GB2088277A

GB2088277A - A Device for Producing Herringboned Belts

Info

Publication number: GB2088277A
Application number: GB8135843A
Authority: GB
Original assignee: Muller Wilhelm Herm & Co KG
Current assignee: Muller Wilhelm Herm & Co KG
Priority date: 1980-12-01
Filing date: 1981-11-27
Publication date: 1982-06-09
Also published as: FR2495048A1; JPS57150559A; DE3045235A1

Abstract

A negative mould 8 of herringbone configurations is disposed on the inner surface 7 of individual rings 6 which are arranged one above the other adjacent the inner surface 5 of an outer housing or casting mould 4. Each ring 6 has oblique indentations extending in only one direction and corresponding to half the maximum width B of the herringboned belt thus produced. Herringboned belts of different widths and shapes may be produced by division or cutting of the finished belt at appropriate positions. A one piece removable core 10 is provided with spaced longitudinal projections 16 onto which traction elements, which are incorporated into the moulded belts, are wound. Finished belts are easily removed from mould 4 after the core 10 is withdrawn upwardly while a lid 15 holds back the rings 6 and the moulded belts. <IMAGE>

Description

SPECIFICATION A Device for Producing Herringboned Belts This invention relates to a device for producing herringboned belts, that is belts having ridges in herringbone configuration, made of rubber of flexible plastics material having traction inserts, preferably made of steel wire, glass silk and wearresistant plastics material, such as polyamide, with a casting mould which consists of an outer housing and an inner core which can be introduced into the housing in which respect the distance between the outer walling of the core and the inner wall of the housing determines the thickness of the belt and in which respect one of these surfaces is provided with the negative mould of the herringbone ridges.

In the case of a mould of this kind which has already been proposed, the negative shape of the herringbone ridges is disposed on the outer surface of the core, in which the core is designed so as to be divisible, in order to be able to remove the finished belt. When this mould is used, after the belt material has cooled down or solidfied, the core together with the belt is extracted from the outer housing, in which respect the belt is now disposed firmly on the outer surface of the core.

The aforesaid secure attachment is additionally strengthened in that arranged on the outside of the core are the so-called winding noses which extend in the longitudinal direction of the core and which, prior to the application of the belt material are provided with respective wire doilings which subsequently form the traction inserts.

As a result of the firm attachment of the finished belt onto the core, it is exremely difficult to remove the belt from the core. This is only possible, in the previously proposed method because the core is designed so as to be divisible, that is it consists of individual segments which can be folded away towards the interior of the core, so that the belt secured on the outer surface of the core is released, and can at this stage be extracted from the negative mould of the herringbone ridges and be removed.

Besides the extremely expensive, complicated and trouble-prone construction of such a core, this arrangement also has the disadvantage that as a result of the division of the core, this type of mould leads to inaccuracies in the belt produced therewith. These inaccuracies may, in particular, be attributed to the fact that the core consisting of individual segments cannot, after repeated use, provide complete true-running accuracy of alignment of the ridges on the belt surface. During repeated use of the device, the original initial position of the core can never quite exactly be achieved again when the individual segments are placed into position.In particular, it is not possible to achieve the original position during reuse when contamination resulting from the nature of the belt material occurs, in which respect relatively slight contamination occurring between the individual core parts can lead to noticeable inaccuracies.

The object of the invention, is accordingly, to provide a method and a device, of the kind mentioned at the beginning, with which, whilst avoiding the above-mentioned disadvantages, true-running herringbone-ridged belts can be produced even when the mould is used repeatedly, in which respect properties of the mould with respect to wear must not have an effect on the accuracy of the belt produced.

In accordance with the invention, this object is achieved in that the negative mould of the herringbone ridges is disposed on the inside of individual rings which are arranged one above the other adjacent the inner surface of the outer housing of the mould, in which respect each ring has a width which corresponds to half the maximum width of the herringboned belt which can be produced with the device in accordance with the invention, and each negative mould of a ring has obligue indentations which extend only in an oblique direction corresponding to half the herringbone angle and in which respect the traction insert is applied to the core of the mould.

