so that it is between the segments 137 . 138 passes through and through these segments 137 . 138 gap bounded on both sides to that in the receiving compartment 134 seated bow holder 114 hinlangt. One of the unloading device 118 assigned control cam and attached to the machine frame gives the spring bolt 136 just before the holder carrier 133 the holder drop point 147 reached freely so that the return spring of the spring bolt 136 the latter from the recess in the bow holder 114 can pull out.

At this point it should be noted that the unloading device 118 except the scraper 148 may have other such wipers that with the wiper 148 together form an axially parallel row and with the gaps in the holder bracket 133 are aligned.

In 4 is a second design variant of the unloading device 118 out 1 shown. The second design variant is in the with the reference numerals 116 . 133 to 141 . 146 and 147 Identified elements with the first design variant is identical and differs from the latter in terms of its different pivoting movement of the holder bracket 133 around the pivot joint 140 than the gear type of the first design variant. Because of the identity, it is not necessary to come out with the 3 in 4 elements referred to the reference symbols taken over again at this point.

The in 4 The type of transmission shown includes one with respect to the unloading device 118 radially oriented geometric axis of rotation 150 , a first bike 151 , a second wheel 152 , a third wheel 153 , a fourth wheel 154 and a the axis of rotation 150 dominant wave 155 on which the second wheel 152 and the third wheel 153 sit tight. The wave 155 and thus the common axis of rotation 150 of the second wheel 152 and the third wheel 153 are pivoted together with the drum base 141 around the axis of rotation 139, with which the fourth wheel 154 is arranged coaxially. The axis of rotation 150 crosses or cuts vertically through the swivel 140 certain common geometric axis of rotation of the first wheel 151 and the holder carrier 133 , The wave 155 is a hollow shaft that rotates on a through the shaft 155 led through carrier axis 157 is stored. The carrier axis 157 is with one axis end in a first attachment point formed by a cross pin or by a screw 158 and also with its opposite axis end in a through a journal of the drum body 141 formed, second attachment point 159 with the drum body 141 rigidly connected.

The first wheel 151 is non-rotatable with the holder bracket 133 connected and could instead by a toothing or a cam with which or the holder carrier 133 is provided directly, be formed. The first wheel 151 , which can also be referred to as a so-called star wheel, has teeth or cams which fit into a groove curve structure 156 of the second wheel 152 , which is a cylindrical or preferably globoid-shaped groove cam drum. The third wheel 153 and the fourth wheel 154 , which is attached to the machine frame in a rotationally fixed manner and is therefore stationary, are in mesh with one another and are designed as bevel gears. Due to the orbital movement of the third wheel around the fourth wheel 154 153 the latter is forcibly rotated by the former around the radially oriented carrier axis 157. The torque generated by this rotation is from the third wheel 153 over the hollow shaft 155 on the second wheel 152 , from this to the first wheel 151 and from the latter to the holder carrier 133 transfer.

The groove curve structure 156 has a constant rotation of the transmission (wheels 151 . 152 ) around the axis of rotation 139 non-uniform translation of this transmission effecting curve geometry. The curve geometry is such that the cam mechanism during the between the decoupling point 116 and the sheet delivery point 146 lying movement phase of the pivoting movement of the holder carrier around the axis of rotation 139 133 the latter rotates around the hinge 140 at a different rotational speed than during that between the sheet delivery point 146 and the holder drop point 147 lying movement phase. The curve geometry ensures that the storage compartment 134 during its movement from the decoupling point 116 up to the sheet delivery point 146 exactly the same as for the first construction variant (cf. 3 ) its at the decoupling point 116 maintains existing orientation relative to the horizontal and that the receiving compartment 134 during its subsequent movement from the sheet delivery point 146 up to the holder drop point 147 is, so to speak, "turned upside down" like this in 3 With the respective orientation of the receiving compartment 134 in points 146 . 147 clarifying, broken dash-dot lines is indicated.

The movement path of the pivoting movement of the holder carrier around the axis of rotation 139 133 is divided into path sections A, B and C with mutually different movement characteristics of the rotary movement of the holder carrier -133 which takes place during this pivoting movement around the swivel joint 140. The three movement characteristics differ in the respective rotational speed around the swivel joint 140 rotating movement from each other.

In the between the decoupling point 116 and the sheet delivery point 146 lying track section A is the gear ratio of the cam mechanism 1 : 1 so that the holder bracket 133 by one and the same angular amount around the axis of rotation 139 and at the same time around the swivel 140 is moved around. In the present example, the holder carrier 133 in track section A through an angle of approximately 90 ° around the axis of rotation 139 pivoted around and at the same time around an angle of about 90 ° around the swivel joint 140 turned around.

In the next and from the sheet delivery point 146 and the holder drop point 147 limited path section B is the gear ratio of the course transmission 1 : 2, so that the pivoting movement of the holder carrier around the axis of rotation 139 takes place within the path section B. 133 has an angular amount that is half the angular amount of the rotational movement of the holder carrier around the swivel joint 140 133 is. In the present example, the holder carrier 133 pivoted within the web section B by an angle of approximately 90 ° around the axis of rotation 139 and thereby rotated by an angle of approximately 180 ° around the swivel joint 140. In path section A, the direction of rotation (with respect 4 : Clockwise) of the movement around the swivel joint 140 opposite to the direction of rotation (with respect to 4 : counterclockwise) of the movement taking place around the axis of rotation 139. With regard to the direction of rotation of the movement taking place around the swivel joint 140, the track sections A and B are identical to one another and these track sections A and B could also differ from one another in the case of a curve geometry of the cam mechanism which differs from the present example.

