CA2227197A1

CA2227197A1 - Composite tubular member having consistent strength and method

Info

Publication number: CA2227197A1
Application number: CA002227197A
Authority: CA
Inventors: Peter A. Quigley; Stephen C. Nolet
Original assignee: Individual
Current assignee: Fiberspar Corp
Priority date: 1995-07-17
Filing date: 1996-07-15
Publication date: 1997-02-06
Also published as: WO1997003820A1

Abstract

An axially extending tubular composite member (100) having a plurality of plies and extending along a longitudinal axis has at least three plies (116, 118, 120) with selectively structured fiber components in each ply. Typically an inner ply (116) has at least one biaxial fiber component, an intermediate ply (118) has at least an axial fiber component that typically is combined with two further fibers to form a triaxial fiber component. Another ply (120) typically has a woven fiber component. A further ply having a biaxial component either replaces the ply of woven fiber or is disposed beneath it over the intermediate ply. A surface veil (122) having fiber and an excess of resin material typically covers at least the innermost or outermost surface of the composite member. An internal web member (112, 114) can be provided, and typically also employs fibers and the matrix material.

Description

W O 97/03820 PCT~US96/11718 COMPOSITE TUBULAR MEMBER HAVING
CONSISTENT STRENGTH AND METHOD

Back~round This invention provides resin-fiber composite tubular members having unique combinations of fiber orient~ti~ ns in different plies, and having selectçrl other lcillrol.;elllent.

The composite members of the invention are advantageously used in various m~nllf~rtllred products, including sports impl~rnl~nt~ such as golf clubs and hockey sticks among others.

Sports implements have long been made with various materials including wood and particularly wood shafts. Wood implements can have high strength as desired and can have a satisfying feel for the user. One drawback of wood, however, is significant variation from item to item, even when made to the same specifications and ~1im~n~ions.

Among the known practices regarding fiber-reillr~,lced resin tubular m~trri~l~ are the bicycle frame structure disclosed in U.S. Patent No. 4,657,795 of Foret. Also in the prior art are U.S. Patents Nos. 5,048,441; 5,188,872, and No. RE 35,081.
One object of this invention is to provide composite tubular members suited for the shaft of a sports implement. Other objects of the invention will in part be obvious and will in part appear hereinafter.

Sulll~ of the Invention The tubular members which the invention provides have resin-fiber composite construction with improvements in durability and particularly in bending strength and in impact strength. Further, the tubular members are generally suited for relatively low cost m:~nllf~r.tllre.
The tubular members of the invention have one or more plies of fibers. In one practice, the multiple-ply composite members are constructed according to m~nnf~rtllre methods described in ~tt~rhm~?nt A, which is a copy of the commonly-~qign~cl U.S. Patent Application Serial No. 08/191,856 filed 3 February 1994 and incorporated herein by this reference.

Typically, an axially eytrntlin~ tubular composite member according to the invention has a plurality of plies. At least some plies include sl-hst~nti~lly continuous fibers. The composite member has a primary bending stiffnrq~ along a lon~it~ in~l axis.

W O 97/03820 PCT~US96/11718 The tubular composite member generally has at least three plies, including an inner or interior ply that commonly has at least one biaxial fiber component çmhe~l~lecl in the matrix m~teri~l As used herein a biaxially fiber component includes two sets of fibers or threads S spirally wrapping in op~o~iLe directions about the axially çxtpn~ling composite member. The t~,vo sets of fibers thus are generally symmetrical and generally extend diagonally relative to the axis of the memhPr An interm~ t~ ply of the composite member typically has at least one axially 10 e,xt~n-1in~ fiber component also disposed with the resin or other matrix material. The intPrrnt~ te ply is disposed contiguously over the interior ply and hence is exterior to the interior ply. The axial fiber component of the inte~rme~ te ply can be a substantially continuous set of fibers exten-lin~ ecsPnti~lly parallel to the elongation axis of the composite m~-nnher. ~ItPrn~tively, a set of axially çxtPn~1ing fibers can follow a helical path, i.e., extend 15 at an acute angle relative to the elongation axis. In one practice the axial fiber is interl~-e~l with two other sets of threads or fibers eYt~n~lin~ symrnetrically in opposite directions relative to the axial fiber, to constitute so-called triaxial fiber structure. The interlacing or diagonally exten~ling sets of fibers enhance ~ illing the axially exten~ling fibers in place and they add strength, including preventing cracks and other stress failures or fractures from 20 prop~g~ting.

In one practice of the invention a further ply overlying the intermediate ply has a woven fiber component. In a typical embodiment, the woven fiber component has the two sets of fibers, and one is oriented axially and the other transversely relative to the longitu~linsll 25 axis. i.e., a so-called 0~ and 90~ fiber orientation relative to the elongation axis.

