GRIPPER CARRIAGE. SHEET-PROCESSING MACHINE COMPRISING A GRIPPER CARRIAGE AND A RADIATION DRYER, AND METHOD FOR TRANSPORTING SHEETS
20190270301 ยท 2019-09-05
Inventors
Cpc classification
B41F21/08
PERFORMING OPERATIONS; TRANSPORTING
B65H2801/31
PERFORMING OPERATIONS; TRANSPORTING
International classification
B41F23/04
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A gripper carriage transports a sheet in a sheet transport direction along a sheet transport path. The gripper carriage has a wall and a reflector. The reflector is associated with a flank of the wall which is trailing, in relation to the sheet transport direction.
Claims
1-50. (canceled)
51. A gripper carriage for transporting a sheet (22) in the sheet transport direction (29) along a sheet transport path (23), wherein at least one radiation dryer (24, 25) is arranged along the sheet transport path (23), wherein the gripper carriage (19) has a wall (20) and a reflector (27), characterized in that the reflector (27) is assigned to a flank (07) of the wall (20) which is trailing with respect to the sheet transport direction (29), and in that the reflector (27) has a reflectivity of at least 40% for the radiation of the radiation dryer (24, 25).
52. The gripper carriage according to claim 51, characterized in that the reflector (27) comprises at least two or precisely two, three, four, five or more reflector elements (27.1, 27.2, 27.3, 27.4, 27.5) spaced apart from one another transversely to the sheet transport direction (29).
53. The gripper carriage according to claim 51, characterized in that the reflector (27) comprises reflector elements (27.1, 27.2, 27.3, 27.4, 27.5) spaced apart from one another, wherein abutting edges (30) of the reflector elements (27.1, 27.2, 27.3, 27.4, 27.5) deviate transversely to the sheet transport direction (29) from the normal of a plane spanned by a gripper pad surface (35).
54. The gripper carriage according to claim 51, characterized in that the reflector (27) or a reflector element (27.1, 27.2, 27.3, 27.4, 27.5) is assigned to the wall (20) via a spacing means (34) or a damping means.
55. The gripper carriage according to claim 51, characterized in that the reflector (27) or a reflector element (27.1, 27.2, 27.3, 27.4, 27.5) is assigned to the wall (20) by means of an adhesive connection, or the reflector (27) assigned to the wall (20) is itself configured as an adhesive strip.
56. The gripper carriage according to claim 51, characterized in that the reflector (27) or a reflector element (27.1, 27.2, 27.3, 27.4, 27.5) is configured to reflect ultraviolet radiation or for a wavelength range of 220 nm to 500 nm.
57. The gripper carriage according to claim 51, characterized in that the reflector (27) or a reflector element (27.1, 27.2, 27.3, 27.4, 27.5) has at least one recess (33) for installation, adjustment, maintenance and/or cleaning work on the gripper carriage (19).
58. The gripper carriage according to claim 51, characterized in that an angle () between a reflector plane (28) or a tangent (28) applied to a curved reflector (27) or a curved reflector element (27.1, 27.2, 27.3, 27.4, 27.5), approximately centered on the vertical extension of said reflector with respect to a gripper pad surface (35), and a sheet 22 or a plane spanned by a gripper pad surface (35) is obtuse or measures between 91 and 120 or is at least approximately 93.
59. The gripper carriage according to claim 51, characterized in that the reflector (27) or a reflector element (27.1, 27.2, 27.3, 27.4, 27.5) comprises a spring steel sheet.
60. The gripper carriage according to claim 51, characterized in that the reflector (27) or a reflector element (27.1, 27.2, 27.3, 27.4, 27.5) comprises an aluminum layer and/or has a protective layer over an aluminum layer.
61. The gripper carriage according to claim 51, characterized in that the gripper carriage (19) has a gripper carriage body (20) and this gripper carriage body (20) is coated in the region of the reflector (27) or a reflector element (27.1, 27.2, 27.3, 27.4, 27.5), or the reflector (27) or a reflector element (27.1, 27.2, 27.3, 27.4, 27.5) is part of the gripper carriage body (20).
