Bicycle frame comprising connectable rollable hollow tubular elements

Abstract

One aspect of the invention relates to a bicycle frame (2,2') comprising at least one first (20) element made of bistable composite material, comprising a first end (201) adapted to be in an unrolled (S1) or rolled up (S2) state in a reversible manner in which: in the unrolled state (S1) the first end (201) is self-supporting and takes a stable elongated shape along a first axis (x) and has a slot (F) of predefined width (L1) along its length (x), in the rolled up state (S2) the slot (F) has a width (L1') greater than the predefined width (L1) and the first end (201) is rolled up around a second axis (y), the bicycle frame (2,2') further comprising a first connector (23,23',24,25,25',28) adapted to connect the first element (20) to a second element of the bicycle frame (2,2') when the first end (201,202) of the first element (20) is in the unrolled state (S1). Figure to be published with the abstract: Figure 2

Description

Title of the invention: Bicycle frame comprising connectable rollable hollow tubular elements TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of bicycle frames.

[0002] The present invention relates to a bicycle frame comprising a plurality of elements tubular and in particular a bicycle frame in which the tubular elements are hollow, rollable and connectable via a connector. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Known in the state of the art are compactable bicycle frames, i.e. transportable, for example by being foldable or dismountable. By "compactable" is meant a bicycle having a smaller footprint in a state suitable for transport than its footprint in a state suitable for cycling. In this, the bicycle is more compact during transport than during cycling.

[0004] These compactable bikes allow their users to take public transport while limiting the impact on other public transport users. In addition, these compacted bikes are easier to transport, making it easier to climb steps with a compacted bike. For everyday use, these bikes are therefore of great interest.

[0005] For this, these compactable bicycles often allow the two wheels to be removed. In addition, or alternatively, folding bicycles have hinges or articulation systems, thus replacing the fixed frame of a bicycle with a folding frame. Indeed, since the wheels are not foldable, the frame and the handlebars are the only two elements of a bicycle on which it is possible to act to reduce the size of the bicycle when not in use. But these folding bicycles still have a large size and weight, unsuitable for example for long transport in a confined space, for example in a train or a car.

[0006] Most prior art bicycles have at least their frame made of metal, mainly for reasons of rigidity and resistance to the user's weight. Metal is a heavy material, difficult to recycle and whose manufacture consumes resources and has a significant environmental impact.

[0007] An example of a prior art bicycle frame is shown in [Fig. 1]. Typically, this bicycle frame is made of metal, for example steel, aluminum and / or titanium. A common bicycle frame shown in [Fig.l] comprises a slant bar 11, a top bar 12 (also called horizontal bar 12), a seat bar 13, two seat stays 14a and 14b, each seat stay being connected to a rear chainstay respectively 15a and 15b. A rear wheel may be received by the bicycle frame via a wheel-coupling means included in each seat stay assembly. A saddle may be received by the bicycle frame in the seat bar. A handlebar and a front wheel attachment fork may be received in the bicycle frame via a head tube to which the upper 12 and oblique 11 bars are welded. Finally, a drive system with a crankset may be received at the junction between the oblique 11 and the seat bar 13, welded together at this junction.

[0008] There is therefore a need to propose a compactable bicycle which does not have the disadvantages of the state of the art. Summary of the invention

[0009] The invention offers a solution to the problems mentioned above, by allowing a bicycle that is more compact than the state of the art once stored, and whose elements have a higher recyclability than the state of the art.

[0010] One aspect of the invention relates to a bicycle frame comprising at least one first element made of bistable composite material, the first element comprising at least one first end adapted to be in an unrolled state or in a rolled-up state, in which: • in the unrolled state the first end is self-supporting and takes a stable elongated shape along a first axis and has a slot of predefined width along its length along the first axis, • in the wound state the slit has a width greater than the predefined width and the first end is wound around a second axis extending transversely to the first axis, • the first end is adapted to change from the wound state to the unwound state reversibly, • the bicycle frame further comprising at least one first connector adapted to connect the first element to at least one second element of the bicycle frame when the first end of the first element is in the unrolled state.