A further practice of the invention employs an outer ply having at least one biaxial fiber component and located over the intermerli~te ply and either in place of a woven fiber component as described above or beneath such a woven fiber component.
Aside from applying fiber components in woven forrn, they can be formed with continuous fiber strands drawn from spools as described in ~tt~rhment A. Alternatives include applying the fibers in preformed fibrous sheets. Furthermore, the fibers can be braided~ stitch~d or knitted.
It is also to be un~l~rct< od that each ply can include two or more subplies. By way of example, the inner ply of a tubular member according to the invention can have two subplies, each with a biaxial fiber component. In a further example, the biaxial fibers can have dir~.cllL fiber angles, relative to the elongation axis, in the two subplies.

WO 97/03820 PCTrUS96111718 A typical further elem~nt of a composite mt-rnher according to the invention is a surface veil, forming either the extreme outer surface of the member or the extreme tubular inner surface, or both. Such a surface veil can f~ ilit~tç the mz~nllfiq-~*lre of the m~rnh.or, 5 particularly in a pultrusion m~nllf~rtllre. An exterior veil can enh~n~ e a~e~allce, an interior veil can improve impact ~ re As is known in the art, a surface veil for these purposes has a relatively large plol o,Lion of resin and a relatively lesser fiber component.

The fibers of a composite member according to the invention are generally selected, 10 using known criteria, from m~t~-ri~lc incll--linp carbon, aramid, glass, linear polyethylene, polyethylene, polyester, and llli~Lul~s thereof.

The matrix material is selected from a group of resin-based materials, such as thermoplastics and th~rmosets. Examples of thermoplastics include: polyetherether-ketone, 15 poly~hc,lylene sulfide, polyethylene, polypropylene, and Nylon-6. Examples of th~rmosetc include: urethanes, epoxy, vinylester, and polyester.

In a further practice of the invention, tubular members having a resin-fiber composite structure have improvements in durability and particularly in impact strength, and yet retain 20 light weight, when constructed with one or more additional structural elements. Such structural elements which the invention provides include selectively concave walls, selected added thickness at corners of walls, added thickness selectively in each of two opposed walls, and internal reinforcement.

The first three ÇC~LU1~S stated above, i.e., concave walls, thickened corners, and thickened walls, are applicable to members having a non-circular cross section and typically to members having a polygonal cross-section. A ~lefc.lcd polygonal cross-section has four or more sides.

The foregoing structural fe~Lules preferably are used in combination with one another, such as opposed concave walls combined with added wall thickness at the corners of those walls, or added thickness at opposed walls and added thickn~c~ at the corners of those walls.

The internal rcillfolcement is applicable in structures having any of various cross sectit-nC, examples of which include a polygonal cross section and a circular cross section.
Examples of such lchlfol~;cll~cllt include an interior rib çxtl~n-ling along at least a portion of the length of the member, either ~-ss~nti~lly parallel to the axis or length of the member or selectively angled, e.g., helical, with regard to the axis of a straight member. Such a rib is preferably provided on each of two opposed walls. Another example of such internal W O 97/03820 PCT~US96/11718 ,chLLolcement is an interior web~ or an axially spaced sncces~ion of interior braces, spanning between opposed walls or between adjacent walls. For example, an interior web or brace in a composite tubular member according to one embodiment of the invention and having a circular or elliptical cross section can follow the path of a chord extentling between two S locations spaced apart around the circumference of the composite member, when viewed in cross section. Colrcsl)olldingly~ in a structure having a polygonal cross section, the internal web or brace extends between ~ c~ nt walls. Further examples include such braces or webs ~-~cten-lin~ between opposed walls or wall portions, including along the path of a diameter of a member having a circular or elliptical cross section.
The interior reinforcement can extend along the full length of the member or along only part of the length. The latter may be ~lcfc.lcd, for example, to decrease weight and to control stiffn~sc.

In one ~ lcd practice, the int~rn~l lchlfo~;cnlent is formed during the initial pultrusion f~hr~ tion of the composite member and accoldi"gly is continuous along the length of the member, or at least along a selected portion thereof. Where such an internal reinforcing web is formed continuously along the length of a member, it can subsequently be removed. as by m~c~hining, from one or more selected portions of the length of the member.
20 This may be desired to reduce the weight of the member.

A further alternative is to fabricate the composite member and add internal reinforcement, by inserting a preformed internal reinforcement element. The internal reinforcement element preferably is added prior to final curing of the polymers of the 25 composite member and of the reinforcement element to ensure a solid ~tt~ .hment of the internal reinforcement member element to the composite member. In accordance with another method of fabrication, the composite member and the internal reinforcing element are formed concul,clllly as part of a resin transfer or compression molding process. This f~hri~tion method provides a system capable of forming a composite member integral with 30 an internal reinforcing element, both having selective characteristics along the length of the member.