62. A sheet processing machine having at least one radiation dryer (24, 25), located along a sheet transport path (23), and at least one gripper carriage (19), wherein the gripper carriage (19) is guided along the sheet transport path (23) in order to transport a sheet (22) in the sheet transport direction (29) and wherein the gripper carriage (19) has a wall (20) and a reflector (27), characterized in that the reflector (27) is assigned to a flank (07) of the wall (20) such that the reflector reflects radiation that is emitted by the radiation dryer (24, 25) with at least one component in the sheet transport direction (29) in a direction opposite the sheet transport direction (29), and in that the reflector (27) has a reflectivity of at least 40% for the radiation of the radiation dryer (24, 25).
63. The sheet processing machine according to claim 62, characterized in that the gripper carriage (19) has a projection spaced apart and/or facing away from a gripper pad surface (35), which projection shades a leading edge region (26) of the sheet (22) gripped by the gripper carriage (19) vertically beneath the radiation dryer (24, 25) from the radiation emitted by the radiation dryer (24, 25).
64. A method for transporting sheets in the delivery of a sheet processing machine that includes at least one radiation dryer (24, 25), arranged along a sheet transport path (23), and at least one gripper carriage (19), wherein the gripper carriage (19) is guided along the sheet transport path (23) in order to transport a sheet (22) in the sheet transport direction (29), and wherein the gripper carriage (19) has a reflector (27) for the radiation emitted by the radiation dryer (24, 25), characterized in that the reflector (27) directs radiation emitted by the radiation dryer (24, 25) onto the sheet (22) being transported by the gripper carriage (19), and in that the reflector (27) has a reflectivity of at least 40% for the radiation of the radiation dryer (24, 25).
65. The method according to claim 64, characterized in that the reflector (27) directs radiation emitted by the radiation dryer (24, 25) onto a leading edge region (26) of the sheet (22) gripped by the gripper carriage (19).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Exemplary embodiments of the invention are illustrated in the set of drawings and will be described in greater detail below.
[0022] In the drawings:
[0023]
[0024]
[0025]
[0026]
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
DESCRIPTION OF PREFERRED EMBODIMENTS
[0035]
[0036] When sheet 22 is traveling along sheet transport path 23 in sheet transport direction 29, its side that was printed on printing cylinder 11 is facing upward. Facing this side and situated between the runs 16, 17 is at least one radiation dryer 24. Radiation dryer 24 comprises at least one radiation source 25 preferably extending over the entire width of the sheet transport plane or the sheet transport path 23 from one chain 13 to the other, with three radiation sources 25 being shown by way of example in
[0037] As an alternative or in addition to positioning the radiation dryer 24 in the sheet ascent area for the purpose of curing printing inks, a radiation dryer 24 may be positioned in a delivery extension. This delivery extension may be used to create a coating pathway segment downstream of a final unit, for example a coating unit or printing unit 02. The reflectors 27 (see below) on the gripper carriages 19 may also be used for coatings, in particular UV-curing coatings, for example. They may also be used with digital printing inks, in particular UV-curing digital printing inks.
[0038] Radiation dryer 24 or radiation source 25 preferably supplies UV radiation that is capable of inducing a chemical drying reaction in the ink and/or the coating that has been printed onto sheet 22. For physical drying, a radiation source that emits radiation in the visible or infrared or microwave spectrum is also possible. The radiation source 25, in particular the UV radiation source 25, may be embodied in particular as a mercury discharge lamp in the form of an elongated tube extending transversely to the sheet transport direction 29 or in the form of an arrangement of UV LED's on a carrier extending transversely to the sheet transport direction 29. The mercury discharge lamp emits radiation with equal intensity around essentially its entire axis in nearly all directions and is therefore typically combined with a reflector that limits such emission transversely to the axis to within an angular range ; based upon their structural configuration, the LED's emit radiation only within such a limited angular range . The angular range may be approximately 120, for example, and/or a gripper carriage 19 may be guided beneath radiation source 25 with a vertical distance of approximately 10 mm between radiation source 25 and gripper carriage body 20.
