ROD CONSTRUCTION

Abstract: A rod (22) is constructed by bonding an assembly of members (23-28) to create a polygonal cross-section. The members of the assembly comprise elements made with fibre reinforcement laid-up in a tri-axial pattern, which elements are generally L-shaped. The free spaces of the assembly are optionally filled with foam.

Description: TITLE ROD CONSTRUCTION FIELD OF THE INVENTION This invention relates to rods and in particular to rods produced by a method which enables production of a rod with a desired set of characteristics when flexed. BACKGROUND OF THE INVENTION Flexible rods find applications in a variety of fields, for example, as fishing rods, which rods are tailored to suit particular applications. Stiffer rods are preferred for heavy fish, whilst very flexible rods are utilised in fly casting. A variety of materials and geometries are employed in these applications. In fishing rod construction, cylindrical section materials both hollow and solid have been used. Round materials pose problems in mounting thereon an aligned set of line guides. Some of the lightweight, flexible materials, such as hollow carbon tube, have poor crush characteristics and poor torsional performance so that the application of fishing line guides to them poses problems. The conventional techni«gue involves binding a wire-form bracket firmly to the rod. Too much pressure can crush a carbon filament tube. Attempting to realign a guide by twisting it about the rod axis can result in a fracture. Other rods less prone to these problems suffer disadvantages in less desirable flexing characteristics. Construction of tube form rods with tapers is not easy. US patent 1932986 to Powell shows a split cane technique for rod assembly from a number of canes. A rod of this type is provided with a taper by reduction of the wedge section dimensions over the length of the elements of the assembly. US 4582758 to Bruce et al shows a development of the above utilising fibre resin reinforced plastic SHEET techniques. The cane wedge is duplicated in reinforced plastic and assembled in much the same way. Whilst a great variety of materials and layup techniques have been tried in the construction of rods, there is scope for improvements. It is desirable to e_stablish a fabrication technique that may be applied to produce a range of rods each with preselected parameters for particular uses. OBJECTS OF THE INVENTION It is an object of the present invention to provide a rod fabrication technique that enables rods to be produced with predetermined properties utilising an assembly of preformed members. Other objects, and various advantages of the invention will hereinafter become apparent. OUTLINE OF THE INVENTION The invention achieves its objects in providing a rod comprising an assembly of elongate members each having abutment faces whereby each elongate member contacts its neighbor; adjacent elongate members being joined together at their abutment faces; characterised in that : the elongate members have a generally T-shape cross-section with a flange capping a web section; the assembly combines all the flanges together to establish a polygonal cross-section; and the web sections of each elongate member being extended in a direction fowards a common axis. The invention also provides a rod comprising: a plurality of elongate members; the elongate members being arranged in an assembly about a central axis with at least one mating surface between adjoining elongate members; and T the elongate members being bonded at their mating surfaces with each elongate member being bonded to its two neighbors about the central axis; characterised in that each elongate member comprises a composite body formed with at least one reinforcing layer with fibres or filaments of reinforcing material extended therethrough in a predetermined pattern the predetermined pattern in planar form comprising a first array of said fibres or filaments extended parallel to the length of the elongate member, a second array of fibres or filaments arrayed across said first array and a third array of fibres or filaments being arrayed oppositely to the second array, relative to the first array, to cut across the first and second arrays: and the reinforcing layer being folded or curved about an axis which is parallel to the central axis and the axis of the first array. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described with reference to preferred embodiments as shown in the accompanying drawings in which : Figure 1 illustrates an array of reinforcements utilised in the invention Figure 2 shows how the laid up fibres of figure 1 are used to establish a basic elongate unit in accordance with the invention. Figure 3 shows an elongate member formed of an assembly of the units of figure 2 Figure 4 shows an alternate elongate member formed from a unit of figure 2. Figure 5 shows an assembly of the elongate members of figure 5 in accordance with the invention. Figure 6 shows an assembly of the elongate members of figure 4 in accordance with the invention. " Figure 7 shows a development of the elongate member of figure 3. Figure 8 shows a development of the elongate member of figure 4. PREFERRED EMBODIMENTS In construction of rods in accordance with the invention, advantage is taken of the properties of reinforced materials such as fibre reinforced plastics. In layup of the material, the orientation of the fibres or filaments is a concern and figure 1 illustrates a particular pattern which is useful. With reference to figure 1, a triaxial pattern is developed with longitudinally extended fibres or filaments 11 of the assembly 10 being those which in use will extend in a direction which is parallel to the elongate axis of the rod. Extended across the array 11 are two further array of fibres or filaments, one to the left, array 12, the other to the right, array 13. Arrays 12 and 13 extend acutely to the direction of array 11 and to each other. In production of the pattern of reinforcement of figure 1, the assembly 10 may be effected with layup of a cloth with a triaxial weave as shown or by overlap of three layers, each comprised of generally parallel fibres or filaments. In use of the later, a layup may be established with a first layer of fibres oriented as in array 11 overlaid by second and third layers being oriented each in one of the directions of arrays 12 and 13. Preferably the three layers are overlaid by a fourth array having the orientation of array 11, to create a sandwich of crossed fibres such as 12 and 13 between two parallel layers oriented along what will be the elongate axis of the rod. If desired, this pattern might be repeated with a succession of crossed layers sandwiched between layers oriented parallel to the elongate axis of the rod. Alternately, an array such as 12 might be sandwiched between two such as 11, with an array such as 13 superimposed and capped by another layer such as 11 to provide a five layer composite. In production of the above, the aim is to include w i th i n the layup, a pattern of fibres or filaments which contains the elements of figure 1 and exhibits a degree of symmetry about the elongate axis. In production of a rod as will be described below layup of an assembly of fibres or filaments as in figure 1 i s made with a geometry of the type indicated in f i gure 2 whereby an elongate member, the basic unit of a rod in accordance with the invention, is produced. An elongate member 14 is produced with a curve about its elongate axis 15 which produces a U or generally V shape member with a base of chosen radius of curvature. The actual geometry of the elongate member 15 so far as its sectional view is concerned, is determined by the properties wanted in the completed rod. m layup of the elongate members, the pattern 10 of figure 1 exists in the member 14 with the array 11 of fibres or filaments extended along the members elongate axis 15 In this configuration, the fibres or filaments are curved or bent about the curve of the u or V shape of the member. In production of the elongate member of figure 2 the arrays of fibres or filaments are set within a su i table material to create a rigid element having the geometry shown. In figure 3, is shown a composite elongate member 20 made from an assembly of two of the members of figure 2 , 16 and 17, which forms the leg of a T-shape element capped by a reinforced layer 18 which is preferably in accordance with figure 1 oriented with array 11 along the elongate length of the composite member. The hollow centre 19 of the composite member may be filled w i th an impregnated material of compatible character to those materials which are chosen for the elements 16 to 18. It may be desirable that the pattern of filaments in the two curved elements be arranged to each be a mirror image of the other. Figure 4 shows an elongate member 24 which has a generally V-shape with the angle of the arms 42 and 43 being set at 60° to enable the assembly as described below with reference to figure 6. The V at the apex may be produced by rolling over a mandrel, machining, etc. Figure 5 shows a rod 22 which is an assembly of six of the elements of figure 3, oriented as shown with the legs of the respective T-shaped members 23 to 28 extended to the centre of the rod and the caps of the T- shapes mated to form a hexagon. This geometry is particularly ^ suited to production of a fishing rod. In other applications, the number of elements might be varied to produce other polygonal assemblies. In production of the assembly of figure 5, the edges of the caps of the T-shape members in accordance with figure 3 are machined at an appropriate angle to provide mating surfaces whereat bonding