The invention will be described in relation to the manufacture of reinforcing elements for a coupling component for torque transmission in a coupling of the type which comprises two coupling members which are connected to respective rotary elements between which torque is required to be transmitted while some small amount of angular misalignment between the rotational axes of the two rotary elements is accommodated. In one arrangement, one of the coupling members is connected to the coupling component at three positions equally spaced about the rotational axis of the coupling component whilst the other coupling member is connected to the coupling component at three positions circumferentially spaced about said axes and between the positions at which the first said coupling member is connected The misalignment between the rotational axes of the rotary elements is acconuoodated by flexing of the coupling component between the positions at which it is connected to the coupling members The coupling component may be in the form of a hexa, ollal or circular annulus, the points of the connection in the hexagonal case being adjacent to the apices of the hexagon.

In another arrangement the coupling component can be in the form of a link which is connected at its ends to the rotary elements, there being a number of such links connected between the rotary elements.

In a coupling component for such a coupling, the thickness thereof is at a maximum at the positions where the respective coupling members are connected thereto and at a minimum therebetween. The tapering thickness of the component between the positions of maximum thickness and those of minimum thickness is necessary to give the component the required flexibility to accommodate misalignment between the axes of the rotary elements and to ensure longevity Often the coupling component is laminated from fibre-reinforced plastics material, the required tapering configuration being achieved by making reinforcing elements by superposing a plurality of differently shaped and dimensioned laminae of fibre-reinforced plastics material.

After the required number of reinforcing elements have been built up using the required number of pieces, they are incorporated with other elements into the coupling component. The laminae may be made of woven fabric pre-preg which is sufficiently tacky for the laminae to stick together. In this case the assembly is subjected to a hot pressing operation to cure the resin and produce the finished or substantially finished coupling component (subject to trimming and like operations thereafter). Alternatively the laminae may be made of woven fabric and he ! d together by a binder, the assembly finally being placed in a mould and having resin injected therein to enrobe the assembly ; the resin then being cured.

Hitherto the production of such reinforcing elements of tapering thickness has necessitated the use of a large number of differently dimensioned pieces of woven material which must be assembled in the correct superposed relation to produce the required tapered configuration of the reinforcing element. The material has been either pre-preg or held together by a binder. This procedure is inconvenient and time consuming in that a large number of differently shaped and dimensioned pieces have to be cut from the material and there is the possibility of error in their assembly It is an object of the present invention to simplify the manufacture of a coupling component as described above by improving ray in which the reinforcing elements are made.

According to one aspect of the invention \\e provide an article comprising a superposed plurality of identical, disc-like laminae, the article having a thickness which varies around the disc and is thickest at a number of tirst areas circumferentially spaced apart around the disc, the thickness in the first areas being made up by the majority of the laminae, and wherein the thickness tapers by stepwise reduction of the number of laminae in second areas on each side of each first area so that there are two second areas between two circumferentially adjacent first areas, the laminae being so shaped and arrange relative to one another as to provide said first areas and said stepwise decrease in thickness in said second areas.

According to another aspect of the invention we provide an article comprising a superposed plurality of disc-like laminae, at least some of which are identical, the article having a thickness which varies around the disc and is thickest at a number of first areas circumferentially spaced apart around the disc, the thickness in the first areas being made up by the majority of the laminae, and wherein the thickness tapers by stepwise reduction of the number of laminae in second areas on each side of each first area so that there are two second areas between two circumferentially adjacent first areas, the identical laminae being superposed in different angular relationships relative to one another about an imaginary axis which passes substantially through the centre of the article in the direction of the thickness thereof so as to provide said first areas and said stepwise decrease in thickness in said second areas.

In each case the article may be divided to form reinforcing elements each of which comprises either a first area with its two adjacent second areas or part of a first area and one second area at the side of the first area part.

Normally there will be at least one through hole in each first area and, in the different zones, the distance of generally radial edges of the second portions from the centres of the holes in the first portions will be different.

