EP1092537A2 - Arrangement for turning sheets in a sheet-fed rotary printing machine - Google Patents

Abstract

A storage drum (3) takes at least two sheets each held by at least one holder. A turning drum (23) positioned after the storage drum has at least one holder for the back edge of the sheet being turned. A vacuum is formed in the area between the sheet to be turned , the storage drum and the turning drum. The outer casing of the turning drum has at least one duct and or at least one through-hole connected with the interior of the turning drum. Air is sucked or blown into the vacuum part (35) via the through-hole.

Description

The invention relates to a device for turning sheets in one Sheet-fed rotary printing machine according to the preamble of claim 1, a Turning device according to the preamble of claim 5, a turning device according to Preamble of claim 10, a turning device according to the preamble of Claim 13 and a turning device according to the preamble of claim 14.

DE 44 24 968 C2 discloses a turning device of the type mentioned here, which has a storage drum, on the outer surface of which several sheets are held become. The storage drum is a turning drum in the direction of travel of the sheet downstream, which is a holding device for the rear edge of the sheet to be turned having. The arrangement of the storage drum and the turning drum is chosen in such a way that their lateral surfaces almost touch at a tangent point. The Storage drum has a first blowing device, with the aid of which a blowing air flow can be applied to the sheet already grasped by the holding device by the Push the sheet away from the storage drum so that the sheet is turned is supported. In addition, above the tangent point to support the Turning process provided a second blowing device, with the help of air in the Tangent point is inflatable to push down the sheet to be turned and thus support the detachment of the sheet from the storage drum.

By detaching the sheet to be turned from the circumference of the storage drum and its further transport with the help of the turning drum is located in the turning area Air entrained by the bow, which locally creates a vacuum that on the subsequent, with the help of the holding device on the peripheral surface of the storage drum held bow acts, which thereby at least partially from the storage drum can be lifted off. Handover of the sheets from the register Storage drum on the turning drum can therefore not be guaranteed in all cases become. Because in order to use a register-based transfer of the sheets stored on the storage drum, especially in perfecting To ensure exact processing conditions for the entire sheet runs of the saved sheet. This is usually done through Tensioner clamped on the rear edge of the storage drum surface, so that all Sheets come to be exactly the same during the saving process. With half-revs Storage drums ensures the equality of both storage drum halves by one ground surface guaranteed. A perfect transfer of the stored However, the bend is only secured when the bend is in it from the suction cups Condition or this position can be maintained. This is high Printing performance, which can be, for example, 15,000 sheets per hour, but not that Case.

In the negative pressure zone between the turning drum and the Storage drum can with such a high printing performance, in between peeling of the previous sheet and the entry of the following sheet into the Vacuum zone only pass about 0.1 seconds, not enough air from outside flow into the space between the turning drum and the storage drum. The blowing streams of the first and second blowing devices of the known Turning device, which serve to support the turning process, can in Do not reduce the vacuum acting to a sufficient extent because the blowing air flow of the second one arranged above the tangent point Blower device due to the very small space between the storage drum and the turning drum, if at all, only very weakly in the below the Tangential point lying turning area and that in the storage drum arranged first blowing device is only active for a very short time on the on the storage drum lifting the overlying sheet at its trailing edge area. Also for this are the Blowing air usual pressure differences the outlet cross sections of the blowing nozzles too small to to compensate for the resulting negative pressure.

It is therefore an object of the invention to a turning device of the type mentioned create, in which even at a high machine speed a register Transfer of the sheet stored on the peripheral surface of the storage drum can be guaranteed.

To solve this problem, a turning device with the features of Claim 1 proposed. This is characterized by the fact that the Reversing drum at least one channel and / or at least one with an interior of the Reversing drum connected through opening are / is, through the air in the Vacuum area can be sucked in and / or inflated. The free flow cross section of the for example in the circumferential direction of the turning drum and if necessary, that of the through opening are so large that it becomes detached of the sheet to be turned from the storage drum and through the turning process the area between the storage drum, the turning drum and the one to be turned Arc forming negative pressure at least such a large amount of air through the channel and / or can suck in the through opening, so that a lifting of the subsequent, on the Outer peripheral surface of the storage drum lying sheet can be prevented. In this embodiment variant, blow devices can be used that cover the vacuum area Blowing and / or compressed air supply, are dispensed with, which causes the structure of the Turning device can be simplified. Another version is at least one blowing / compressed air supply device is provided, for example the interior of the turning drum is supplied with blown air or compressed air which is supplied via the Through opening in the reversible drum jacket reaches the negative pressure area. The At least one through opening is seen in the direction of rotation of the turning drum the rear edge of the sheet to be turned, provided on the turning drum Subordinate holding device. Alternatively or additionally, it is also possible for a Blown air / compressed air flow is introduced into the vacuum area via the duct. Everyone Embodiments has in common that the afterflow of air through the channel and / or the passage opening into the vacuum area through the one acting there Negative pressure is at least supported.

According to a development of the invention, it is provided that at least one wall of the Channel at least partially through one in the lateral surface of the turning drum introduced flattening is formed. In connection with the present one Invention under a "flattening" is a flat or substantially flat surface understood a circular or curved surface. With an advantageous Embodiment is provided that the turning drum in the area of the flattening mostly has a substantially circular cross-section, the channel wall - seen in the direction of flow of the air - at least in its flattening upstream area has a different, preferably smaller radius of curvature than the turning drum.

