Page conveying device

Abstract

The invention relates to a device for conveying sheets, comprising plates which together form a chain which revolves along a track and is driven by a mechanism. The plates each have an opening for holding a sheet on an upper side of the respective plate by suction of air. According to the invention, the mechanism has at least one drive element (13) which rotates about at least one axis (14) when the plate is driven and engages in a friction-fit manner directly in succession with the plate (2) or with a rail (10) arranged on the plate (2).

Description

Technical Field

[0001] The invention relates to a device for conveying sheets, comprising plates which together form a chain which revolves along a track and is driven by a mechanism. Background Art

[0002] DE 10 2019 210 251 A1 describes such a device, which is used in a printing press for conveying sheets past an inkjet print head during printing. In this prior art device, the mechanism has a threaded spindle and the plates are equipped with a driver. When the respective plate is driven, its driver cooperates with the threaded spindle. The disadvantage of this form-fitting coupling between the threaded spindle and the driver is that during the cooperation, the plate carrying the sheets may vibrate, which affects the printing quality. Summary of the invention

[0003] The object of the present invention is to provide a device for transporting sheets which is suitable for use in a digital printing press.

[0004] The object of the present invention is achieved by a device for conveying sheets, which includes plates, which together form a chain, which rotates along a track and is driven by a mechanism (or mechanical device), characterized in that: the plates respectively have openings for holding the sheets on the upper side of the corresponding plates by suctioning air; the mechanism has at least one driving element, which, when driving the plates, rotates around at least one axis and directly and successively cooperates with the plates or with a rail arranged on the plates in a friction fit.

[0005] In the variant in which the drive element cooperates directly with the plate, no rails need to be arranged on the plate.

[0006] In the device of the present invention, the temporary coupling between each plate and the mechanism is in the form of friction fit. When driving the plate, the driving element runs smoothly on the rail without shaking. Therefore, the device of the present invention is very suitable for use in a digital printing machine.

[0007] The expansion solutions of the present invention described below can be implemented individually or in any combination if they are not technically exclusive:

[0008] In a variant where the drive element cooperates directly with the plate, the drive element may cooperate with the side of the plate.

[0009] In another variant, each plate may have a single rail, the mechanism may have a counter-pressure element, and the single rail may be located between the drive element and the counter-pressure element when driven.

[0010] In another variant, each plate may have two rails, the mechanism may have a counter-pressure element, and the drive element and the counter-pressure element may be located between the two rails during actuation.

[0011] In both variants, the drive element can be a wheel or an endless belt.

[0012] In both variants, the counterpressure element can be a wheel or an endless belt.

[0013] In both variants, the drive element can be spring-loaded and in turn pressed by the spring against the rail of the plate.

[0014] In both variants, the counterpressure element can be spring-loaded and in turn pressed by the spring against the rail of the plate.

[0015] Further developments emerge from the following description of the exemplary embodiments and the figures, which can be realized individually or, if they are not technically mutually exclusive, in combination with one another or with the above-mentioned developments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the attached figure:

[0017] Figure 1 An overall view of the sheet conveying device is shown;

[0018] Figure 2 and 3 A variant of a sheet transport plate of the device is shown, wherein the plate is shown in detail in a perspective view; and

[0019] Figures 4 to 12 A variant of a plate drive mechanism of the device is shown, wherein the mechanism is shown schematically in cross-section. DETAILED DESCRIPTION

[0020] Figure 1 A device is shown for conveying sheets 1 on plates 2 in direction 3 past a printing head 4. The printing head 4 is an inkjet printing head. The plates 2, which are identical in structure, together form an endless chain 5, which rotates on an elliptical track 6 in direction 7. The chain 5 has a straight section 8, to which the printing head 4 is assigned. Rollers 9 are rotatably fastened to the plates 2, which rollers run on the track 6. The plates 2 each have an upper side and a lower side. During their conveyance, the sheets 1 are located on the upper side and pass through openings 16 in the plates 2 (see Figure 2 and Figure 3) is held by the sucked air. At least one rail 10 is fastened to the underside, the rail extending parallel to the direction 3. An electric motor 11 drives the chain 5 via a mechanism 12 in the direction 7. Here, elements 13 of the mechanism 12 successively come into contact with the rails 10 of the plates 2. The elements 13 are preferably located in the region of the section 8. The elements 13 rotate about at least one geometric axis 14 and transmit their movement to the rail 10 of the respective plate 2 by means of a friction fit, thereby causing the rail to move parallel to the direction 3. The friction fit ensures that no shaking or wobbling occurs during the movement, which would not be possible with a form-fitting tooth fit between the element 13 and the rail 10.