According to another aspect of the invention we provide a method of making a disc-like article having a thickness which varies around the disc and is thickest at a number of first areas circumferentially spaced apart around the disc, and wherein the thickness tapers in second areas on each side of each first area so that there are two second areas between two circumferentially adjacent first areas, the method comprising superposing a plurality of disc-tike taminae. at least some of which are identical, in different angular relationships relative to one another about an imaginary axis which <BR> <BR> <BR> <BR> <BR> passes substantially through the centre of the article in the direction of the thickness thereof so as to provide said first areas in which the thickness is made up by the majority of the laminae and in which said tapering thickness is provided by a stepwise decrease in the number of laminae in said second areas.

From another aspect we provide a method of making a disc-like article having a thickness which varies around the disc and is thickest at a number of first areas circumferentially spaced apart around the disc, and wherein the thickness tapers in second areas on each side of each first area so that there are two second areas between two circumferentially adjacent first areas, the method comprising superposing a plurality of identical, disc-like laminae which are so shaped and arrange relative to one another as to provide said first areas in which the thickness is made up of the majority of the laminae and in which said tapering thickness is provided by a stepwise decrease in the number of laminae in said second areas.

As described above the article may be divided to form reinforcing elements.

Preferably the thickness of the first area contains all the identical laminae and preferably all the laminae are identical. The laminae may be of plastics material reinforced with fibres and be superposed so that the fibres in different laminae extend in a number of different directions. The laminae are normally made from a fibre composite pre-preg.

Each lamina may have a plurality of circumferentially spaced zones 1,2, 3, 4,-----n differing in shape, each zone forming part of a first area and parts of the second areas adjacent to said first area, the laminae being superposed so that each first area of the article is formed of parts of n zones and consists of a different zone from each lamina. The zones may comprise a number of circumferentially spaced-apart first portions which are separated by cut-out portions, the laminae being superposed so that the first portions provide the first areas and, together with the cut-out portions, the second areas. There nia% be a through 1 hole in each first portion the laminae being superposed with the holes in their respective first portions in alignment by engaging the holes therein with a plurality of pegs.

The method may be used to make a reinforcing element for a fibre composite component bv making an article as described above and dividing the article into a plurality of elements along lines generally radial of the disc, each of the elements either comprising a first area and two adjacent second areas, one on each side of said first area, or part of a first area and one adjacent second area at the side of the first area.

A fibre composite coupling component may be made by locating at least two reinforcing elements as described above at the desired spacing and relative locations, laying up plies of fibre composite material between the elements and so that such plies overlap the elements and incorporating the elements in the component.

The invention will now be described in detail by way of example with reference to the accompanying drawings in which:- Figure I is a view of a prior art coupling component showing the parts from which it is made ; Figure 2 is a plan view and elevation of a reinforcing element for the coupling of Figure I Figure 3 is a cross-section showing how the fixing portions of the coupling of Figure I are assembled ; Figure 4 is a view of a lamina of a first design used to make an article embodying the invention ; Figure 5 is a view of an article comprising six laminae of the design of Figure 4 superposed in different angular relationships ; Figure 6 shows the article of Figure 5 having been divided to form reinforcing elements for a coupling component ; Figure 7 is a view of a second form of lamina for making an article embodyinO the invention ; Figure 8 is a view of an article comprising six laminae of the shape shown in Figure 7 superposed in different an ; ular relationships, Figure 9 shows how the article of Figure 8 may be divided to form reinforcing elements for a coupling component such as shown in Figure !.

Figure 10 is a view of a third form oftamina for making an article enabodying the invention : Figure)) is a view of an article comprising three taminae of the shape shown in Figures superposed in different angular relationships.

Figure 19 shows how the article of Figure t i cart be divided to form reinforcing elements, Figure 13 is an elevation of a coupling! ink incorporating reinforcing etements as shown in Figure) 2, and Figure 14 is a section through the link of Figure 13.

Referring first to Figure), this shows a priol art hexat, onal couplin ;, component and the parts from which it is made. The component is indicated generally at 10 and comprises six leaves 1 1 extending along the sides of the hexagon and fixing portions 12 at the corners of the hexagon. The component may be made from a plurality of laminates of fibre composite pre-preg which have been hot pressed to form the final component as will be described below.

The leaves 11 are made up of a plurality of laminae 13 and the fixing portions 12 by the ends of those laminae and by reinforcing elements 14 and rings 15 A reinforcing element is shown in Figure 2 and consists of six superposed laminae 16 to 21 of gradually increasing area. The central portion of the reinforcing element constitutes a first area 22 and has the thickness of six laminae. On each side of the first area there is a second area 23 consisting of the exposed edges of the laminae 17 to 21.

