WO2013072305A1

WO2013072305A1 - Apparatus and method for feeding inserts during extrusion moulding

Info

Publication number: WO2013072305A1
Application number: PCT/EP2012/072483
Authority: WO
Inventors: Stephen FUGARD; Philip MILNES
Original assignee: Defendoors Ltd
Priority date: 2011-11-14
Filing date: 2012-11-13
Publication date: 2013-05-23
Also published as: GB201119539D0

Abstract

An extrusion moulding apparatus (10) comprising a hollow body (12); a die (18) coupled in use to the hollow body (12); and drive means (16) for driving mouldable material (20) through the hollow body (12) and the die (18). Insertion means (30) are provided for inserting objects (32) into the mouldable material (20) in the hollow body (12) or die (18). Disclosed is also a method for producing an extrudate (20) in which objects (32) are wholly or partially embedded in the mouldable material (20), spaced apart along its length.

Description

APPARATUS AND METHOD FOR FEEDING INSERTS DURING EXTRUSION MOULDING

Field of the invention The present invention relates to extrusion moulding. The invention also relates to protective strips for vehicles.

Summary of the Invention A first aspect of the invention provides an extrusion moulding apparatus comprising a hollow body; a die coupled in use to the hollow body; and drive means for driving mouldable material through the hollow body and the die, wherein the apparatus further includes insertion means for inserting at least one object, preferably a plurality of objects, into said hollow body or into said die. The arrangement is such that, in use, the or each object is inserted into the mouldable material in said hollow body or die.

Preferably, said insertion means is arranged to insert a plurality of objects into said mouldable material in successive respective insertion operations. Each insertion operation preferably involves the insertion of a respective one of said objects.

Preferably, said insertion means is arranged to insert the or each object into said hollow body or die in a direction that is non-parallel with the direction in which said drive means drives said mouldable material through said die. This allows the or each object to be inserted from a side of the extrudate as it is being formed. For example, said insertion means may be arranged to insert the or each object into said hollow body or die in a direction that is substantially perpendicular to the direction in which said drive means drives said mouldable material through said die. Preferred embodiments of the apparatus produce an extrudate in which a plurality of said objects are wholly or partially embedded in said mouldable material, spaced apart along its length.

Preferably, said insertion means is configured to determine, and optionally configurable to adjust, the extent to which the or each object is inserted into said hollow body or die, measured in a direction that is substantially perpendicular to the direction in which said drive means drives said mouldable material through said die.

Advantageously, said insertion means is arranged to insert the or each object at a location where, in use, the mouldable material is in a mouldable form, typically in liquid or molten form. As a result, the or each object can be inserted wholly or partly into the mouldable material before it sets or solidifies. Typically, the insertion location is located before the die (with respect to the direction of travel of the mouldable material), usually between the die and the drive means. To this end, the insertion means is arranged to insert said object(s) into said hollow body. Alternatively, the insertion means is arranged to insert said object(s) into said die, preferably adjacent the inlet of the die.

In preferred embodiments, said insertion means comprises a dispensing end through which the or each objects is dispensable. The insertion means typically comprises a guide for delivering objects to the dispensing end. Preferably, the guide comprises a magazine shaped and

dimensioned to hold multiple instances of an object.

The insertion means preferably also includes actuation means for actuating objects in order to effect dispensation from the dispensing end.

The actuating means may comprise any suitable mechanical actuating device, preferably an automated actuating device but alternatively a manually operable actuating device. For example, the actuating device may comprise resilient biasing means. Alternatively, the actuating device may comprise one or more manually operable or automated actuators, e.g. one or more ram. Alternatively still, the actuating device may comprise a pressurised gas device. The actuating device is preferably operable to cause one object to be dispensed at a time. A latch device may be provided for selectably retaining or releasing objects at the dispensing end. Preferably, the latch device is configured to release one object at a time.