[0021] Figure 2 A variant is shown with only one single rail per panel 2. This rail 10 is arranged in the middle of the panel 2. The rail 10 has a groove 17 and a projection 18 at each end. At one end, the groove 17 is arranged at the top and the projection 18 at the bottom, at the other end, the arrangement is reversed. The projection of the rail 10 of the adjacent panel enters the groove 17, while the projection 18 enters the groove of the rail 10 of the other adjacent panel. This mutual cooperation of the rails 10 of the panels 2 enables the element 13 to run smoothly from one rail to another, and enables the rails 10 of the panels 2 to be positioned at an angle to each other when passing through curved sections of the track 6 without collisions.

[0022] Figure 3 A variant is shown in which the rail 10 forms a rail pair together with a parallel rail 15, which is arranged on the underside. Both rails 10, 15 are offset to the same extent outward from the middle of the plate 2. With regard to the grooves 17 and the projections 18, Figure 3 The design of the track 10 and 15 of the middle variant is Figure 2 Track 10 of the medium variant is exactly the same.

[0023] exist Figure 2 and Figure 3 5. It is shown that each plate 2 has a hinge pin 19 and a hinge hole 20. In the state where the plates 2 are assembled into the chain 5, the hinge pin 19 of a plate 2 is inserted into the hinge hole of an adjacent plate, and the hinge pin of another adjacent plate is inserted into the hinge hole 20 of a plate 2 located between two adjacent plates in the chain 5. All plates 2 of the chain 5 are connected to each other by a rotary hinge 21 consisting of such a hinge pin 19 and hinge hole 20. The roller 9 is arranged coaxially with the rotary hinge 21.

[0024] Figure 4-12 based on Figure 1 The viewing direction is given in 22.

[0025] Figure 4-7 A variant of the mechanism 12 is shown, which can be Figure 2The variant shown in which each panel 2 has only one rail 10 is used.

[0026] Figure 4 A variant is shown in which the element 13 is an endless belt 41 which revolves around wheels 42, 43 and thus around two axes. The wheels 42 are driven by the motor 11 and drive the belt 41. The belt 41 drives the feed movement of the rail 10 and transmits the drive movement indicated by the arrow from the wheel 42 to the wheel 43. The wheels 44, 45 are pressed against one side of the rail 10 by springs 46, 47 and press the other side of the rail 10 against the belt 41.

[0027] Figure 5 A variant is shown in which the rail 10 is pressed against the wheels 52, 53 via wheels 54, 55. The wheels 54, 55 are pressed against the rail 10 via springs 56, 57, which are located between the wheels 52, 53 on one side and the wheels 54, 55 on the other side. A wheel 58 is arranged coaxially with the wheel 52 and is connected to it in a rotationally fixed manner, for example via a common axis, and a wheel 59 is arranged coaxially with the wheel 53 and is connected to it in a rotationally fixed manner, for example via a common axis. The motor 11 drives the wheels 52 and 58. An endless belt 51, which is wound around the wheels 58, 59, transmits the driving movement from the wheel 58 to the wheel 59, with which the wheel 53 also rotates. The wheels 52, 53 drive the feed movement of the rail 10 and thus the feed movement of the plate 2. Here, the element 13 is formed by the wheel 52, and there is also another such element, namely the wheel 53.

[0028] Figure 6 A variant is shown in which the rail 10 is pressed against the wheels 62, 63 by means of wheels 64, 65. In this variant, the element 13 is constituted by the wheel 62 and there is another such element, namely the wheel 63. The wheels 64, 65 are pressed against the rail 10 by means of springs 66, 67, which are located between the wheels 62, 63 on one side and the wheels 64, 65 on the other side. The motor 11 drives the wheel 62, whose driving movement is transmitted to the wheel 63 via the wheel 68. The wheel 68, which is arranged in the middle, rests against both wheels 62, 63.

[0029] Figure 7A variant is shown in which a belt 70 and a further belt 71 rest on opposite sides of the rail 10. The element 13 consists of an endless belt 71 which is wound around wheels 72, 73. The belt 71 can thus turn around two axes, namely the axis 14 around which the wheel 72 rotates and the axis around which the wheel 73 rotates. The endless belt 70 is wound around wheels 74, 75 which are loaded by springs 76, 77 so as to press the belt 70 against one side of the rail 10. The other side of the rail 10 is thereby pressed against the belt 71. The wheel 72 is driven by the motor 11 and drives the belt 71. The belt 71 drives the feed movement of the rail 10 in a friction fit and transmits the drive movement indicated by the arrow 5 from the wheel 72 to the wheel 73.

[0030] Figure 4-7 The variants in each have the feature that, when driving the plate 2, the rail 10 is clamped between at least one rotating drive element (element 13, wheel 53) and at least one rotating counterpressure element (wheels 44, 45; 54, 55; 64, 65, belt 70).

