GB2330551A

GB2330551A - A method of moulding a hurley

Info

Publication number: GB2330551A
Application number: GB9823006A
Authority: GB
Inventors: Gary Joseph Fahey; Conchur O'bradaigh; Cornelius Joseph Stack
Original assignee: DNA Prep Galway Ltd
Current assignee: DNA Prep Galway Ltd
Priority date: 1997-10-21
Filing date: 1998-10-21
Publication date: 1999-04-28
Also published as: GB9823006D0

Abstract

There is provided a moulded hurley (1) of thermoplastics material have a core portion, a net-like covering over the core formed from flexible reinforcing material (3) and an outer layer of plastic material (4) encapsulating the core. The reinforcing material (3) is in the form of a sock which has a variable angle of weave and may have a different diameter along its length to ensure that the reinforcing is at the correct angle to the hurley handle and the bas at each position along the hurley to provide the correct flexibility and strength. In one method of manufacture, a sock of composite yarn is mounted on a bladder which is placed inside a mould. The bladder is inflated and the mould heated to melt the thermoplastic material of the composite to impregnate the fibres of the composite. In another, a sock made of reinforcing material is placed into the mould embracing an injection tube. A foamed plastics material, for example, while the tube is withdrawn. The plastics expands under heat to force the sock outwards.

Description

A Moulded Hurley" Introduction The present invention relates to the manufacture of playing sticks and in particular to the construction and manufacture of a hurley by a moulding process.

The invention relates to composite hurleys and those manufactured from a plastics material usually having a core portion, a net-like covering over the core formed frorn lengths of flexible reinforcing material and an outer layer of plastics material encapsulating the core and the reinforcing materiaL The core and outer layer of plastics material may be all of the one material.

The term "hurley" in this specification includes not alone the conventional hurley for playing hurling, camogie and shinty, but also sticks for the playing of hockey and other such games, all of which have essentially an elongate shaft or handle, terminating in a playing or ball striking head or blade. However, the invention is particularly directed towards hurley sticks. The term "bas" is more commonly used to identity the striking head of a hurley and is thus used in this specificaFion.

In general all such playing sticks have an elongate handle which defines a shaft axis and then a bas axis which extends intermediate the top and bottom of the blade to intersect the shaft wcis.

There are serious problems in the provision of good huriey sticks at present.

Obtaining, for example, a sufficient quantity of well grown ash is becoming difficult, indeed the same problem of obtaining suitable natural material applies to many other forms of playing stick Not alone are the actual raw ingredients difficult to obtain, but it is becoming increasingly difficult to get craftsmen to spend the time and effort on producing a hurley stick that will have the connect grain formation on its bas and handle. The cratsmen are now in an increasingly short supply. It is becoming more and more difficult for players to obtain high quality hurley sticks, It is well known for many years to provide a construction of hurley comprising a core of foamed plastics material covered with a moulded on layer of a synthetic fibre material used for reinforcing. Such a core may be manufactured from a foamed polyurethane and the reinforcing fibre material may be fibreglass, carbon fibre, polyester materials or indeed any synthetic fibre materials such as sold under the Trade Marks KEVLAR, TUIARON and NYLON. All of this is well known.

In this specification the term 7composite yarn is used to encompass cornmingled or co-blended yarn of reinforcing fibres and thermoplastic polymer fibres and also mixtures of reinforcing fibres and powders of thermoplastics polymers. Such yams are well known and are described for example in European Patent specification No 466618 (Schappe).

It is also, for example, known to reinbme such hurleys and hockey sticks with a mesh of material. It is known, for example, from US Patent Specification No.

5,050,878 (Deleris) that if a mesh is first woven of a constant weave angle when it is placed over a core or indeed if it is moulded into a hurley stick which has varying thicknesses along its length, that the fibre angle will effectively vary over the length of the hurley sticK.

Unfortunately known constructions of moulded hurleys have heretofore not been sufficiently like conventional hurleys in that they have not played in the same way as a conventional hurley and have thus been unacceptable to players. The same flexibility and toughness has not been present.

The term "thermoforming" is used in this specification to cover any forking which uses heat, whether it be moulding, such as. for exaniple, of thermosetting materials, or the general heat formation by the foarning of plastics materials, whether they be thermosetting or not or a mixture of both.

The present invention is directed towards providing an improved construction of such a hurley.

