RETRACTOR DEVICE

Abstract

The invention involves a spreading device (1) for multiple material sheet strips (4) cut from a material sheet (5) by a material sheet cutting device. The material sheet strips (4) are fed to the spreading device (1) along a transport path in order to be subsequently transported, offset parallel to one another, to a winding shaft arrangement and to be wound onto a common winding shaft. The spreading device (1) comprises two deflection elements (2 and 3), which each extend transversely to the transport path and are configured and arranged such that a strip spacing (9) between two adjacent to one another along a transport path are successively enlarged over the first and second deflection elements (2 and 3) of the guided material sheet strips (4). The deflection elements (2, 3) are arranged in a rotationally fixed manner. Each deflection element (2 and 3) comprises a number of openings (15) in a transport contact area (13) of a deflection sheath surface (12) of the deflection elements (2 and 3) covered by the material sheet strips (4) transported over it, through which compressed air can be blown in order to create a friction-reducing air layer between the material sheet strips (4) and the deflection sheath surfaces (12) of the deflection elements (2 and 3) in the transport contact area (13).

Claims

1. A spreading device (1) for multiple material sheet strips (4) cut from a material sheet (5) by a material sheet cutting device, wherein the material sheet strips (4) are fed to the spreading device (1) along a transport path in a feed plane (6) and leave the spreading device (1) in a discharge plane (7) in order to be subsequently transported, offset parallel to one another, to a winding shaft arrangement and to be wound onto a common winding shaft, wherein the spreading device (1) comprises two deflection elements (2 and 3), which each extend transversely to the transport path and are configured and arranged such that a strip spacing (9) between two material sheet strips (4) guided adjacent to one another along a transport path in succession over the first and second deflection elements (2 and 3) is greater in the discharge plane (7) than in the feed plane (6), wherein the deflection elements (2 and 3) are arranged to be non-rotatable, and in that each deflection element (2 and 3) comprises a number of openings (15) in a transport contact area (13) of a deflection sheath surface (12) of the deflection elements (2 and 3) covered by the material sheet strips (4) transported thereover, through which compressed air can be blown in order to create a friction-reducing air layer between the material sheet strips (4) and the deflection sheath surfaces (12) of the deflection elements (2 and 3) in the transport contact area (13), wherein: the two deflection elements (2, 3) are arranged and configured such that the feed plane (6) and the discharge plane (7) are offset parallel to each other, and the deflection elements (2, 3) are configured such that the material sheet strips (4) are transported between the two deflection elements (2, 3) at least approximately at a right angle relative to the feed plane (6) and the discharge plane (7).

2. The spreading device (1) according to claim 1, characterised in that the deflection sheath surfaces (12) or the transport contact surfaces (13) of the deflection elements (2 and 3) are made of a porous and air-permeable material.

3. The spreading device (1) according to claim 1, characterised in that the deflection sheath surfaces (12) or the transport contact surfaces (13) of the deflection elements (2 and 3) are made from a perforated sheet metal or from a perforated thin-walled material layer.

4. The spreading device (1) according to claim 3, characterised in that the deflection sheath surfaces (12) or the transport contact surfaces (13) of the deflection elements (2 and 3) have a number of holes with an opening diameter of less than 0.5 mm, preferably less than 0.2 mm.

5. The spreading device (1) according to claim 1, characterised in that the two deflection elements (2 and 3) are arranged and designed configured such that the feed plane (6) and the discharge plane (7) are offset parallel to one another.

6. The spreading device (1) according to claim 1, characterised in that the deflection elements (2 and 3) are configured in the shape of a segment of a circle in a cross-sectional area extending along the transport path.

7. The spreading device (1) according to claim 1, characterised in that a deflection sheath surface (12) of each deflection element (2 and 3) has a deflection curvature along the transport path of a material sheet strip (4) and, transversely to the transport path, a deflection curvature extending over all material sheet strips (4).

8. The spreading device (1) according to claim 7, characterised in that the spreading curvature of a deflection element (2 and 3) which extends over all material sheet strips (4) is formed by subsequent reshaping of a deflection element blank that is not initially curved in a spreading direction.

9. The spreading device (1) according to claim 1, characterised in that the deflection sheath surfaces (12) of the two deflection elements (2 and 3) form a wrap-around section of the same size for each material sheet strip (4) along the transport path.

Description

[0019] Various exemplary embodiments of the inventive concept are explained in more detail hereinafter and are shown schematically and by way of example in the drawings. Shown are:

[0020] FIG. 1: a perspective view of a spreading device comprising two deflection elements, whereby multiple material sheet strips arranged adjacent to one another are guided along a transport path around the deflection elements and deflected in the process

[0021] FIG. 2: a top view of a deflection element,

[0022] FIG. 3: a sectional view through the deflection element shown in FIG. 2 along a sectional line III-III in FIG. 2,

[0023] FIG. 4: a sectional view through a differently configured deflection element,

[0024] FIG. 5: a sectional view of another differently configured deflection element, and

[0025] FIG. 6: a top view of a deflection element produced by forming and shown by way of example in FIG. 5

[0026] FIG. 1 is, by way of example, an illustration of one spreading device 1 embodiment. The spreading device 1 comprises a first deflection element 2 and a second deflection element 3. A material sheet 5 that has already been separated into multiple material sheet strips 4 is fed to the spreading device 1 at a feed plane 6. The material sheet strips 4 are each deflected by the two deflection elements 2, 3 and leave the spreading device 1 in a discharge plane 7 that is offset parallel to the feed plane 6. During transport along a transport path indicated by an arrow 8, the material sheet strips 4 are not only deflected by the deflection elements 2 and 3, but are also spread out relative to one another, so that in the discharge plane 7 a strip spacing 9 between neighbouring material sheet strips 4 is greater than the strip spacing in the feed plane 6 before entering the spreading device 1.

