Mould for Furnace/Steam Bending of Plastic or Rubber Tubes and a Method of Producing It

Abstract

The invention relates to a mould for furnace/steam bending of plastic or rubber tubes, which comprises a shaping labyrinth (3). The shaping labyrinth (3) comprises at least two adjacent parts (I, II), each of which is provided at the end intended to connect to the adjoining part with a connecting flange (6) for joining the adjacent parts (I, II) of the labyrinth (3). The invention also relates to a method of producing a mould for furnace/steam bending of plastic or rubber tubes, in which is formed a shaping labyrinth (3), whose shape is subsequently adjusted according to the control master jig of the tube to be shaped. Afteradjustement of the shape of the labyrinth (3), the adjusted labyrinth (3) is scanned by a 3D scanner and subsequently a digital 3D model of the individual parts (I, II) of the labyrinth (3) is created for the 3D printer, whereupon at least one part (I, II) of the labyrinth (3) is printed on the 3D printer and the individual parts (I, II) of the labyrinth (3) are joined, the surface is blurred and, optionally, the adjacent parts (I, II) of the labyrinth (3) are additionally joined also undetachably, apart from being joined detachably.

Claims

1. A mould for furnace/steam bending of plastic or rubber tubes, which comprises a shaping labyrinth (3), characterized in that the shaping labyrinth (3) comprises at least two adjacent parts (I, II) connected to each other, each of which is at the end intended for this connection provided with a connecting flange (6) for being connected to the adjacent part (I, II) of the labyrinth (3).

2-9. (canceled)

Description

DESCRIPTION OF DRAWINGS

[0012] The invention is schematically represented in drawings, wherein FIG. 1 shows an exemplary embodiment of a mould with a labyrinth comprising two parts connected by flanges, FIG. 2 shows a sector of the labyrinth comprising three parts connected by flanges, FIG. 3 represents an exemplary embodiment of a flange for connecting the parts of the labyrinth and FIG. 4 shows an exemplary embodiment of a labyrinth formed by two parts and connecting eyes for attaching it to the mould frame.

EXAMPLES OF EMBODIMENT

[0013] The invention will be described with reference to an embodiment of a mould for furnace/steam bending of plastic or rubber tubes. The mould is in the functional state mounted on a frame of a furnace/steam bending device of plastic or rubber tubes, namely on a stiffener 1, which is mounted on the unillustrated frame of the device.

[0014] Struts 2 are fastened to the stiffeners 1. A shaping labyrinth 3, hereinfter only labyrinth, is attached to the struts 2 by means of connecting eyes 20 arranged along the length of the labyrinth 3. The labyrinth 3, in a known manner, serves to give the desired spatial shape to the unillustrated the tube being shaped in the elastic state of its material, i.e. the labyrinth 3 substantially acts as a tube-forming template.

[0015] The labyrinth 3 is longitudinally divided into at least two parts I, II, which are provided at mutually adjacent ends with connecting flanges 6, by which the two parts I, II are joined to each other by suitable means, preferably detachably by means of screw joints 7 (screws and nuts). Thus, if necessary, it is possible to produce and replace only worn or damaged parts I, II of the labyrinth 3 or to create very long labyrinths 3. The connecting flanges 6 are disposed in the bends of the labyrinth 3 and/or in straight parts of the labyrinth 3 between the bends.

[0016] To be able to adjust the mutual position of the adjacent parts 1 and II of the labyrinth 3, the connecting flanges 6 are provided with a system of connecting holes 60, adapted therefor, e.g., with different mutual spacings, or connecting holes 60 elongated in the direction of the circumference of the flanges 6, as shown in FIG. 3. The connecting holes 60 of the connecting flanges 6 are optionally provided with recesses 61 for the heads of the binder screws and/or for nuts.

[0017] In the embodiment shown in FIG. 2, at least one modification insert 62 is inserted between the connecting flanges 6 of the adjacent parts I, II of the labyrinth. By its shape and profile the modification insert 62 makes it possible to additionally adjust the length, turning or angle between the individual adjacent parts I, II of the labyrinth 3.

[0018] In the illustrated exemplary embodiment, the areas of connection of the individual adjacent parts I, II of the labyrinth 3 are after previous detachable connection of the adjacent connecting flanges 6, e.g., also joined undetachably, they are welded to each other, so that the adjusted and precise joints cannot be disconnected or changed.

[0019] The labyrinth 3 as such is created by some of the known methods, e.g., by first preparing a drawing of the tube to be shaped as a product for which the respective labyrinth 3 is intended. According to the spatial shape of the tube to be shaped, a tube having a comparable internal diameter, such as the outer diameter of the tube to be shaped, is used to form the labyrinth 3. The tube for forming the labyrinth 3 is spatially shaped on a sufficiently precise bending machine or on a hand bending machine, so that its spatial longitudinal shape of the inner cross-section corresponds to the spatial outer shape of the tube to be shaped. Subsequently, depending on whether it is steam moulding or moulding in a furnace, the ends of this semi-finished product are welded to the respective head of the future labyrinth, alternatively also to the nuts and holders 20. Next, paths for cutting a longitudinal slot in the tube are drawn on the tube and part of the tube surface is cut out to form the labyrinth 3. Then the labyrinth 3 is ground and polished. In the next step, the labyrinth 3 is attached to a strut 2 and a stiffener 1 and the shape of the labyrinth 3 is then adjusted according to the control master jig of the tube to be shaped. In this manner, one labyrinth 3 is formed.

[0020] The method of producing a mould according to the present invention consists in that, after adjusting the shape of the labyrinth 3 according to the control master jig of the tube to be shaped, the adjusted labyrinth 3 is scanned by a 3D scanner. Thus a digitized form of the adjusted labyrinth 3 is obtained, to which are afterwards added separating sites for dividing the labyrinth 3 into individual parts I, II, of the labyrinth 3, optionally also with connecting flanges 6 with holes 60 and at least one connecting eye 20. From such modified data, a digital 3D model of the individual parts I, II of the labyrinth 3 is subsequently created, which is usable for the 3D printer, and the individual parts I, II of the labyrinth 3 are then printed from a suitable material on a suitable 3D printer. According to a preferred embodiment, at least one part I, II is 3D printed, including at least one flange and/or at least one eye clamp 20. According to another embodiment, at least one part I, II of the labyrinth 3 is 3D printed and is additionally provided with at least one connecting flange 6 of at least one eye clamp 20, which are made in a separate production process, whether by using 3D printing technology or by conventional production methods, such as machining, cutting, etc. In another unillustrated example of embodiment, the labyrinth 3 with flanges 6 and connecting eyes 20 is formed by a combination of the preceding embodiments, e.g., some parts I, II of the labyrinth 3 are made using 3D printing technology, including the flanges 6 and connecting eye 20, other parts I, II of the labyrinth 3 are created on a 3D printer and the flanges 6 and the connecting eyes 20 are attached thereto additionally, etc.

[0021] The individual parts I, II of the labyrinth 3 are subsequently joined together, the surface is polished, or the adjacent parts I, II of the labyrinth 3 in addition to being connected detachably, are additionally joined together also undetachably, e.g., by welding, and the composite labyrinth 3 is attached to the frame of the strut 2 and the stiffener 1 and is ready for use. Optionally, at least one part I, II of the labyrinth 3 can be configured in this manner.

INDUSTRIAL APPLICABILITY

[0022] The invention is applicable in series production of plastic or rubber shaped tubes.