Rivet

Abstract

A rivet 1 for securement in a hole has a plurality of rivet segments 11, 12 ,13. Each rivet segment 11, 12 ,13 includes a head portion 111, 121, 131 and a shaft portion 112, 122, 132. Each shaft porti

Description

This invention relates generally to a rivet. More specifically, although not exclusively, this invention relates to a removable rivet. A rivet is a type of fastener which secures two components together. Usually such rivets are considered to provide a permanent fixture, meaning that the structure cannot be disassembled easily once rivetter together. This might be disadvantageous for maintenance, repair, reuse and / or recycling of the structure or components of the structure, for example due to dissimilar materials or a necessity to damage the structure to disassemble it. Some removable fasteners are known, but these are often difficult to remove from the structure and so may not fully alleviate the aforementioned disadvantages. Further, these removable fasteners are often difficult to install in the first place, due to a requirement that the fasteners securely fasten components together and thus requiring, for example, stiffer parts to engage with the structure. Such rivets are also prone to failure, for example due to fracture caused by the increased stiffness of the materials. It would therefore be advantageous to overcome at least some of these drawbacks. Accordingly, an aspect of the invention provides a rivet for securement in a hole, the rivet comprising a plurality of rivet segments, each rivet segment including a head portion and a shaft portion, wherein the rivet segments include a wedge segment insertable between the other segments to force, in use, the other segments apart such that the shaft portion engages the hole. Another aspect of the invention provides a rivet for securement in a hole, the rivet comprising a plurality of rivet segments, each rivet segment including a head portion and a shaft portion, each shaft portion comprising a series of gripping features along its length, wherein the rivet segments include a wedge segment insertable between the other segments to force, in use, the other segments apart such that the gripping features engage the hole. Advantageously, the shaft portion may grip edges of the hole at multiple positions along the length of the shaft portion. This may improve the versatility of the rivet. The gripping features may start proximal to or adjacent the head portion. The wedge segment may comprise opposed sides. Each opposed side may comprise a series of gripping features along its length. Each opposed side may have a curved or arcuate shape. The wedge segment may comprise opposed faces. The opposed faces may extend between the opposed sides. One or both of the opposed face may comprise a tapered side or a tapered portion. Each opposed face may be substantially planar or comprise a plurality of planar sections. The wedge segment may comprise a tapered, or wedge-shaped, portion at an opposite end of the wedge segment to the head portion. The tapered or wedge-shaped portion may comprise a taper on one side, e.g., only one side, of the shaft portion of the wedge segment. The tapered or wedge-shaped portion may extend partway along the shaft portion. The wedge segment may comprise a gap between the opposed sides. The gap may extend from an end of the shaft portion opposite to the head portion. The gap may extend from an end of the shaft portion opposite to the head portion, partway along the shaft portion of the wedge segment. The gap may extend from an end of the shaft portion opposite to the head portion, to the head portion. The shaft portion may comprise two elongated members separated by the gap. Each elongated member may provide one of the opposed sides. Each elongated member may comprise the gripping features. Each elongated member may extend from the head portion. Each elongated member may have a cantilevered connection to the head portion. The rivet segments may include side segments or main segments between which the wedge segment is insertable. Each side segment may comprise a part-cylindrical or part-frustoconical outer side comprising a series of gripping features along its length. Each side segment may be connected together. Each side segment may be parts of a single component. Each side segment may be connected together by a tether extending between ends of each side segment opposite to the respective head portion. The tether may be flexible. Each gripping feature may comprise a radial protrusion. Each gripping feature may comprise a protrusion extending from the respective segment in a radial direction. Each gripping feature may have a circumferential length. Each gripping feature may be, e.g. be in the form of, a ridge ora strip. Each gripping feature may be, e.g. be in the form of, a ridge or a strip protruding from a body of the respective segment. Each gripping feature may be a ridge or a strip which extends in a circumferential direction around the shaft portion. Each gripping feature may comprise a lead-in surface which is tapered radially inwardly with distance away from the head portion. Each gripping feature may comprise a lead-in surface which is tapered and faces with a directional component away from the head portion. Each gripping feature may comprise a gripping surface which faces towards the head portion or with a directional component towards the head portion. The gripping surface of each gripping feature may be substantially perpendicular to a length direction of the respective