The invention accordingly compri~e~ an article of manufacture po~.se~sing features.
PIO1~JC1 lies and relations of elements exemplified in the articles hereinafter described. and 35 compri~ the several steps and the relation of one or more of such steps with respect to each of the others for fabricating such articles. and the scope of the invention is indicated in the claims.

Brief Description of Drawin~
For a fuller underst~nfling of the nature and objects of the invention, reference is to be made to the following detailed description and the accompanying drawing, in which:

S FIGURE 1 shows a transverse cross-section and l~mgit-l~lin~l fragment of a composite tubular member according to one practice of the invention;

FIGURE 2 shows a transverse cross-section and longitudinal fragment of a composite tubular member according to a fur~her practice of the invention;
FIGURE 3 shows a transverse cross-section and longitudinal fragment of a composite tubular member according to yet another practice of the invention, FIGURES 4 through 9 show transverse cross-section and longit~l-lin~l fr~gm~nte of composite tubular members according to fulther practices of the invention and having selectively c~nfi~llred and lch~folced wall portions;

FIGURES 10 through 15 show transverse cross-section and longitudinal fragment.e of composite tubular members according to further practices of the invention and having internal reinforcement; and FIGURES 16 and 17 show sports implements. namely, a hockey stick and a lacrosse stick ntili~ing shafts according to the invention.

Description of Illustrated Embo-limente Figure 1 shows a transverse cross section and longitudinal fragment of a composite tubular member 100 according to one plc~ll~d practice of the invention. The illustrated member 100 has a rectangular cross section with two wide opposed walls 102 and 104 and two narrow opposed walls 106 and 108. The tubular member 100 can be constructed eeetonti~lly as described in .~tt~hm~nt A to form, for example, the shaft of a hockey stick or of a lacrosse stick. Each wall 102, 104, 106 and 108 of the illustrated member 100 has generally uniform thickness along the length of the member and the four walls are of eesenti~lly the same thickness. Thus, the illustrated member 100 is preferably continuous along at least a selected length, i.e., has the same cross section at successive locations along that selected length. This continuous cross sectional configuration facilitates m~nnf~cture~
for example with pultrusion procedures as described in Att~chment A.

The member 100 further has, as also shown in Figure 1, internal reinforcement in the form of a web 110 that spans between and is joined solidly to the opposed wider walls 10~

W O 97/03820 PCT~US96/11718 and 104 of the member. The reinforcing web 110 is continuous along at least a selected portion of the length of the member 100. The illustrated member 100 thus has a hollow tubular interior within the walls 102~ 108, aside from the web 110.

S In a l,-efe~lcd embodiment of the member 100, as shown, two el- nF~ted strips of fabric 112 and 114 are formed into side-by-side closed qllR~ Rtloral tubes. The abutting walls of the two tubes, as formed by the fabric, form the web 110 of the member 100.

An elnngRtecl strip of fabric 116 is then formed into a closed tube enclosing the two side-by-side tubes formed by the fabrics 112 and 114.

A ply 118 of axially-e~t~n~ling fibers is then disposed over the layer forrned by the fabric 116.

Another elongated strip of fabric 120is formed into a closed tube enclosing the fiber ply 118 (and the structure therein formed by the fabrics 116, 114 and 1 12). An outer ply of the structural member is formed by an elongRtPfl strip of fabric 122, also formed into a tubular enclosure.

The foregoing assemblage of fiber plies is impregnRt(?(l with resin 124, typically an epoxy resin, and the resultant composite is cured.

The foregoing procedure of fabricating the member 100 can advantageously be practiced in a pultrusion system with a fixed, i.e.? stationary, mandrel on which the fabric and fiber layers are formed, and within an outer die-like forming member.

Inone~ f~l.edembodimentofthemember lOO,eachfabric 112and 114isa p~c~fo..ned fabric having fibers, typically of fiberglass, carbon or aramid, and oriented at zero degrees and at ninety degrees relative to the longit---linRl length of the member 100. Such a 30 fabric commonly has a woven structure.

The fabric 116 in this embodiment is a preformed fabric, preferably non-woven, i.e..
of stitched or knitted structure, with fibers oriented at + forty-five degrees relative to the lon~it~l-linRl axis ofthe member 100. ~IternRtively, braided or woven fabrics oriented at ~t 35 forty-five degrees relative to the lnngit~ inRI axis of the member 100 may be used. Such a fabric 116 thus forms an inner ply of the member 100 and which has a biaxial fiber component. The fabrics 112 and 114, which are within the ply formed by the fabric 116, form another inner ply of the member 100. The illnctrRtecl member 100 thus has an inner ply CA 02227l97 l998-0l-l6 W O 97/03820 PCTrUS96/11718 having two subplies, one formed by the fabric 116 and another formed by the fabric 112 and 114. The fabric 1 16 can be, for example~ of glass, carbon or aramid fibers.