At the drop-off point at the holder 147 beginning and at the decoupling point 116 ending track section C, the holder carrier moves 133 only around the axis of rotation 139, namely by an angle of approximately 180 °, and the holder carrier moves 133 not around the swivel 140. The movement of the holder carrier 133 around the axis of rotation 139 is continuous and the movement of the holder carrier 133 around the swivel joint 140 which is inevitably associated with this movement by the gear coupling via the bevel gear mechanism and the cam mechanism is due to the curve geometry of the second wheel 152 underlying motion law discontinuous and includes a rest phase located in the web section C. The training of the wheels 151 . 152 comprehensive cam gear as a so-called cam-controlled rotary stepping gear enables the previously explained movement period with the rest phase.

At the in 4 The second design variant shown is the scraper 148 due to the at the drop-off point 147 present "overhead alignment" of the receiving compartment 134 in contrast to the first construction variant (cf. 3 ) not necessarily required.

In the 5 to 7 Alternative variants of a locking device are shown to each other, of which two copies per rear bow holder 114 are provided. Each of the rear bow holders 114 a pair of the locking devices is thus assigned. A copy of the pair is on the so-called drive side of the machine 100 arranged and serves to couple and decouple the bow holder in question 114 to and from the traction device 103 and the other copy of the pair is arranged on the so-called operating side and is used to connect and disconnect the last-mentioned bow holder 114 to and from the traction mechanism of the second traction mechanism transmission. Each of the locking devices comprises at least one latch that is permanently attached to the respective rear bow holder 114 is attached. Each of the rear bow holders thus has 114 at least one bolt on its holder end on the drive side and at least one bolt on its holder end on the opposite machine side, the operator side. Due to the mirror-symmetrical design of the two locking devices of each of the rear bow holders 114 the following detailed description of one locking device of the respective pair is valid for the other locking device of this pair.

According to the in 5 shown first training variant, the locking device is a locking pliers 162 with pliers jaws 163 . 164 , which together with operating arms 165 . 166 form two levers and a swivel 167 are articulated together. The locking pliers 162 which is part of the bow holder 114 is via a hinge pin of the swivel joint 167 on another component, e.g. B. a cross member, the bow holder 114 attached. The pliers jaws 163 . 164 form two cooperating bolts of the locking device.

When coupling the bow holder 114 the latter becomes a train through the loading device 117 medium 103 there and in to the chain pin shown 160 moved vertically, so the two jaws of the pliers 163 . 164 into chain gaps, which are between the chain pin 160 and its two adjacent chain pins. This in the coupling point 115 the locking pliers are engaged 162 in the traction device 103 takes place with the locking pliers still open at the time of the intervention 162 , In a closing step following the engagement step, a gearbox, which is located in 5 the actuating arms is shown in a highly schematic manner based on its actuating force F. 165 . 166 spread apart. As a result, the locking pliers 162 closed so the pliers jaws 163 . 164 the chain pin between them 160 cling positively.

The gear mechanism shown on the basis of its actuating force F can comprise a wedge which is engaged when the locking pliers are closed 162 against the action of a return spring from a guide curve between the actuating arms 165 . 166 is driven and the latter consequently pushes apart, the wedge acting as a cam follower and its return spring on the bow holder 114 are arranged and the guide curve along which the wedge slides or rolls on the machine frame of the machine 100 is arranged.

In an alternative embodiment to its last-explained design, the gear mechanism can also comprise a toggle lever with two lever arms connected to one another via a knee joint, the lever arm ends on one of the actuating arms each with their lever arm ends remote from the knee joint 165 . 166 are articulated. The knee glides or rolls on the guide curve fixed to the frame, which increasingly presses against the action of the return spring on the knee joint during the closing process and thereby the lever arms and at the same time the actuating arms 165 . 166 spreads apart.

Regardless of whether the transmission comprises the wedge or instead the toggle lever, when the rear bow holder 114 is uncoupled from the traction means 103 first by means of the gear, e.g. B. by the action of the return spring, the actuating arms 165 . 166 moved towards each other so that the jaws of the pliers 163 . 164 the chain pin they enclose 160 release again, and is then in the decoupling point 116 as a result of the discharge device 118 carried out removal of the bow holder 114 from the traction means 103 the locking pliers 162 from the traction device 103 pulled out or from the chain pin 160 deducted.

According to the in 6 shown second embodiment of the locking device, the latter is designed as a plug connection. The plug-in connection includes the extended chain pin 160 and includes as a "female" counterpart to the extended chain pin 160 a jack that acts as a latch 168 with a locking hole. The traction device 103 which in 6 shown in cross section is a so-called "chain with extended chain pin". The jack 168 is with a curve following element 169 , e.g. B. a cam roller, equipped, and by means of a linear guide, for. B. an elongated hole 170 in a cross member 171 the bow holder 114 , on the bow holder 114 in the axial direction of the chain pin 160 slidably mounted towards and away from the latter.

When coupling the rear bow holder 114 to the traction device 103 is by means of the loading device 117 first the bow holder 114 into engagement with the traction device 103 brought so that one at a hook-shaped end of the cross member 171 molded centering tooth 172 is pushed into a chain gap between two chain pins. After this the alignment of the bow holder 114 relative to the traction device 103 serving intervention of the centering tooth 172 it is ensured that the locking hole of the jack 168 exactly in axial alignment with the chain pin acting as a plug pin 160 located. Through the two chain pins, between which the centering tooth 172 has been pushed is a positional securing of the bow holder 114 against shifting the bow holder 114 relative to the traction device 103 given in its running direction. Each of these two last-mentioned chain pins penetrates the chain link 161 and one with this chain link 161 immediately adjacent link plate and the centering tooth 172 sits during his engagement between the last two link plates, which thereby secure the position of the bow holder 114 relative to the traction device 103 in the axial direction of the chain pin 160 cause. In order to ensure complete securing of the position, one is arranged on the machine frame and with the cam follower element 169 interacting leadership curve 174 the blockage of the jack 168 abandoned as soon as the curve following element 169 a certain curve point of the guide curve 174 has reached, so that a locking spring 173 the socket 168 to the chain pin 160 shifted and put on the latter. Just before the rear bow holder 114 through the unloading device 118 in the decoupling point 116 from the traction means 103 is separated again, the centering tooth 172 is pulled out of the chain gap, the locking device is unlocked by the guide curve 174 along which the curve following element 169 moved, the jack 168 against the action of the locking spring 173 from the chain pin 160 withdraws again.