Optionally, a controller is configured to link the operation of the insertion means with the operation of the drive means, for example to set the rate at which objects are dispensed depending on the speed at which the drive means conveys mouldable material towards the die.

In one embodiment, said at least one object comprises a plurality of magnets. A second aspect of the invention provides an extrusion moulding method for an extrusion moulding apparatus comprising a hollow body; a die coupled in use to the hollow body; and drive means for driving mouldable material through the hollow body and the die, wherein the method comprises inserting at least one object, preferably a plurality of objects, into said hollow body or into said die.

From a third aspect, the invention provides a protective strip for a vehicle, the protective strip comprising a length of extruded material in which a plurality of magnets are at least partly and preferably wholly embedded and spaced apart in a longitudinal direction. The magnets are preferably located adjacent a reverse face of said protective strip. Advantageously, said protective strip is formed using the apparatus of the first aspect of the invention and/or the method of the second aspect of the invention.

A fourth aspect of the invention provides a protective strip for a vehicle, the strip being formed, at least partly but preferably wholly, from a mouldable material mixed with magnetized material. The mouldable material preferably comprises plastics (polymeric material) or rubber. The magnetized material may comprise ferromagnetic, magnetic ferrite, or otherwise magnetized, particulate material.

A fifth aspect of the invention provides a method of manufacturing a protective strip for a vehicle, the method comprising mixing mouldable material and magnetised material; and moulding the mixed materials to form said strip. The strip may be formed by any convenient moulding process, e.g. extrusion moulding, but injection moulding is preferred.

A sixth aspect of the invention provides a protective strip for a vehicle comprising a magnetized strip embedded in the protective strip, preferably by co-extrusion of mouldable magnetized material with mouldable plastics, rubber, or other mouldable material. The magnetized strip is preferably located adjacent a reverse face of the protective strip.

A seventh aspect of the invention provides a method of manufacturing a protective strip for a vehicle, the method comprising co-extruding mouldable magnetized material with mouldable plastics, rubber, or other mouldable material to produce a magnetized strip embedded in the protective strip.

A eighth aspect of the invention provides a protective strip for a vehicle, one or more magnets being fixed to a reverse face of the strip, the magnets being covered by a layer of protective material, preferably of plastics or rubber.

Plastics or rubber are particularly suitable for use as the mouldable material, Thermoplastic Elastomer (TPE) rubber being preferred.

Further advantageous aspects of the invention will be apparent to those ordinarily skilled in the art upon review of the following description of preferred embodiments and with reference to the accompanying drawings.

Brief Description of the Drawings

Embodiments of the invention are now described by way of example and with reference to the accompanying drawings in which:

Figure 1 is a schematic view of an extrusion moulding apparatus embodying one aspect of the present invention;

Figures 2A and 2B respectively show a plan underside view and a side sectioned view of a protective strip embodying a further aspect of the invention;

Figures 3A and 3B respectively show an end view and a side view of a protective strip embodying another aspect of the invention;

Figure 4 shows an end sectional view of the protective strip of Figures 3A and 3B in situ;

Figure 5 is a plan view of the protective strip of Figures 3A and 3B shown in a rolled state; Figure 6 shows an end sectional view of an alternative protective strip embodying another aspect of the invention; and

Figure 7 shows a protective strip embodying any relevant aspect of the invention.

Detailed Description of the Drawings

Referring now to Figure 1 of the drawings there is shown, generally indicated as 10, an extrusion apparatus embodying one aspect of the invention. The apparatus 10 comprises a hollow body 12, which may be referred to as an extruder barrel, and which defines a chamber 14. The body 12 is coupled to a die 18, preferably a cross-head die. During use, mouldable material in liquid form is fed from the body 12 into the die 18.