[0011] Thanks to the invention, a more compact bicycle frame than in the prior art is proposed, when each element of the bicycle frame is in the rolled-up state. An advantage of the invention is the possibility of rolling up only a part of each element, and keeping the other part unrolled. This makes it possible, for example, to create extensible elements, i.e. elements whose length can be modified, a larger part of the element passing from the rolled-up state to the unrolled state to lengthen the length of the stable unrolled shape along the first axis. This is made possible thanks to the use of a technology called “bistable reeled composite” or “bistable reeled composite” material. composite” in English, abbreviated BRC. For example, the Rolatube® brand offers this type of composite, which can be used in the present invention.

[0012] The invention also makes it possible to propose a bicycle frame that is more recyclable than in the prior art, that is to say comprising a greater number of recyclable components. This is made possible by eliminating the use of metal, which is absent from wound bistable composite materials. In addition, these materials comprise a large number of textile fibers, which are more easily recyclable than the metals of the prior art, and for lower energy consumption than in the prior art.

[0013] In addition to the characteristics which have just been mentioned in the preceding paragraph, the bicycle frame according to one aspect of the invention may have one or more complementary characteristics among the following, considered individually or according to all technically possible combinations.

[0014] In one embodiment, the first element forms a part of the bicycle frame among: • A top tube, • An oblique tube, • A seat tube, • A guy line, • A rear base.

[0015] In one embodiment, the second element comprises a first end made of bistable composite material adapted to be in an unwound state or in a wound state and the connector comprises at least: • a first end adapted to receive the first end of the first element and • a second end adapted to receive the first end of the second element.

[0016] In one embodiment, each end of the connector comprises at least one clamping means adapted to hold in the connector the end of the element that the connector receives when the clamping means is tightened.

[0017] In one embodiment, the first member comprises a second end and is adapted to transition entirely from the wound state to the unwound state in a reversible manner, the bicycle frame comprising a second connector configured to connect the second end of the first member to a third member.

[0018] In one embodiment, the bicycle frame according to the invention comprises: • A slash, • A seat bar, • A connector suitable for connecting the slash bar to a steering socket suitable for receiving an assembly comprising a handlebar and a fork for fixing a front wheel of a bicycle, • A connector adapted to connect the slash bar and the seat bar and comprising means for mounting a crankset of a bicycle drive system, • A connector suitable for connecting the seat bar to a means of receiving a bicycle saddle, • The oblique bar and the saddle bar each being formed by at least one element made of bistable composite material adapted to be in the unrolled state or in the rolled-up state reversibly.

[0019] In one embodiment, the oblique bar and the saddle bar are each formed by two elements made of bistable composite material adapted to be in the unrolled state or in the rolled-up state reversibly, the two elements being fitted into each other so as to no longer have an open slot.

[0020] In one embodiment, the bicycle frame further comprises an upper bar formed by at least one element made of bistable composite material adapted to be in the unrolled state or in the rolled-up state reversibly.

[0021] In one embodiment, the upper bar is formed by two elements made of bistable composite material adapted to be in the unrolled state or in the wound state reversibly, the two elements being fitted into each other so as to no longer have an open slot.

[0022] In one embodiment, the bicycle frame further comprises: • Two sets each including: • A guy line, • A rear base, • Each set comprising a means of association with respectively one side of a rear bicycle wheel, • Each stay and each rear base being formed by at least one element made of bistable composite material adapted to be in the unrolled state or in the rolled-up state reversibly.

[0023] In one embodiment, each stay and each rear base is formed by two elements made of bistable composite material adapted to be in the unrolled state or in the wound state reversibly, the two elements being fitted into each other so as to no longer have an open slot.

[0024] In one embodiment, the bistable composite material comprises a first substrate prestressed in the elongated stable shape, and a plurality of prestressed fibers extending along the second axis in the wound state, the plurality of fibers being under tension in the wound state, the fibers being selected from carbon fibers and / or glass fibers, the substrate being made of a material selected from a plastic and / or a metal.

[0025] In one embodiment, each connector is made of at least one material chosen from a thermoplastic elastomer such as Polyamide or TPU (thermoplastic polyurethane), and / or a metal.