According to the in 7 The third embodiment variant of the locking device shown is at the relevant holder end of the bow holder 114 a pair of sliding bolts arranged, which a first sliding bolt 175 and a second slide latch 176 includes. The sliding latches 175 . 176 are along axes 177 . 178 on each other slidably mounted to and away from each other. The first sliding bar 175 is along the axis 177 into one from the chain pin 160 together with an adjacent chain pin 160a Chain gap formed when coupling the rear bow holder 114 in the traction device 103 into or in engagement with the latter and when uncoupling the rear bow holder 114 from the traction device 103 slidably mounted out. The chain pin 160 forms together with another adjacent chain pin 160b another chain gap, into and out of which the second sliding bolt 176 along its axis 178 is slidably mounted. Each of the chain pins 160 . 160a . 160b forms a possible connection point for connecting the rear bow holder 114 to the traction device 103 , The mutually oblique axes 177 . 178 lie in one and the same plane and intersect at an apex S.

The axes 177 . 178 may differ from the embodiment shown but also in two different planes, which are in the direction of a central axis of the chain pin 160 , that is perpendicular to the image plane of the 7 , are offset from one another, the axes 177 . 178 take a so-called "skewed" position to each other and do not intersect at the apex S but only cross.

In both cases, ie with axes crossing or intersecting 177 . 178 , the vertex S lies on that of the cross member 179 opposite side of the chain pin 160 and thus within an imaginary, endless connecting line VL, on which all chain bolts of the traction means 103 lie. The two essentially bolt-shaped sliding bolts 175 . 176 is a safety spring each 180 which the respective sliding bolt (spring bolt) 175 respectively. 176 stops in the respective chain gap, and a curve follower 181 , over which the respective sliding bolt 175 or 176 against the action of the safety spring 180 is pulled out of the chain gap. In addition, each of the two sliding latches 175 . 176 one in the direction of the apex S at an angle β on the respective axis 177 or 178 tapered wedge or cone surface. If the bow holder 114 to the traction device 103 is coupled and the locking device is locked, as shown in 7 is shown, contact the slide latch 175 . 176 the chain pin they enclosed 160 in two on the circumferential surface of the chain pin 160 located terminal points P1, P2. A third clamping point P3, which is from the bow holder 114 , especially from its cross member 179 , together with that of the chain pin 160 enforced chain link 161 , is formed, cooperates with the other two clamping points P1, P2 in the manner of a three-point mounting or clamping. The two wedge or cone surfaces cause the elimination of any bearing play when closing the locking device, so that the locking of the bow holder 114 is not shaky at all and is very tight instead. One the curve following elements 181 the sliding latch 175 . 176 actuating guide curve, e.g. B. in the form of a link guide, is shaped with respect to their curve geometry such that both in the coupling point 115 as well as in the decoupling point 116 only one of the two sliding bolts at a time 175 . 176 is shifted and the other sliding bar maintains its position, being in the coupling point 115 the leading sliding bolt 175 and in the decoupling point the trailing slide bolt 176 is withdrawn.

In 8th is a substrate sheet 212 processing machine 200 shown in a section. The machine 200 is one of the substrate sheets 212 printing rotary printing machine and comprises at least one printing unit, e.g. B. an offset printing unit or a flexographic printing unit, which has a printing form cylinder and an impression cylinder, and further comprises a sheet transport device 201 , The sheet transport device 201 is a sheet delivery, which the printing material sheets 212 successively to a delivery pile 202 promoted and deposited on the latter.

The sheet transport device shown in the detail 201 includes a self-contained or endless traction device 203 which is around a drive wheel 204 and a deflection wheel 205 rotates in a direction of rotation indicated by an arrow symbol. The traction device 203 is a chain, in particular a sleeve or preferably roller chain composed of chain pins, link plates and chain bushes / chain rollers, and the wheels 204 . 205 are therefore sprockets. The traction device 203 forms together with the wheels partially wrapped by him 204 . 205 a first traction mechanism of the machine 200 , A second traction mechanism gearbox of the machine 200 which, according to the view 8th is covered by the first Zugmitte transmission, includes (chain) wheels connected to the drive wheel 204 and the deflection wheel 205 over waves 206 . 207 are rotatably connected, and further comprises an endless traction means, the same (chain) length as the traction means 203 has and with the traction 203 rotates synchronously. The two last-mentioned traction mechanism transmissions, which are essentially identical to one another and which together form a chain conveyor (specifically: chain gripper delivery), lie in two different, imaginary spatial planes that are parallel to one another and to one another in the axial direction of the wheels 204 . 205 and thus in the image plane of 8th are offset vertically.

The traction device 203 are pairs of bow holders 209 . 210 . 211 assigned to holding the substrate sheet 212 during which by means of the traction device 203 Transport carried out by at least one gripper system for holding the printing sheet having cylinders 208 , e.g. B. one Impression cylinder or a transfer drum, to the delivery stack 202 serve. Each of the bow holder pairs 209 . 210 . 211 holds one of the substrate sheets 212 at its front bow end using a front bow holder 213 and at its rear bow end by means of a rear bow holder 214 stuck at the same time. The bow holder 213 . 214 are designed as trusses, each with its one end on the traction means 203 and is attached or attachable with its other end to the traction means of the second traction mechanism transmission. The traverses extend parallel to one another and relative to the direction of rotation of the traction means 203 vertically in the longitudinal direction of the truss. Each of the bow holders 213 . 214 is provided with sheet holding elements that are in a relative to the sheet leading edge and the sheet trailing edge of the sheet holder 213 . 214 between the sheets of printing material held between them 212 parallel row are arranged.