may be effected so as to produce the requisite polygonal structure. The legs of the T-shapes, if it is chosen extend them to the Centre may be also machined at an angle to provide mating surfaces at which bonding may be effected. Figure 6 shows how the member of figure 4 may be assembled to produce a polygonal structure. The assembly 29 of figure 6 comprises six members 30 to 35 assembled with their arms butted and bonded together. In production of a polygonal assembly other than a hexagon, all that is required is that the member of figure 4 be produced with its arms 42 and 43 at a different angle appropriate to the chosen geometry. The assembly may have a winding thereabout to provide flat outer surfaces. In production of the assemblies of figures 5 and 6 a fair degree of free space exists and figures 7 and 8 show adaptations of the members of figures 3 and 4 which utilise this free space to good purpose. Figure 7 shows a member 36 with infills 37 and 38 which converts the T-shape to a wedge shape with the angle of the wedge determined by the number of elements to be assembled to create a chosen polygonal geometry. The infills 38 and 37 serve to encompass the leg 44. in bending the rod in a plane through the leg 44 to compress the leg, the tendency for the leg is to buckle. The pressure of the infills about the leg oppose this and add to the resiliency of the rod. The tendency to buckle may be resisted by an increased radius of curvature in the elements 16 and 17. In a rod which is loaded to one end, strength might be provided with a taper to larger dimensions, but if only the depth of the leg is increased, the tendency to buckle will be greater. This latter effect is compensated for by increasing the radius of curvature of the elements 16 and 17 as the dimensions increase. In figure 8, -the infill 41 in the open V of member 39 provides a flat outer surface such that in assembly of the members to produce the rod 29 of figure 6 these results a polygonal body with flat outer surfaces which are then convenient mounting surfaces for features such as the line guides of a fishing rod. A more solid outer surface may be established with a winding thereabout. The provision of the flat surface enables a line of guides to be mounted along the rod with the guides established in proper linear alignment without any of the difficulties or adjustments required in making rods with cylindrical rods. It is possible to provide rods using the above techniques with a taper therealong. An element such as the member of figure 4 may be tapered by being placed SUBSTITUTE SUEZ " apex down in the groove of a flat, which groove is machined with a progressive change in depth so that the member lies therein with a tapered length of material projected above the flat, which, if it be ground off down to the flat, leaves a length of member 24 in the groove which is tapered. Assembling the requisite number of these elements produces a tapered rod much as is usual in the production of tapered split cane rods. In the same way a member such as 36 of figure 7 may be machined over its length to reduce the area of its wedge to produce a taper. In preparation of a rod in accordance with the above described production techniques, the physical properties of the rod may be selected by choice amongst various parameters. In preparation of the elements of the T section, for example, the radius 45 (see Figure 1) is a critical factor. An increase in this radius produces rods with a slow action when their return from a bent configuration is considered. A decrease produces a crisper action which, in the case of fishing rods, provides the action desired in a fly fishing rod. In preparation of the array of fibres or filaments, a choice of material, fibre diameter, number of fibres per layer, number of layers, in addition to the radius of curvature, affects the qualities of the rod. So to does the nature of the fillers, the bonding materials or techniques employed to unify the assembly. However, in construction of rods, the factors which are most significant to the character of the rod are its triaxial reinforcement patten and the radius of curvature worked into the pattern in production of the generally T and V shape sections used to construct the rod. In production of fishing rods, the quality of the rod will be affected by the choice of T or V elements for the assembly. T-shape elements are more useful for game fishing rods whereas the V-shape may be more useful for a lighter type of fishing rod. Rods produced by the above means make economical use of exotic fibres with a more crush proof construction. in flexing, the rods of the invention provide increased power with the sensitivity that a fisherman requires being able to be retained. The invention enables production of a light rigid structure which when tapered enables the action of the