The fibers in the ply 1 18 can be of carbon or of glass, or can be a hybrid, i.e., a combination of glass and of carbon, by way of e~nnple. These fibers form the ply 118 as an int~nn~ te ply in the member 100 and with at least an axial fiber component.

The fabric 120 in the illustrated embodiment is a ~lero.lned fabric of glass and/or carbon, preferably of non-woven structure and having fibers oriented at l forty-five degrees relative to the member l~ n~ihlAin~l axis. This fabric thus forms an outer ply of the member 100 and which also has a biaxial fiber component.

The fabric 122 that forms the illustrated outer ply of the member 100 is preferably a pl~Iblllled fabric typically of woven structure, with fibers oriented at zero and at ninety degrees relative to the lonf~ih~Ain~l axis ofthe member 100. This fabric 122 forms an exterior ply of the member, t-Yt~?rn~l to the outer ply formed with the fabric 120.

The primary function of each layer in the member 100 is that the inn,-r nnst fabrics 112 and 114 provide intern~l impact resict~nc~e, particularly by forming the internal reinforcing web 1 10. Each fabric 116 and fabric 1 18 forms a ply providing torsional stiffness to the member 100. The axially-oriented fibers in the ply l 18 provide bending load strength, i.e., axial stiffnes~ to the member 100. The fabric 122 provides ~xt~rn~l wear resistance to the member 100.

The member 100 can be further formed, prior to curing, with one or more light gauze or surface veil plies 126 of l ler"llled gauze or veil-like fiber that is highly resin-absorbent.
These surface gauze or veil plies enhance the abrasion re~i~t~nc~e ofthe member 100 and can provide an attractive surface finish.

More generally, the invention can be practiced, in one in~t~nrç, with fibers oriented at angles other than those for the particular embodiment described above. For example, the fabrics 112 and 114 can be arranged ~,vith the fibers oriented generally between + 30~ and between 60~ and 120~ relative to the longitudinal axis ofthe member 100. More ple~ d ranges of fiber angles for these fabrics are + 15~ and between 75~ and 1 15~ relative to that axis.

Similarly, each fabric 116 and 120 can be arranged with fibers oriented between + 30~
and + 60~ relative to the lnn~ihlAin~l axis of the member 100. More preferred ranges of the fiber angles for each of these fabrics are between + 40~ and + 50~. Further, in most practices W 097/03820 PCT~US96/11718 of the invention, the two sets of fibers of each fabric -- which generally are orthogonal to each other within the fabric -- are oriented on the member symmetrically relative to the longit~l~lin~l axis ofthe member.

S The lt n~ihlflin~l seams of the dirrt ~ lt strips of fabric that form the several plies of the member 100, as described above, are preferably formed at ~lirr~lGlll, spaced apart locations in the member 100. For example, the longit~l~in~l seams in the tubes forrned by the fabrics 112 and 114 can be disposed along opposed member walls 106 and 108. The longitll~lin~l seams ofthe fabrics 116, 120 and 122 can also be located along dirr~ walls of the member 100.

Features attained with a composite member having the structure described and shown are that it has high bending strength and stiffnecs, and high torsional rigidity. It also has, through the wall thickness, durability and impact resi~t~n~e. Further by way of illustrative example and without limitation, a member 100 as ~i~sçribed above and shown in Figure 1 and suited for use as a hockey stick shaft can have a web thickness of 0.034 inch and a thickn~ss in each wall 102, 104, 106 and 108 of 0.082 inch.

Figure 2 shows another construction for a member l O0', which illustratively has a quadralateral cross section transverse to an elongation axis. as shown. The member 100' has arl inner ply 116' with a biaxial fiber component, an interrne~ te layer 118' with a triaxial fiber component, and an external ply 12 7' illustratively having a woven fiber component with a 0~/90~ fiber orientation.

The illustrated member 100' also has an outer ply 120' interposed b~Lw~en the in~orrn~ te ply 118~ and the external ply 122', and which illustratively also has a biaxial fiber component similar to the inner ply 116'. Further, each biaxial fiber component of the inner and outer plies 116' and 120' includes a stitching fiber 116A' and 118A'. The foregoing fiber components of the member 100' are embedded in a resin matrix that extends through all the plies to form the fiber components into a single unitary structure.

Although illustrated with a hollow reinforcement-free interior, the member 100' of Figure 2 ~It~rn~tively can have a reinforcing rib 110' as shown in phantom.

A surface veil 126' preferably is applied over the outer surface of the member 100'7 as Figure 2 further shows.