These sheet holding elements could be suction nozzles, so that each or at least one, e.g. B. the rear, the two bow holder 213 . 214 would form a suction rod.

In fact, however, the sheet holding elements are designed as grippers for clamping the sheet front edge or the sheet rear edge, so that at least one, namely the front, or preferably each of the two sheet holders 213 . 214 is designed as a so-called gripper bridge. In 8th are all sheet holders of the sheet transport device 201 only shown schematically by all front bow holders 213 with a dot symbol and all rear bow holders 214 are marked with a cross symbol.

At the in 8th The illustrated embodiment of the invention are shown before the start of printing operation, that is, with the traction means stationary 203 , all rear bow holders 214 on the traction mechanism 203 at a bracket distance 215 relative to the respective front bow holder 213 by the operator of the machine 200 manually attached. The holder spacing 215 depends on the respective format length of the substrate sheets to be transported 212 from. The one between the front bow holder 213 and the rear bow holder 214 of the respective pair of bow holders 209 . 210 . 211 existing holder spacing 215 can be varied from print job to print job by the operator moving the rear sheet holders 214 closer to the front sheet holders for subsequent short sheet processing 213 and for the purpose of subsequent processing. long substrate sheet further away from the front sheet holders 213 to the traction device 203 by means of quick-release fasteners with which the rear bow holder 214 are fitted.

So that this format conversion of the sheet transport device 201 from one to the other sheet format length is easy and quick, the operator can use a conversion aid. The assembly and disassembly of the rear bow holder 214 to the traction device 203 and from the traction device 203 Serving conversion auxiliary device can be immobile and consequently continuously, ie also during those periods in which the conversion auxiliary device is not used, such as. B. in printing, in the machine 200 remain installed. Instead, the conversion auxiliary device, the z. B. a lifting device for lifting the rear bow holder 214 can also be mobile and therefore only for short-term use in the machine 200 be provided during the machine setup or changeover times.

In 9 is an example of one of the rear bow holders 214 shown in a cross section. From the graphic representation it can be seen that the bow holder 214 a geometric axis of rotation 216 , around which a first lever 217 , a second lever 218 and a third lever 219 are pivotally mounted to each other. The second lever 218 and the third lever 219 that about the axis of rotation 216 are pivotally connected to each other, are on their axis of rotation 216 opposite lever ends using snap fasteners that act as quick-release fasteners 220 . 221 , in the 9 highly schematic and in the 10 to 12 are shown in detail using an example, along a (chain) guide 222 running traction means 203 releasably attached.

A positioning eccentric designed as an eccentric shaft 223 is relative to the axis of rotation 216 over which the first lever 217 articulated with the second lever 218 and the third lever 219 is connected, offset on the first lever 217 arranged. A first curve following element 224 in the form of a cam roller is relative to the axis of rotation 216 and to the eccentric 223 offset at the first lever 217 arranged. The first curve following element 224 is on a first lever arm of the first lever 217 and the eccentric 223 is on a second lever arm of the first lever 217 arranged. A second cam follower element also designed as a cam roller 225 is over a fourth lever 226 with the eccentric 223 connected. The eccentric 223 and the fourth lever 226 could be made together from one and the same piece and instead are each made from a different piece and non-rotatably connected. The eccentric 223 and the first lever 226 are on the first lever via a pivot 227 217 attached so that they are adjustable to the latter.

A first spring arm 228 and a second spring arm 229 together form a pair of pliers for gripping and holding the trailing edge of the sheet. The z. B. made of spring steel spring arms 228 . 229 are with interacting jaws 230 . 231 , between which the printing material sheet can be clamped. The first spring arm 228 seated with his foot 232 firmly on a parallel to the axis of rotation 216 longitudinally extending leg 233 of the third lever 219 ,

The third lever 219 and the first spring arm 228 can also, instead of being composed, one-story and z. B. in the form of a single sheet metal part.

The first spring arm 228 has an essentially zigzag-shaped profile with bending points at which the first spring arm 228 is angled and that as bending joints 234 to 236 act. The second spring arm too 229 points as flexures 237 . 238 acting bending points. The eccentric 223 is between the spring arms 228 . 229 arranged and by means of the eccentric 223 partially wrapping around the first spring arm 228 holding clamp 239 rotatably mounted. The clamp 239 is by a tongue of the first spring arm bent around the adjusting eccentric 223 228 educated. The tongue or clamp 239 has a rag that is bent into a U-profile and one has the spring arms 228 . 229 connecting web 240 forms. The jetty 240 is on his side cheek with the first spring arm 228 and on its other side cheek with the second spring arm 229 screwed or riveted.

The in 9 illustrated bow holder 214 works as follows:
A curve through which the second curve sequence element 225 is performed, causes a deflection of the latter. This deflection inevitably makes the eccentric 223 from its in 10 shown rotary position, in which the broad sides of the eccentric 223 the spring arms 228 . 229 are turned into a transverse position, in which narrow sides of the eccentric 223 the spring arms 228 . 229 are facing. The eccentric 223 is over an angle of rotation of approximately 90 ° from the first-mentioned rotational position, in which the clamping jaws 230 . 231 due to the spring action of the spring arms 228 . 229 are tensioned against each other, rotated into the transverse position. By turning the eccentric 223 the second spring arm 229 from the first dam 228 pushed away and bent elastically so that the jaw forming a gripper 231 of the second spring arm 229 from the jaw forming a gripper pad 230 of the first spring arm 228 is lifted off and the spring pliers are opened. During this opening or immediately after this opening of the spring pliers, another curve, which guides the first curve follower element, steers 224 performs the latter, so the first lever 217 around the axis of rotation 216 to the traction means 203 is pivoted towards _: Due to the eccentric 223 given connection of the first lever 217 with the first spring arm 228 the latter becomes due to the pivoting movement of the first lever 217 elastic to the traction device 203 bent towards it. The movement of the first spring arm 228 to the traction mechanism 203 has the consequence that the spring tongs are placed over the rear edge of the printing material sheet, which is approximately at the level of the traction means 203 located.