Drive means, typically in the form of a screw driving mechanism 16 is arranged to convey mouldable material into the die 18 from the body 12. The drive means is usually automated, e.g. driven by a motor (not shown). Although only partly shown in Figure 1 , the body 12 and drive means 16 are typically part of a feed system, which usually includes a feed hopper (not shown), or other storage device, from which the mouldable material is conveyed into the die 18 by the drive means. In such cases, the driving screw 16 is conveniently located in chamber 14 (only part of the chamber 14 and screw 16 being shown in Figure 1 ).

Typically, the mouldable material is stored (e.g. in the feed hopper) in solid, particulate form, in which case the apparatus 10 may include or be co-operable with heating means (not shown) for melting the mouldable material. Usually, a heater is incorporated into, or co-operable with, the feed system in order to melt the mouldable material as it is fed through the chamber 14. For example, the mouldable material may be introduced into one end (not shown) of the chamber 14 in particulate from, whereupon the drive means 16 conveys it towards the die 18 past or through a heater (which for example may be arranged to heat the internal walls of the chamber). Alternatively, or in addition, the heating means can be provided by frictional forces within the chamber 14, in particular caused by the action of the screw 16. In any event, the mouldable material is in mouldable, typically liquid, form when it reaches the die 18. The die 18 is coupled to the body 12 such that the mouldable material can be pushed through the die 18. In use, the mouldable material, which is in mouldable, typically liquid, form, and usually heated, is fed from the body 12 through the die 18 to form an extrudate 20. The die 18 defines an internal passage 19 (which may be considered to form part of the chamber 14 during use) the shape of which determines the shape (and in particular the cross-sectional shape) of the extrudate 20. Typically, the molten mouldable material cools after it has passed through the die 18 such that the extrudate 20 is solid. A calibrator 21 may also be provided for controlling and cooling the extrudate 20 to maintain the desired shape. The shape and configuration of the calibrator 21 may be selected to correspond with the shape and configuration of the die 18. Optionally, cooling means (not shown) may be provided, e.g. in operative association with the calibrator 21 , to aid the cooling process. The mouldable material typically comprises plastics (sometimes referred to as polymeric material), rubber or metal. Thermoplastic Elastomer (TPE) rubber is preferred. It is typically material that melts when heated and solidifies when cools. Alternatively, a material that solidifies in response to the additional of one or more setting agents may be used. The apparatus 10 further includes insertion means 30 for inserting one or more objects 32 into the mouldable material, preferably multiple discrete objects. To this end, the body 12 is shaped to define an inlet 34 to the chamber 14. In the illustrated embodiment, the insertion means 30 comprises a mechanical device having a dispensing end 36 through which the objects 32 can be dispensed. The insertion device 30 is fitted to the inlet 34 such that the objects 32 can be delivered into the chamber 14 via the dispensing end 36. For example, the dispensing end 36 may be substantially flush with the internal surface of the chamber 14 or may project into the chamber 14. The device 30 typically comprises a guide 38 for delivering the objects 32 to the dispensing end 36. The guide 38 may take any suitable form, e.g. comprising a tube or other member shaped to receive objects 32 in a desired orientation and to deliver them to the dispensing end 36. Advantageously, the guide 38 comprises a magazine shaped and dimensioned to hold multiple instances of an object 32.

The insertion device 30 preferably also includes means for actuating the objects 32 in order to effect dispensation from the dispensing end. The actuating means may for example comprise any suitable mechanical actuating device (not shown), preferably an automated actuating device but alternatively a manually operable actuating device. For example, the actuating device may comprise one or more springs (or other resilient biasing means) arranged to urge the objects 32 towards and out of the dispensing end 36, and a latch device for selectably retaining or releasing the objects 32 at the dispensing end. The latch device is operable

(manually or automated) to retain the objects 32 in the insertion device against the bias of the biasing means, or to release the objects allowing them to be dispensed under the action of the biasing means. Preferably, the latch device is configured to release one object at a time. Alternatively, the actuating device may comprise one or more actuators, e.g. one or more rams, which may be manually operable but preferably automated, e.g. by electrical, hydraulic or pneumatic means. Alternatively still, the actuating device may comprise a pressurised gas device, e.g. an air-jet device. Irrespective of the type of actuating device used, the latch device described above may be provided to control the dispensing of the objects 32.