[0039] When a gripper carriage 19 is approaching the radiation source 25, as shown in
[0040] To correct this uneven distribution, a reflector 27 is preferably disposed, in particular mounted, on a trailing flank 07, with respect to the sheet transport direction 29, of a wall of the gripper carriage 19, in particular on a flank 07 or surface of gripper carriage 19 oriented opposite the sheet transport direction 29. Reflector 27 may be a planar strip which extends along gripper carriage 19, preferably over the entire length of gripper carriage 19 or radiation source 25. Reflector 27 preferably extends over at least 80% of the width of the gripper carriage body 20 of gripper carriage 19 and/or over a width that is determined by the two outer gripper fingers 21 of gripper carriage 19 and/or the maximum width of a sheet 22 to be processed. It may be formed by a highly polished metal sheet; preferably, it comprises a layer of metal, in particular aluminum, applied, in particular vapor deposited, onto a flat substrate, and particularly preferably an air-tight protective layer, for example of quartz, covering the metal layer. A reflector 27 of this type has a reflectivity for the radiation of the radiation dryer 24, in particular for the UV radiation of the UV radiation source 25, of at least 40%, in particular at least 60%, preferably at least 75%. The reflectivity near the emitted wavelength is particularly preferably 80%.
[0041] Applied layer stacks (equivalent to the dichroic reflectors) of hafnium oxide and silicon oxide are another alternative. The thickness of the layers is appropriate for reflection within a certain wavelength range. The more layers of a given thickness are applied, the higher the reflectance. This enables the layer system to be constructed such that in addition to reflecting UV radiation and light (for curing-like the dichroic reflector in the UV module), IR radiation is reflected. This prevents the gripper carriage 19 from becoming heated by IR radiation. However, both variants are possible.
[0042] A part of gripper carriage 19, in particular a part of gripper carriage body 20, may also be formed as a reflector 27. In that case, a surface of gripper carriage 19, for example, in particular a surface of gripper carriage body 20, is embodied as having a low degree of roughness. This can be accomplished by mechanical processing and/or by coating, for example. In such processes, the coating is optimized in particular not only in terms of decreased roughness but also in terms of increased reflection. The property of reflection is material dependent, in particular; for example, chromium may be unsuitable. Reflector 27 may be configured as an adhesive strip, for example, in particular as an aluminum adhesive strip.
[0043] Reflector 27 may extend as a single integral piece or in multiple pieces along gripper carriage body 20, transversely to the sheet transport direction 29. For attaching said reflector, screw holes may be distributed along reflector 27; additional openings, which should occupy only a small portion of the reflector surface, may be provided for sensors that serve, for example, for monitoring the correct position and/or drying of sheet 22 on gripper carriage 19. Alternatively or additionally, reflector 27 may be attached by clamping and/or gluing.
[0044] A flat surface of reflector 27, or the reflector surface itself, preferably forms a reflector plane 28. In the embodiment shown here, reflector 27, in particular reflector plane 28, is at least nearly perpendicular to the sheet transport direction 29 and/or perpendicular to the sheet transport plane and/or perpendicular to sheet 22, or perpendicular to a plane spanned by a gripper pad surface 35 (see below). Deviations from this orientation are possible but must not exceed 30. Reflector plane 28 may be understood, for example, as a spatial plane which is spanned by the surface of reflector 27.