The spring pliers are designed as a so-called immersion gripper, which moves with the traction means during its rotation 203 from its in 9 shown diving position between the two strands of the traction device 203 in its required to grasp the trailing edge of the sheet and in comparison with the immersion position with regard to the traction means 203 position further out appears. This appearance, in which the trailing edge of the sheet between the jaws 230 . 231 device, takes place in a loop 241 the wrapping of the drive wheel 204 through the traction mechanism 203 , This wrap point 241 should be in the direction of rotation of the traction device 203 seen as close as possible behind a sheet transfer point 242 lying in which the printing material sheet or its sheet leading edge from the cylinder 208 to the front bow holder 213 of the corresponding pair of bow holders is handed over (cf. 8th ) to get voted. The second curve following element 225 Actuating curve has a curve geometry on the basis of which the positioning eccentric 223 from its transverse position, in which the spring arms 228 . 229 from the eccentric 223 held apart, turned back to its clamping position as soon as the trailing edge of the sheet between the jaws 230 . 231 located. While turning the eccentric 223 the second spring arm snaps 229 due to its inherent elasticity back to the first spring arm 228 so that the rear sheet edge of the printing material sheet between the clamping jaws 230 . 231 is firmly clamped.

That for opening the spring pliers and thus letting go of the trailing edge of the bow and for immersing the spring pliers in a further inside between the strands of the traction means 203 lying area required movements occur in a relative to the previously described reverse order and therefore do not need to be explained in detail.

The snap fasteners 220 . 221 having and by means of the latter on the traction means 203 coupled lever ends of the second lever 218 and the third lever 219 move during the circulation of the sheet holder 214 periodically towards and away from each other. There is a greater distance, measured in a straight line, between these two lever ends if the lever ends lie along a straight section (run) of the traction device's orbit 203 move. The distance to be measured in a straight line between the two lever ends is shorter if the latter is along one due to the wrapping of one of the wheels 204 . 205 through the traction mechanism 203 move curved portion of the orbit. The second lever 218 and the third lever 219 are through one Spring, not shown, between the second lever 218 and the third lever 219 is arranged and strives to use the two levers 218 . 219 spread apart, braced against each other. The spring can e.g. B. a Drehbzw. Leg spring, the one on the axis of rotation 216 determining pivot pin is attached and which one on the second lever 218 supported leg and one on the third lever 219 has supported legs.

The identical design of the snap fasteners 220 . 221 is explained in detail in the following 10 to 12 using the example of the snap fastening 220 shown.

A particular advantage of the snap fastening 220 can be seen in their cost-effective production method, which is briefly outlined below. 12 shows one for the production of the third lever 219 including the snap fastening 220 provided blank sheet in an intermediate production stage. In this intermediate production stage, a dividing line is already in a spring plate from which the sheet metal blank is made by means of a punching tool or laser cutting 243 introduced and thereby formed a tongue in the form of the minuscule "f". In 12 are bending lines 244 indicated on which the tongue in a subsequent manufacturing stage in the form of the in 10 and 11 spring bolt shown 245 is bent. In addition, in 12 can be seen that in the sheet metal blank, ie the later third lever 219 , a pass hole 246 for an extended. chain pins 247 of the traction device 203 is introduced.

The traction device 203 is a "chain with extended chain pin" and consists of the chain pin 247 and other such chain pins, link plates 248 and chain rollers (or chain bushings) 249 , The traction device 203 and the snap fastener 220 are in 10 in top view and in 11 shown in a cross section. The 10 and 11 show those with the traction device 203 locked position of the spring bolt 245 , The chain pin is in this locked position 247 in the pass hole 246 so the bow holder 214 in its required holder spacing 215 the corresponding position is fixed and engages behind the spring bolt 245 with his hook 250 that of the chain pin 247 and its adjacent chain pin penetrated chain link 248 so that the connection between the bow holder 214 and the traction device 203 is secured. On stop faces 252a . 252b of the third lever 219 adjacent blocking arms 253 . 254 of the spring bolt 245 prevent the spring bolt 245 too far through after the spring bolt has been removed and bent 245 remaining recess passes out of the sheet metal blank and thus ensure the correct position of the hook 250 relative to the link plate 248 , This security would almost as well be a single one of the blocking arms 253 . 254 cause.

For varying the holder spacing 215 in a first step (unlocking or unlocking step) the hook 250 except behind the chain link 248 , so regarding

11 upward, curved. During this reversible deformation of the spring bolt 245 becomes the catch 250 pivoted against the effect of its inherent elasticity around the bending line 244, which forms a bending joint.

In a second step (decoupling or dismantling step) the third lever 219 using its own elasticity in the axial direction of the chain pin 247 from the traction device 203 bent. This is the catch 250 on the chain link 248 moved past and the pass hole 246 from the chain pin 247 deducted. Thus the bow holder 214 from the traction device 203 replaced.

In a third step, the third lever 219 or its pass hole 246 on another chain pin of the traction device 203 than the chain pin 247 put back on. Depending on the length of the sheet format to be processed, this other chain pin becomes dependent on the length of the traction mechanism 203 existing and possible chain pin selected and is closer to the front bow holder 213 than the chain pin 247 or further away from the front bow holder 213 than the chain pin 247 , so that there is a changed holder distance between the rear bow holder and the front bow holder of the respective bow holder pair.