Another elongated reinforced composite member 130, according to the invention and as shown in Figure 3, has a web 132 secured to and sp~nning between opposed walls 130A

CA 02227l97 l998-0l-l6 WO 97/03820 PCT~US96/11718 g_ and 130B. Alternatively. the web 132 can span between walls ofthe composite member 130.
otherthan 130Aand 130B. Theillustratedweb 132hasacore 134enclosedwithinafibrous sleeve 136. The core 134 can be of various m~tt ri~l~ depending on the weight and strength lc4uirclllents, examples of which are wood and plastic, typically rigid, synthetic resin foam.
- 5 The core 134 of the web 132 in other practices can be partially or entirely hollow and can ~It~rn~tively employ a l~., .;..~lçr1 structure with dirrelclll layers, typically of wood and/or synthetic rn~tl-ri~

The fibrous sleeve 136 can be woven, braided or otherwise formed over the core 134.
Another practice is to insert the core 134 into a ~ r~ l,l,cd hose of fibrous m~tPri~l that cn~ lçc the sleeve 136. In either case, the sleeve 136 can be formed of fiberglass, carbon.
or kevlar, or a hybrid combination thereof.

Figure 3 further shows that during illustrative fabrication ofthe member 130, the web 132 formed by the core 134 within the fibrous sleeve 136 is seated between two tines or side-by-side legs 138A and 138B of a mandrel 138 having an end portion 138C that joins together the two tines or legs.

The several fibrous plies that form the walls of the member 130 are then formed, in succession, over the mandrel 138 and thus are formed or built up onto the assembled core and sleeve, which are held in place between the tines of the mandrel onto which the walls are formed.

An innermost surface veil, with a fiber structure and excess resin, preferably is the first layer formed onto the mandrel 138, to f~cili~te the m~nnf~hlre of the member 130 onto the mandrel 138. The mandrel is removed from the member 130, typically after all the plies are applied and before the end of the mz~mlf~-~turing process.

Figure 4 shows a transverse cross section and longitudinal fragment of a composite tubular member 150 having walls 152, 154, 156 and 158. The tubular member 150 can be constructed as described above with reference to Figures 1~ 2, and 3, and as further described in Attachment A, to form, for example, the shaft of a hockey stick. Each wall 152 and 154 of the member, which together form a pair of opposed walls, is concave. The concavity of the opposed walls preferably is symmetrical, as shown.
- One p,cr~"~cd construction of the member 150 has a m~gnihl(le of concavity of the opposed walls 152 and 154 such that the minimum width of the shaft at the mid-point of the concavity, ~lesign~tt?~ in Figure 4 as (X), is less than the maximum width of the shaft, ign~t.oA as (Y). by the equation .

WO 97/03820 PCT~US96/11718 y 2 1 01 x (Eq. l) Figure S illustrates another form of the quadrilateral composite member 152' in which 5 bothpairsofopposedwalls 1~2'and 154'and 156'and 158'areconcave. The~lcr~ Gd m~gnitll~le of concavity of each pair of opposed walls is in accord with equation (1). The concavity of the opposed walls 152' and 154' is preferably symmetrical, as is the concavity of the opposed walls 156' and 158'.

Figure 6 shows a lon~ituflin~l fragment of a composite m~mhPr 160, such as a hockey stick shaft or a lacrosse stick shaft, having a rectangular cross section with top and bottom walls 162 and 164 thicker than side walls 166 and 168. This configuration is typical in a hockey stick shaft. Each wall 162. 164, 166 and 168 of the illustrated member 160 has uniform thicknl?~s, in the cross section shown in Figure 6, except at the corner where it joins another wall. In the illustrated composite member 160, the outer p~,.;phcl~ of the four walls has a right rectangular cross section, and the ~e~iphGl y of the inner s~ r~c is similar but with corners beveled at approximately 45~ angles or with the inner surfaces of the corners having a radius to create the desired increased thickness in the corner. One plef~ d m~gnitl-Ae of the difference in wall thickness is in accord with Equation 2 below, where the rlimencion (A) is the minim~l thickness of a wall, e.g., at its midpoint, and the ~lim~n~ion (B) is the thickness of that wall as measured in the same direction, at one corner thereof.

B21.05A (Eq.2) A composite member 170 having five equal-width walls 172, 174, 176, 178 and 180,i.e., which is pentagonal in a cross section transverse to the length as shown in Figure 7, has a m~rim~l wall thickness in each wall at the corners, similar to the construction of the member 160 of Figure 6. The illustrated structure of the composite member 170 is regular. in that all walls and all corners are the same as others, and all included angles of the pentagonal cross section are equal. The m~im~l wall thickness at a corner, ~le~ign~t~l (B), is greater than the minim~l wall thickness, ~leeign~t( ~1 (A), and the two thickn~ees of each wall preferably are in accord with Equation (2).