[0045] At the moment when reflector 27 passes through the position of maximum approach toward radiation source 25, shown in
[0046] If a vertical reflector 27 arranged over the entire surface were to have a reflectivity of precisely 100%, then with a symmetrical radiation source 25, said reflector could compensate precisely for the shading by gripper carriage 19. To compensate for reflection losses, it would be conceivable for the reflector 27 to be embodied as concave in profile transversely to the longitudinal direction of gripper carriage 19, as depicted in
[0047] Furthermore, by tilting reflector 27 forward, as shown in
[0048]
[0049] Reflector 27, in particular the reflector elements 27.1, 27.2, 27.3, 27.4, are assigned to a flank 07 or surface of the wall of gripper carriage 19 which is trailing with respect to the sheet transport direction 29. The trailing flank 07 is therefore a flank or surface of gripper carriage 19 that faces the sheet 22 to be transported. The trailing flank 07 of the wall may merge continuously or discontinuously, for example, into an adjoining surface that comprises or forms the surface of gripper carriage 19 that faces away from the sheet transport plane, and this surface may further be connected to the leading flank of gripper carriage 19. However, the wall may also be formed by a panel of gripper carriage 19. In particular, the trailing flank 07 may be a surface arranged on a side of the wall in particular of a gripper carriage body 20 or a carrier body 20, which side faces away from a gripper shaft 09, and/or a surface aligned at least nearly parallel to the normal of the sheet transport plane or the normal of a plane spanned by a gripper pad surface 35.
[0050] Preferably, reflector 27 has at least two reflector elements 27.1, 27.2, 27.3, 27.4, in this case precisely four such reflector elements, which reflect radiation. These reflector elements 27.1, 27.2, 27.3, 27.4, in particular spaced apart from one another, are arranged transversely to the sheet transport direction 29 or parallel to the sheet leading edge. Each of the four reflector elements 27.1, 27.2, 27.3, 27.4, in particular, is assigned to the trailing flank 07 or surface of the wall of gripper carriage 19, transversely to the sheet transport direction 29. In particular, some or all of the reflector elements 27.1, 27.2, 27.3, 27.4 lie within a common plane, or the reflector elements 27.1, 27.2, 27.3, 27.4 are arranged within said common plane. One surface of reflector 27 or the surfaces of some or all of the reflector elements 27.1, 27.2, 27.3, 27.4 together form a reflector plane 28. Reflector plane 28 can be understood as a spatial plane.
[0051] In the case of a reflector 27 having multiple reflector elements 27.1, 27.2, 27.3, 27.4, these reflector elements 27.1, 27.2, 27.3, 27.4 are preferably arranged adjacent to one another via abutting edges 30. In that case, the reflector elements 27.1, 27.2, 27.3, 27.4 are arranged spaced from one another by a distance a, which preferably measures between 0.1 mm and 5 mm. Particularly preferably, the reflector elements 27.1, 27.2, 27.3, 27.4 are arranged spaced from one another by a distance a that measures at least approximately 1.5 mm. Reflector 27 or the reflector elements 27.1, 27.2, 27.3, 27.4 may also be equipped with recesses 33, which may also be provided, for example, in the region of the abutting edges 30 between the reflector elements 27.1, 27.2, 27.3, 27.4.
[0052] In particular, the spaced-apart reflector elements 27.1, 27.2, 27.3, 27.4 may have abutting edges 30 that deviate from the normal of the sheet transport plane or the normal of a plane spanned by a gripper pad surface 35, i.e. from the orthogonal to the sheet transport path 23. These abutting edges 30 of the reflector elements 27.1, 27.2, 27.3, 27.4 are aligned parallel to one another, in particular, and are preferably arranged lying within a common plane such that each is formed at an angle of 1 to 45 from the normal or the orthogonal of the sheet transport plane or the sheet transport path 23. Particularly preferably, at least two reflector elements 27.1, 27.2, 27.3, 27.4, and in this case particularly preferably all of said reflector elements, are formed with abutting edges 30 facing one another at an angle of at least approximately 20 from the normal of the sheet transport plane. Reflector 27, more particularly each of the two outer reflector elements 27.1, 27.4, which are arranged facing the chains 13, preferably has an external outer edge 31 which is aligned at least nearly parallel to the normal of the sheet transport plane or the normal of the plane spanned by a gripper pad surface 35.