Each second area decreases stepwise in thickness fi-om the first area 22 to the edge 24 of the reinforcing element. The reinforcing element is provided with a through hole 25 and these holes line up with the holes 26 and 27 in the taminae) 3 The assembly is put <BR> <BR> <BR> <BR> together as shown in Figure 3. There are four reinforchl,, elements 14,, 142 14 144 forming part of the fixing portion 12 and which are laid up with the laminae 13 as shown. It will be noted that the laminae 13 have inclined ends 28 which substantially line up with the edges 24 of the reinforcing elements. Each fixing portion is completed <BR> <BR> <BR> <BR> by a ring) 5 at each end, the ring having a hole 29 which lines up with the holes 26 and 27 in the laminae 13 and the holes 25 in the reinforcing elements The holes are used to receive bolts to connect the coupling element to members on rotary shafts to be coupled. This construction is shown in GB-A-2s2 ? =128.

Heretofore, the reinforcing elements 14 have been made by separately cutting <BR> <BR> <BR> <BR> the appropriate shapes for the laminae 16 to 2t from pre-preg, superposing them, assemblh1=, them with the remaining elements of the coupling as shown in Figure 3 and <BR> <BR> <BR> <BR> then hot pressing the whole assembly to cure it Alternatively the reinforcement has been assembled, the assembly put in a naould and resin injecte to form the component The parts have been aligned, during assembly, by pegs passing through the holes 25.

26,27 and 29. It is, however, a time consuming business to assemble the reinforcing elements as described.

The invention is based on the idea of making the reinforcing elements by superposing a plurality of disc-like laminae to form an article having a thickness which varies around the disc and then dividing the laminated disc to form a plurality of reinforcing elements.

Figure 4 shows one form of lamina which may be used. This may be formed of composite material, i. e. fibre reinforced pre-preg, the resin being epoxy resin, or woven fibre reinforcement containing a binder. The lamina may be considered to be divided into six zones A-F, the zone A being between the lines 30 and 31, the zone B being between the lines 31 and 32, the zone C being between the lines 32 and 33, the zone D being between the lines 33 and 34, the zone E between the lines 34 and 35 and the zone F between the lines 35 and 30.

Each zone comprises a first portion and two second portions one on each side of the first portion. Thus zone A comprises a shaded first portion 36 and two second portions 37 and 38. Zone B comprises a shaded first portion 39 and on each side thereof a second portion 40 and 41. Zone C comprises a shaded first portion 42 and on each side thereof a second portion 43 and 44 Zone D comprises a shaded first portion 45 and on each side thereof a second portion 46 and 47. Zone E comprises a shaded first portion 48 and on each side thereof a second portion 49 and 50 and finally zone F comprises a shaded first portion 51 and on each side thereof second portions 52 and 53. The sizes and shapes of the first portions in each zone, i. e. the portions 36,39, and 51 are identical. It will be seen that the second portions in each zone differ in shape and that the zones differ in shape The distances of the gellel-allv radial edges of the second portions from the centre of the hole in the associated first portion varies between the zones Six of the laminae shown in Figure 4 are superposed in different angutar relationships relative to one another about an imaginary axis 54 which passes through the centre of the assembly and in the direction of the thickness of the assembly Such an assembly is shown in Figure 5 The assembly comprises six first areas 55-60 <BR> <BR> <BR> <BR> respectivel\. Each of these areas is the shape of a first portion (eg. 36) of a lamina and each first area has a thickness of six laminae and will consist of the superposed first portions 36 « 39,42,45,48 and 51 of the six different laminae. Between each pair of adjacent first areas, such as the areas 55 and 60, are two second areas. Thus the first such second area 61 is between the lines 62 and 63 and the second such area 64 is between the lines 63 and 65. The thickness of each second area tapers from adjacent the first area 55 or 60 down to the line 63 separating the two second areas. Thus, for example, in the area 61 the part 66 has a thickness of five laminae, the part 67 four laminae, the part 68 three laminae, the part 69 two laminae and the part 70 one lamina.

Similarly the thickness increases from the single lamina 70 up to the first area 60 in steps.