shaft portion. Alternatively, each gripping surface of each gripping feature may be tapered at a steeper angle to the lead-in surface. Advantageously, the rivet may be removable. Each gripping feature may be adjacent another gripping feature. Each gripping feature may be adjacent another gripping feature such that the shaft portion has a ridged (.e.g., provided by a series, e.g., a repeated series, of ridges) or serrated or undulating gripping side / s. Each gripping feature may comprise a triangular cross-section. The series of gripping features may be arranged along a majority of a length of the shaft portion between the head portion and a terminal end of the shaft portion. A majority of a length of the shaft portion, between the head portion and a terminal end of the shaft portion, may comprise gripping features. The terminal end of the shaft portion may be a terminal end of the rivet. The series of gripping features may be arranged along an entirety of a length of the shaft portion between the head portion and a terminal end of the shaft portion. An entirety of a length of the shaft portion, between the head portion and a terminal end of the shaft portion, may comprise gripping features. The gripping features may be substantially evenly and / or equally and / or regularly distributed along the respective shaft portion. Each rivet segment may comprise, or be made from, plastic. Each rivet segment may comprise, or be made from, a fibre reinforced plastic material. The fibre reinforced plastic material may be nylon (polyamide, PA), polypropylene (PP), polyphenylene sulphide (PPS) or polyethylene terephthalate (PET) with glass, carbon or basalt reinforcement fibres. Each rivet segment may be additively manufactured, for example 3D printed. The rivet may be a removable fastener. It will be understood that the term “removable” refers to a non-permanent fastener, such that a structure can be disassembled without damaging or destroying components of the structure. Each rivet segment may be a unitary structure. Another aspect provides a structure comprising a first member, a second member, and one of any of the aforementioned rivets, the rivet passing or being passable through aligned or alignable holes in each of the first and second member. The structure may comprise a third member. The structure may comprise a plurality of rivets, each rivet being one of the aforementioned rivets. The first member and the third member may be secured or securable to the second member by each rivet. The first member and the third member may be secured or securable to the second member via the shaft portion of each rivet which passes or is passable through a respective hole in the first or third member which is aligned with a hole in the second member. Each rivet may be removably secured or securable in the respective aligned holes. The first member may be orientated at an angle to the third member. The first member may be substantially perpendicular to the third member. The first member may extend away from the third member partway along the length of the first member. Either or both of the first and third member may be a beam, e.g., a tubular beam. The third member may be a connection plate. The third member may be secured or securable to one side of the or each beam by the rivets. The or each beam may be a hollow beam, e.g., a tubular beam. The connection plate may be a first connection plate of a connector. The first connection plate may be secured or securable to a first side of the or each beam. The connector may comprise a second connection plate which is secured or securable to a second side of the or each beam. The connector may comprise a second connection plate which is secured or securable to a second side of the or each beam via the shaft portion of each rivet which passes through a respective hole in the or each second side which is aligned with a hole in the second connection plate. The second connection plate may be located on an opposite side of the connector to the first connection plate. The connector may comprise an enclosure or an internal volume with an aperture for the first member a passage for the third member. The channel may be defined by side walls and / or internal webs of the connector. The side walls may connect the first and second connection plates together. The passage may be defined by overhanging portions of the first and second connection plates. The connector may be a unitary structure. Alternatively, the connector may comprise two halves which are joined or joinable together. Any of the first member, second member, third member, connection plate, first or second connection plate or connector may comprise a fibre reinforced plastic material. Either or both of the first and third member may comprise a braided fibre reinforced plastic material. The fibre reinforced plastic material or braided fibre reinforced plastic material may be nylon (polyamide, PA), polypropylene (PP), polyphenylene sulphide (PPS) or polyethylene terephthalate (PET) with glass, carbon or basalt reinforcement fibres. Any number of the first member, second member, third member, connection plate, connector, and the plurality of rivets may comprise, or may be made from, the same material. E.g., all of the first member, second member, third member, connection plate, connector, and the plurality of rivets may comprise, or may be made from, the same material. The structure may be, or may be for, an automobile structure. The structure may be or may comprise an A-pillar for an automobile. Another