Further advantageous configurations result from the remaining subclaims.

To solve the problem, a turning device with the features of Claim 5 proposed. This is characterized by the fact that the Storage drum at least one edge-open recess, at least one channel and / or at least one connected to an interior of the storage drum Through opening are / is provided, via the air in the negative pressure area can be introduced. The recess, for example, over the entire length of the Storage drum can extend laterally, i.e. towards the edge of the machine, and in Circumferential direction closed at least so far that from its open side blown air cannot escape. The one brought into the recess "Air package" that immediately before the recess is inserted into the Vacuum area is introduced with the help of at least one blowing device is in the Turning area due to the negative pressure from the recess sucked out, which means that the vacuum in the turning area is at least harmless Dimension can be reduced. The recess that is in a free area between two arranged on the storage drum lying sheet can in the circumferential direction Storage drum be extended so far that in a certain angle of rotation position the storage drum briefly a direct passage between one above the roller nip formed between the turning drum and the storage drum Area of the sheet-fed rotary printing machine and the vacuum area is given, so that Follow in the ambient air and / or blow / compressed air directly via the Outer surface of the storage drum open recess in the Vacuum area can be blown. Additionally or alternatively, the Air passage opening from the interior of the storage drum to a blown air / compressed air supply device can be connected in the vacuum area be sucked in or blown in. In another embodiment is connected to the environment and / or with a blowing device cooperating channel supplied to the vacuum area air.

Further advantageous configurations result from the remaining subclaims.

To solve the problem, a turning device with the features of Claim 10 proposed. This is characterized by the fact that the turning drum eccentrically mounted and the holding device is arranged thereon that already in When the holding device takes over the trailing edge of the sheet, there is free space is formed between the turning drum and the storage drum. With the help of light Free space between the opposite outer surface of the Storage drum and the turning drum, is a flow connection between the Environment and by the sheet to be turned, the turning drum and the Storage drum limited vacuum area can be produced. The free one Flow cross-section of the free space is at least so large that during the Flow a sufficient amount of air into the vacuum area during the turning process or can be introduced so that when turning the bow due to the entrained air negative pressure in this area to a harmless Dimension reduced and thus a lifting of the following, on the storage drum overlying bow can be prevented. The free space allows ambient air preferably flow in automatically. It is also possible that through the free space Blown air is blown into the turning area of the bow.

Further advantageous configurations result from the remaining subclaims.

To solve the problem, a turning device is also proposed, which Features of claim 13. This is characterized in that the Reversing drum - seen in cross section - at least one on its outside Flattened, which - seen in the direction of rotation of the turning drum - on the Reversing drum provided holding device for the sheet trailing edge is arranged downstream. The flattening by at least one on the outside of the turning drum introduced flat or essentially flat surface is used in a certain rotational position of the turning drum, a space between the turning drum and the storage drum, through which air is in the turning range of the Holding device of the turning drum detected sheet can be introduced. Here too can lift off the following, held on the circumference of the storage drum Bow can be avoided by too high a vacuum in the turning area.

To solve the problem, a turning device is also proposed, which Features of claim 14 and is characterized in that by at least one stationary blowing device compressed air laterally in the Vacuum area can be introduced. The compressed air or blown air can, for example, directly be blown into the negative pressure area or, in the case of an advantageous one Embodiment of the turning device - in one provided in the storage drum Distribution room that communicates with the negative pressure area via at least one flow path in preferably a direct connection.

Further advantageous configurations result from the remaining subclaims.

In an advantageous embodiment of the turning device, it is provided that the storage drum can also serve as a printing cylinder or from a pressure cylinder can be formed.

Figur 1

eine Seitenansicht eines Ausführungsbeispiels einer Wendeeinrichtung für Bogen;

Figuren 2 bis 8

jeweils eine Seitenansicht eines Ausführungsbeispiels der erfindungsgemäßen Wendeeinrichtung;

Figur 9

eine Seitenansicht eines weiteren Ausführungsbeispiels der Wendeeinrichtung und

Figur 10

einen Querschnitt durch die Wendeeinrichtung gemäß Figur 9.

The invention is explained below with reference to the drawing. Show:

Figure 1

a side view of an embodiment of a turning device for sheets;

Figures 2 to 8

each a side view of an embodiment of the turning device according to the invention;

Figure 9

a side view of another embodiment of the turning device and

Figure 10

a cross section through the turning device according to Figure 9.

The turning device 1 described below is generally for turning sheets can be used in a sheet-fed rotary printing press that is used in straight printing and / or in perfecting Back pressure can be operated.

Figure 1 shows a side view of an embodiment of a turning device 1, the is used in a sheet-fed rotary printing machine for turning sheets. The Turning device 1 comprises a storage drum 3 which is a first holding device 5 for the - seen in the direction of rotation of the storage drum 3 - one of the front edge Outer surface 7 of the storage drum 3 adjacent sheet and a second Has holding device 9 for the rear edge of the sheet. Furthermore, there is a third Holding device 11 for the front edge and a fourth holding device 13 for the Provided trailing edge of a subsequent sheet. The sheets are in the direction of travel seen the bow (arrow 15) - from one of the storage drum 3 upstream Cylinder 17 brought up. The second holding device 9 and the third holding device 11 are placed at a distance from one another in an outer surface 7, open edge 19 and the first holding device 5 and the fourth Holding device 13 in a second recess 21 arranged opposite one another arranged. The recesses 19, 21 extend at least substantially over the total length of storage drum 3.