Statements of Invention According to the invention, there is provided a method of moulding a hurley having a handle terminating in a bas comprising the steps of: preparing a net-like sock of reinforcing material having a variable angle of weave; inserting the sock info a mould having the necessary cavity shape to form ths hurley; introducing a thermo-forming plastics material into the mould; and forcing the sock outwards to assune a position close to the outer surface of the mould cavity.

The great advantage of having a variable angle of weave is that it is possible to customise any hurley to a particular player or indeed to a class of players. It is possible to vary the flexibility as desired.

In one embodiment of the invention the diameter of the sock is also variable along its length.

In another embodiment of the invention the sock is woven on a mandrel having the required intemal shape of the finished sock.

Ideally additional longitudinally extending fibres are introduced into the mould.

In a further embodiment of the invention additional orthogonally extending fibres are introduced into the mould.

Ideally the additional fibres form part of the sock In one embodiment of the invention the reinforcing material is a composite yam and in which the steps are performed of prior to inserting the sock into the mould, placing the sock over an inflatable bladder; and inflating the bladder while heating the mould to force the sock outwards to form an outer skin surrounding a hollow core.

Ideally the composite yarn is formed from reinforcing fibres and thermoplastic fibres, or from reinforcing fibres and powdered thermoplastics, mixed or blended together.

In another embodiment the plastics material is an engineering polymer.

Ideally the plastics material is an engineering polymer chosen from polyamidel 2 (PA-I 2), polyamidefi (PA4), polyethylene-terephthalate (PET) or polypropylene (PP), or other suitable polymers.

Ideally the reinforcing fibre is chosen from aramid, glass, carbon or polyethylene.

In one embodiment of the invention an infill material is introduced into the hollow core.

Ideally the density of the infill material is varied from bas to handle.

Preferably the density of the infill material is greatest at the bas and decreases from the bas to the outer end of Ifle handle.

Ideally infill material is a foarned plastics material.

In another embodiment of the invention the bladder is dirnensioned such as to vary the thickness of the surrounding thermoplastics material in the mould.

In a further embodiment of the invention additional thermoplastics material or extra composite yams are added to vary the wall thickness of the formed hurley.

Ideally the bladder is removed after the outer skin has been forrned.

In one embodiment of the invention the steps are performed of prior to inserting the sock into the mould, placing the sock over an injection tube; and introducing a foaming plastics material into the mould, while withdrawing the injection tube.

Ideally the angle of weave is so chosen as to have the angle to the shaft axis along the shaft of between 15 to 45 and preferably between 33 to 370.

Ideally the angle of weave is so chosen as to have the angle to the bas axis along the bas of between 45 to 75" and preferably between 47 to 55V.

Detailed Desenptinn of the Invention The invention will be more clearly understood from the following description of an embodiment thereof given by way of example only with reference to the accompanying drawings and graphs in which: Fig. 1 is a perspective view of the hurley according to the invention; Fig. 2 is a detailed sectional view of portion of the hurley of Fig. 1; Fig. 3 is a plan view of a reinforcing material when applied to the hurley as indicated by the arrow 111 in Fig. 1: Fig. 4 is a plan view of the reinforcing material wlen applied to the hurley as indicated by the arrow IV of Fig. 1; Fig. 5 is a plan view of a hurley identifying the various portions of a hurley; Fig. 6 is a diagrammatic view of a braiding machine used in accordance with the invention; Fig. 7 is an end crosssectional view of a composite yarn used in the manufacture of the hurley; Fig. 8 is a graph showing the difference in stiffness in the hurley against the fibre angle; and Fig. 9 is a graph showing the stiffness variations of two hurleys described herein Before refemng to the drawings, it is important to appreciate that it has been known for some considerable time that an important element in controlling the flewbility and indeed providing the necessary strength to the hurley is by controlling the fibre angle or angle of the reinforcing material with respect to the shaft axis. Conventionally the way to do this is to use a constant diameter and constant angle braided sock or other reinforcing material whether it is actually in the form of a sock or not on the core of the hurled. This method does not allow full control of the fibre or reinforcing angle as it conforms to the mould in exactly the same manner each time. This is discussed in more detail below.

