Abstract
A forming device for reforming a material web into a tube, comprising a shoulder part with a shoulder surface and a prism part with a prism surface, wherein the shoulder surface and the prism surface are connected to one another along a spatial reforming edge, which has at least one reforming edge portion with a slight curvature and at least one reforming edge portion with a strong curvature, wherein in the prism part, at least in the region of a reforming edge portion with a strong curvature, an inner former element with an inner former surface facing the prism surface is arranged in such a manner that between the prism surface and the inner former surface, a gap which runs along the reforming edge is formed, the width of said gap being adjustable.
Claims
1. A forming device for reforming a material web into a tube, comprising a shoulder part with a shoulder surface and a prism part with a prism surface, wherein the shoulder surface and the prism surface are connected to one another along a spatial reforming edge, which has at least one reforming edge portion with a slight curvature and at least one reforming edge portion with a strong curvature, wherein in the prism part, at least in the region of a reforming edge portion with a strong curvature, an inner former element with an inner former surface facing the prism surface is arranged in such a manner that between the prism surface and the inner former surface, a gap which runs along the reforming edge is formed, the width of said gap being adjustable.
2. The forming device as claimed in claim 1, wherein the inner former element is movably mounted perpendicularly to a longitudinal axis of the prism surface.
3. The forming device as claimed in claim 2, wherein the inner former element is flexibly mounted perpendicularly to the longitudinal axis of the prism surface.
4. The forming device as claimed in claim 1, wherein the inner former element is movably mounted in the direction of a longitudinal axis of the prism surface.
5. The forming device as claimed in claim 4, wherein the inner former element is flexibly mounted perpendicularly to the longitudinal axis of the prism surface.
6. The forming device as claimed in claim 3, wherein the inner former surface forms an acute angle α with the longitudinal axis of the prism surface.
7. The forming device as claimed in claim 1, wherein the inner former element can be fixed in at least two characteristic positions, which represent a minimal gap width and a maximal gap width.
8. The forming device as claimed in claim 7, wherein the inner former element can be fixed between the characteristic positions in at least one intermediate position.
9. The forming device as claimed in claim 8, wherein the inner former element can be fixed in any intermediate position.
10. The forming device as claimed in claim 8, wherein the inner former element can be fixed in one of multiple discrete intermediate positions.
11. The forming device as claimed in claim 8, wherein screening is provided which defines the intermediate positions.
12. The forming device as claimed in claim 1, wherein each inner former element is operatively connected to an actuator, in order to generate movement relative to the reforming edge.
13. The forming device as claimed in claim 1, wherein the reforming edge has at least two reforming edge portions with a strong curvature, wherein an inner former element has an inner former surface extending over the at least two reforming edge portions with a strong curvature.
14. The forming device as claimed in one of claims 1 to 13, which comprises at least two forming elements which are movable relative to one another for adjusting the tubular cross section being produced, said forming elements each having a reforming edge portion with a strong curvature, wherein in the region of the reforming edge portion with a strong curvature of each forming element, an inner former element which is movement-coupled with the forming element is arranged.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The invention is explained in greater detail below with the help of exemplary embodiments and associated drawing figures. In the drawings
[0027] FIG. 1 shows a forming device according to the invention with inner former elements by comparison with a state-of-the-art forming device with a filler tube;
[0028] FIG. 2 shows a forming device of the proposed kind according to a first exemplary embodiment in a perspective view;
[0029] FIG. 3 shows a side view of the forming device according to FIG. 2 with the inner former elements in two characteristic positions;
[0030] FIG. 4 shows the characteristic positions of the inner former elements of the forming device from FIGS. 2 and 3 as a perspective view;
[0031] FIG. 5 shows geometric relations in a first characteristic position (working position),
[0032] FIG. 6 shows geometric relations in a second characteristic position (maintenance position),
[0033] FIG. 7 shows a forming device of the proposed kind according to a second exemplary embodiment as a perspective view;
[0034] FIG. 8 shows a perspective detail view of the forming device according to FIG. 5;
[0035] FIG. 9 shows the characteristic positions of the inner former elements of the forming device from FIGS. 5 and 6 as a perspective view;
[0036] FIG. 10 shows examples of possible embodiments of the inner former elements.