The first holding device 5 and the third holding device 11 are shown here as Clamping devices formed, each several at a distance from each other and - Seen in the longitudinal direction of the storage drum 3 - grippers arranged one behind the other have, which hold the respective sheet in its leading edge area and the sheet fix the position on the outer circumferential surface of the storage drum 3. The second Holding device 9 and the fourth holding device 13 are here of suction devices formed, each at least one sucker, preferably several at a distance from each other and - seen in the longitudinal direction of the storage drum 3 - one behind the other have arranged suction cups, with the help of which the respective sheet in its Trailing edge area can be kept. Alternatively, the first and third Holding devices 5 and 11 as suction devices, each with at least one suction device be trained.

The second and fourth holding devices 9, 13 and the first and third, respectively Holding devices 5, 9 keep the respective sheet tensioned on the storage drum 3, the suction force is not sufficient at high machine speeds, to prevent the sheet from lifting off from the storage drum 3. A handover of the respective sheet to one of the Storage drum 3 downstream turning drum 23 can with a high printing performance the sheet-fed rotary printing press only with the aid of the holding devices 5, 9, 11, 13 be guaranteed.

The storage drum 3, on which two sheets can be stored in this embodiment are formed in two parts, the two drum halves being comb-like are and have tines that interlock, so that an adjustment of the Storage drum on the length of the sheet is possible by the distance of each holding devices 5 and 9 or 11 and 13 assigned to an arc is changed. The two drum halves are preferably of exactly the same design and have a precisely ground outer peripheral surface.

The distance between the turning drum 23 and the storage drum 3 is selected such that an outer surface 25 of the turning drum 23 and the outer surface 7 of the Storage drum 3 almost touch each other. The turning drum 23 has one Holding device 27 for the rear edge of the material to be turned on the storage drum 3 stored sheet on, which in this embodiment as a clamping device 28th is formed, the plurality at a distance from one another and in the longitudinal direction Turning drum 23 seen - arranged one behind the other grippers. The construction and the function of the clamping device 28 shown in five positions A to E in FIG. 1 is known per se, so it is not dealt with in more detail here.

The holding device 27 of the turning drum 23 cannot with one in the figures illustrated embodiment can also be formed by a suction device, the at least one suction device, preferably several in the longitudinal direction of the turning drum seen - has suction cups arranged one behind the other, with which the trailing edge of the sheet of a sheet to be turned is detectable. It is also conceivable that only one can find out about the entire length of the turning drum 23 extending suction cup is used.

In the following, the function of the turning device 1 is based on a turning process explained in more detail: In a tangent point 29 between the almost touching Storage drum 3 and turning drum 23 is the rear edge of one with the help of Holding devices 5, 9 held on the outer surface 7 of the storage drum 3 Sheet 31 is gripped by the clamping device 28, which is in position A. In position B of the clamping device 28 is that shown with a broken line Arch 31 already in its middle and rear area from the outer surface 7 the storage drum 3 is lifted off while he is still at the front edge area Outer outer surface 7 abuts. The arch 31 is in position C of the clamping device 28 essentially completely lifted off the storage drum 3 or replaced, whereby the previous trailing edge of the sheet now becomes the leading edge. In the Position D of the clamping device 28 is the sheet 31 completely from the Storage drum 3 lifted off and already turned. In the area of position E the Clamping device 28 is the sheet to one of the turning drum 23 downstream Hand over cylinder 33.

By detaching the held on the outer surface 7 of the storage drum 3 Bow and its entrainment by the clamping device 28 of the turning drum 23, that is when moving the sheet away from the storage drum 3, forms between the Storage drum 3 facing side of the sheet, the turning drum 23 and the Storage drum 3 an area 35 shown in Figure 1 with a dashed line in which there is a vacuum due to the air entrained by the bow. This Negative pressure causes a sheet 37 following the sheet 31 to have its leading edge has approximately reached the tangent point 29 when the one holding the arch 31 Clamp 28 has reached position C begins to move away from the storage drum surface to take off. When the clamp 28 is in the D position the leading edge of the subsequent sheet 37 has a point 39 on the outer surface 7 reached, is therefore already arranged in the vacuum region 35 and is there by the present negative pressure - as indicated in Figure 1 - from the outer surface 7 of the Storage drum 3 lifted off. When the clamp 28 reaches position E, the leading edge of the following sheet 37 is located at point 41. It is can be seen that the subsequent sheet 37 by the negative pressure and on it acting centrifugal forces lifted from the outer surface 7 of the storage drum 3 is because the holding forces of the second and fourth, each having a plurality of suction cups Holding devices 9, 13 are too small.

In order to compensate for the negative pressure that forms when turning a sheet, At least to reduce it to a harmless level, the invention sees various Possible solutions, which are explained in more detail below with reference to FIGS. 2 to 10 become. Parts that are shown in FIGS. 2 to 10 and already based on FIG. 1 have been explained, are provided with the same reference numerals, so that to that extent Reference is made to FIG. 1.