Thus the assembly of the laminae comprises a plurality of first areas each of which has, in the present case, a thickness of six laminae and two second areas between each two first areas in which the number of laminae decreases stepwise from the first area towards the junctions between adjacent second areas of two adjacent <BR> <BR> <BR> zones. If there were n laminae each first area would have a thickness of n laminae and each second area would decrease in thickness from the first area and would have n-1, n-2 etc. laminae as the thickness decreased stepwise from the first area.

It is possible, as shown in Figure 6, to divide the article shown in Figure 5 to form a number of reinforcing elements. Thus a reinforcing element is shown in Figure 6 at 71. This includes the first area 55 shown in Figure i with the second area 61 on the one side of it and a similar second area 79 on the other side of it. Thus the thickness of the reinforcing element in the first area 55 is six laminae and as described above tapers down to one lamina at the edges 73 and 74 of the reinforcing element The article is divided into six such reinforcing elements along generally radia) lines It will be noted that each lamina is provided with six circumferentially spaced holes 74. These holes are used to locate the laminae as the\ are assembled. Thus there will be provided a jig having six pegs or projections on which the laminae are assembled so that they are aligned as they are superposed in their different angular relationships about the axis 54. For example, taking a particular first area 55, if the first portion 36 is at the bottom then superposed on that would be the tirst portion 51 of the next lamina and on top of that the first portion 48 of the next lamina and on top of that the first portion 45 of the next lamina and on top of that the first portion 42 of the next lamina and finally the first portion 39 of the last lamina. Each first area thus contains the first portion of each lamina. lt will be noted from Figure 4 that the second portions of the lamina has cut out portions which include bridging parts which are at different distances from the axis 54. Thus the bridging part 76 is nearest to the axis 54 with the bridging parts 77,78, 79,80 and 81 being progressively further from the axis 54. One can check that the assembly has been correctly laid up by the fact that there are no gaps between the bridging parts.

Referring now to Figures 7 to 9, these show a different shaped lamina which is hexagonal. The lamina has six cut-outs 93 to 98 respectively which are spaced around an imaginary central axis 99 of the lamina. There are also six equi-angularly spaced holes 100. The cut-outs are of similar shape but of different widths and as in the previous embodiment the lamina can be divided into six zones Thus there is a zone <BR> <BR> <BR> <BR> 101 between the lines 102 and 103, a zone 104 between the lines 103 and 105. A zone 106 between the lines 105 and 107, a zone 108 between the lines 107 and 109, a zone l lO between the lines 109 and 1 11 and finally a zone 12 between the lines 111 and 102. As before, each zone contains a first portion and on each side of the first portion two second portions. The first portions of the various zones are shaded.

As in the embodiment Figures 4 to 6, six of the laminae shown in Figure 7 are arrange in superposed relation at different angutar positions around the imaginary axis 99. This results in an assembly as shown in Figure 8 The shaded first portions of the laminae are superposed and thus the assembly has six first areaj 113, 114, 115, 1 i6, 117 and I IS each of which has a thickness of six laminae and these first areas are obtained by superposing the shaded first portions of the laminae by arranging them in different angutar positions about the axis 99 as described.

On each side of each first area is a second area where me thickness decreases stepwise thus for example on one side of the first area t) 5 is a second area in which the thickness decreases, the portion I 1a havin a thickness of five laminae, the portion 119 four laminae, the portion 120 three laminae, the portion 121 two laminae and the portion 122 one lamina comin down to the aperture ! 23. There is a similar arrangement on the other side of the first area 115.

The assembly is laid up on a jig in which pegs engage me holes 100 to locate the laminae. To make the reinforcing elements the assemble! is trimmed around the dotted line 124 and the centre 124a removed. As a result the assembly is then divided <BR> <BR> <BR> <BR> by the cut-outs on generally radial lines such as the lines from 25 in Figure 9 to produce six reinforcing elements one of which is shown at 126 and which comprises the first area 127 having a thickness of six laminae, a second area 128 on each side whose thickness gradually decreases stepwise as described above.

The reinforcing elements 71,126 produced by the methods described in relation to Figures 4 to 9 are assembled into a coupling component as described in relation to Figures 1 to 3 and replace the reinforcing elements 14 shown in those figures.