Referring to the drawings and initially to Figs. 1 to 4 thereof, there is illustrated a hurley indicated generally by the reference numeral 1, having an inner core 2 of a foamed plastics material covered by a braided material in this case an aramid reinforcing material 3 such as sold under the Trade Mark KEVLAR, all of which is encapsulated in an outer plastics cover 4. The braided reinforcing material 3 is so arranged so that its fibres 5 are at a smaller angle to the shaft axis adjacent the top of the handle such as at Ill than at the blade such as illustrated at IV. The smaller fibre angle gives a stiffness to the handle section and the larger fibre angle on the lower blade region helps to avoid splitting by providing transverse strength and toughness.

Referring now to Fig. 5 there is illustrated various positions on a hurley.

To manufacture a sock for use according to the present invention, firstly a solid mandrel 10 is made of the same general shape as the finished hurley, but will be slightly less than the outer dimensions of the hurley Then the mandrel 10 is placed in a braiding machine 15 as illustrated in Fig. g 6 and the braiding machine which rotates in the direction of the arrow A, as well as moving back and forth in the direction of the arroW B is used to form a braided sock of reinforcing material 3. Then the sock is removed for subsequent use.

Another method of providing a sock which will also allow complete control of the fibre architecture and ensure that the correct fibre angles are achieved in the hurley is the production of a constant diameter variable angle of weave sock. Essentially, this would be the same as a conventional braiding without the use of a formed mandrel, but which would allow the correct angle of the reinforcing material or tire to be achieved at any position along the hurley.

The sock is manufactured from various reinforcing material and in its simplest it can be a sock of suitable reinforcing material such as defined above, namely an aramid reinforcing material 3. In certain other embodiments as will be described hereinafter, the reinforcing material forming the sock also forms the outer skin. In this case the reinforcing material is a composite yarn such as illustrated in Fig. 7.

Referring now to Fig. 7 there is illustrated a composite yarn indicated generally by the reference numeral 20 formed from a plurality of reinforcing fibres 21 and thermoplastic fibres 22 which may be commingled. The composite yam 20 would obviously be denser than shown. The reinforcing fibres 21 can be longitudinally arranged or twisted around the thermoplastic fibres 22. The reinforcing fibres 21 would generally be continuos or long aligned high performance fibres such as ararnid, glass carbon or polyethylene commingled with polymer fibres such as polyarnide-12 (PA12), polyamide-6 (PA-6), polyethyleneterephthalate (PET) or polypropylene (PP), or other suitable polymers, all of which are well known. It is also possible to produce a commingled thermoplastic yarn, or composite yarn, in which the thermoplastic polymer is in the form of a powder. which is mbced with the reinforcing fibres, in one case with each yam (of reinforcing fibres and thermoplastic powder) enclosed in a sheath of plastic material. The composite yarn 20 can be formed in many ways, however, it is important to appreciate that in one process there is no need for a composite wrarn, while in another process according to the invention it is essential.

When a constant woven angle is produced, and the constant angle sock used to cover the hurley, a new fibre angle is produced at each position on the hurley, as shown in Table 1 below, for locations 1 to 7. This fibre angle is the angle the fibre subtends with the shaft axis. In the particular example a 50 mm diameter sock was produced having a weave angle of 45n, Table I Sock diameter (mm) Hurley diameter Hurley angle PcsWion (1-7) mm (degrees) 50 25.9 21.5 1 50 25.8 21.4 2 50 27.1 22.5 3 50 29.3 24.5 5'4 4 50 33.4 28.2 50 39.8 34.3 6 50 50.6 45.7 7 Referring now to Table t it will be seen that at position 1 the actual angle that the fibre has with the shaft axis is 21.5", though originally woven at 45= The problem is for this particular construction of sock and this particular size of huriey, the angles will remain the same as given above and cannot be altered.

The only way to alter the final hurley angles with a constant weave, constant diameter sock is to use a different angle on the initial sock i.e. 43 instead of 45" or use a different diameter of sock, for example 54 mm in place of 50mm.

However, since the hurley shape dictates the final fibre angle, it Is thus not possible to fully control the fibre angle. Two examples of hurleys are now given.

Table 2 Dlmenslons of Braided Hurleys, Hurley 1 (Hurley 2).