Figure 2 shows a side view of an embodiment of the invention Turning device 1 in a sectional view. The holding device 27 of the turning drum 23 has a plurality of grippers 43, of which only one in the illustration according to FIG. 2 the gripper 43 can be seen. The grippers 43 are at a distance from one another and arranged one behind the other over the length of the turning drum 23. The grippers 43 are introduced into the outer circumferential surface 25 of the turning drum 23 Flattened 45 is arranged, which in this embodiment extends over the entire Length of the turning drum 23 extends. Due to the flat 45 is one of the Outer lateral surface 25 set back in the direction of the axis of rotation of the turning drum 23 flat surface 47 is formed, on which the grippers 43 are releasably attached. Area 47 comes on its - seen in the direction of rotation of the turning drum 23 - the clamping device 28 downstream end directly into the circular cross section of the turning drum 23, while at the other end of surface 47 there is a curved wall section 49 connected, which extends over an angular range of approximately 70 ° and is stepless in the outer contour of the turning drum 23 merges. The radius of curvature of the Wall section 49 is smaller than the radius of the turning drum 23 Flattening 45 and an incision made in the outer surface 25, whereby the curved wall section 49 is formed, is an over the entire length of the Turning drum 23 extending channel 51, which is in this Embodiment extends over an angular range of approximately 140 ° and over the Ambient air can flow into the vacuum region 35, as with arrows 53 indicated. To the introduced into the negative pressure area 35 via the channel 51 To increase the amount of air, a blowing device, not shown in the figures be provided, with the aid of which a blown air or compressed air flow into the channel 51 can be blown.

In another embodiment of the turning device 1, which is not in the figures is shown, the turning drum has several described with reference to Figure 2 in Seen in the longitudinal direction of the turning drum 23 arranged one behind the other Flattenings 45, each with a channel 51, the flattenings 45 are preferably at least so wide that they each have at least one gripper 43 be able to record. So there remain intact between the channels 51 Outer lateral surface sections of the turning drum 23 are available, which leads to better strength / rigidity properties the turning drum compared to that based on FIG. 2 described turning drum with the continuous flat 45 leads. Of course, it is also possible to add one of a recess, a groove or the like in the outer circumferential surface of the turning drum channel or several such channels in one lying between two grippers 43 To introduce the outer jacket section of the turning drum 23 in which there is no holding element (Gripper, sucker) of the holding device 27.

In the embodiment shown in Figure 2, the channel 51 is designed such that the air flow in channel 51 directed against the direction of rotation of the turning drum 23 is. The channel 51 is thus aligned in such a way that the Reversing drum 23, the ambient air is virtually shoveled into the channel 51, so that a particularly large amount of air is introduced into the vacuum region 35 in a short time can be, whereby a lifting of the subsequent sheet from the storage drum 3rd can be safely prevented. In another, not shown in the figures The channel 51 or channels 51 can also be embodied in this way be designed and aligned so that the air flow through the channel 51 in the direction of rotation the turning drum 23 is directed. In this case, the air can, for example, from the area of the machine lying above the tangent point 29. The introduction of blown air or compressed air is also in this exemplary embodiment possible.

FIG. 3 shows a further embodiment of the turning device 1 in a side view, in which the turning drum 23 is seen in a direction of rotation of the turning drum 23 Holding device 27 upstream peripheral area at least one in Figure 3 not has through opening shown, which is connected to an interior 55. To A first embodiment variant provides that through the in the vacuum region 35 acting negative pressure through the passage air from the interior 55 of the Reversing drum 23 is sucked into the negative pressure region 35, which causes the subsequent sheet lying on the outer surface 7 of the storage drum 3 acting force is reduced to a harmless level. Another one It is envisaged that the interior 55 does not have one in FIG shown rotating union in a shaft journal of the turning drum 23 connected is to which a blowing / compressed air supply device is connected, so that the Through opening in the jacket of the turning drum 23 blowing or compressed air in the Vacuum area 35, ie behind the turned sheet, can be blown, as with Arrows 53 indicated. In an advantageous embodiment, a Angle-controlled valve provided in the blowing / compressed air supply, so that the Through opening is only supplied with blown / compressed air if the Turning drum 23 is in a rotational position in which a flow connection exists between the through opening and the vacuum region 35.

The at least one through opening in the jacket of the turning drum 23 can overlap the entire length of the turning drum 23 and in its circumferential direction over one extend certain circumferential angle. Instead of the slot-shaped design of the Through opening can also be several at a distance from each other over the entire Length of the turning drum 23 arranged through openings can be provided, are sucked in or blown into the vacuum region 35 via the air can.

FIG. 4 shows a further embodiment of the turning device 1 in a side view, in which the opposite, the holding device 5, 13 and 9, 11th receiving recesses 19, 21 each have at least one, not shown Through opening are connected to an interior space 57 of the storage drum 3, the via a hole or the like formed, not shown in Figure 4 Rotary feedthrough in a shaft journal of the storage drum 3 with the environment can be connected. In Figure 4, the storage drum 3 is in a rotational position, in which the recess 21 is arranged in the vacuum region 35 or the Vacuum area 35 is opposite. As indicated by arrows 53, the im Area 35 present negative pressure air from the interior 57 of the storage drum 3 sucked in, whereby the negative pressure in the negative pressure region 35 is reduced. If at a transfer of a subsequent sheet, the recess 19 in the Vacuum region 35 is displaced, air can pass through the recess 19 Follow the vacuum area 35. The recesses 19, 21 extend in this Embodiment over a peripheral region of the storage drum, which is so large that in a specific rotational angle position of the storage drum 3, the recess 21 or 19 is arranged entirely in the vacuum region 35. The suction of air into the vacuum region 35 via the respective recess takes place immediately after the transfer of the trailing edge of the sheet from the holding device 9 or 13 to the turning drum 23.