The invention has been described in relation to the use of six identical laminae in Figures 4 to 6 and Figures 7 to 9. However it is not necessary that there be six laminae, there could be more or less, nor is it necessary that all the laminae be identical although this is preferred.

The reinforcing elements made in accordance with Figures 6 to 9 have been shown as being incorporated into a ring-like coup) ing component However reinforcing elements could also be included at the ends of a coupling link as described below.

Referring now to Figures 10 to 12, these show a lamina which is somewhat similar in shape to that of Figure 7 The lamina has three first cut-outs 130, 131 and 132 which are identical and have a generatty triangutar portion, shown for the cut-out 130 at 133, and a generatty inwardlv extending (radial slit 134 The lamina also has three second cut-outs! 35.) 36and ! 37 The cut-out 136 is similar to the cut-outs 130 to 132 and the cut-outs 135 and I. 7 are similar The lamina can be considered to have three zones separated by lines 13Sn 139 and 140.

Thus there is a zone 141 between the lines 38 and ils9, a zone 142 between the lines 139 and 140 and a zone 143 between the lines 140 and t38 Each zone has a first portion and at each side of the first portion, a second portion The first portions in each case are shaded Thus the zone 141 has a first portion 144 which contains the cut-out 130 and second portions 145 and 146 formed by parts of the cut-outs) 35 and 137 on each side thereof. The zone 142 includes the shaded first portion 147 which contains the cut-out 131 and on each side thereof a second portion 148 and 149 which also contains parts of the cut-outs 135 and 136. Finally, the zone 143 has a shaded first portion 150 containing the cut-out 132 and on each side second portions 151 and 152. Each of the first portions 144,147 and 150 has two holes 200.

Figure I1 shows an article which is made up of three laminae such as in Figure 10 which have been laid up in different angular positions around the imaginary axis 153. The assembly comprises three first areas 154,155 and 156. Each of the first areas contains one of the cut-outs 130, 131 and 132 and also two of the holes 200.

Each first area 154-156 has a thickness of three laminae. On each side of each first area is a second area in which the thickness decreases stepwise. Thus, for example, for the first area 154 there are second areas 157 and 158. Taking the second area 158 by way of example there is a part 159 which is two laminae thick and a part 160 which is one lamina thick. The same arrangement is present at each side of each of the other first areas 155 and 156.

The article shown in Figure I I may be divided to form reinforcing elements.

Thus the article is trimmed around the circle 161. The centre of the article is also cut- out along the circle 162. This results in the article being in six pieces as shown in Figure 12 because the circle 162 intersects the inner ends of the cut-outs. Each of these parts forms a reinforcing element and one of these is shown at 163 vit includes <BR> <BR> <BR> <BR> half of the first area 156. The upper edge in Figure) 2 being defined by the edge of the cut-out 1') 2. The lower edge portion 164 is formed by the second area which is below the first area 156 in Figure 1 1 Thus the reinforcing element has a stepped thickness along the edge portion 164 but is offutt thickness atong the othet-edge portion 165. <BR> <BR> <BR> <BR> <P>Two reinforcing elements 163 can be incorporated into a coupling fink as shown in Figures 13 and 14, the link being indicated generally at 166 The end portions 167 of, the link are provided by one or more of the reinforcing elements arranged so that the <BR> <BR> <BR> <BR> stepwise reduction in thickness is arranged at 168 between the fixing portion and the leaf 170 of the link. The link is made by laying up as many reinforcing elements as required with plies to form the leaf 170 and, if the laminae are made of pre-preg, the assembly can be hot pressed or if the laminae are not made of pre-preg then the assembly can be put in a mould and resin injecte.

The invention has been described in detail with reference to the use of fibre composite reinforced material. The fibre will preferably be a woven fibre but could be a uni-directional fibre if required. The material may be pre-preg or held together by a binder. Superposing the laminae in different orientations about said axis causes the fibre reinforcement in the reinforcing elements to extend in different directions to give them strength.

The invention is not limited to the use of fibre-reinforced composite but could also be used, if desired, to make an assembly of wood laminae in which the wood grains extend in different directions in the assembles The features disclosed in the foregoing description. or the following claims, or the accompanying drawings, expressed in their specific forms or in teans of a means for perfoaning the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilise for realising the invention in diverse forms thereof.