aspect provides a method of manufacturing any of the aforementioned rivets, the method comprising additively manufacturing, for example 3D printing, each of the plurality of rivet segments. The method may comprise additively manufacturing, for example 3D printing, each of the plurality of rivet sections using a fibre reinforced plastic material. Another aspect provides a method of manufacturing any of the aforementioned structures, the method comprising manufacturing the first and / or third members using braided fibre reinforced plastic. Another aspect provides a method of manufacturing any of the aforementioned structures, the method comprising braiding fibres to form the first and / or third members from braided fibre reinforced plastic. Another aspect provides a method of converting the aforementioned structure between an assembled state and a disassembled state, by inserting and removing, respectively, the rivets from each of the aligned holes. For the avoidance of doubt, any of the features described herein apply equally to any aspect of the invention. Another aspect of the invention provides a computer program element comprising and / or describing and / or defining a three-dimensional design, e.g. of the rivet or structure described above or an embodiment thereof. The three-dimensional design may be for use with a simulation means or an additive or subtractive manufacturing means, system or device. The computer program element may be for causing, or operable or configured to cause, an additive or subtractive manufacturing means, system or device to manufacture the rivet or components of the structure described above or an embodiment thereof. The computer program element may comprise computer readable program code means for causing an additive or subtractive manufacturing means, system or device to execute a procedure to manufacture the rivet or components of the structure described above or an embodiment thereof. A further aspect of the invention provides a computer program element comprising computer readable program code means for causing a processor to execute a procedure to implement one or more steps of the aforementioned method. A yet further aspect of the invention provides the computer program element embodied on a computer readable medium. A yet further aspect of the invention provides a computer readable medium having a program stored thereon, where the program is arranged to make a computer execute a procedure to implement one or more steps of the aforementioned method. A yet further aspect of the invention provides a control means or control system or controller comprising the aforementioned computer program element or computer readable medium. For purposes of this disclosure, and notwithstanding the above, it is to be understood that any controller(s), control units and / or control modules described herein may each comprise a control unit or computational device having one or more electronic processors. The controller may comprise a single control unit or electronic controller or alternatively different functions of the control of the system or apparatus may be embodied in, or hosted in, different control units or controllers or control modules. As used herein, the terms “control unit” and “controller” will be understood to include both a single control unitor controller and a plurality of control units or controllers collectively operating to provide the required control functionality. A set of instructions could be provided which, when executed, cause said controller(s) or control unit(s) or control module(s) to implement the control techniques described herein (including the method(s) described herein). The set of instructions may be embedded in one or more electronic processors, or alternatively, may be provided as software to be executed by one or more electronic processor(s). For example, a first controller may be implemented in software run on one or more electronic processors, and one or more other controllers may also be implemented in software run on or more electronic processors, optionally the same one or more processors as the first controller. It will be appreciated, however, that other arrangements are also useful, and therefore, the present invention is not intended to be limited to any particular arrangement. In any event, the set of instructions described herein may be embedded in a computer-readable storage medium (e.g., a non-transitory storage medium) that may comprise any mechanism for storing information in a form readable by a machine or electronic processors / computational device, including, without limitation: a magnetic storage medium (e.g., floppy diskette); optical storage medium (e.g., CD-ROM); magneto optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g., EPROM ad EEPROM); flash memory; or electrical or other types of medium for storing such information / instructions. Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, unless such features are incompatible. For the avoidance of doubt, the terms “may”, “and / or”, “e.g.”, “for example” and any similar term as used herein should be interpreted as non-limiting such that any feature so-described need not be present. Indeed, any combination of optional features is expressly envisaged without departing from the scope of the invention, whether or not these are expressly claimed. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner. Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a view of a rivet; Figure 2A and 2B are views of a wedge segment of the rivet of Figure 1; Figure 3 is a view of a side segment of the rivet of Figure 1; Figure 4A and 4B are views of a structure; and Figure 5 is a view of a connector used in the structure of Figures 4A and 4B. Referring now to Figure 1, there is shown a rivet 1 for securement in a hole. The rivet 1 is preferably for securing two or more plate-like parts or sections together. The rivet 1 of this example may otherwise be referred to as a removable rivet, a fastener or a removeable fastener. The rivet 1 comprises a plurality of rivet segments 11, 12, 13. In this example the rivet segments include two side segments 11, 12 and a wedge segment 11. Each rivet segment 11, 12, 13 comprises a head portion 111, 121, 131 and a shaft portion 112,122, 132. Terms such as length, length direction, radius, radial direction, lateral direction, circumference and circumferential direction are used herein, and it will be appreciated that these relate to directions relevant to the rivet 1 when the segments 11, 12, 13 are assembled together, as shown in Figure 1. That is, the rivet 1 is generally cylindrical in shape, and so the length direction is an axial direction of the cylindrical shape, the radial / lateral direction is a radial direction of the cylindrical shape, and the circumferential direction is a circumferential direction of the cylindrical shape. The shaft portion 112, 122, 132 of each rivet segment 11, 12, 13 of the rivet 1 comprises gripping features 113, 123, 133 along its length. In this example, the head portion 111, 121, 131 of each segment 11, 12 ,13 has a larger lateral or radial size than the shaft portion 112, 122, 132 of the respective rivet segment 11, 12 ,13. This means that, when the rivet segments 11, 12, 13 are assembled to provide the rivet 1, a head of the rivet 1 has a larger diameter than a shaft of the rivet 1, the head being provided by the head portions 111, 121, 131 combined and the shaft being provided by the shaft portions 112, 122, 132 combined. In use and as is described in more detail subsequently, the side segments 11, 12 are insertable into the hole first, and then the wedge segment 13 is insertable between the side segments 11, 12 to force the side segments 11, 12 apart, such that the gripping features 113, 123 ,133 of the side segments 11,12 and of the wedge segment 13 engage the edges of the plates defining the hole. In most cases, the head of the rivet 1 would abut a surface of one of the plate-like parts. Referring now to Figures 2A and 2B, the wedge segment 13 is shown. The gripping features 133 of the wedge segment 13 are arranged on opposed sides, or opposed edges, of the shaft portion 132. In this example, each opposed side has a curved or arcuate shape in the circumferential direction. The wedge segment 13 comprises opposed faces 134. Each opposed face 134 extends between the opposed sides. In this example, each opposed face 134 extends across the entire length of the wedge segment 12. That is, the shaft portion 132 and the head portion 131 of the wedge segment 12 each comprise parts of the opposed faces 134. As best illustrated in Figure 2B, the wedge segment 13 is wedge-shaped at a leading end of the wedge segment 13, the leading end being an opposite end of the wedge segment 13 to the head portion 131. In this example, the wedge-shaped portion of the shaft portion 132 of the wedge segment 13 extends partway along the length of the shaft portion 132. However, it will be appreciated that the wedge-shaped portion could extend over any distance of the shaft portion 132. In this example, the wedge-shape is provided on only one of the opposed faces 134 of the shaft portion 132, wherein an end of this face is tapered. In this example, the other opposed face 134 is flat along an entire length. However, it will be appreciated that both opposed faces could be tapered. In this example, one of the opposed faces 134 is entirely flat or planar, and the other opposed face 134 comprises two flat or planar sections, an upper section being parallel with the other opposed face, and a lower section providing the tapered portion. The wedge segment 13 may comprise a gap 135 between the opposed sides, extending from the end of the wedge segment 13 opposite to the head portion 131 and partway along the shaft portion 132 to proximal the head portion 131. The shaft portion 132 therefore comprises two elongated members separated by the gap 135. Each elongated member comprises one of the opposed sides so that the gripping features 133 are provided on each elongated member. Each elongated member extends from the head portion 131 and is connected to the head portion 131 via a cantilevered connection. The gap 135 enables the elongated members to bend allowing for easier insertion of the wedge segment 13. Referring now to Figure 3, one of the side segments 12 is shown. Whilst only one side segment 12 is shown, the two side segments 11, 12 are the same and so this description applies equally to the other side segment 11. In this example, the shaft portion 112, 122 of each side segment 11, 12 is part-cylindrical in shape. That is, the cross-sectional shape of the shaft portion 112, 122 of each side segment 11, 12 is partially circular or, more specifically, has the shape of a segment of a circle. The side segment 12 has a gripping side, which comprises the gripping features 123 and which is curved or arcuate in shape in the circumferential direction. Defined between radial edges of the gripping side is a contact face 124, which is flat or planar. The contact face 124 extends along