[0026] In one embodiment, each connector is manufactured by three-dimensional printing or by injection molding or by thermocompression.

[0027] Another aspect of the invention relates to a bicycle comprising the bicycle frame according to the invention and: • A front wheel, • A rear wheel, • A handlebar, • A front wheel fixing fork.

[0028] In one embodiment of the bicycle according to the other aspect of the invention, the bicycle further comprises a wheel drive system comprising a crankset.

[0029] The invention finds a particular advantage in the implementation of existing bicycle frames in which it is possible to replace the metal tubular elements with the bistable composite material elements of the invention, and to add connectors. This makes it possible to make the bicycle modular, while limiting the number of welds and metal parts.

[0030] The invention and its various applications will be better understood upon reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0031] The figures are presented for information purposes only and in no way limit the invention. • [Fig.l] shows a schematic representation of a state-of-the-art bicycle frame. • [Fig.2] shows a schematic representation of a bistable composite material element as included in a bicycle frame according to the invention. • Figures 3A and 3B respectively show a schematic representation of an unrolled state and a rolled state of a bistable composite material as included in a bicycle frame according to the invention. • Figures [Fig.4A] and [Fig.4B] respectively show a schematic representation of an unrolled state and a rolled-up state of an element made of bistable composite material as included in the bicycle frame according to the invention. • [Fig.5] shows a schematic representation of a bicycle frame according to a first embodiment of the invention. • [Fig.6] shows a schematic representation of a first mode of rea use of a connector included in a bicycle frame according to the invention. • Figures 7 A, 7B and 7C respectively show a schematic representation of respectively second, third and fourth embodiments of connectors included in a bicycle frame according to the invention. • [Fig.8] shows a schematic representation of a bicycle frame according to a second embodiment of the invention. • Figures [Fig.9A], [Fig.9B], [Fig.9C], [Fig.9D], [Fig.9E], [Fig.9F] show schematic representations according to different sectional views of a fifth embodiment of a connector included in a bicycle frame according to the invention. • [Fig.10] shows a schematic representation of a sectional view of an embodiment of an element of a bicycle frame according to the invention. DETAILED DESCRIPTION

[0032] Unless otherwise specified, the same element appearing in different figures has a single reference.

[0033] The invention relates to the use of bistable composite material wound in a bicycle frame. Such a material can be used as a replacement for an element of a state-of-the-art bicycle frame, preferably as a replacement for one or more tubes of a state-of-the-art bicycle frame.

[0034] [Fig. 2] shows a schematic representation of an element 20 made of bistable composite material. According to the invention, such an element 20 is included in a bicycle frame.

[0035] The element 20 has two ends 201 and 202. Each end is either in an unwound state S1, like the end 201 in [Fig.2], or in a wound state S2, like the end 202 in [Fig.2].

[0036] In the unrolled state SI, the end 201 is self-supporting and takes a stable elongated shape along a first longitudinal axis x. This elongated shape is preferably a tubular shape, that is to say a hollow shape extending along an axis and of substantially circular section. This elongated shape has a slot of predefined width along its length along the x axis, as shown in [Fig.3A] and [Fig.3B]. Thus, the end 201 has the shape of an open tube along its length, where the opening follows the longitudinal axis x.

[0037] In the wound state S2, the slit has a width greater than the predefined width of the slit, that is to say that the end 202 of the element 21 is more flattened than when it takes a tubular shape in the unwound state SL. When one end of the element 20 is sufficiently flattened, the end can be wound on itself, around a transverse axis y. Of course, the invention is not limited to the ends of the element 20 in that the entire element 20 is preferentially wound around the axis y in the wound state S2 and fully unwound in an elongated, preferably tubular, form with a slot, in the unwound state SI, and in that the element 20 is adapted to pass entirely from the wound state S2 to the unwound state SI in a reversible manner, following the action of a predefined force on the element 20.