Figure 8 shows a structure 182 similar to the member 170 of Figure 7. except that it has a hexagonal cross section, as illustrative of the shaft of a lacrosse stick. The member is elong~tetl along an axis 184, as are the members shown in other figures.

Figure 9 shows a composite member 186 having multiple features in accord with the invention. In particular. the illu~LIdlt:d member 186 has concave walls and each wall 188 and , W O 97/03820 PCTtUS96tll718 190 in one pair of opposed walls has a greater thickness than in the other pair of opposed walls 192 and 194. The member 186 has a third feature, namely that the walls have added thickness at corners. Each wall of the illu~tr~t~cl member 186 has ullirc,~ thickness along the width of the wall, except at each corner, where the wall thickness is larger. The increased 5 wall thickness at each corner preferably is in accord with Equation 2, which relates ",i,,;....,..
thickness of a wall (A) to the m~xim~l thicL n~ (B) of that wall.

In accordance with one aspect, each member 150, 160, 170, 182 and 186, shown in Figures 4, 5, 6, 7, 8 and 9 respectively, is pl~r~al)ly continuous along at least a selected 10 length, i.e., has the same cross section at successive locations along that selected length. This continuous cross sectional configuration f~-~ilit~tec m~nllf~rtllre, for example, with pultrusion procedures as described in ~t~rllment A. The dirr~,re.lL wall thickn~cses at dirr~l~,."
locations circumferentially about the cross section of each member 150, 160, 170, 182 and 186 can be ~tt~in~-l with added resin, and can be ~tt~in.od with a combination of added resin 15 and added fibers, typically axial, i.e., longibl-lin~l In another aspect of the invention, each member 150, 160, 170, 182 and 184, has a varying cross-sectional geometry along the length of the composite member. Such members having a varying cross-section can be produced with a molding process. These members with 20 varying geometry advantageously provide a higher performance tubular member having. as collll,~ed to those members produced by a pultrusion process, an increased strength per weight ratio.

Figures 10, 11, 12 and 13 illustrate, respectively, composite members 200. 202, 204 25 and 206, each of which hlCOll~UldLeS internal lcillfolc~ nt For clarity of illustration. each composite member 200-206 is illustrated with uniform thickness throughout the walls including corners. However, the internal reinforcement shown and described belowpreferably is combined with one or more of the structural features described above with reference to Figures 4 through 9.
The intern~l lchlfolc~lllent of member 200 in Figure 10 is a tube 200a that spans between and is joined solidly to opposed walls 200b and 200c of the member. The reinrolcillg tube 200a is continuous along at least a selected portion of the length of the member 200.
- The member 202 of Figure 11 has an internal l~infolcillg web 202a joined to and sp~nning between a pair of opposed walls 202b and 202c of the member. These are illustrated as the wider walls of the member and the web 202a is preferably continuous along at least a selected length of the member 202. The r~hlr~l.;illg web 202a is secured within the W O 97/03820 PCT~US96/11718 -12-member 202 after each such element has been initially formed. The web 202a typically has the cross section of an I beam, as illustrated. In other practices of the invention, the web 202a is formed during the formation of the member 202, as in a pultrusion or a molding fabrication, and hence is formed integrally with the walls 202b and 202c, the thickness of 5 those walls can be increased slightly adjacent the juncture with the web 202a, to for n structure corresponding to the flanges on a conventional I beam. The structures described above with reference to Figures 1, 2 and 3 are further ~ltprn~tives for ~tt~ining the member 202 with the web 202a.

The hexagonal composite member 204 of Figure 12 has a regular h~Y~g~n~l cross section and has a multiple-element internal reinrol.ielllcnt member 204a. The illl-~t~?cl reinforcement member 204a has a transverse cross section as shown, configured with six radially ext~n~ling spoke-like l~inforc~lllent elements uniformly spaced around the circumference and each joined at its radially outer end to the midpoint of one wall of the 15 member 204. Further, the radial elernent~ are joined together at their i..~ ;e-;lion, at the midpoint or axial center of the composite member 204.

The composite member 204 of Figure 12 can, for example, be the shaft of a lacrosse stick, and each composite member 200,202 of Figures 10 and 11 can be incorporated in the 20 shaft of a hockey stick.

As a further feature of the invention, a tubular composite member can have an internal reinforcing element that is a foam-filled tubular core. Figure 13 illustrates this practice of the invention with a tubular composite member 206 that is int~rn~lly reinforced with a tubular 25 core element 206a, the int~rn~l hollow of which is filled with an exp~n~ed polymer resin foam 206b.