With this arrangement the result is acheived that the cast herringboned belt can, after being completed, be removed very easily from the mould, in that the core, which is smooth in the longitudinal direction, is withdrawn upwardly out of the outer housing, whereupon, possibly in conjunction with removal of a lid which holds back the rings and/or the finished belt, the finished belt can be folded inwards and thus extracted from the mould and removed upwardly.

At the same time, because in accordance with the invention the core preferebly consists of a single piece, it is ensured that even after repeated use of the mould the absolute accuracy of the core position with the corresponding accuracy of the belt produced therewith is maintained.

After the herringboned belt has been extracted from the mould, it is split up into individual strips, possibly of different widths, which may then for their part be turned inside out, so that, as is usually necessary for herringboned belts of this kind, the ridges lie on the inside.

The device in accordance with the invention has the further advantage that it makes possible the production of herringboned belts of different widths by use of the same rings widths. If, in the manner described, the oblique ridges correspond in one direction to half the maximum width of a belt that is to be produced and thus to the width of a ring, then, using the same rings, by division or cutting of the finished belt at a certain distance along a parallel set of ridges it is possible to produce herringboned belts of different widths. If, for example, the division or cutting occurs at half way along the ring width of the oblique ridge width respectively and the herringboned belt remains uncut along the line of separation between two rings, herringboned belts having half the maximum width are produced.If the division or cutting under the same pre-requisites is shifted towards the one or the other side, alternate narrow and wide herringboned belts are produced with one and the same operation. Further variations, for example the production of asymmetrically herringboned belts and also the use of rings of different widths, are readily possible.

The use of the rings which contain the negative moulds of the herringboned ridges has the advantage that the moulds can be produced very easily in an exact, neat manner.

The production of negative moulds on the inner surface of a cylinder usually presents certain difficulties. However, by splitting up the herringbone ridges onto two respective rings adjoining one another the herringbone tip does not need to be milled out with special tools, the miller has access to both sides, and in known 'per se' manner only rectilinear ridges need to be produced. The herringbone ridges are produced by the assembly of the individual rings. This necessitates the use of adjusting devices which ensure the repeated exact alignment of the rings with regard to one another both in the radial and circumferential direction. In order to facilitate radial alignment it is advantageous if the individual rings are provided, on their mutually facing surfaces, with encircling offsets or shoulders, which engage with adequate accuracy of fit over one another.In order to facilitate alignment in the circumferential direction, fitting pins, screws or the like can be provided which extend parallel to the ring axis and which are inserted into corresponding bores in the rings.

These fitting pins or screws can at the same time serve for connecting the rings to one another and/or the outer housing.

At the same time, these fitting pins or screws may serve to restrain the lid engaging over the gap between the rings and the core. The lid, in known 'per se' manner, serves for holding back the finished belt upon extraction of the core.

Insofar as winding noses are held to be expedient, in order to lay the traction inserts into the neutral axis of the belt or the vicinity thereof, these windings noses are disposed as longitudinal webs in known 'per se' manner on the outer surface of the core. This has the result that in the case of the finished and used belt the grooves corresponding to the winding noses are disposed on the outside of the belt. If the customary arrangement is used in which the spacing of the winding noses corresponds to the pitch of the ridges, it is advantageous to place the winding noses substantially in the centre of the ridges, in other words at that location in which a material accumulation of the belt occurs. The crosssectional reduction resulting from the presence of the grooves caused by the winding noses can thus not have a disadvantageous effect.

The invention will be explained in more detail hereinunder with reference to exemplified embodiments in the drawings.

Fig. 1 is a view, in detail of the surface of a portion of a herringboned belt, to which the invention is applied; Fig. 2 is a cross-section of one embodiment of the device in accordance with the invention; Fig. 3 is a detail of portions of the individual insert rings of the device shown in Fig. 2 in the wound-off state and seen from the inside; Fig. 4 is a section on the line IV/IV of Fig. 2; Fig. 5 is a portion of the section shown in Fig. 4 to a larger scale and makes clear the association of the winding noses, arranged on the core, with the ridges of the finished belt; and Fig. 6 is three schematic representations illustrating various possibilities of producing, with the device in accordance with the invention, belts of different shapes and widths.