[0038] The ends 201 and 202 are adapted to change from the wound state S2 to the unwound state SI in a reversible manner, i.e. to change from the wound state S2 to the unwound state SI and to change from the unwound state SI to the wound state S2. For this, the bistable composite material comprises at least one substrate prestressed in the stable elongated shape, i.e. the substrate is prestressed in the tubular shape, but the substrate is deformable, i.e. by exerting a force greater than a predetermined force, the substrate can move away from its stable elongated shape. The material comprises a matrix of fibers. The matrix of fibers is for example glass fibers and / or carbon fibers, preferably glass fibers.The fiber matrix is ​​not under tension in the unwound state SL. When passing into the wound state S2, i.e. when exerting a force on the substrate, the fibers in the direction normal to the direction of the exerted force will contract. By contracting, these fibers will constrain the element 20 in the wound state S2. Thus, the material is stable, thanks to the fibers, in the wound state S2, the fibers keeping the element 20 wound, and the material is also stable, thanks to the substrate, in its unwound state SI, the substrate keeping the slot less wide than when it is open, i.e. keeping the element 20 in a tubular shape. The substrate is made of a plastic material, preferably polypropylene. The substrate may comprise plastic threads, to provide the prestressing. The fibers may be bonded to the substrate by a polymer, which acts as a bonding matrix.The material used may be a material such as that known as Rolatube®.

[0039] [Fig.3A] shows a schematic representation of an unrolled state of the element 20 seen in cross-section (in a plane along the y axis) and of a wound state of the element 20 seen in cross-section (in a plane along the y axis).

[0040] As shown in [Fig.3A], the element 20 is in an unwound state SI and has a circular or substantially circular section. The element 20 in the unwound state SI comprises a slot F of width LL. The width L1 is preferably between 0.5 and 1 centimeter, preferably equal to 1 centimeter. The narrower the slot, the more difficult it is to constrain the element 21 so that it passes from the unwound state SI to the wound state S2. Indeed, the smaller the width L1 of the slot F, the longer the fibers 203 along the circular circumference, and the less force they exert to constrain the element 20 in the wound state S2.

[0041] By exerting an additional force, often manual, at the slot F, a user can then pass the element 20 from the unrolled state S1 to the wound state S2. For this requires the user to enlarge the slit F, passing the element 20 from a stable state SI to another stable state S2. Since the element 20 is not stable in the intermediate states, it is not possible for the user to maintain the element 20 in an intermediate state, or with difficulty.

[0042] When the element 20 is in the wound state S2, the width L1' of the slot F is greater than the width L1 of the slot F in the unwound state SL. The element 20 also has a lower height HT in the wound state S2 than the height H1 of the element 20 in the wound state SL. In other words, the element 20 is flattened in the wound state S2.

[0043] When the element 20 is entirely in the unwound state S1, the element 20 has an overall shape of a tube open along the longitudinal slot F. This tube is self-supporting, that is to say that it has sufficient strength to carry its own weight when placed on stable ground. In addition, the tube has sufficient strength to withstand a stress imposed on its ends, in the same way as a metal or rigid plastic tube. The only way to wind the element 20 manually is to exert a force at the slot F, to widen the slot F.

[0044] When the element 20 is entirely in the wound state S2, the element 20 has the overall shape of a serpentine, that is to say a substantially flat strip wound on itself around the transverse axis y. To move to the unwound state, it is sufficient to exert a tensile force on the free end of the strip and unwound the element 20.

[0045] The invention uses the advantages of this rollable bistable composite material to propose a bicycle frame comprising at least one element which is compact when rolled up and has sufficient strength when unrolled, for example in tubular form.

[0046] Thus, an example of a bicycle frame according to a first embodiment of the invention is shown schematically in [Fig. 5]. In this first embodiment, the bicycle frame 2 comprises at least one element made of bistable composite material, preferably three elements made of rollable bistable composite material.

[0047] The bicycle frame 2 shown in [Fig. 5] comprises a first element 20, a second element 21 and a third element 22, all three made of rollable bistable composite material. The first element 20 forms an upper bar of the bicycle frame, the second element 21 forms a slant bar of the bicycle frame, and the third element 22 forms a saddle bar of the bicycle frame 2. Each element 20 to 22 respectively comprises two ends, for example ends of a tube comprising a slot (not shown). Each element 20 to 22 is in an unrolled state SI, so that it can be connected to the other elements of the bicycle frame 2 via connectors. In the unrolled state, each element 20 to 22 has an outer diameter of between 30 and 40 millimeters, preferably 36.5 millimeters. The connectors preferably have an outer diameter of between 40 and 50 millimeters. meters, preferably 42.5 millimeters. The top bar is optional, not being present on some bicycle frames.