Cross- Thickness Width (mrn) Circumference Equivalent section (mm) (mm) Diameter (mm) 1 21.1(21.2) 29.8 (29.2) 81.5 (80) 25.9 (25.5) 2 19 (20.8) 31.3 (30.4) 81(81) 25.8 (25.8) 3 17.8 (18.9) 34 (32.4) 85 (84) 27.1(26.7) 4 17 (17.1) 38.6 (37.4) 92 (90) 29.3 (28.6) 5 16.7 (15.5) 45.7 (43.6) 105 (100) 33.4 (31.8) 8) 6 15.8 (14.1) 56 (54.8) 125 (120) 39.8 (38.2) 7 16.3 (16.2) 73 (73) 159 (157) 50.6 (50.0) The above Table 2 illustrates the dimensions of two hurleys, namely hurley No. I and hurley No. 2. Table 3 shows the change in fibre angle for the respective hurleys. It was found, as one would expect, that hurley No. 1 was more flexible and less stiff than hurley No. 2.

Table 3 Change in Fibre Angle

Section Hurley 1 Hurley 2 (fibre angle) (fibre angle) 1-2 48 20 2-3 54 28 3-4 57 28 4-5 60 36 5-6 67 40 6-7 75 50 Then a constant diameter variable angle sock was produced.

We have found that the angle of weave will vary to achieve an angle to the shaft axis of from 15" to 45 depending on the volume of reinforcing material used and the degree of flexibility required. Ideally the angle of weave is chosen to have the angle to the shaft axis of between 33 to 37 . Similarly, our experiments have shown that the angle of weave is selected to achieve an angle between 45 and 75" to the bas axis along the bas, preferably 47 to 55 .

Table 4 Hurley No. 1 - Constant Diameter Sock Known diameter Diameter Known angle Degrees Position (sock) (mm) (hurley) mm (degrees) 30 25.9 48 59.4 1 30 25.8 54 70.2 2 30 27.1 57 68.2 3 30 29.3 60 62.5 4 30 33.4 67 55.8 5 30 39.8 75 467 6 30 50.6 75 34.9 7 Table 4 above shows the constant diameter variable angle sock required to give the fibre angle patterns for hurley No. 1 as illustrated in Table 3. This table shows that a 30 mm diameter preformed sock with the angles varied in accordance with the table will give the required known fibre angle, i.e. the fibre angles taken from Table 3 for hurley No. 1.

Table 5 Honey No. Constant Diameter Sock Known diameter Diameter Degrees Position (sock) (mm) (hurley) mm 45 25.5 37.1 1 45 25.8 55.0 2 45 26.7 52.3 3 45 28.6 67. 6 4 45 31.4 87. 5 45 38.2 64.5 6 45 50 43.6 7 Table 5 illustrates that using a 45 mm constant diameter sock with varying fibre angles woven as shown will give the same fibre angles as given in Table 3 for hurley No. 2.

Fig. 8 illustrates the stiffness versus fibre angle of the two hurleys, while Fig. 9 illustrates the different stiffness at the same relative positions for the two hurleys.

In a method of forming a hurley according to the present invention a woven sock is mounted on an inflatable bladder and in this embodiment the woven sock is manufactured from a composite yam. The inflatable bladder carrying the sock is inserted into a conventionai mould. The mould is sealed, the bladder Is inflated and the mould is heated. Then the thermoplastic material forming part of the composite yarn melts and impregnates the reinforcing fibres, thus forming an outer skin around the bladder and against the interior walls of the mould, there is thus formed a hurley. The mould is cooled and the hurley removed in conventional manner. The bladder is then removed from the hurley and an infill material is introduced into the hurley. Ideally the density of the infill material is varied from bas to handle, this may be done by providing weights, or by providing a foamed plastics material of different density. Ideally the density of the infill material is greater at the bas and decreases from the bas to the outer end of the handle. The most useful infill material is indeed a foamed plastics material which can be either heat foamed or cold tamed. There is no limitation on the core material.

It will be appreciated that the bladder maybe left in the hurley, in which case It is a disposable bladder or as in the embodiment above, it may be removed.

Similarly the dimensions of the bladder may be altered so as to vary the thickness of the surrounding thermoplastics material in the mould and thus to provide an outer skin of different thickness.

Similarly additional plastics material and/or composite yarns may be added to the sock to vary the wall thickness of the formed hurley. This may be added directly to the sock, or may be simply added in the mould.

In another method of carrying out the invention the sock is manufactured from a reinforcing material, but it is not a composite yarn. In this embodiment the sock is placed loosely into the mould embracing an injection tube. Then another thermoforming plastics material, in this case a foamed plastics material, is introduced into the mould while withdrawing the injection tube. The foamed plastics material will expand under heat and force the sock outwards, thus achieving the same result.