When attaching the third lever 219 a wedge surface slides on the selected chain pin 251 of the hook 250 on the narrow side of the link plate that the hook 250 to resort to later. In the course of this sliding movement, the hook 250 due to the wedge effect of the wedge surface 251 while pushing on the bow holder 214 on the traction device 203 pushed away from the narrow side of the link plate until the hook 250 has completely exceeded the narrow side and as a result jumps back so that the hook 250 automatically falls behind the link plate (locking or

Securing step). The spring bolt 245 is so designed that it has a hook due to its inherent elasticity 250 snaps automatically or into the traction mechanism 203 snaps.

The steps outlined are also on the snap fastener 221 and on one with the snap fasteners 220 . 221 Mirror-symmetrically designed pair of snap fasteners that attach to the snap fasteners 220 . 221 opposite end of the bow holder 214 is arranged and can be optionally connected to the traction mechanism of the second traction mechanism transmission.

In 13 is another machine 300 shown in a section. The machine 300 includes with the reference numerals 301 . 303 . 304 . 306 . 309 . 310 . 312 to 315 designated elements which do not need to be explained again because they are already in connection with the machine 200 (see. 8th ) have been explained and for the machine 200 with the value of the reference number reduced by the difference "100". For example, the wave corresponds 306 the wave 206 ,

The machine 300 is just like the machine 100 . 200 a rotary printing press with a sheet delivery. The front bow holder 313 is at one end of the traction mechanism 303 and attached at its opposite end to the second traction means of the single traction means pair of the sheet boom. There is also a front traverse on the two traction devices 316 who have favourited the front bow holder 313 in the direction of travel of the traction device 303 is preceded and a rear traverse 317 who have favourited the front bow holder 313 and the rear bow holder 314 is interposed, attached. The trusses 316 . 317 are relative to the front bow holder 313 along the traction device 303 slidably mounted. As connection springs for connecting the rear bow holder 314 with the front bow holder 313 and the traction device 303 acting leaf springs 318 . 319 , each at its front spring end with the front cross member 316 and at the rear end of the spring with the rear crossmember 317 are firmly connected in one along the trusses 316 . 317 extending row and arranged parallel to each other.

Instead of the leaf springs connected in parallel 318 . 319 whose arrangement is best derived from the 14 corresponding top view can be seen, only a single leaf spring can be provided, for. B. in the form of a flexible sheet.

The leaf springs shown 318 . 319 are at a certain distance from the traction device 303 on the rear crossmember 317 slidably mounted relative to the latter, so that the leaf springs 318 . 319 together with the front traverse 316 and the rear bow holder 314 form a movable unit. By moving this unit relative to the front bow holder 313 the distance between the brackets is forward 315 shortened and by moving this unit relative to the front bow holder 313 to the rear, i.e. against the direction of travel of the traction mechanism 303 , the holder distance 315 increased. In 13 is the example of the pair of bow holders 309 the setting for the maximum printable sheet format length and, for example, using the pair of sheet holders 310 the setting required for the minimum format is shown. It goes without saying that for the operation of the machine 300 for both pairs of bow holders 309 . 310 one and the same setting must be selected. The rear bow holder 314 is not direct but only indirectly via the leaf springs 318 . 319 with the traction device 303 flexibly connected. Via support feet 320 . 321 the rear bow holder is in the form of narrow metal strips 314 at times on the traction device 303 and the parallel running traction device. The support feet 320 . 321 rest on chain pins of the respective traction device. The leaf springs 318 . 319 are curved in an S-shape and are under tension. Im between the bow holders 313 . 314 lying length section of the leaf springs 318 . 319 are in the direction of between the traction means 303 lying space elastically bent. At times the rear bow holder 314 from a curved or rail-shaped guide 322 performed, which is fixed to the machine frame.

In 13 are a first circumferential angle range γ _{1 of} the wheel 304 inside which the rear bow holder 314 from an actuator 323 is caught or stabilized in position, and a second circumferential angular range γ ₂ adjoining the first circumferential angular range γ _{1 is} indicated, within which the rear bow holder 314 through the actuator 323 is controlled so that it grips the rear end of the sheet. Within the first circumferential angular range γ lie from the wheel 304 together with the traction device 303 formed tangential point 324 , in which the wrapping of the wheel 304 through the traction mechanism 303 begins, and an arc transfer point 325 in which the front bow end of the cylinder 308 to the front bow holder 313 is handed over. The second circumferential angle range γ ₂ lies between the arc transfer point 325 and a tangent point 326 , in which the wrapping of the wheel 304 through the traction mechanism 303 ends.

In 15 is the actuator 323 , which comprises two cam mechanisms. A cross-shaped support arm 327 , a first control curve 328 and a second control curve 329 are coaxial with the wheel 304 arranged. The control curves 328 . 329 can be two disks connected to one another or molded onto one and the same disk. The control curves 328 . 329 are rotatably attached to the machine frame. The support arm 327 is rotatable with the shaft 306 connected so the wheel 304 and the support arm 327 rotate together. Eccentric to the shaft 306 and coaxial with each other are a first operating lever 330 and a second operating lever 331 swivel with the support arm 327 connected. The operating levers 330 . 331 are L-shaped and are connected via tappets that act as cam followers 332 . 333 that in the support arm 327 are slidably supported by the control cams 328 . 329 controlled. The first control curve 328 pivots the first operating lever 330 and the second control curve 329 pivots the second operating lever 331 depending on the angular positions that the support arm 327 in the course of its rotation. The first lever 330 is at its outer end with a wedge-shaped profiled compartment 334 for the positive mounting of the rear bow holder 314 Mistake. The second lever 331 is at its outer end with spring bolts 335 equipped the rear bow holder 314 in the storage compartment 334 hold. The spring bolts, of which in 16 only one can be seen is in one to the rear bow holder 314 parallel row arranged. Each of these spring bolts 335 has a center point 344 which in a wedge-shaped profiled longitudinal groove of the rear bow holder 314 occurs when the outer ends of the levers 330 . 331 due to the corresponding curve geometries of the control curves 328 . 329 to be moved towards each other.