[0048] In one embodiment, the upper bar 20 has for example a length A of between 350 and 550 millimeters, preferably between 400 and 500 millimeters, more preferably 396.5 millimeters.

[0049] In one embodiment, the oblique bar 21 has a length determined by the lengths A of the upper bar and C of the saddle bar, and by the angles 01 and 02. The oblique bar 21 has, for example, a length B of between 300 and 600 millimeters, preferably between 400 and 500 millimeters, preferably still 466.5 millimeters.

[0050] In one embodiment, the saddle bar 22 has for example a length C of between 300 and 500 millimeters, preferably between 300 and 400 millimeters, more preferably 316.5 millimeters.

[0051] The upper bar 20 is connected to the saddle bar 22 by a connector 23. The saddle bar is connected to the oblique bar 21 by a connector 25. The upper bar 20 is connected to the oblique bar 21 by a connector 24.

[0052] The bicycle frame 2 shown in [Fig. 5] comprises seat stays and rear bases of the state of the art, not shown. These two seat stays and these two rear bases are for example made of metal, welded together, and connected to the connectors 23 and 25, for example by welding, by fitting and / or by screwing.

[0053] For example, and as shown in [Fig. 5], the ends of the elements 20, 21 and 22 are in an unwound state SI and are connected via the connectors 23, 24 and 25. In [Fig. 5], the three elements 20, 21 and 22 are entirely in the unwound state SI, but the invention also covers the cases where one of the ends of at least one of the elements 20, 21 and 22 would be in a wound state S2, making it possible to modify the length of the tube by varying the length of the element which is in the wound state S2 and the remaining length of the element which is in the unwound state SL.

[0054] In a preferred embodiment, at least one of the different bars 20, 21 and 22, preferably each of the different bars 20, 21 and 22, is formed of two elements nested in their unrolled state SI, as shown in [Fig. 10]. For example, the upper bar 20 is formed by the nesting of two elements 20a and 20b in their unrolled state SL. This nesting is carried out in such a way as to no longer have a visible slot, that is to say that a part of one of the two elements 20a and 20b covers the slot of the other element 20a or 20b. Preferably, the slots Fa and Fb are opposite, that is to say they are in opposition with respect to the longitudinal axis x along which the upper bar 20 extends. This allows the upper bar 20 to be more resistant to the forces exerted by the user on the bicycle frame. Preferably, all the tubes of the bicycle frame 2 are doubled, that is to say are formed of two elements made of a rollable bistable composite material nested in their unrolled state SI. To disassemble the bicycle frame 2, simply remove each tube from the connectors, separate the two elements forming each tube, and roll each element up on itself so that it is in the rolled up state S2.

[0055] The various connectors and their embodiments will now be described. In the invention, preferably, the connectors comprise a clamping means, making it possible to hold the element received by the connector in the connector. Such a clamping means comprises for example a thread and tapped hole system and / or a screw-nut type system.

[0056] In a first embodiment of the connectors of the bicycle frame according to the invention shown in [Fig.6], the connectors comprise an end 231 of first diameter less than the diameter of the element 20 that the connector is adapted to receive and a thread 232 on a tubular part of second diameter greater than the first diameter, preferably of second diameter equal or substantially equal to the diameter of the element 20.

[0057] The element 20 can then fit into the end 231 and, using for example a ring 233 comprising a tapped hole, the element 20 is held to the connector 23 once the ring 233 is screwed around the thread 232. The ring 233 can be removable, that is to say can be removed from the element 20, or can be included in the element 20, for example because the element 20 comprises a means of holding the ring around the element 20, for example by fixing the ring to the element 20.