The apparatus 10 preferably includes, or is co-operable with, a controller for controlling the operation of the insertion device 30. For example, the controller may control the operation of the latch device and/or any automated actuator that may be provided. The controller may take any convenient form, for example a suitably programmed microprocessor, microcontroller or PLC.

In typical embodiments, the controller is also configured to control the drive means 16. Optionally, the controller may be arranged to link the operation of the insertion device 30 with the operation of the drive means 16, e.g. to set the rate at which objects 32 are dispensed depending on the speed at which the drive means 16 conveys the mouldable material towards the die 18.

The inlet 34, and therefore the dispensing end 36, is positioned such that the objects are insertable into the chamber 14 at a location where, in use, the mouldable material within the chamber 14 is in a mouldable form, typically in liquid or molten form. As a result, the objects 32 can be inserted wholly or partly into the mouldable material before it sets or solidifies. The insertion position is advantageously located such that the viscosity of the mouldable material is high enough to prevent leakage out through the insertion inlet 34 and low enough to enable insertion of the object 32 into the mouldable material. This position may vary depending on the configuration of the embodiment. Typically, however, the inlet 34 is located before the die 18 (with respect to the direction of travel of the mouldable material), usually between the die 18 and the end of the drive means 16. As such, the inlet 34 is formed in the body 12 (or barrel) of the apparatus 10. Alternatively, the inlet may be formed in the die 18, preferably adjacent the inlet of the die 18.

The depth at which the objects 32 are inserted into the mouldable material may be determined by the position of the dispensing end 36 (e.g.

depending on whether the dispensing end is flush with the internal surface of the chamber 14 or projects into the chamber 14) and/or the

configuration of the actuating device, which may be arranged to push the objects 32 into the chamber 14 beyond the dispensing end 36. In the illustrated embodiment, the insertion device 30 is arranged to insert the objects into the mouldable material such that they are substantially flush with the surface of the mouldable material. In some embodiments, the depth may be adjustable by, for example, adjusting the extent to which the dispensing end projects into the chamber 14 and/or by adjusting the extent to which the actuating device pushes objects into the chamber 14.

In the illustrated embodiment, the insertion device 30 is arranged to insert objects 32 in a direction that is substantially perpendicular to the

longitudinal axis of the chamber 14. Alternatively, the insertion device 30 may be arranged to insert objects 32 in a direction that is oblique with respect to the longitudinal axis of the chamber 14. More generally, the insertion device 30 is preferably arranged to insert objects 32 into the mouldable material in a direction that is oblique or substantially

perpendicular with respect to the direction in which the material is fed through the die 18 (which corresponds with the longitudinal axis of the extrudate 20). This allows objects 32 to be inserted into the material from the side, which enables the depth of the insertion to be selected. It also allows multiple discrete objects 32 to be incorporated into the extrudate 20 at spaced apart intervals along its length.

In the case where multiple objects 32 are to be inserted, the spacing between adjacent objects 32 may be determined by the dispensing rate of the insertion device 30 and the speed of flow of the mouldable material, either or both of which may be determined by and/or adjustable by, the controller. It is particularly preferred that the insertion device 30 is capable of inserting multiple discrete objects in a succession of insertion operations. Accordingly, it is preferred that the actuating means, including any actuating devices described herein, are operable to perform a

corresponding succession of actuating operations, e.g. under manual control or under control of the controller.

As the mouldable material cools, or otherwise solidifies, the objects 32 are retained in position by the material. In a preferred embodiment, the objects 32 are magnets and the mouldable material is preferably plastics or rubber. Thermoplastic Elastomer (TPE) rubber is preferred. The insertion device 30 is arranged to incorporate multiple magnets 32 along the length of the extrudate 20 at spaced apart intervals. The preferred arrangement is such that the magnets 32 are located adjacent a surface 40 of the extrudate 20, but embedded such that the magnets are not exposed.