an entire length of the side segment 12, in this example. That is, both the head portion 121 and the shaft portion 122 comprise parts of the contact surface 124. Referring now to all of Figures 1 to 3, the gripping features 113, 123, 133 are described in more detail. Each gripping feature 113, 123, 133 is in the form of a radial protrusion which is a ridge or a strip which extends in the circumferential direction around the respective shaft portion 112,,122, 132. Each gripping feature 113, 123, 133 comprises a lead-in surface which is tapered and which faces with a directional component away from the respective head portion 111, 121, 131. In other words, each lead-in surface is sloped or tapered radially inwardly with distance away from the respective head portion 111, 121, 131. Each gripping feature 113, 123, 133 comprises a gripping surface which faces towards, e.g., with a directional component towards, the respective head portion 111, 121 ,131. In this example each gripping surface is substantially perpendicular to the length direction of the respective shaft portion 112, 122, 132, but it will be appreciated that each gripping feature 113, 123, 133 may instead be tapered, and may be at a steeper angle to the lead-in surface. Each gripping feature 113, 123, 133 therefore has a triangular crosssection. Each gripping feature 113, 123, 133 is adjacent another gripping feature 113, 123, 133 in this example, such that each shaft portion has a ridged, e.g., in that there is a series of ridges, or serrated gripping side. In this example, the series of gripping features 113, 123, 133 are arranged along an entire length of the shaft portion 112, 122 ,132 between the head portion 111 ,121 ,131 and a terminal end of the shaft portion 112, 122 ,132. However, it will be appreciated that the series of gripping features 113, 123, 133 may instead be arranged along any amount of the length, for example a majority of the length, of the shaft portion 112, 122 ,132 between the head portion 111 ,121, 131 and the terminal end of the shaft portion 112, 122 ,132. Also, it will be appreciated that the gripping features 113, 123, 133 may instead be spaced apart along the length direction. The terminal end of the shaft portion 112, 122 ,132 may also be a terminal end of the rivet 1, as in this example. In this example, the gripping features 113, 123, 133 are substantially regularly distributed along the respective shaft portion 112, 122,132. In this example each rivet segment 11, 12 ,13 is made from fibre reinforced plastic and is 3D printed. The fibre reinforced plastic material may be nylon (polyamide, PA), polypropylene (PP), polyphenylene sulphide (PPS) or polyethylene terephthalate (PET) with glass, carbon or basalt reinforcement fibres. However, it will be appreciated that other materials and manufacturing methods may also be used, for example plastic or metal and for example moulding, stamping or forging. In order to assemble a structure, for example to connect two plate-like parts of components of a structure together, a hole in each plate-like part is aligned and the two side segments 11, 12 of the rivet 1 are inserted into the aligned holes until the head portion 111, 121 of each side segment 11,12 abuts one of the plate-like parts. The wedge segment 13 is then inserted between the side segments 11,12 such that each opposed face 134 of the wedge segment 13 abuts a contact surface 114, 124 of a respective one of the side segments 11, 12. The wedge segment 13 is pushed into the aligned holes until the head portion 131 of the wedge segment 13 abuts the plate-like part. When the wedge segment 13 is inserted between the side segments 11, 12, the side segments 11, 12 are urged apart such that the gripping features thereof are forced into contact with edges defining the holes of the platelike parts. Furthermore, the gap 135 between the elongated members of the wedge portion 13 allows the elongated members to elastically deform inwards as the gripping features 133 move over the edges of the holes, and this elasticity forces the gripping features 133 of the wedge segment 13 into contact with the edges defining the holes of the plate-like parts. In this way, gripping features 113, 123, 134 may engage the edges defining the holes around the entire circumference of the hole, thereby improving the robustness of the securement between the plate-like parts, as well as reducing a risk that the wedge segment 13 inadvertently moves out of the aligned holes. Furthermore, the design may mean that the plate-like parts can be disassembled by removing the wedge segment 13, which also allows the side segments 11, 12 to also be removed from the aligned holes. The may provide a structure which can be disassembled for maintenance or repair, or to recycle or reuse each part of the structure. In this way, the rivet 1 may provide a removable fastener, in that joints which secured using the rivet 1 are not permanent joints. Referring now to Figures 4A and 4B, there is shown a structure 2. In this example the structure 2 is an A-pillar for an automobile, but it will be appreciated that the concept described herein is applicable to many other structures for automobiles as well as for other equipment unrelated to automobiles. The structure 2 comprises a first member 21, a second member 22, and a connector 23. The first member 21 is a curved beam which is tubular in shape. The second member 22 comprises a plurality of tubular beams arranged alongside one another. The second member 22 extends in a substantially perpendicular