[0053]
[0054]
[0055] Gripper carriage 19 is configured for transporting a sheet 22 in the sheet transport direction 29 within a sheet transport plane along the sheet transport path 23. Gripper carriage 19 has a wall, with the reflector 27 being assigned to a flank 07 of said wall which is trailing with respect to the sheet transport direction 29. Preferably, gripper carriage 19 includes a carrier body 20, in particular as a single integral piece, which is or can be disposed, preferably at both ends, on the chains 13 of the chain transport system 12 (not shown in further detail) via plates 03. Gripper carriage 19 can then be held and/or guided at each of its two ends via two pins 04 which are spaced apart from one another in the sheet transport direction 29 and are assigned to the plates 03. In particular, pins 04 may be part of the chains 13 of the sheet transport system 12. At one end or at both ends, gripper carriage 19 preferably further supports a roller lever 05, to which a cam follower 06 can be assigned. Via control means, such as control cams, the gripper fingers 21 of gripper carriage 19 can be controlled for clamping and releasing a sheet 22. In particular, by means of the control means, in particular control cams, and the roller levers 05 preferably each supporting a cam follower 06, gripper fingers 21 can be controlled for receiving and for releasing a sheet.
[0056] Preferably, reflector 27 has at least two, in particular precisely five reflector elements 27.1, 27.2, 27.3, 27.4, 27.5 that reflect radiation. These reflector elements 27.1, 27.2, 27.3, 27.4, 27.5, in particular spaced apart from one another, are arranged transversely to the sheet transport direction 29 or parallel to the sheet leading edge. In particular, each of the reflector elements 27.1, 27.2, 27.3, 27.4, 27.5 is assigned to the wall, in particular to the carrier body 20, of the gripper carriage 19, transversely to the sheet transport direction 29. More particularly, some or all of the reflector elements 27.1, 27.2, 27.3, 27.4, 27.5 lie within a common plane, or the reflector elements 27.1, 27.2, 27.3, 27.4, 27.5 are arranged within said common plane. Additionally, reflector 27 or a reflector element or relevant reflector element 27.1, 27.2, 27.3, 27.4, 27.5 can have at least one recess 33 for installation, adjustment, maintenance and/or cleaning work on the gripper carriage 19.
[0057]
[0058] Gripper carriage 19 includes a gripper shaft 09, transversely to the sheet transport direction 29, which cooperates with gripper fingers 21 that are spaced from one another axially. Gripper shaft 09 is thus situated downstream of the wall, in particular the carrier body 20, with respect to the sheet transport direction 29. Gripper shaft 09 is therefore associated with the leading flank of the wall, in particular of the largely integral carrier body 20. Transversely to the sheet transport direction 29, gripper carriage 19 has at least one gripper pad 08, with each gripper pad forming a clamping nip with a movable gripper finger 21. An at least partially continuous strip having at least one gripper pad surface 35 may be used as gripper pad 08. Preferably, however, multiple individual gripper pads 08 with respective gripper pad surfaces 35 are used. The at least one gripper pad surface 35 or the gripper pad surfaces 35 span a plane that may correspond, for example, to the surface of the sheet 22 in the horizontal sheet transport path 23. The gripper pads 08 are assigned to carrier body 20 in the region of the sheet transport path 23.
[0059] Gripper shaft 09 is operatively connected at its end faces to the provided roller levers 05. When roller lever 05 supporting cam follower 06 is actuated, preferably by control means, the gripper fingers 21 can be controlled in relation to the gripper pads 08. Gripper shaft 09 can thereby actuate or move the gripper fingers 21 directly or via transmission means and thereby separate the gripper fingers 21 from the gripper pads 08. During sheet transport, the gripper fingers 21 are preferably pressed by one or more spring elements, for example a torsion spring 10, against the gripper pads 08 of the gripper carriage 19. Gripper carriage 19 may have a height perpendicular to the plane spanned by the gripper pad surfaces 35 of at least approximately 72 mm, for example, and the extension of reflector 27 or of a reflector element 27.1, 27.2, 27.3, 27.4, 27.5 or a relevant reflector element perpendicular to said plane may be at least approximately 63 mm.