The resultant extrudate is illustrated in Figures 2A and 2B in the form of a protective strip 120 for vehicles. The magnets 32 are located adjacent the underside of the strip 120 to facilitate removable magnetic attachment of the strip 120 to the side of a vehicle. Figures 3A, 3B, 4 and 5 illustrate a protective strip 220 embodying an alternative aspect of the invention. The strip 220 is formed, at least partly but preferably wholly, from a mouldable material mixed with magnetized material such that the strip 220 acts as a magnet. The mouldable material preferably comprises plastics (polymeric material) or rubber.

Thermoplastic Elastomer (TPE) rubber is preferred. The magnetized material may comprise ferromagnetic, magnetic ferrite or otherwise magnetized particulate material (e.g. powder, shavings or filings). In preferred embodiments, the mouldable material and magnetised material are mixed prior to being moulded to the desired shape and size. The strip 220 may be formed by any convenient moulding process, e.g. extrusion moulding, but injection moulding is preferred since this allows the strip 220 to have a non-constant cross-sectional profile.

The preferred strip 220 acts as a permanent magnet to allow removable magnetic attachment of the strip 220 to the side of a vehicle. When not in use, the strip 220 may be rolled up for convenient storage (Figure 5). Figure 6 shows an end sectional view of an alternative protective strip 320 in which mouldable magnetized material is co-extruded with mouldable plastics or rubber (or other suitable mouldable material) to create a magnetized strip 322 embedded in the protective strip 320. Optionally, the strip 320 is created using a die shaped to form one or more air cavities 324 in the strip 320. The magnetized strip 322 is located adjacent the underside of the strip 320 to facilitate removable magnetic attachment of the strip 320 to the side of a vehicle.

Alternatively still, a protective strip (not illustrated) for a vehicle may be provided with one or more magnets fixed to its underside, e.g. by adhesive, the magnets being covered by a layer of protective material, preferably of plastics or rubber. The material and thickness of the protective layer is selected to protect the vehicle from being marked by the magnet(s) while still allowing the magnet(s) to magnetically hold the protective strip to the vehicle. In the preferred embodiment, a plurality of magnets are spaced apart along the length of the protective strip.

Typically, the protective strips 120, 220, 320 are dimensioned to fit along the side of a vehicle, especially a car, extending at least partly along the or each side door. The strips may be any suitable length, e.g. between 300mm and 2000mm, usually between 1000mm and 1500mm. The preferred strips are approximately 1200mm in length. The width of the strip may for example be approximately 20mm to 50mm. The depth of the strip may for example be approximately 10mm to 50mm at its thickest point. Figure 7 shows the strip 120, 230, 330 in situ on a car 70.

It will be understood that apparatus embodying the invention are not limited to inserting magnets or creating protective strips for vehicles.

Moreover, the invention is not limited to the embodiments described and illustrated herein, which may be modified or varied without departing from the scope of the invention.

Claims

CLAIMS:

1 . An extrusion moulding apparatus comprising a hollow body; a die coupled in use to the hollow body; and drive means for driving mouldable material through the hollow body and the die, wherein the apparatus further includes insertion means for inserting at least one object into said hollow body or into said die.

2. An apparatus as claimed in claim 1 , wherein said driving means and said insertion means are co-operable in use such that said at least one object is inserted into said mouldable material in said hollow body or die.

3. An apparatus as claimed in claim 1 or 2, wherein said insertion means is arranged to insert a plurality of objects into said mouldable material in successive respective insertion operations.

4. An apparatus as claimed in claim 3, wherein said insertion means is arranged to insert a respective one of said plurality of objects into said mouldable material in each respective insertion operation.