DETAILED DESCRIPTION
[0037] FIG. 1 represents in the upper drawing FIG. 1A a forming element 12 of a forming device 1 according to the invention with an inner former element 5. For comparison, the lower drawing FIG. 1B shows a forming element 12 of a state-of-the-art forming device 1 known per se with a filler tube 8 which projects horizontally by the amount F into the prism part of the forming device 1, so that the tubular cross section is kept open while the tube is filled with the packing material, i.e. in order to prevent the tubular cross section from collapsing. A direct comparison between the drawing FIGS. 1A and 1B with one another shows that the inner former element 5 does not project into the tubular cross section, but only has a direct geometric operative relationship with the reforming edge 4 of the forming element 12, in that a comparatively narrow gap remains between the inner former element 5 and the reforming edge 4, the gap width of which is only approx. two to three times the thickness of the material web in the exemplary embodiment, as a result of which the reforming of the material web into a closed cross section by the reforming edge 4 and the inner former element 5 is carried out jointly. According to the arrangement of the inner former element 5 relative to the forming element 12, this effect is found, in particular, in the reforming edge portion with a strong curvature 42, in which the inner former surface 51 of the inner former element 5 is arranged relative to the reforming edge 4.
[0038] The forming device is configured in such a manner that it is designed for producing a rectangular tubular cross section. The reforming edge 4 therefore has reforming edge portions with a slight curvature 41 and reforming edge portions with a strong curvature 42. The inner former elements 5 in this case are arranged in such a manner, and their inner former surfaces 51 are formed in such a manner, that they follow the contour of the reforming edge 4 in the region of the corners of the tubular cross section, and therefore in reforming edge portions with a strong curvature 42, so that they act jointly with the reforming edge 4 to reform the material web guided through between them. The inner former elements 5 are movably arranged relative to the reforming edge 4 in such a manner that the gap width between the inner former surface 51 and the reforming edge 4 is adjustable. This is achieved in that the inner former surface 51 forms an acute angle α with the prism surface of the forming device relative to a longitudinal axis of the prism surface, i.e. the transport direction of the packing material, and the inner former element 5 is movable in the direction of this longitudinal axis. Through this configuration, the adjusting range ΔA of the inner former element 5 in the transport direction of the packing material is always greater than the change ΔG in the gap width between the inner former surface 5 and the reforming edge 4 which it causes:
ΔA=ΔG/sin α
[0039] FIGS. 2 to 6 show in different representations an overall view of a first exemplary embodiment of a forming device 1 of the proposed kind as a perspective view, the forming device with two characteristic positions of the inner former elements in side view and in perspective view, and the geometric relations on the forming device in both characteristic positions. Two forming elements 12, which are formed in such a manner that a material web guided over them is reformed into a tubular cross section, are arranged on a base plate 11. Lying on the base plate 11, items which are to be packed can be pushed into the formed tubular cross section. Before the start of the reforming region, front guide elements are therefore arranged on the base plate 11, which guide elements limit the transport path of the items being packed. Rear guide elements 13 are arranged on the base plate 11 behind the two forming elements 12, said guide elements guiding the finally packed items along the transport path. Viewed in the transport direction, two inner former elements 5 are arranged between the front guide elements 13 and the two forming elements 12, each an inner former element having an inner former surface 51 facing the reforming edge 4. Each of the two inner former elements 5 is mounted so as to be movable in the transport direction of the items being packed in a longitudinal hole in the base plate 11 and can be fixed in a desired position by means of a screw. In order to introduce a material web into the forming device, the inner former elements 5 can be moved manually into a characteristic position in which the gap width has a maximum dimension between the inner former surface 51 and the reforming edge 4 in each case. If this is achieved, the inner former elements 5 can likewise be moved into a second characteristic position manually and fixed, in which position the inner former surface 51 comes into a spatial relationship and operative connection with the reforming edge 4, which guides and conducts the material web, in particular in reforming edge regions with a strong curvature 42, and in this way contributes directly to the reforming of the material web into a tubular cross section.