Fig. 1 shows in detail a portion of the surface of a herringboned belt 1 made of rubber or flexible plastics material. The herringbone ridges of the belt 1 are designated by numeral 2. The belt 1 is provided with traction inserts 3 made of steel wire, glass silk or wear-resistant plastics material, such as polyamide.

A practical embodiment of the device of the invention, as shown in Fig. 2 is capable of operating to produce the belt shown in Fig. 1. This device consists of an outer housing 4 forming a casting mould. and, provided on the inner surface 5 of the outer housing, several individual rings 6 which are arranged one above the other and which bear on their respective inside surfaces 7 the negative mould 8 of the herringbone ridges 2.

Each ring 6 has, in this respect, a width B which corresponds to half the maximum width B, (see Fig. 1 i of the herringboned belt which can be produced with the device in accordance with the invention.

The housing 4 has a central guide 9 for a core 10 in which is formed in one piece, in which respect the guide 9 engages into a bore 11 of the core 10. The herringboned belt is produced in the gap 13 between the outer surface 14 of the core and the mould 8 of the rings 6. This gap is covered by a lid 15 which connects the outer surface 14 of the core 10.

The outer surface 14 of the core 10 is, moreover, provided with winding noses 16 which carry the traction insert 3 (see also Fig. 5) and ensure that this is enclosed by the material of the A belt. The rings 6 are aligned both in the radial and circumferential direction, in which respect alignment in the radial direction is effected by steps or shoulders 17 which are arranged on the mutually-facing surfaces of the rings 6. In the circumferential direction the rings 6 are adjusted with regard to one another by fitting pins or screws 18, indicated schematically in Fig. 2, which engage through the rings 6 and can also serve for the connection of the rings 6 to one another and/or to the outer housing 4. At the same time the pins or screws 18 can serve for the fastening of the lid 15.

Fig. 3 shows a detail from the individual insert rings 6 in accordance with Fig. 2 in the wound-off state seen from within. It is apparent from Fig. 3 that the inner surfaces 7 of the rings 6 have the negative moulds 8 for the herringbone ridges, in which respect each negative mould of a ring 6 has oblique ridges which extend in only one oblique direction corresponding to half the herringbone angle. In this way the inner ridges can, as required, be produced easily and perfectly, since the ridges can be accurately milled from both sides.

Fig. 4 is a section on line IV/IV of Fig. 2, and reveals the distribution of the winding noses 1 6 over the circumference of the core 10, in which respect the spacing of the winding noses may be approximately equal to the pitch of the ridges on the belt. in the case of one particular embodiment, for example, the circumferential length on the core may be about 660mm.

Independently thereof, with the device in accordance with the invention, belts having lengths between 50 and 1500mm may readily be produced and further variations upwards and downwards with respect to these exemplary figures are possible.

Fig. 4 also indicates the distribution of the fitting pins or screws 18 over the circumference of the rings 6. By means of these pins or screws 18, the rings 6 are aligned with regard to one another in the circumferential direction.

Fig. 5 shows a detail from Fig. 4 on an enlarged scale with part of a finished belt 19, in which respect, the spacing of the winding noses 16 corresponds to the pitch of the ridges. The winding noses 16 arranged as longitudinal webs on the outside of the core 10 produce grooves 20 in the finished belt, in which respect, in the arrangement shown in Fig. 5, the winding noses 16 lie approximately in the centre of each respective ridge 21, in other words at hat location in which a material accumulation of the belt already occurs. The cross-section reduction, caused by the grooves 20 of the winding noses, of the belt can consequently not have a disadvantageous effect in the case of this arrangement.