5. An apparatus as claimed in any preceding claim, wherein said insertion means is arranged to insert said at least one object into said hollow body or die in a direction that is non-parallel with the direction in which said drive means is configured to drive said mouldable material through said die.

6. An apparatus as claimed in claim 6, wherein said insertion means is arranged to insert said at least one object into said hollow body or die in a direction that is substantially perpendicular to the direction in which said drive means is configured to drive said mouldable material through said die.

7. An apparatus as claimed in any preceding claim, wherein said insertion means is configured to determine the distance by which the or each object is inserted into said hollow body or die, measured in a direction that is substantially perpendicular to the direction in which said drive means is configured to drive said mouldable material through said die.

8. An apparatus as claimed in claim 7, wherein said insertion means is configurable to adjust said distance.

9. An apparatus as claimed in any preceding claim, wherein said insertion means is arranged to insert said at least one object at a location where, in use, the mouldable material is in a mouldable form, for example in liquid or molten form.

10. An apparatus as claimed in any preceding claim, wherein said insertion means is arranged to insert said at least one object at a location before the die with respect to the direction of travel of the mouldable material in use.

1 1 . An apparatus as claimed in claim 10, wherein said location is between the die and the drive means.

12. An apparatus as claimed in claim 10 or 1 1 , wherein said location is in said hollow body.

13. An apparatus as claimed in any one of claims 1 to 9, wherein the insertion means is arranged to insert said at least one object into said die, preferably adjacent an inlet of the die.

14. An apparatus as claimed in any preceding claim, wherein said insertion means comprises a dispensing end through which said at least one object is dispensable.

15. An apparatus as claimed in claim 14, wherein said the insertion means comprises a guide for delivering said at least one object to the dispensing end.

16. An apparatus as claimed in claim 15, wherein the guide comprises a magazine shaped and dimensioned to hold multiple instances of an object.

17. An apparatus as claimed in any one of claims 14 to 16, wherein the insertion means includes actuation means for actuating said at least one object in order to effect dispensation from the dispensing end.

18. An apparatus as claimed in claim 17, wherein the actuating means comprises a mechanical actuating device, preferably an automated actuating device or a manually operable actuating device.

19. An apparatus as claimed in claim 18, wherein said actuating device comprises resilient biasing means arranged to urge said at least one object towards a dispensing end of said insertion means.

20. An apparatus as claimed in claim 18 or 19, wherein the actuating device comprises one or more manually operable or automated actuators, for example one or more ram.

21 . An apparatus as claimed in claim 18, wherein the actuating device may comprise a pressurised gas device.

22. An apparatus as claimed in any one of claims 18 to 21 , wherein the actuating device is operable to cause said at least one object to be dispensed one at a time.

23. An apparatus as claimed in any preceding claim, further including a latch device for selectably retaining or releasing said at least one objects at a dispensing end of said insertion means.

24. An apparatus as claimed in claim 23, wherein the latch device is configured to release one object at a time.

25. An apparatus as claimed in any preceding claim, further including a controller configured to co-ordinate the operation of the insertion means with the operation of the drive means.

26. An apparatus as claimed in claim 25, wherein said controller is configured to set the rate at which objects are dispensed depending on the speed at which the drive means is configured to convey mouldable material towards or through the die.

27. An apparatus as claimed in any preceding claim, wherein said at least one object comprises a plurality of magnets.

28. An extrusion moulding method for an extrusion moulding apparatus comprising a hollow body; a die coupled in use to the hollow body; and drive means for driving mouldable material through the hollow body and the die, wherein the method comprises inserting at least one object into said hollow body or into said die.

29. A method as claimed in claim 29, further including inserting said at least one object into said mouldable material as it is driven through said hollow body or die.

30. A method as claimed in claim 28 or 29, further including producing an extrudate in which a plurality of said objects are wholly or partially embedded in said mouldable material, spaced apart along its length.