[0031] Figure 8-12 Variations of the mechanism 12 are shown, which may be Figure 3 The variant shown has two rails 10 per panel 2 for use.

[0032] Figure 8 A variant is shown in which the element 13 is an endless belt 80 which is pressed against the rail 10 by wheels 81, 82, 83. The belt 80 is wound around the wheels 82, 83. The wheel 81 is smaller than the wheels 82, 83 and is arranged between them. The wheels 84, 85, 86 are pressed against the rail 15 by springs 87, 88, 89. The springs 87, 88, 89 are intended to keep the wheels 84, 85, 86 away from the other rail 10. The wheel 81 is loaded in the opposite direction by a spring 90. The wheel 82 is driven by the motor 11 and drives the belt 80. The belt 80 drives the feed movement of the rail 10 in a friction fit and transmits the drive movement indicated by the arrow from the wheel 82 to the wheel 83.

[0033] Fig. 9A variant is shown in which wheel 91 rests on wheels 92, 93 which rest on rail 10. Element 13 is formed by wheel 92 which is driven by motor 11. Wheel 91 is a friction wheel and transmits the drive movement from wheel 92 to wheel 93. Alternatively, wheel 91 or wheel 93 can also be driven by motor 11. Wheels 92, 93 drive the feed movement of plate 2 in the direction 3 or 7 in a friction-fitting manner. Wheels 94, 95 rest on the other rail 15 and are connected to each other in a friction-fitting manner via wheel 96. Wheels 94, 95 can run together, that is, driven in a friction-fitting manner by the rail 15 passing by. Alternatively, one of wheels 94, 95, 96 can be driven by motor 11. Wheels 92, 93 each have a rubber-elastic circumferential surface and are pressed against the inner side of rail 10 by their spring effect. The wheels 94 , 95 also each have a rubber-elastic circumferential surface and press against the inner side of the other rail 15 by their spring effect.

[0034] Fig.10 A variant is shown in which the wheels 102, 103 bear against the inner side of the rail 10 and the wheels 104, 105 bear against the inner side of the other rail 15 under pressure. The wheel 104 is in rolling contact with the wheels 102, 103 and the wheel 103 is in rolling contact with the wheels 104, 105. The wheels 103, 104, 105 are loaded by springs 106, 107, 108, respectively. The force of the springs 106, 107, 108 is resolved into two components by the wheels 103, 104, 105, respectively. For example, the wheel 105 is pressed against the rail 15 by one force component of the spring 107 and against the wheel 103 by another force component of the spring 107. The wheels 103, 104, 105 can be moved by the springs 106, 107, 108, while the wheel 102 is immovable and is designed as a support for the wheel 104. The wheel 102 drives the linear feed movement of the rail 10. This causes the plate 2, which is fixedly connected to the two rails 10, 15, to move in the directions 3, 7. In this case, the element 13 is formed by the wheel 102.

[0035] Fig.11A variant is shown in which, when the respective plate 2 is driven, the belt 110 lies against the rail 10 and the belt 111 lies against the other rail 15. The belt 110 is wound around wheels 112, 113 and the belt 111 is wound around wheels 114, 115. Wheel 112 forms a gap 116 with wheel 114, wheel 113 forms a gap 117 with wheel 114 and a gap 118 with wheel 115. In the gaps 116, 117, 118, the belts 110, 111 are pressed against each other. The belts 110, 111 run from the gap 116 to the gap 118 in mutual contact. The belts 110, 111 consist of a rubber-elastic material and act as a preloaded spring, wherein it serves to press the rails 10, 15 apart from each other. The motor 11 drives the wheel 112, which drives the belt 110. The element 13 that drives the rail 10 in a friction-fitting manner is formed by a belt 110. The belt 110 drives the belt 111 in a friction-fitting manner. Alternatively, the motor 11 can also additionally drive a wheel 114, in which case the wheel 114 drives the belt 111. The rail 10 is moved in the direction 3, 7 by the belt 110 and the rail 15 is moved by the belt 111, so that the plate 2 is moved accordingly.

[0036] Fig.12 A variant is shown in which an endless belt 120 forms the element 13 and rests on the rail 10. The belt 120 is wound around wheels 121, 122 and in the section between gaps 124, 125 is in contact with a wheel 123 which forms said gap together with the wheels 121, 122. The wheel 123 rests on the other rail 15. A wheel 126 is arranged between the wheels 121, 122 and is pressed against the inner side of the belt 120 by a spring 127, the outer side of said belt 120 being thus pressed against the rail 10. The wheel 123 is arranged between wheels 128, 129 which are pressed against the rail 15 by springs 130, 131, respectively. The wheels 126, 128, 129 are smaller than the wheels 121, 122, 123. The motor 11 drives the wheel 121 in rotation, which drives the rotary motion of the belt 120. The rotary motion of the belt 120 is converted into a translation of the plate 2 by means of the frictional contact between the belt 120 and the rail 10 .