In another embodiment of the turning device 1 shown in FIG. 4 the interior 57 is connected to a blowing / compressed air supply device, for example via the rotary feedthrough, so that via the recesses 19, 21 in one corresponding rotation angle position of the storage drum 3 blowing / compressed air in the Vacuum area 35 can be blown in, the blowing / compressed air supply the recesses 19, 21 is preferably controlled by angle of rotation, that is, the Recesses 19, 21 are then with the blown / compressed air supply device Blowing / compressed air is supplied as soon as a part of the respective recess in the Vacuum area 35 is retracted. Otherwise there will be no recesses 19, 21 Blown / compressed air supplied.

Figure 5 shows a further embodiment of the turning device 1, which is different from the differs from FIG. 4 only differs in that the recesses 21 and 19 have no connection to the interior of the storage drum 3 have, but only open to the outer surface 7 of the storage drum 3 out Form rooms. The recesses 19 is in the circumferential direction of the storage drum 3 by side walls 59 and 61, at the bottom by a connecting the side walls 59, 61 Bottom 63 and laterally closed by end walls, of which according to the illustration Figure 5 shows only the end wall 65. The recesses 19, 21 are identical constructed, that is, the recess 21 also has side walls 59, 61, one Bottom 63 and end walls 65.

In the embodiment of the turning device 1 shown in Figure 5 is above of the tangent point 29 in the area of the closing nip between the clockwise rotating turning drum 23 and the counter Clockwise rotating storage drum 3 with a blowing / compressed air supply device connected - not shown- provided blowing device with their help into the respective recess arranged in front of the tangent point 29, in this rotational position of the storage drum 3, the recess 21, blowing / compressed air can be introduced, as indicated by arrows 67. The one in the recess injected air can escape into the vacuum region 35 as soon as the Storage drum 3 is in a corresponding rotational angle position. That in the Recess 19 or 21 blown "air packet" leads in the formed Vacuum area 35 between the sheet to be turned, the turning drum 23 and the Storage drum 3 to reduce the negative pressure, so that a lift off subsequent arc from the outer surface 7 of the storage drum 3 safely can be avoided.

FIG. 6 shows a further embodiment of the turning device 1 in a side view, in the through-openings 69 and 71 in the side wall 61 of the recess 21 are introduced through which a connection between the recess 21 and a part of the interior 57 consists of the through the openings 69 and 71 and the Recess 21 air can be sucked into the vacuum region 35 as soon as at least one Part of the recess 21 is in the vacuum region 35. The air flows out the inside of the storage drum 3 in the vacuum region 35 are indicated by arrows 53 indicated.

The recess 19 also has at least one, not shown in Figure 6 Through opening on that a connection between the interior 57 of the Storage drum 3 and the recess 19, so that also on the Recess 19 sucked air from the interior 57 into the vacuum region 35 can be, if the storage drum 3 in a corresponding Angle of rotation position.

In an advantageous embodiment of the turning device 1 shown in FIG. 6 it is provided that the first - seen in the direction of rotation of the storage drum 3 Holding device 5 or the third holding device 11 upstream part of the Storage drum casing each at least one, preferably several Through openings are arranged, the outer surface 7 of the Connect storage drum 3 to the interior 57, which in turn via the Through openings 69, 71 of the respective recesses 19 and 21, respectively connected is. These through openings are, for example, for a half-speed Storage drum, the drum halves of which have interlocking teeth, in advantageously formed by the spaces between the tines. In which the Through area (s) having the lateral surface area of the storage drum 3 is located on the outside of the following sheet 37 so that by sucking the air from the interior 57 in the vacuum region 35, a vacuum on the on Outer surface 7 is transferred to the underside of the sheet. This will make the Arch preferably held smooth on the outer surface 7, so that even a high peripheral speed of the storage drum 3 a lifting of the sheet 37th can be safely prevented. In this embodiment, the turning device supports the generated by the negative pressure present in the negative pressure region 35 Air flow thus at the same time also the fixation of the following bow on the Storage drum 3, which on its leading edge and trailing edge through the Holding devices 5, 9 and 11, 13 is held and tensioned.

Figure 7 shows a further embodiment of the turning device 1, in which the Turning drum 23 from an eccentric 75 connected to a drive shaft 73 is formed, which are rotatably connected together. The turning drum 23 has in terms of their manufacture a particularly advantageous shape so that they are easier in us can thus be produced cost-effectively. The turning drum 23, the Axis of rotation 77 has an eccentricity e to the center 79 of the eccentric 75, points in FIG its outer lateral surface 25 extends over the whole or essentially the whole Length of the turning drum 23 extending flat 81 on which the Clamping device 28 formed holding device 27 is arranged. The Clamping device 28 has several - seen in the longitudinal direction of the turning drum 23 one behind the other arranged grippers 43, of which in the illustration according to FIG. 7 only a gripper 43 can be seen. The grippers 43 are at a distance from one another arranged, between two grippers 43 a preferably unobstructed Gap (not shown) exists.