direction from the first member 21, partway along the first member 21, and the first and second members 21,22 are connected together by the connector 23, as is described subsequently. Referring to Figure 5, the connector 23 is shown in isolation. The connector 23 comprises a first connection plate 231 which is located on an opposite side of the connector 23 to a second connection plate 232. The connector 23 comprises side walls 233 and internal webs 234 which connect the first and second connection plates 231, 232 together. The internal webs 234 define an internal channel of the connector 23 for the second member 22 to pass through. The first and second connection plates 231, 232 have overhanging portions which overhang the side walls 233 and internal web 234 at one side of the connector 23, to provide a passage therebetween, for receiving the first member 21.The first and second connector plates 231, 232 each comprise a plurality of holes 235 distributed across the parts which correspond to the channel and passage for receiving the first and second members 21, 22. In this example, the connector 23 is formed of two halves, each half having one of the two connection plates 231, 232 and having parts of the side walls 233 and internal webs 234. The two halves are joined together to define an internal volume of the connector, which therefore forms an enclosure. However, in other examples the connector 23 is 3D printed and so is a unitary structure. The connector 23 of this example is made of a fibre reinforced plastic material such as nylon (polyamide, PA), polypropylene (PP), polyphenylene sulphide (PPS) or polyethylene terephthalate (PET) with glass, carbon or basalt reinforcement fibres. In this example the tubular beams of the first and second members 21, 22 are manufactured using braided fibre reinforced plastic, whereby fibres, which are pre-impregnated with plastic, for example thermoplastic, are braided and then the braided tubes are moulded into the tubular beam shapes. However, it will be appreciated that other manufacturing methods and materials are envisaged. Referring to Figures 4A and 4B, the assembly of the structure 2 is now described. The tubular beams of the second member 22 are inserted into the channel defined by the internal webs 234 and the first and second connector plates 231, 232 of the connector 23. The tubular beam of the first member 21 is inserted into the passage provided by the overhanging parts of the first and second connector plates 231, 232. An end of the second member 22 therefore abuts, or is proximal to, a side surface of the first member 21. Opposing sides of the tubular beam of the first member 21 comprise holes (not shown). These opposing sides of the first member 21 provide plate-like parts of the first member 21. The holes are aligned with the holes 235 passing through the overhanging parts of the first and second connector plates 231,232. A rivet 1, as was described with reference to Figure 1-3, is then inserted into each of the aligned holes 235 between the overhanging parts of the first and second connection plates 231, 232 and the first member 21, to secure the connector 23 to the first member 21. Insertion of each rivet 1 is as described previously with reference to Figures 1-3. Opposing sides of each tubular beam of the second member 22 comprise holes (not shown). These opposing sides of each tubular beam of the second member 22 provide plate-like parts. These holes are aligned with the holes 235 passing through the first and second connector plates 231, 232 which correspond to the channel which is partially defined by the internal webs 234. One of the rivets 1, as was described with reference to Figure 1-3, is then inserted into each of the aligned holes 235 between the first and second connection plates 231, 232 and the second member 22, to secure the connector 23 to the second member 22. Insertion of each rivet 1 is as described previously with reference to Figures 1-3. As described previously, the structure 2 can be disassembled by removing each rivet 1 from the aligned holes. This means that the structure 2 can be maintained or repaired, or individual parts thereof can be reused or recycled. In one example, all of the first and second members 231, 232, connector 23 and rivets 1 are made using the same material, thereby improving recyclability. In another example, the first and second side segments 11,12 are connected together by a tether. The tether is formed unitarily with the first and second side segments and is flexible such that it can be bent for the first and second side segments 11, 12 to be inserted into a hole. The tether extends from the end of each side segment 11, 12 opposite to the head portion. The may mean that a single component, which comprises both side segments, only needs to be handled during assembly processes. It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. For example, the first and second member may not comprise plate-like parts, as the rivets may be received in a blind hole. Furthermore, difference geometry of gripping feature may be 5 used, for example undulating or less severe gripping surfaces thereof. Further, the shaft of the rivet, which is provided by an assembly of the shaft portions, may be frustoconical instead of cylindrical. That is, each side surface may have a partially frustoconical shape. It will also be appreciated by those skilled in the art that any number of combinations of the 10 aforementioned features and / or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.