[0027] Each of the two deflection elements 2 and 3 extends transversely to the transport path over the entire width of the fed material sheet 5, or over the entire width of the spread material sheet strips 4. The deflection elements 2 and 3 have a circular arc segment shape in a cross-sectional area extending along the transport path, as also shown schematically in FIG. 3. Each deflection element 2 and 3 comprises a base body 10 and a sheath element 11 made of a porous and air-permeable material. An outwardly directed outer surface of the sheath element 11 forms a deflection sheath surface 12 for the material sheet strips 4 transported over the deflection elements 2 and 3, which rest against the deflection sheath surface 12 within a transport contact area 13 of the deflection sheath surface 12, separated only by a narrow air cushion, and are thus deflected. The transport contact area 13 or transport contact surface is the area of the deflection sheath surface 12 against which the material sheet strips 4 rest during transport along the transport path. The transport contact area 13 can coincide with the deflection sheath surface 12 or be a partial area of the deflection sheath surface 12.

[0028] The sheath element 11 is fixed to the base body 10 of the deflection elements 2 and 3 such that an interior space 14 is formed between the sheath element 11 and the base body 10. Compressed air can be fed into the interior space 14 and is then blown out through the large number of individual openings 15 in the porous material of the sheath element 11 and escapes. As a result, a friction-reducing layer of air is formed in the transport contact area 13 between the deflection sheath surface 12 and the material sheet strips 4 transported over it.

[0029] The deflection sheath surface 12 of the deflection elements 2 and 3 formed by the sheath element 11 features an expanding curvature extending transversely to the transport path across all material sheet strips 4, which is recognisable as the outer contour 16 of the sheath element 11 in a top view of a deflection elements 2 and 3 shown in FIG. 2. In the exemplary embodiment shown in the drawings, the spreading curvature is constant over the entire extension of the deflection elements 2 and 3 transverse to the transport path. For practical purposes, a radius of curvature of several metres is often sufficient and the splay curvature in the illustration in FIG. 2 is only shown clearly exaggerated for illustration purposes.

[0030] FIGS. 4 and 5 show examples of further variants of a deflection elements 2 and 3. In the embodiment shown in FIG. 4, the deflection elements 2 and 3 have an arc-shaped sheath element 11 made of a porous material, which is placed on the base body 10. The shape of the base body 10 is predetermined in the areas adjacent to the sheath element 11 such that a continuous and approximately stepless and seamless surface is formed at the transition from the base body 10 to the deflection sheath surface 12 formed by the sheath element 11.

[0031] Multiple funnel-shaped interior spaces 14 are formed in the base body 10 adjacent to the sheath element 11, which almost completely cover a contact surface 17 of the sheath element 11 facing the base body 10. Compressed air can be blown into the sheath element 11 over a large area through these interior spaces 14, which forms a friction-reducing air layer for the material sheet strips 4 sliding over it after exiting through the porous material of the sheath element 11. The compressed air can, for example, be supplied via compressed air lines 18, which are fitted and pressed into compressed air ducts 19 formed in the base body 10.

[0032] In an embodiment shown schematically in FIG. 5, the deflection elements 2 and 3 comprise a perforated plate 20 that is curved along the transport path along a quarter circle. The perforated plate 20 is made from a thin sheet into which a large number of spaced holes 21 were subsequently drilled using a laser drilling device. An opening diameter of the holes 21 is preferably significantly smaller than 0.5 mm. The perforated plate 20 is connected to the base body 10 along a circumferential edge 22. A transition from the base body 10 to the perforated plate 20 is specified with as little friction as possible.

[0033] The base body 10 can, for example, have a shape as illustrated schematically and by way of example in FIG. 5. It is also possible for the base body 10 to have a tubular shape, with a slot extending in the longitudinal direction, into which the perforated plate 20 is fitted.

[0034] The deflection elements 2 and 3, which are only shown schematically in FIG. 6, is formed from a straight-lined forming blank by a forming process that creates the spreading curvature. The forming blank is initially produced in a straight line in a longitudinal direction of the deflection elements 2 and 3, which extends perpendicular to a cross-sectional area of the deflection elements 2 and 3 shown in FIGS. 3 to 5, which can be achieved with regard to the base body 10, for example, by strand extrusion or by a suitable low-cost forming process. The deflection element blank, which is initially produced in a straight line, can then be deformed by a suitable forming step and provided with the required expansion curvature. This forming step can also be performed very precisely and at the same time cost-effectively, so that it is possible to manufacture the deflection elements 2 and 3 in a way that is particularly advantageous from an economic point of view.