~ ltern~tive to an int~rnz~l reinforcing çlennent that spans fully between opposed walls or wall sections of a tubular element, Figure 14 illustrates a practice of the invention with a 30 tubular composite member 210, illustratively circular in cross section, and formed as in a pultrusion process, as described in ~tt~hmPnt A~ with one or more selectively circumferentially located intern~l ribs. The illustrated member 210 has four such ribs. 210a, 21 Ob, 210c and 21 Od, e~ually spaced about the circumference of the circular cross section.
This practice in the invention, i.e.. with internal reinforcement that extends radially only part 35 way, and not entirely, to an opposing wall portion, can provide added structural rigidity to a composite member, with a higher degree of elasticity than with an internal l.,hlf~r~;~lllent elennent that spans fully between opposed wall portions, as in each of Figures 10, 11, 12 and 13. Further, although illustrated with a composite member of circular cross section~ the W O 97/03820 PCTrUS96/11718 internal reinforcement illll~tr~tef1 in Figure 14 can be used with composite members having other configurations, as shown in others of the drawings.

Figure 15 illu~lldle~ a practice of the invention with int~-rn~l reinforcement of a - S tubular composite member where the lchlrc~lc~lllent is not continuous along the length of the member. In particular, the tubular composite member 212 of Figure 15 is int~rn~l1y reinforced with an element 212a that is at least partially preformed, e.g., with partial curing of polymer resin and which is finally cured or cured to the final stage after assembly within the composite member. The p,er~ll-led lchlr~l.;t;lllent element 212a, as shown, is similar to an I-beam structure having a web s~ between end flanges. However, the web is disco~ ous and has only an axially succession of web-like braces 212b that extend diametrically between opposed walls or wall portions of the composite member 212. The discontinuous l~hlfol.;illg element 212a can be formed as a discontinuous member, or it can be formed as a continuous member which is further processed to remove sections along the le;nfol.;illg element. The lc;hlfolcillg element 212a provides a ~IIU ;lul~; that selectively reduces the total weight of the composite member while providing selective reinr,l-;c;ll,cnt to the composite member.

Figures 16 and 17, respectively. illustrate a hockey stick 214 and a lacrosse stick 216, each constructed with a shaft 21 4a. 21 6a that is a tubular composite member of the type described above in Figures 4 through 15.

In particular, the hockey stick 214 has a conventional blade 21 4a, secured at a lower end of the shaft 21 4a, and has a cap 21 4c secured to the upper other end of the shaft 214a.
The illustrated shaft 214a has int~rn~l reinforcement 214d, as described above with reference to any of Figures 10, 11, 12, 13, 14 and 15, ç~t~nfling for a portion only of the length of the shaft.

Similarly, the lacrosse stick 216 of Figure 17 has a conventional lacrosse net 216b secured to one end of a lacrosse handle shaft 216a. The shaft has an int~rn~l reinforcement element 21 6d ç~t~nrlin~ at least along the lower portion, i.e., the portion to which the net 216b is secured.

Each shaft 21 4A and 21 6B thus is axially elong~ted with a handle portion at one end.
At the other end~ the shaft has a socket-like receptacle or other structure for seating and ~ thereby mounting a sports implement. This implement is the hockey blade 21 4A in the embodiment of Figure 16 and is the lacrosse net 21 6B in the embodiment of Figure 17.

WO 97/03820 PCTrUS96/11718 It will thus be seen that the invention attains the objects set forth above, among those made a~p~ellt from the prece~1ing description, and since certain changes may be made in ca~Tying out the above method and in the articles set forth without departing from the scope of the invention, it is int.on~le~l that all matter contained in the above description or shown in 5 the acco,ll~lying drawings be il~ eled as illustrative and not in a 1imiting sense.

It is also to be 1m~l~r~tood that the following claims are inten~le-l to cover all generic and specific fe~ of the invention described herein, and all st~tem~ntc of the scope of the invention which, as a matter of language, might be said to fall therebetween.
Having described the invention~ what is claimed as new and secured by Letters Patent is:

Claims

1. An axially extending tubular composite member having a plurality of plies and having primary bending stiffness along a longitudinal axis, said member having the improvement comprising A. at least one interior ply having at least a biaxial fiber component with a matrix material, B. at least one intermediate ply having at least one axially extending fiber component disposed within said matrix material, said intermediate ply being exterior to said interior ply, and C. at least one exterior ply having a woven fiber component with threads oriented longitudinal to said longitudinal axis and threads oriented transverse to said longitudinal axis, and disposed with said matrix material, said exterior ply being exterior to said intermediate ply.

2. A tubular composite member according to claim 1 having the further improvement comprising a veil covering said exterior ply, said veil including said matrix material.

3. A tubular composite member according to claim 1 having the further improvement comprising at least one outer ply having at least a biaxial fiber component disposed with said matrix material and located between said intermediate ply and said exterior ply.

4. A tubular composite member according to claim 1 wherein said fiber component of said intermediate ply includes a first axial fiber and second and third fibers each oriented diagonally relative to said first fiber, so that said first. second, and third fibers together form a triaxial fiber component.