The curve geometries or contours are such that the actuating levers 330 . 331 As already described, the rear bow holder in a first step 314 grasp after the rear bow holder 314 through a just before the tangent point 324 and next to the traction device 303 arranged, inclined plane or an equivalent guide 345 in the direction of between the strands of the traction device 303 lying space inwards for gripping the rear bow holder 314 favorable position has been distracted.

In a second step, which is predetermined by the curve geometries, the two operating levers 330 . 331 while maintaining their position relative to each other synchronously around an axis of rotation 336 against the direction of rotation of the support arm 327 and the traction device 303 pivoted so that the operating lever 330 . 331 together with the rear bow holder 314 held by them by the traction means 303 away and further inside the sheet transport device 301 plunge into it and as a result a collision with the cylinder 308 at the passage of which is safely avoided. This happens within the first circumferential angle range γ ₁ , even before the rear bow holder 314 the sheet transfer point 325 reached.

The curve geometries of the control cams also cause the outer lever ends of the actuating levers 330 . 331 in a third step to be moved towards each other, one of which is the spring bolt 335 stressful spring 337 is compressed even more and a spring tongs serving as a gripper for clamping the rear sheet edge 338 is opened. The opening happens by one on the second operating lever 331 arranged first wedge surface 339 along a second wedge surface 340 that slides on a spring arm 341 is arranged, and the spring arm 341 against the effect of its own elasticity from the leaf spring 319 pushes or pushes away so that one on the spring arm 341 arranged first jaw (Greifenger) 342 of one interacting with the latter and on the leaf spring 319 arranged, second jaw (gripper pad) 343 is lifted off. The spring arm 341 is angled and on the rear bow holder 314 and the rear spring end of the leaf spring 319 attached by screws or rivets in such a way that the spring arm 341 against the leaf spring 319 is preloaded and always striving for the first jaw 342 on the second jaw 343 to press, ie the pliers 338 close.

While the operating lever 330 . 331 with the pliers held open by them 338 move through the second circumferential angle range γ ₂ , the operating levers 330 . 331 , due to the geometries of the control curves 328 . 329 on which the pestle 332 . 333 roll or slide around the axis of rotation 336 in the direction of rotation of the traction means 303 , so regarding 14 clockwise, pivoted outward so that the operating lever 330 . 331 consequently back to the level of the traction device's orbit 303 or the circumference of the wheel 304 Pop up. In the course of this ascent movement, the rear bow holder picks up 314 the leading bow end and becomes the open pliers 338 over this rear sheet end of the printing material sheet 312 which is then loosely between the two jaws 342 . 343 located. In the fourth step mentioned, the leaf springs 318 . 319 elastically bent and pre-tensioned.

In a fifth step, which takes place automatically within the second circumferential angle range γ ₁ , the spring pliers 338 closed again and the substrate sheet 312 between the two jaws 342 . 343 firmly clamped. To close this spring pliers 338 to effect, the outer end of the second operating lever 331 through the second control curve 329 from the outer end of the first operating lever 330 slightly swung away.

In a last one of the control curves 328 . 329 effected, sixth step, the outer ends of the two operating levers 330 . 331 spread apart. Then the front bow holder pulls 313 over the substrate sheet 312 the rear bow holder 314 from the storage compartment 334 out and becomes the substrate sheet 312 due to the preload of the leaf springs 318 . 319 between the two bow holders 313 . 314 pulled tight or held. The leaf springs 318 . 319 namely strive to the rear bow holder 314 from the front bow holder 313 push away. The leaf springs 318 . 319 are dimensioned with regard to their spring force in such a way that the substrate sheet 312 when tightened by the leaf springs 318 . 319 is not torn. The on the substrate sheet 312 acting spring force of the leaf springs 318 . 319 can if necessary by adjusting the rear crossmember 317 be adjustable so that the spring force of the material and the resilience of the substrate sheet 312 can be set accordingly.