[0058] The three figures 7A, 7B and 7C represent examples of implementation of connectors according to the first embodiment of the connectors according to the invention and according to the first embodiment of the bicycle frame according to the invention, that is to say the bicycle frame 2 of [Fig.5] in which only the upper bar 20, oblique bar 21 and saddle bar 22 are made of rollable bistable composite material.

[0059] [Fig.7A] shows a schematic representation of a connector 23 adapted to connect the upper bar 20 and the saddle bar 22. For this, the connector 23 comprises two ends 231 and 232, the end 231 being adapted to receive the upper bar 20, and the end 232 being adapted to receive the saddle bar 22. The end 231 is adapted to receive the upper bar 20 by having dimensions suitable for receiving the upper bar 20, that is to say that the end 231 comprises a first tube 2311 of diameter smaller than the diameter of the upper bar 20, to be able to be inserted into the upper bar 20, and a clamping means 2312 of diameter equal or substantially equal to the diameter of the upper bar 20 and allowing the upper bar 20 to be held on the connector 23.Similarly, the end 232 is adapted to receive the saddle bar 22 by having dimensions suitable for receiving the saddle bar 22, i.e., the end . 232 comprises a first tube 2321 of diameter smaller than the diameter of the saddle bar 22, so as to be able to be inserted into the saddle bar 22, and a clamping means 2322 of diameter equal or substantially equal to the diameter of the saddle bar 22 and allowing the saddle bar 22 to be held in the connector 23.

[0060] Preferably, the two ends 231 and 232 of the connector 23 form a right or substantially right angle 03, that is to say deviating at most 5 degrees from 90 degrees.

[0061] The connector 23 further comprises a means for receiving a bicycle saddle 233, for example an open tube end, into which it is possible to slide a support tube of a bicycle saddle and around which or to which it is possible to fix a system for holding the saddle to the bicycle frame 2.

[0062] [Fig.7B] shows a schematic representation of a connector 24 adapted to connect the upper bar 20 and the oblique bar 21. For this, the connector 24 comprises two ends 241 and 242, the end 242 being adapted to receive the upper bar 20, and the end 241 being adapted to receive the oblique bar 21. The end 242 is adapted to receive the upper bar 20 by having dimensions suitable for receiving the upper bar 20, that is to say that the end 242 comprises a first tube 2421 of diameter smaller than the diameter of the upper bar 20, to be able to be inserted into the upper bar 20, and a clamping means 2422 of diameter equal or substantially equal to the diameter of the upper bar 20 and allowing the upper bar 20 to be held on the connector 24.In the same way, the end 241 is adapted to receive the oblique bar 21 by having dimensions suitable for receiving the oblique bar 21, that is to say that the end 241 comprises a first tube 2411 of diameter less than the diameter of the oblique bar 21, to be able to be inserted into the oblique bar 21, and a clamping means 2412 of diameter equal or substantially equal to the diameter of the oblique bar 21 and allowing the oblique bar 21 to be held in the connector 24.

[0063] Preferably, the two ends 241 and 242 of the connector 24 form a closed angle 01, that is to say less than 90 degrees, preferably between 20 and 40 degrees, preferably still 36.5 degrees.

[0064] The connector 24 further comprises a steering socket 243, for example in the form of an open tube, comprising two ends 2431 and 2432 so as to be able to receive a bicycle front wheel fixing fork and a handlebar, connected together by a tube sliding in the steering socket 243.

[0065] [Fig.7C] shows a schematic representation of a connector 25 adapted to connect the saddle bar 22 and the oblique bar 21. For this, the connector 25 comprises two ends 251 and 252, the end 251 being adapted to receive the saddle bar 22, and the end 252 being adapted to receive the oblique bar 21. The end 251 is adapted to receive the saddle bar 22 by having dimensions suitable for receiving the saddle bar 22, that is to say that the end 251 comprises a first tube 2511 of diameter smaller than the diameter of the saddle bar 22, to be able to be inserted into the saddle bar 22, and a clamping means 2512 of diameter equal or substantially equal to the diameter of the saddle bar 22 and allowing the saddle bar 22 to be held at the connector 24. In the same way, the end 252 is adapted to receive the oblique bar 21 by having dimensions suitable for receiving the oblique bar 21, that is to say that the end 252 comprises a first tube 2521 of diameter smaller than the diameter of the oblique bar 21, to be able to be inserted into the oblique bar 21, and a clamping means 2522 of diameter equal or substantially equal to the diameter of the oblique bar 21 and allowing the the slash 21 in the connector 25.