The grippers 43 of the clamping device 28, which rotate when the turning drum 23 follow a circular path around the axis of rotation 77 are arranged such that the through the Eccentric shape of the turning drum 23 resulting imbalance at least partially is balanced.

Due to the eccentric mounting or configuration of the turning drum 23, a gap, hereinafter referred to as free space 83, is formed between the outer lateral surfaces 7, 25 of the turning drum 23 and the storage drum 3 when it is rotated about the axis of rotation 77. The free space 83 is smallest when the turning drum 23 is in an angular position in which a fixed point X _{0 is arranged} on the outer circumferential surface 25 of the turning drum 23 in the region of the tangent point 29. In this rotational position of the turning drum 23, its outer surface 25 almost touches the outer surface 7 of the storage drum 3. If the turning drum 23 continues to rotate clockwise, as shown by an arrow, the free space 83 initially becomes ever larger. By rotating the turning drum 23, the grippers 43 are shifted into their take-over position, in which the rear edge of the sheet to be turned is gripped. This take-over position is in the area of the tangent point 29. Since the grippers 43 are arranged on the side of the turning drum 23 opposite the point X ₀ , the outer lateral surfaces 7, 25 now have their greatest distance from one another when the trailing edge of the sheet is taken over; the free space 83 is therefore the greatest at this moment. If the turning drum 23 now rotates further clockwise, the free space 83 — corresponding to the outer contour of the turning drum 23 in this exemplary embodiment — again becomes smaller and smaller until it is almost closed again.

In the area of the tangent point 29, the trailing edge of the sheet 31 is thus removed from the Grasped 43 and started this from the outer surface 7 of the Lift off storage drum 3. Because already when you take over the trailing edge of the sheet the grippers 43 the free space 83 and the spaces described above between there are two grippers 43, one over the gaps Flow connection between the loosening and turning of the bow itself forming vacuum region 35 and that above the turning drum 23 and the Storage drum 3 located surrounding area exists and sucks in ambient air , it can be ensured that the negative pressure that forms in area 35 is preferably only so small that the subsequent sheet is lifted off the Outer surface 7 of the storage drum 3 can be excluded. As soon as the Gripper 43 have passed through the tangent point 29, the ambient air can also in Area of the grippers 43, which no longer block the free space 83, from above into the Subsequent flow of vacuum area 35, as indicated by arrows 53. The inflow of Ambient air through the free space 83 between the outer surface 7, 25 and respective space between two adjacent grippers 43 in the Vacuum area 35 is further supported by the fact that the gap (Free space 83) between the turning drum and storage drum 3 after the grippers 43 have passed the tangent point 29, narrowed and by the turning drum body Ambient air is pressed into this gap.

In order to supply the desired amount of air to the vacuum region 35 in a very short time, can also blow air or compressed air from above through into the free space 83 the free space 83 are blown.

In the embodiment of the turning device 1 shown in FIG Clamping device 28 of the turning drum 23 is designed such that between the Flattening 81 and the grippers 43 each have a slot 82 through which likewise Ambient air and / or blowing / compressed air can flow into the vacuum region 35, as indicated by arrows 53 '.

In order from the surroundings through the free space 83 between the turning drum 23 and the To increase storage drum 3 into the vacuum area 35, can the turning drum 23 also at least one blade, for example similar to a vane fan, which have the afterflow of air into the free space 83 improves or specifically supplies air to the free space 83, which then flows from there into the Area 35 to reduce the negative pressure that forms there. That shovel can, for example, in the area between two grippers 43 or in the direction of rotation of the Turning drum 23 seen - in a subordinate to the grippers 43 Outer jacket area of the turning drum can be arranged. The shovel can too be integrally formed with the turning drum 23, that is, the outer contour of the The turning drum has a scoop-like shape at at least one point. This Embodiment of the turning drum is more complex to manufacture. With their Use technical aspects should therefore be disregarded.

In another embodiment, not shown, of the one based on FIG. 7 Turning device 1 explained has the holding device 27 on the turning drum 23 only a gripper 43, which is arranged on the flat 81 and is extends at least substantially over the entire length of the turning drum 23. At this embodiment is when the gripper 43 passes through the Tangent point 29 suddenly a connection between the environment and the Vacuum area 35 released because the moment the sheet trailing edge is taken over by the gripper 43 of the free space 83 between the outer surface 7, 25 of the Storage drum 3 and the turning drum 23 exists, but the gap through the Gripper 43 itself is still closed and only when the gripper 43 passes Tangent point 29 the flow connection is made. This too Embodiment of the turning drum 23 has advantages in terms of its manufacture compared to known turning drums.