100

machine

101

Sheet transport device

102

delivery pile

103

traction means

104

drive wheel

105

guide wheel

106

wave

107

wave

108

cylinder

109

Bow holder pair

110

Bow holder pair

111

Bow holder pair

112

printing material

113

front bow holder

114

rear bow holder

115

coupling point

116

Abkoppelpunkt

117

loader

118

unloading

119

support spacing

120

cache

121

storage element

122

traffic jam

123

separating device

124

star wheel

125

Transfer drum

126

receiving compartment

127

receiving compartment

128

Plungers

129

Plungers

130

positioning

131

positioning

132

bars

133

holder carrier

134

receiving compartment

135

positioning

136

Plungers

137

segment

138

segment

139

axis of rotation

140

swivel

141

Drum base

142

sun

143

planet

144

idler

145

swivel

146

Arc discharge point

147

Holders delivery point

148

scraper

149

pad

150

axis of rotation

151

first wheel

152

second wheel

153

third wheel

154

fourth wheel

155

wave

156

Cam and groove structure

157

carrier axis

158

first attachment point

159

second attachment point

160

chain pins

160a

chain pins

160b

chain pins

161

link plate

162

Tie pliers

163

jaw

164

jaw

165

actuating arm

166

actuating arm

167

swivel

168

jack

169

Curve follower

170

Long hole

171

crossbeam

172

Zentrierzahn

173

securing spring

174

guide curve

175

first slide bolt

176

second slide bolt

177

axis

178

axis

179

crossbeam

180

securing spring

181

Curve follower

200

machine

201

Sheet transport device

202

delivery pile

203

traction means

204

drive wheel

205

guide wheel

206

wave

207

wave

208

cylinder

209

Bow holder pair

210

Bow holder pair

211

Bow holder pair

212

printing material

213

front bow holder

214

rear bow holder

215

support spacing

216

axis of rotation

217

first lever

218

second lever

219

third lever

220

snap-in

221

snap-in

222

guide

223

adjustment cams

224

first Curve follower

225

second Curve follower

226

fourth lever

227

swivel

228

first spring arm

229

second spring arm

230

jaw

231

jaw

232

foot

233

leg

234

bending joint

235

bending joint

236

bending joint

237

bending joint

238

bending joint

239

clamp

240

web

241

Umschlingungspunkt

242

Sheet transfer point

243

parting line

244

elastic line

245

spring bolt

246

fitting hole

247

chain pins

248

link plate

249

chain roller

250

hook

251

wedge surface

252a

stop surface

252b

stop surface

253

blocking arm

254

blocking arm

300

machine

301

Sheet transport device

302

303

traction means

304

drive wheel

305

306

wave

307

308

cylinder

309

Bow holder pair

310

Bow holder pair

311

312

printing material

313

front bow holder

314

rear bow holder

315

support spacing

316

front traverse

317

rear traverse

318

leaf spring

319

leaf spring

320

Support foot

321

Support foot

322

guide

323

actuator

324

tangency

325

Sheet transfer point

326

tangency

327

Beam

328

first cam

329

second cam

330

first actuating lever

331

second actuating lever

332

tappet

333

tappet

334

receiving compartment

335

Plungers

336

axis of rotation

337

feather

338

spring pliers

339

first wedge surface

340

second wedge surface

341

spring arm

342

first jaw

343

second jaw

344

centering

345

guide

A

web section

B

web section

C

web section

F

force

P1

terminal point

P2

terminal point

P3

terminal point

S

vertex

VL

connecting line

α

angle

β

angle

γ ₁

first Circumferential angle

γ ₂

second Circumferential angle

Claims (10)

Method for transporting a sheet holder at its front end through a front sheet holder ( 113 ; 213 ; 313 ) and at the same time at the back of the bow ( 114 ; 214 ; 314 ) substrate sheet of a first format length held by a rear sheet holder and one by the front sheet holder at its front sheet end and at the same time by the rear sheet holder at its rear sheet end ( 114 ; 214 ; 314 ) held substrate sheet of a second format length in one of the substrate sheets ( 112 ; 212 ; 312 ) processing machine, characterized in that the two bow holders on one and the same rotating traction means ( 103 ; 203 ; 303 ) the machine during the transport of the printing material sheet having the first format length in a different holder distance ( 119 ; 215 ; 315 ) are held to one another as during the transport of the printing material sheet having the second format length. A method according to claim 1, characterized in that the rear sheet holder ( 114 ) during the continuous circulation of the traction device ( 103 ) automatically and periodically from the traction device ( 103 ) replaced and then again on the traction device ( 103 ) is attached. Method for changing the format of a one at its front sheet end by a front sheet holder ( 113 ; 213 ; 313 ) and at the same time at its rear bow end by a rear bow holder ( 114 ; 214 ; 314 ) held printing material sheets of a first format length and a printing material sheet of a second format length held at its front sheet end by the front sheet holder and at the same time at its rear sheet end by the rear sheet holder, characterized in that, depending on a length difference between the two format lengths, a holder spacing ( 119 ; 215 ; 315 ), in which the two Bow holder to each other on one and the same revolving traction device ( 103 ; 203 ; 303 ) are kept fixed, is changed. Sheet transport device for transporting printing material sheets in a machine ( 100 ; 200 ; 300 ), with a front bow holder ( 113 ; 213 ; 313 ) for holding a front bow end and a rear bow holder ( 114 ; 214 ; 314 ) for holding a rear sheet end of one of the printing material sheets ( 112 ; 212 ; 312 ), in which the front bow holder and the rear bow holder together form a pair of bow holders ( 109 ) form and on one and the same rotating traction device ( 103 ; 203 ; 303 ) are attached, in particular for carrying out the method according to one of claims 1 to 3, characterized in that the machine ( 100 ; 200 ; 300 ) at least one positioning device for positioning the rear sheet holder ( 114 ; 214 ; 314 ) in different-sized format lengths of the printing material sheets and different-sized holder distances ( 119 ; 215 ; 315 ) relative to the front bow holder ( 113 ; 213 ; 313 ) includes. Sheet transport device according to claim 4, characterized in that the positioning device and other such a first connection point (chain pin 160 ), a second connection point (chain pin 160a ) and a coupling element (locking pliers 162 ) are that the first connection point (chain pin 160 ) further than the second connection point (chain pin 160a ) from the front bow holder ( 113 ) removed on the traction device ( 103 ) is arranged that the coupling element (locking pliers 162 ) on the rear bow holder ( 114 ) and is designed to be compatible with each of the two connection points, so that the rear bow holder ( 114 ) via the coupling element optionally to form a large holder distance in the first connection point (chain pin 160 ) and to form a small bracket distance in the second connection point (chain pin 160a ) on the traction device ( 103 ) can be coupled. Sheet transport device according to claim 5, characterized in that the coupling element together with the respectively selected of the connection points a snap connection ( 220 ; 221 ) forms. Sheet transport device according to one of claims 4 to 6, characterized in that a strand of the traction means ( 103 ) and a buffer ( 120 ) for temporarily storing the rear sheet holder ( 114 ) together determine a first cycle in which the rear bow holder ( 114 ) and rear bow holder of further pairs of bow holders ( 111 . 112 ) circulate and that the traction device ( 103 ) determines a second circuit in which the front bow holder ( 113 ) and front bow holder of the other pairs of bow haters ( 111 . 112 ) circulate. Sheet transport device according to claim 4, characterized in that the positioning device is a connecting spring (leaf spring 319 ) over which the rear bow holder ( 314 ) with the traction device ( 303 ) is elastically connected. Sheet delivery with a sheet transport device designed according to one of claims 1 to 8 ( 101 ; 201 ; 301 ). Sheet printing machine with a trained according to claim 9 Sheet delivery.