5. A tubular member according to claim 1 further comprising an internal web-likereinforcement spanning across the tubular interior of the member between and secured to two spaced apart wall portions.

6. A tubular member according to claim 5 wherein said web-like reinforcement includes a fiber component disposed with said matrix material.

7. A tubular member according to claim 5 wherein said web-like reinforcement includes a substantially rigid core disposed between fibers disposed with said matrix material.

8. A tubular member according to claim 1 wherein said member has a cross sectiontransverse to said longitudinal axis in the form of a closed plane figure having at least four sides, and with at least two opposed wall portions.

9. A tubular member according to claim 8 having the further improvement wherein said two opposed wall portions have a first medial thickness and have a greater thickness than said first thickness at longitudinally-extending edges thereof.

10. A tubular member according to claim 8 having the further improvement wherein said member has a lesser wall thickness at the middle of said two opposed wall portions then at axially-extending edges of said opposed wall portions.

11. A tubular member according to claim 8 wherein said two opposed wall portions are symmetrically concave.

12. A composite member according to claim 1 wherein the fiber materials of said biaxial fiber component and of said axial fiber component are selected from the group of fiber materials consisting of polyester, glass, carbon, aramid, and mixtures thereof.

13. An axially extending tubular composite member having a plurality of plies and having primary bending stiffness along a longitudinal axis, said member having the improvement comprising A. at least one interior ply having at least a biaxial fiber component with a matrix material, B. at least one intermediate ply having at least an axial fiber component disposed with said matrix material, said intermediate ply being exterior to said interior ply, C. at least one outer ply having at least any one of (i) a biaxial fiber component and (ii) an axial fiber component, said fiber component being disposed with said matrix material and said outer ply being exterior to said intermediate ply, and D. an internal web-like reinforcement spanning across the tubular interior of the member between and secured to two spaced apart wall portions.

14. A tubular composite member according to claim 13 having the further improvement comprising a further ply exterior to said outer ply and having a woven fiber component.

15. A tubular composite member according to claim 13 having the further improvement comprising a surface veil coating at least one of the inner surfaces of said interior ply and the outer surfaces of said exterior ply.

16. A sports implement shaft elongated along an axis and having a handle portion at one axial end and having at the other axial end a seat portion for attachment to a sports head, said sports implement shaft comprising a tubular member having opposed wall portions and structured with resin and withmultiple plies of substantially continuous fiber imbedded in said resin and including at least first, second, and third fibers, each disposed at selected different angles relative to said axis, and a web member within said tubular member and spanning between and secured to saidopposed wall portions, said web member extending along at least a selected axial length of said tubular member.

17. A sports implement having an axially elongated shaft member with a handle portion at one axial end and a head member secured to the other axial end. said implement having the improvement wherein said shaft member comprises a tubular member having opposed wall portions and structured with resin and withmultiple plies of substantially continuous fiber imbedded in said resin and including at least first, second, and third fibers, each disposed at selected different angles relative to said axis, and a web member within said tubular member and spanning between and secured to saidopposed wall portions, said web member extending along at least a selected axial length of said tubular member.

18. An axially extending composite tubular member having a plurality of plies and having primary bending stiffness along a longitudinal axis, and comprising at least one interior ply having a matrix material and a first fiber component with fibers oriented at an angle relative to said longitudinal axis of between thirty degrees and sixty degrees, and more particularly between forty degrees and fifty degrees, and an internal weblike reinforcement spanning across the tubular interior of the member between and secured to two spaced apart wall portions, said first fiber component being structured to provide significant torsional stiffness to the composite member and said internal weblike reinforcement being structured to provide significant impact resistance to the composite member.

19. A method of fabricating an axially extending composite tubular member having a structure according to claim 18 and comprising the steps of forming first and second fabric strips into axially extending side-by-side closed tubes, the abutting walls of which form said internal weblike reinforcement, and forming a fibrous fabric into a longitudinally extending ply enclosing said first and second plies and having fibers that constitute said first fiber component of said interior ply.

20. A method of fabricating an axially extending composite member having a structure according to claim 18 and comprising the successive steps of forming said web-like reinforcement, disposing said web-like reinforcement between side-by-side mandrel members, and forming said plies of said tubular member over said mandrel members and web-like reinforcement.

21. An axially extending tubular composite member having a plurality of plies and having primary bending stiffness along a longitudinal axis, said member having the improvement comprising A. at least one interior ply having at least a biaxial fiber component with a matrix material, B. at least one intermediate ply having at least one axially extending fiber component disposed within said matrix material, said intermediate ply being exterior to said interior ply, and C. at least one exterior ply having at least a biaxial fiber component disposed with said matrix material, said exterior ply being located exterior to said intermediate ply.