In the embodiment of the turning device 1 shown in FIG Turning drum 23 on a base body, which is a substantially elliptical Has cross section. The shape of the turning drum body is, among other things, by a plurality of flats 85 are formed on the outer lateral surface 25. At the Turning drum 23 holding devices 27 and 27 'are provided, which are opposite are arranged. The holding devices 27, 27 'are here of clamping devices 28 or 28 ', the at least one, preferably a plurality of grippers 43 or 43 'for the rear edge of a sheet to be turned. The Clamping devices 28, 28 'are preferably of identical design and each have at least one, preferably a plurality of lifting elements 30 or 30 ', which are formed, for example, by suction devices and -in the direction of rotation of the turning drum seen- are arranged upstream of the associated clamping device. The Lifting elements 30, 30 'serve to lift one on the outer surface 7 of the Storage drum 3, which serves here as a printing cylinder, resting sheet in his Trailing edge area.

Due to the non-circular outer contour of the turning drum 23, the rotation of the Turning drum 23 a space 83 between the turning drum body and the Storage drum 3 formed, the larger when turning the turning drum 83 and gets smaller again. Ambient air and / or blown air enters through the free space 83 the negative pressure area 35, so that the negative pressure in the area 35 at least as far it is reduced that a subsequent sheet is lifted off the storage drum 3 can be excluded.

FIG. 9 shows a further embodiment of the turning device 1 in a side view, with the help of a with a blow / compressed air supply device, not shown connected blowing device 86 blowing / compressed air in the Vacuum area 35 can be introduced. The blowing device 86 comprises blowing nozzles, from which only three blowing nozzles 87 can be seen in the illustration according to FIG. 9. Further blowing nozzles 89 of the blowing device 86 are shown in FIG Cross section through the exemplary embodiment of the turning device 1 shown in FIG. 9 shows.

The blowing nozzles 87 are on a first storage frame 91 of the sheet-fed rotary printing press and the nozzles 89 on the opposite side on a second storage rack 93 fixed attached. At the storage racks 91, 93 is in this embodiment at least the storage drum 3 rotatably mounted. As can be seen from Figure 9, the Blow nozzles 87, preferably also the blow nozzles 89, on an imaginary circular path arranged, the center of which lies on the axis of rotation of the storage drum 3. The The arrangement of the blowing nozzles 87, 89 is selected such that it is arranged in a corresponding manner Rotation angle position of the storage drum 3 compressed air or blown air in which over the First recess 19 extending over the entire length of the storage drum 3 or second recess 21, which in the outer surface 7 of the Storage drum 3 are introduced, is laterally inflatable, as indicated by arrows 53. For this purpose, in the area of the recesses 19, 21 in the end walls 95 and 97 of the Storage drum 3 each provided at least one opening 99.

If the openings 99 coincide with the fixed ones Blowing nozzles 87, 89 are located, can either blow air or compressed air in the as Distribution space for the air-serving recess 21 or 19 blown be the over the open side of the recess 21 on the outer surface 7 of the Storage drum 3 can flow into the vacuum region 35. The blowing nozzles 87, 89 are aligned here in such a way that the blowing flows (arrows 53) in the central region of the Storage drum 3 meet.

As can be seen from FIG. 9, in this exemplary embodiment the blowing nozzles 87, optionally also the blowing nozzles 89, a circular cross section. Of course, the blowing nozzles 87, 89 can be according to another, not shown Embodiment also be slit-shaped.

Due to the fixed arrangement of the blowing nozzles 87, 89, a rotation angle is controlled Delivery of blown air or compressed air into the recesses 19, 21 realized because the blown / compressed air only then be blown into the recess 19 or 21 can if the openings 99 are arranged opposite the blowing nozzles 87, 89. Of course, there is also a clocked supply of blown / compressed air to the Blow nozzles 87, 89 possible.

All embodiments of the turning device 1 have in common that the Turning of a sheet resulting vacuum region 35 between the storage drum 3, the turning drum 23 and the side of the sheet facing the storage drum 3 by supplying air to this area, which takes place automatically or with the help at least one blowing device can be forced or supported, can be reduced.

The patent claims submitted with the application are proposed without Prejudice for obtaining further patent protection. The applicant reserves the right still others previously only disclosed in the description and / or in the drawings Features to claim.

Relationships used in the subclaims point to further training the subject of the main claim and the subsidiary claims by the Characteristics of the respective subclaim; they are not considered a waiver Achievement of an independent, objective protection for the characteristics of the to understand related subclaims. The subjects of these subclaims However, they also form independent inventions that are one of the objects of have independent design of the preceding subclaims.

The invention is also not based on the embodiment (s) of the description limited. Rather, numerous changes and modifications are within the scope of the invention Modifications possible, especially such variants, elements and combinations, which, for example, by combining or modifying individual, in conjunction with in the general description and the embodiments as well as the claims described features and contained in the drawings respectively Elements are inventive and can be combined to create a new one Lead object.

Claims (19)