[0037] Figures 8 to 12 The variants are respectively characterized in that at least one rotating drive element (element 13, wheel 93, 103) and at least one rotating counter-pressure element (wheel 84, 85, 86, 104, 105, 123, 128, 129, belt 111) are arranged between the two rails 10, 15, and when the plate 2 is driven, the rails 10, 15 are tensioned by the drive element and the counter-pressure element.

[0038] Reference numerals list

[0039] 1 board

[0040] 2 boards

[0041] 3 Directions

[0042] 4 printing heads

[0043] 5 Chain

[0044] 6 tracks

[0045] 7 Directions

[0046] 8 sectors

[0047] 9 Rollers

[0048] 10 tracks

[0049] 11 Motor

[0050] 12 Institutions

[0051] 13 Components

[0052] 14 Axis

[0053] 15 tracks

[0054] 16 Opening

[0055] 17 Grooves

[0056] 18 Bump

[0057] 19 Hinge pin 20 Hinge hole 21 Swivel hinge 22 Viewing direction 23-24---41 Belt

[0058] 42 rounds

[0059] 43 rounds

[0060] 44 rounds

[0061] 45 rounds

[0062] 46 Spring 47 Spring 48-50---51 Belt

[0063] 52 rounds

[0064] 53 rounds

[0065] 54 rounds

[0066] 55 rounds

[0067] 56 Spring

[0068] 57 Spring

[0069] 58th round 59th round

[0070] 60-61---

[0071] 62 rounds

[0072] 63 rounds

[0073] 64 rounds

[0074] 65 rounds

[0075] 66 Spring

[0076] 67 Spring

[0077] 68 rounds

[0078] 69 ---

[0079] 70 belt

[0080] 71 belt

[0081] 72 rounds

[0082] 73 rounds

[0083] 74 rounds

[0084] 75 rounds

[0085] 76 Spring

[0086] 77 Spring

[0087] 78-79---

[0088] 80 belt

[0089] 81 belt

[0090] 82 rounds

[0091] 83 rounds

[0092] 84 rounds

[0093] 85 rounds

[0094] 86 rounds

[0095] 87 Spring

[0096] 88 Spring

[0097] 89 Spring

[0098] 90 Spring

[0099] 91 wheel 92 wheel 93 wheel 94 wheel 95 wheel 96 wheel 97-101---102 wheel 103 wheel 104 wheel 105 wheel 106 spring 107 spring 108 spring 109---110 belt 111 belt 112 wheel 113 wheel 114 wheel 115 wheel 116 gap 117 gap 118 gap 119---120 belt 121 wheel 122 wheel 123 wheel 124 gap 125 gap

[0100] 126 rounds

[0101] 127 Spring

[0102] 128 rounds

[0103] 129 rounds

[0104] 130 Spring

[0105] 131 Spring.

Claims

1. A device for conveying sheets (1), comprising plates (2) which together form a chain (5) which revolves along a track (6) and is driven by a mechanism (12), characterized in that: The plates (2) each have an opening (16) for holding the sheet (1) on the upper side of the respective plate (2) by suctioning air; and The mechanism (12) has at least one drive element (13) which, when driving the plate (2), rotates about at least one axis (14) and directly and successively engages with the plate (2) or with a rail (10, 15) arranged on the plate (2) in a friction fit.

2. The device according to claim 1, characterized in that Each plate (2) has a unique rail (10); The mechanism (12) has a counter-pressure element; and During drive, the single rail (10) is located between the drive element (13) and the counterpressure element.

3. The device according to claim 1, characterized in that Each plate has two rails (10, 15); The mechanism (12) has a counter-pressure element; and The drive element (13) and the counterpressure element are located between the two rails (10, 15) during drive.

4. The device according to any one of claims 1 to 3, characterized in that The drive element (13) is a wheel (52, 62, 92, 102) or an endless belt (41, 71, 80, 110, 120).

5. The device according to any one of claims 1 to 3, characterized in that The counterpressure element is a wheel (44, 45, 54, 55, 64, 65, 87, 88, 89, 94, 95, 104, 105, 123, 128, 129) or an endless belt (70, 111).

6. The device according to any one of claims 1 to 3, characterized in that The drive element (13) is loaded by a spring (90, 127) and in turn presses against the rail (10) of the plate (2).

7. The device according to claim 2 or 3, characterized in that The counter-pressure elements are loaded by springs (46, 47, 56, 57, 66, 67, 76, 77, 87, 88, 89, 106, 107, 130, 131) and are pressed in sequence onto the rails (10, 15) of the plate (2).

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