[0060] Preferably, at least the trailing wall with respect to the sheet transport direction 29 is aligned at least nearly perpendicular to the sheet transport plane or to the sheet transport path 23 and/or transversely to the sheet transport direction 29. Therefore, reflector 27 or a reflector element 27.1, 27.2, 27.3, 27.4, 27.5 or relevant reflector element is preferably aligned at least nearly perpendicular to the sheet transport plane or to the sheet transport path 23 and/or transversely to the sheet transport direction 29. The wall may be part of a gripper carriage body 20 or part of the carrier body 20 of gripper carriage 19, for example. In particular, the wall may have a projection which is spaced and/or faces away from the sheet transport plane or from the sheet transport path 23, pointing or oriented opposite the sheet transport direction 29. In the region of the sheet transport plane, reflector 27 or a reflector element or relevant reflector element 27.1, 27.2, 27.3, 27.4, 27.5 is arranged, for example, flush with the wall, in particular with the carrier body 20. In this case, reflector 27, or a reflector element or relevant reflector element 27.1, 27.2, 27.3, 27.4, 27.5 may extend from at least nearly the sheet transport plane up to the projection of the carrier body 20. The projection of carrier body 20 may also project beyond reflector 27 or a reflector element or relevant reflector element 27.1, 27.2, 27.3, 27.4, 27.5, opposite the sheet transport direction 29.
[0061] One surface of reflector 27 or the surfaces of some or all of the reflector elements 27.1, 27.2, 27.3, 27.4, 27.5 together form a reflector plane 28. Reflector plane 28 can be understood as a spatial plane. The reflector elements 27.1, 27.2, 27.3, 27.4, 27.5 assigned to the trailing flank 07 of the wall, in particular of the support body 20, preferably have a common reflector plane 28, which forms an angle with a sheet 22 gripped by gripper carriage 19 or with the plane spanned by the gripper pad surfaces 35. The angle between reflector plane 28 and the sheet 22 or the spanned plane can measure between 60 and 120, for example. Particularly preferably, the angle formed between reflector plane 28 and a sheet 22 or the spanned plane is obtuse, i.e. measuring between 91 and 120. In particular, the angle between reflector plane 28 and sheet 22 or the spanned plane measures at least approximately 93. In addition, gripper carriage 19 may be assigned adjustment means, for example for displacing reflector 27 or one or both outer reflector elements 27.1, 27.4, 27.5 so as to influence or optimize the reflected drying radiation. Further, at least one sensor for determining the position and/or the degree of drying of a sheet 22, 26 could be provided, optionally in conjunction with a control device.
[0062]
[0063] Reflector 27 or a reflector element 27.1, 27.2, 27.3, 27.4, 27.5 or relevant reflector element can also be assigned to the wall by means of an adhesive connection. Reflector 27 may also extend continuously over the entire width of the sheet transport path 23. Preferably, reflector 27 or a reflector element 27.1, 27.2, 27.3, 27.4, 27.5 or relevant reflector element can comprise an aluminum layer. Additionally, a protective layer may be provided over the aluminum layer. The protective layer can preferably contain silicon or quartz.
[0064]
[0065] In particular, reflector 27 can have reflector elements 27.1, 27.2, 27.3, 27.4, 27.5 spaced apart from one another, which have abutting edges 30 that deviate from the normal of the sheet transport plane or from the normal of a plane spanned by the gripper pad surfaces 35, i.e. from the orthogonal to the sheet transport path 23. These abutting edges 30 of the reflector elements 27.1, 27.2, 27.3, 27.4, 27.5 are aligned parallel to one another, in particular, and are preferably arranged lying within a common plane such that each is at an angle of 1 to 45 from the normal of the sheet transport plane or the spanned plane. Preferably, at least two reflector elements 27.1, 27.2, 27.3, 27.4, 27.5 and particularly preferably all of said reflector elements, are formed with abutting edges 30 facing one another at an angle of at least approximately 10 from the normal of the sheet transport plane. In that case, reflector 27 or each outer reflector element 27.1, 27.5 has an external outer edge 31 which is aligned at least nearly parallel to the normal of the spanned plane. Furthermore, reflector 27 or a reflector element or relevant reflector element 27.1, 27.2, 27.3, 27.4, 27.5 may have one or more recesses 33, which can also be assigned to an abutting edge 30 and/or outer edge 31.