Device for turning sheets in a sheet-fed rotary printing press, with a storage drum for at least two sheets, which are each held by at least one holding device, and with a turning device arranged downstream of the storage drum and having at least one holding device for the trailing edge of the sheet to be turned, whereby by detaching the sheet to be turned is formed by the storage drum and its entrainment by the turning drum in the region between the sheet to be turned, the storage drum and the turning drum,
characterized,
that at least one channel (51) and / or at least one through opening connected to an interior (55) of the turning drum (23) is / is provided in the jacket of the turning drum (23), can be sucked in via the air into the vacuum region (35) and / or is inflatable. Turning device according to claim 1,
characterized,
that at least one wall of the channel (51) is at least partially formed by a flattened portion (45) made in the lateral surface of the turning drum (23). Turning device according to one of the preceding claims,
characterized,
that the holding device (27) arranged on the turning drum (23) has at least one gripper (43) which is arranged on the flattened portion (45). Turning device according to one of the preceding claims,
characterized,
that the channel (51) is introduced into the outer circumferential surface (25) of the turning drum (23) and extends over a peripheral region of the turning drum (23). Device for turning sheets in a sheet-fed rotary printing press, with a storage drum for at least two sheets, which are each held by at least one holding device, and with a turning device arranged downstream of the storage drum and having at least one holding device for the trailing edge of the sheet to be turned, whereby by detaching the sheet to be turned is formed by the storage drum and its entrainment by the turning drum in the region between the sheet to be turned, the storage drum and the turning drum, in particular according to one of the preceding claims 1 to 4,
characterized,
that in the jacket of the storage drum (3) at least one open-edged recess (19, 21), at least one channel and / or at least one through opening (69, 71) connected to an interior (57) of the storage drum (3) are provided the air can be introduced into the vacuum region (35). Turning device according to claim 5,
characterized,
that air can be sucked into and / or blown into the vacuum region (35) via the channel and / or the through opening (69, 71). Turning device according to claim 5 or 6,
characterized,
that the vacuum area (35) is connected via the channel and / or the passage opening (69, 71) to a jacket area of the storage drum (3) which has at least one channel and / or at least one passage opening which / which defines the interior (57 ) connects the storage drum (3) with a region of the outer surface (7) on which a subsequent sheet rests. Turning device according to one of the preceding claims 5 to 7,
characterized,
that the channel and / or the through opening are / are connected to a compressed air and / or blown air supply device and / or to the environment. Turning device according to one of the preceding claims,
characterized,
that at least one of the holding devices (5, 13; 9, 11) arranged on the storage drum (3) is arranged in the recess (21; 19). Device for turning sheets in a sheet-fed rotary printing press, with a storage drum for at least two sheets, which are each held by at least one holding device, and with a turning device arranged downstream of the storage drum and having at least one holding device for the trailing edge of the sheet to be turned, whereby by detaching the sheet to be turned is formed by the storage drum and its entrainment by the turning drum in the region between the sheet to be turned, the storage drum and the turning drum, in particular according to one of the preceding claims 1 to 9,
characterized,
that the turning drum (23) is mounted eccentrically and the holding device (27) is arranged on it in such a way that a space (83) between the turning drum (23) and the storage drum (3) already at the moment the sheet trailing edge is taken over by the holding device (27). is formed. Turning device according to claim 10,
characterized,
that the turning drum (23) is designed in such a way that, in a certain rotational angle position of the turning drum (23), the distance between its outer surface (25) and the outer surface (7) of the storage drum (3) is almost zero. Turning device according to one of the preceding claims 10 or 11,
characterized,
that at least one flat (81) is introduced into the outer lateral surface (25) of the turning drum (23), which preferably extends at least essentially over the entire length of the turning drum (23), and that the holding device (27) on the flat (81 ) is arranged. Device for turning sheets in a sheet-fed rotary printing press, with a storage drum for at least two sheets, which are each held by at least one holding device, and with a turning device arranged downstream of the storage drum and having at least one holding device for the trailing edge of the sheet to be turned, whereby by detaching the sheet to be turned is formed by the storage drum and its entrainment by the turning drum in the region between the sheet to be turned, the storage drum and the turning drum, in particular according to one of the preceding claims 1 to 12,
characterized,
that the turning drum (23) - seen in cross section - has at least on its outside at least one flattened area (85), which - viewed in the direction of rotation of the turning drum (23) - is arranged downstream of the holding device (27). Device for turning sheets in a sheet-fed rotary printing press, with a storage drum for at least two sheets, which are each held by at least one holding device, and with a turning device arranged downstream of the storage drum and having at least one holding device for the trailing edge of the sheet to be turned, whereby by detaching the sheet to be turned is formed by the storage drum and its entrainment by the turning drum in the region between the sheet to be turned, the storage drum and the turning drum, in particular according to one of the preceding claims 1 to 13,
characterized,
that compressed air and / or blown air can be introduced laterally into the vacuum region (35) by means of at least one fixedly arranged blowing device (86). Turning device according to claim 14,
characterized,
that in the outer circumferential surface (7) of the storage drum (3) there is at least one recess (19; 21) open towards the circumferential surface, into which blow air and / or compressed air can be blown in laterally with the aid of the blowing device (86), and that in a defined one Angular position of the storage drum (3) there is a flow connection between the recess (19,21) and the vacuum region (35). Turning device according to one of the preceding claims,
characterized,
that the blowing device (86) has a plurality of blowing nozzles (87, 89) which are arranged on opposite sides of the sheet-fed rotary printing press and are aligned with respect to one another in such a way that their blowing / compressed air flows in the vacuum region (35) and / or in the recess (19, 21 ) meet. Turning device according to one of the preceding claims,
characterized,
that the recess (19, 21) extends over a peripheral region of the storage drum (3) and rotates together with the storage drum (3). Turning device according to one of the preceding claims,
characterized,
that the introduction of compressed air and / or blown air into the vacuum region (35) is controlled by the angle of rotation. Turning device according to one of the preceding claims,
characterized,
that the storage drum (3) also serves as a printing cylinder.

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