Additionally longitudinally or orthogonally arranged fibres may be used as part of the reinforcing material and preferably may form part of the sock.

The use of an expandable bladder has been found particularly useful for commingled foamed plastics materials, while the use of a foaming plastics material is in many cases advantageous for moulding of the core and for providing internal pressure.

In the specification the terms "comprise, comprises, comprised and comprising" or any variation thereof and the terms include, includes, induded and including" or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation and vice versa The Invention is not limited to the embodimert hereinbefore described which may be varied in both construction and detail.

Claims

CLAIMS 1. A method of moulding a hurley having a handle terminating in a bas comprising the steps of: preparing a net-like sock of reinforcing material having a variable angle of weave; inserting the sock into a mould having the necessary cavity shape to form the hurley; introducing a thermo-forming plastics material into the mould; and forcing the sock outwards to assume a position close to the outer surface of the mould cavity. z A method as claimed in claim 1 in which the diameter of the sock is also variable along its length.

3. A method as claimed in claim 2 in which the sock is woven on a mandrel having the required internal shape of the finished sock 4. A method as claimed in any preceding claim in which additional longitudinally extending fibres are introduced into the mould.

5. A method as claimed in any preceding daim in which additional orthogonally arranged fibres are introduced into the mould.

6. A method as claimed in claim 4 or 5 in which the additional fibres form part of the sock 7. A method as claimed in any preceding claim in which the reinforcing material is a composite yam and in which the steps are performed of: prior to inserting the sock into the mould, placing the sock over an inflatable bladder; and inflating the bladder while heating the mould to force the sock outwards to form an outer skin surrounding a hollow core.

8. A method as claimed in claim 7 in which the composite yarn is formed from reinforcing fibres and thermoplastics materials braided together.

9. A method as claimed in claim 7 in which the composite yam is formed from reinforcing fibres and powdered thermoplastics malerial blended together.

10. A method as claimed in claim 8 or 9 in which the plastics material is an engineering polymer.

11. A method as claimed in claim 10 in which the engineering polymer is chosen from polyarnide-12 (PA-I 2), polyarnideT (PA-6), polyethylene-terephthalate (PET) or polypropylene (PP), or other suitable polymers.

12 A method as claimed in any of claims 8 to 11 in which the reinforcing fibre is chosen from aramid, glass, carbon ar polyethylene.

13. A method as claimed in any of claims 7 to 12 in which an infill material is introduced into the hollow core.

14. A method as claimed in claim 13 in which the density of the iritiII material is varied from bas to handle.

15. A method as claimed in claim 14 in which the density of the inml material is greatest at the bas and decreases from the bas to the outer end of the handle.

16. A method as claimed in any of claims 12 to 15 inclusive in which the infill material is a foamed plastics material.

17. A method as claimed in any of claims 7 to 16 inclusive in which the bladder is dimensioned such as to vary the thickness of the surrounding thermoplastics material in the mould.

18. A method as claimed in any of claims 7 to 17 in which additional thermoplastics material is added to vary the wall thickness of the formed hurley.

19. A method as claimed in any of claims 7 to 17 inclusive in which additional composite yarn is added to vary the wall thickness of the formed hurley.

20. A method as daimed in any of claims 7 to 19 in which the bladder is removed after the outer skin has been formed.

A A method as claimed in any of claims 1 to 5 inclusive in which the steps are performed of prior to inserting the sock into the mould, placing the sock over an injection tube; and introducing a foaming plastics material into the mould, while withdrawing the injection tube.

22. A method as claimed in any preceding claim in which the angle of weave is so chosen as to have the angle to the shaft axis along the shaft of between 15 to 450.

23. A method as claimed in any preceding claim in which the angle of weave is so chosen as to have the angle to the shaft axis along the shaft of between 33 to 3P.

24. A method as claimed as daimed in any preceding claim in which the angle of weave is so chosen as to have the angle to the bas axis along the bas of between 45 to 75 .

25. A method as claimed as claimed in any preceding claim in which the angle of weave is so chosen as to have the angle to the bas pjs along the bas of between 47 to 55 .

26. A method substantially as described herein with reference to and as illustrated in the accompanying drawings.