rod to be moved to a region therealong to enable the rod ot be tailored for specific purposes. A slow taper may move the action of the rod in flexing to a middle part whereas a fat taper will move the action to the tip. In a preferred form of the invention the rod comprises a bonded carbon fibre structure whose elements are bonded together by a bonding agent such as a resin adhesive with high mechanical and dynamic strength. A prepreg material might be provided to fill out the hollow cure of the T-shape section. A foam material might fill out hollows of the assembly. A man skilled in the art will be aware of the range of materials that might be drawn upon in fabrication of a rod in accordance with the invention. The actual combination of materials will depend upon the use the rod is put to. the environment it must endure, and factors such as weight, cost, availability of materials, etc. In preferred forms, carbon fibres may be bonded by epoxy resin. Polyurethane and polyvinylchloride foams may be used as fillers. Glass and carbon fibre windings may be wrapped about the outer surfaces and bonded with epoxy resins. Depending on uses and loadings, any of the vast range of fibres, bonding agents, fillers and windings may find use in performance of the invention. SUBSTITUTE SHEET

Claims: CLAIMS 1. A rod comprising an assembly of elongate members each having abutment faces whereby each elongate member contacts its neighbor; adjacent elongate members being joined together at their abutment faces; characterised in that : the elongate members have a generally T-shape cross-section * with a flange capping a web section; the assembly combines all the flanges together to establish a polygqpal cross-section; and the web sections of each elongate member being extended in a direction fowards a common axis. 2. A rod as claimed in claim 1 wherein the T-shaped elongate members are formed from two outwardly curved elements joined at the leg of the T and spanned at the cap of the T by a planar element, the space therebetween being filled out with a filler. 3. A rod >as claimed in claim 2 wherein the T-shaped elongate members axe reduced in cross-section towards one end such that their assembly is tapered towards said end. 4. A rod as claimed in any one of claims 1 to 3 wherein the T-shaped elongate members have their space beneath their caps filled out with a filler that produces, in section, a wedge shaped member whose tapered faces are butt joined. 5. A rod as claimed in claim 1 comprising : a plurality of elongate members; the elongate members being arranged in an assembly about a central axis with at least one mating surface between adjoining elongate members; and the elongate members being bonded at their mating surfaces, each elongate member being bonded to its two neighbors about the central axis; SUBSTITUTE SHEET characterised in that each elongate member comprises a composite body formed with at least one reinforcing layer of fibres or filaments of reinforcing material extended therethrough in a predetermined pattern the predetermined pattern in planar form comprising a first array of fibres or filaments extended parallel to the length of the elongate member, a second array of fibres or filaments arrayed across said first array and a third array of fibres or filaments being arrayed oppositely to the second array, relative to the first array, to cut across the first and second arrays: and the reinforcing layer being folded or curved about an axis which is parallel to the central axis and the axis of the first array. 6. A rod as claimed in claim 5 wherein the elongate members are generally V-shaped, the fold or curve being at the base of the V, a plurality of the members being adhered together about a central axis the flat outer surfaces of adjacent V shapes being bonded together to frame the rod. 7. A rod as claims n claim 6 wherein the hollow of the V shape is filled out with a filler up to the top of the V-shape to establish a flat outer surface. 8. A rod as claims in claim 5 wherein the elongate members are T-shaped being formed of two of the folded composite bodies bonded in an outwardly opened configuration that is capped by a planar sheet of material to complete the T-shape. 9. A rod as claims in claim 8 wherein the space between the two folded bodies and the planar cap is filled out by a filler material. 10. A rod as claimed in claims 9 wherein the space beneath the arms of the T-shape are filled out to produce a wedge shaped section. SUBSTITUTESHEET 11. A rod as claimed in any one of claims 5 to 10 wherein the elongate members are reduced in cross- section towards one end and their assembly produces a rod that is tapered to that end. '

Inventors: MCGINN JOHN HUGH, MCGINN, JOHN, HUGH
Applicants: MCGINN DESIGNER RODS PTY LTD
Application year: 1990
Main classification: A01K87
IPC codes: A01K87