[0066]
[0067] Spacing means 33, for example, which may be assigned to the fastening elements, for example, in particular the screw connectors 32, and/or arranged separately, are assigned to reflector 27 or to a reflector element 27.1, 27.2, 27.3, 27.4, 27.5 or relevant reflector element. Here, said spacing means 33 assigned to the screw connectors 32 are washers made of steel, for example. The spacing means 33 spaced apart from the screw connectors 32 may be configured, in particular, as damping means, for example as adhesive felt elements. Alternatively, reflector 27 may be configured as an adhesive strip and assigned to the wall, in particular to a gripper carriage body 20 or carrier body 20. Gripper carriage 19 may also have a gripper carriage body 20, which can be coated in the region of the reflector 27 or a reflector element 27.1, 27.2, 27.3, 27.4, 27.5 or relevant reflector element. Reflector 27 or a reflector element 27.1, 27.2, 27.3, 27.4, 27.5 or relevant reflector element may also be part of the gripper carriage body 20.
[0068] A sheet processing machine preferably has at least one radiation dryer 24, 25 arranged along the sheet transport path 23 and at least one and preferably multiple gripper carriages 19. The one or more gripper carriages 19 transport a respective sheet 22 in the sheet transport direction 29 along the sheet transport path 23; the gripper carriages 19 are preferably similar in configuration. Each of the gripper carriages 19 preferably has a reflector 27 or one or more reflector elements 27.1, 27.2, 27.3, 27.4, 27.5 for reflecting the radiation emitted by the radiation dryer 24, 25, said reflector or reflector element(s) being assigned to a wall, in particular to a wall of a gripper carriage body 20 or carrier body 20. More particularly, the reflectors 27 are assigned to a flank 07, which is trailing with respect to the sheet transport direction 29, of the wall, in particular of the gripper carriage body 20 or carrier body 20, of a respective gripper carriage 19, such that said reflector reflects the radiation, emitted by the radiation dryer 24, 25 with at least one component in the sheet transport direction 29, opposite the sheet transport direction 29.
[0069] Each of the gripper carriages 19 may also have a projection which is spaced apart from and/or faces away from the sheet transport plane or the sheet transport path 23, and which shades the leading edge region 26 of the sheet 22 gripped by the gripper carriage 19, vertically beneath the radiation dryer 24, 25, from the radiation emitted by the radiation dryer 24, 25. In particular, reflector 27 or a reflector element or relevant reflector element 27.1, 27.2, 27.3, 27.4, 27.5 has a reflectivity of at least 40%, in particular at least 60%, preferably at least 75% for the radiation of the radiation dryer 24, 25. A preferably used polished spring steel sheet, which is coated with aluminum and provided with a silicon protective layer, can achieve a reflectivity of about 80%.
[0070] During the transport of sheet 22 in the delivery of a sheet processing machine by a respective gripper carriage 19, the radiation emitted by the radiation dryer 24, 25 is directed onto the sheet 22 being transported by gripper carriage 19. The radiation emitted by the radiation dryer 24, 25 is directed in particular directly and/or immediately onto the sheet 22 gripped by gripper carriage 19. In particular, the radiation emitted by the radiation dryer 24, 25 is directed onto the leading edge region 26 of the sheet 22 gripped by gripper carriage 19, so that this leading edge region 26 experiences increased drying.
[0071] While preferred embodiments of a gripper carriage, a sheet processing machine comprising a gripper carriage and a radiation dryer and methods for transporting sheets, all in accordance with the present invention, have been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes could be made thereto without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the appended claims.