[0040] FIGS. 5 and 6 show in various views the geometric relations at the proposed forming device. In FIG. 5 the inner former element 5 is located in a characteristic position, which is a working position. The adjusting range A1 of the inner former element 5 is maximal here, relative to the guide element 13. The gap width G1 in this position is minimal, so that the contribution of the inner former element 5 to the reforming of the material web into a tubular cross section is maximal. The inner former element 5 is in a characteristic position in FIG. 6 which is a maintenance position. The adjusting range A2 of the inner former element 5 is minimal here, relative to the guide element 13. The gap width G2 is maximal in this position, meaning that the contribution of the inner former element 5 to the reforming of the material web into a tubular cross section is minimal, unless this gap width has been chosen because a thicker material web is being processed, which requires a correspondingly greater gap width.
[0041] FIGS. 7 to 9 show in different representations an overall view of a second exemplary embodiment of a forming device 1 of the proposed kind as a perspective view, a perspective detail view of the forming device, and the characteristic positions of the inner former elements of the forming device as a perspective view. Two forming elements 12 which are formed in such a manner that a material web 7 guided over them is reformed into a tubular cross section are arranged on a base plate 11. Lying on the base plate 11, items which are to be packed can be pushed into the formed tubular cross section. Before the start of the reforming region, front guide elements 13 are therefore arranged on the base plate 11, which guide plates limit the transport path of the items being packed. Rear guide elements 13 are arranged on the base plate 11 behind the two forming elements 12, said guide elements guiding the finally packed items along the transport path. Viewed in the transport direction, two inner former elements 5 are arranged on the base plate 11 between the front guide elements 13 and the two forming elements 12, each inner former element having an inner former surface 51 facing the reforming edge 4. Each of the two inner former elements 5 is mounted so as to be movable in the transport direction of the items being packed in an elongate hole in the base plate 11. Two actuators 6 are arranged on the underside of the base plate 11 which are each operatively connected to one of the two inner former elements 5 in such a manner that the inner former elements 5 can be moved towards, or away from, the reforming edge, and can be thereby be fixed in a desired position. It is therefore possible for each inner former element 5 to move to and fix the desired characteristic position without manual intervention, for example determined by a machine controller.
[0042] FIG. 10 shows four examples of possible embodiments of the inner former elements 5, and also of the shape and arrangement of the inner former surfaces 51 thereof relative to the forming elements 12 and the reforming edge 4. The upper representation 10A shows in side view the viewing direction C and a plane of intersection D, which has been applied to the lower representations 10B to 10E, in order to explain possible configurations of inner former elements 5. Depicted schematically therein are the base plate 11 and the two forming elements 12, which are jointly configured to produce a rectangular tubular cross section, which are composed of reforming edge portions with a slight curvature 41 and reforming edge portions with a strong curvature 42. The embodiment according to the representation 10B corresponds to the form and arrangement of the inner former elements 5 of the exemplary embodiments already explained in FIGS. 2 to 6 and 7 to 9, in which two inner former elements 5 each extend along a reforming edge portion with a strong curvature 42 in the upper half of the tubular cross section. An alternative embodiment is depicted in representation 10C, in which an inner former element 5 has an inner former surface 51 which extends in the upper half of the tubular cross section over two corner regions with reforming edge portions with a strong curvature 42 and also a reforming edge portion with a slight curvature 41 arranged therebetween. A further alternative embodiment is shown in representation 10D, in which each inner former element 5 has an inner former surface 51, which extend in a lateral region of the tubular cross section in each case over two corner regions with reforming edge portions with a strong curvature 42 and also a reforming edge portion with a small curvature 41 arranged therebetween. Another alternative embodiment is shown in depiction 10E, in which two inner former elements 5, each with an inner former surface 51, extend along a reforming edge portion with a strong curvature 42 in each case in the upper half of the tubular cross section.
LIST OF REFERENCE SIGNS
[0043] 1 forming device [0044] 11 base plate [0045] 12 forming element [0046] 13 guide element [0047] 2 shoulder surface [0048] 3 prism surface [0049] 4 reforming edge [0050] 41 reforming edge portion with slight curvature [0051] 42 reforming edge portion with strong curvature [0052] 5 inner former element [0053] 51 inner former surface [0054] 6 actuator [0055] 7 material web [0056] 8 filler tube [0057] A adjusting range of the inner former element [0058] A1, A2 characteristic positions of the inner former element [0059] G gap width [0060] G1, G2 gap width in a characteristic position