Claims

1. A rivet for securement in a hole, the rivet comprising a plurality of rivet segments, each rivet segment including a head portion and a shaft portion, each shaft portion comprising a series of gripping features along its length, wherein the rivet segments include a wedge segment insertable between the other segments to force, in use, the other segments apart such that the gripping features engage the hole.

2. A rivet according to claim 1, wherein the gripping features start adjacent the head portion.

3. A rivet according to either of claim 1 or claim 2, wherein the wedge segment comprises opposed sides, each opposed side comprising a series of gripping features along its length.

4. A rivet according to any preceding claim, wherein the rivet segments include side segments between which the wedge segment is insertable, each side segment comprising a part-cylindrical outer side, the part-cylindrical outer side comprising a series of gripping features along its length.

5. A rivet according to any preceding claim, wherein each gripping feature is a ridge which extends in a circumferential direction around the respective shaft portion, each gripping feature comprising a lead-in surface which is tapered radially inwardly with distance away from the head portion and a gripping surface which faces with a directional component towards the head portion.

6. A rivet according to claim 5, wherein the gripping surface of each gripping feature is substantially perpendicular to a length direction of the respective shaft portion.

7. A rivet according to claim 6, wherein each gripping feature is adjacent another gripping feature such that the shaft portion has a serrated surface.

8. A rivet according to any preceding claim, wherein the series of gripping features are arranged along a majority of a length of the shaft portion between the head portion and a terminal end of the shaft portion.

9. A rivet according to any preceding claim, wherein the gripping features are substantially regularly distributed along the shaft portion.

10. A rivet according to any preceding claim, wherein each rivet segment comprises a fibre reinforced plastic material.

11. A rivet according to any preceding claim, wherein each rivet segment is 3D printed.

12. A rivet according to any preceding claim, wherein the rivet is a removable fastener.

13. A structure comprising a first member, a second member, and a rivet according to any preceding claim, the rivet passing or being passable through aligned or alignable holes in each of the first and second member.

14. A structure according to claim 13, comprising a third member and a plurality of rivets, each rivet being a rivet according to any preceding claim, wherein the first member and the third member are secured or securable to the second member via the shaft portion of each rivet which passes or is passable through a respective hole in the first or third member which is aligned with a hole in the second member.

15. A structure according to claim 13 or claim 14, wherein each rivet is removably secured or securable in the respective aligned holes.

16. A structure according to claim 14 or claim 15, wherein either or both of the first and third member is a tubular beam, and wherein the second member is a connection plate which is secured or securable to one side of the or each beam by the rivets.

17. A structure according to claim 16, wherein the connection plate is a first connection plate of a connector, the first connection plate being secured or securable to a first side of the or each beam, the connector comprising a second connection plate which is secured or securable to a second side of the or each beam by the shaft portion of each rivet passing through a respective hole in the or each second side which is aligned with a hole in the second connection plate.

18. A structure according to any of claims 13 to 17, wherein any of the first member, second member, third member or connector comprise a fibre reinforced plastic material.

19. A structure according to any of claims 13 to 18, wherein any number of the first and second member, the third part, and the plurality of rivets comprise the same material.

20. A structure according to any of claims 13 to 19, wherein the structure is a structure for an automobile structure.

21. A structure according to any of claims 13 to 20, wherein the structure comprises an A-pillar for an automobile.

22. A method of manufacturing a rivet according to any of claims 1 to 12, the method comprising 3D printing each of the plurality of rivet segments.

23. The method of claim 22, comprising 3D printing each of the plurality of rivet sections using a fibre reinforced plastic material.

24. A method of manufacturing the structure according to any of claims 13 to 21, the method comprising braiding fibres which are pre-impregnated with plastic to subsequently form the first member from braided fibre reinforced plastic.

25. A method of manufacturing according to claim 24, wherein the rivets are manufactured using the method of claim 22 or claim 23.

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