Fig. 6 shows schematic representations of various possibilities of producing, with the device in accordance with the invention, different belt widths and shapes. As shown in Fig. 6a, four rings 6 of the type illustrated in Figs. 2 and 3, may be used to produce a herringboned belt having an entire width B2 which can be split up in various ways. A quarter of the total width B2 corresponds to the width B, which is at the same time half the maximum width B, of the belt which can be produced with the device in accordance with the invention. If the completed belt 22 having the entire width B2 is now split along the line 23, then two herringboned belts or strips 24 and 25 arise, each having the maximum width B,. These two belts or strips, 24, 25 are illustrated in Fig. 66.

The belt 22 removed from the device and having the total width B2 may alternatively be split along the lines 26, whereby three narrower belts or strips 27 and two edge strips 28 arise, as shown in Fig. 6c. Since the production of the edge strips 28 is not meaningful, it is advantageous, for such a division, to use in the device additional edge supplementing rings 29, which supplement the edge strips 28 to form two additional complete herringboned belts or strips.

Depending on where the cuts 26 are placed, alternately wide and narrow belts or strips or even asymmetrically herringbone belts of strips can be produced in a single operation.

Claims

1. A device for producing herringboned belts made of rubber or flexible plastics material having traction inserts, preferably made of steel wire, glass silk and wear-resistant plastics material, such as polyamide, with a casting mould which consists of an outer housing and an inner core which is insertable into the housing, in which respect the distance between the outer wall of the core and the inner wall of the housing determines the thickness of the belt and in which respect one of these surfaces is provided with the negative mould of the herringbone ridges, characterised in that the negative mould of the herringbone ridges is disposed on the inside of individual rings which are arranged one above the other adjacent the inner surface of the outer housing of the mould, in which respect each ring has a width which corresponds to half the maximum width of the herringboned belt which can be produced with the device in accordance with the invention and each negative mould of a ring has oblique indentations which extend only in an oblique direction corresponding to half the herringbone angle, and in which respect the traction insert is applied to the core of the mould.

2. A device as claimed in claim 1, characterised in that the rings, and a gap between the rings and the core are covered by a lid which is arranged on the housing.

3. A device as claimed in claim 1 or 2, characterised in that the core is formed in one piece.

4. A device as claimed in any of the preceding claims characterised in that adjusting devices are provided with which the rings are alignable both in the radial and circumferential direction.

5. A device as claimed in claim 4, characterised in that the individual rings are provided, on their mutually facing surfaces, with encircling offsets or shoulders which engage over one another in an exactly fitting manner in order to facilitate radial alignment of said rings.

6. A device as claimed in claim 4, characterised in that fitting pins, screws or the like are provided which extend parallel to the ring axis and which are inserted into corresponding matching bores in the rings in order to facilitate circumferential alignment of said rings.

7. A device as claimed in claim 6, characterised in that the fitting pins or screws serve at the same time for connecting the rings to one and another and/or to the outer housing.

8. A device as claimed in claim 6 or 7, characterised in that the lid which engages over the gap between the rings and the core is restrained by the fitting pins or screws.

9. A device as claimed in any of the preceding claims characterised in that winding noses, formed as longitudinal webs, for carrying the traction inserts are arranged on the outer surface of the core.

10. A device as claimed in claim 9 characterised in that the spacing of the winding noses corresponds to the pitch of the ridges and in that the winding noses lie substantially in the centre of each ridge.

11. A method of producing herringboned belts with a device in accordance with any of the preceding claims characterised in that, by varying the position of division or cutting along an oblique ridge, herringboned belts or strips of different widths are produced.

12. A method as claimed in claim 11, characterised in that herringboned belts or strips having half the maximum width are produced when division or cutting of the belt produced with the device occurs half way along the ring width or the oblique ridge width respectively, whilst the herringboned belt remains uncut along the line of separation between two rings.

13. A method as claimed in claim 12, characterised in that alternate narrow and wide herringboned belts or strips are produced with one and the same operation, when division or cutting of the belt is shifted towards the other side.

14. A method as claimed in claim 12 or 13 characterised in that asymmetrically herringboned belts or strips may be produced by appropriate positioning of the division or cutting of the belt.

1 5. A device for producing herringboned belts substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.