[0066] Preferably, the two ends 251 and 252 of the connector 25 form a closed angle 02, that is to say less than 90 degrees, preferably between 40 and 60 degrees, preferably still 57.4 degrees.

[0067] The connector 25 further comprises means for mounting a crankset of a bicycle drive system, for example an open tube 253 extending along an axis transverse to the plane in which the oblique bar 21 and seat bar 22 extend longitudinally. Thus, it is possible to slide a crankset through one side of the means for mounting a crankset 253, and to block the crankset in translation through the other side of the means for mounting a crankset 253, thus reversibly securing the crankset to the bicycle frame 2.

[0068] In the implementation examples of Figures 7A to 7C, the connectors can also be adapted to receive, for example by welding or by removable or non-removable fixing, the seat stays and rear bases of the rest of the bicycle frame 2, the seat stays and rear bases not being made of bistable composite material.

[0069] In a second embodiment of the bicycle frame according to the invention shown in [Fig.8], the bicycle frame 2' also has its seat stays 26 and its rear bases 28 made of rollable bistable composite material. For this, the connectors 23 and 25 are adapted into connectors 23' and 25'. The connector 23' comprises at least one additional end 234 per seat stay that it receives, i.e., conventionally, two ends 234 each respectively adapted to receive one of the two seat stays 26. The connector 25' comprises at least one additional end 254 per rear base that it receives, i.e., conventionally, two ends 254 each respectively adapted to receive one of the two rear bases 27.

[0070] The bicycle frame 2' further comprises a connector 28 comprising four ends: two ends 282 adapted to each receive one of the two seat stays 26, and two ends 281 adapted to each receive one of the two rear bases 27. The ends 281 and 282 are of the same type as the ends of the other connectors 23, 23', 24, 25 and 25', that is to say they may comprise a clamping means for holding the stay 26 or the rear base 27 in the connector 28.

[0071] The connector 28 further comprises a means 283 for attaching a rear bicycle wheel.

[0072] In other embodiments, the structure of the bicycle frame has a predefined number of connectors and a predefined number of elements. All the elements are made of rollable bistable composite material and can be, simultaneously, in a rolled state S2. Thus, it is possible to obtain a very compact bicycle frame 2, having a size defined by the dimension of the elements when in the rolled state S2, as well as by the dimensions of the connectors, which are not made of rollable bistable composite material. The connectors are preferably made of plastic, for example injection molded or manufactured by three-dimensional printing, thermoplastic or metal.

[0073] It is also possible to wind an element around another element already in the wound state S2. Thus, it is possible to obtain a single wound block comprising all the elements, and the size is further reduced.

[0074] All the wound elements and connectors can be transported in a carrying bag or in a cover, suitable for this purpose.

[0075] Figures 9A to 9F show schematic representations of a second embodiment of a connector of a bicycle frame according to the invention, according to different sectional views.

[0076] The connector 30 shown in Figures 9A to 9F comprises at least one sliding end 301, an opening 302 formed by the space created between tabs 303 and an outer wall 304, and one end 305.

[0077] The sliding end 301 comprises a tapped hole in its center, that is to say the center of which is the longitudinal axis x, adapted to receive a screw thread, thus creating a screw / nut system, the nut being formed by the sliding end 301. The screw (not shown) is inserted through the second end 305 of the connector 30, on the side of the connector 30 opposite the side of the connector 30 where the sliding end 301 is placed. The second end 305 comprises a hole for inserting the screw, the hole having a diameter greater than the diameter of the screw thread but less than the diameter of the screw head, making it possible to hold the screw in the connector 30 when its screw thread is screwed into the tapped hole of the sliding end 301. Thus, the sliding end is also held in the connector 30.

[0078] When the screw is screwed in or out, the sliding end 301 slides into a generally circular opening, a center of which is the longitudinal axis x, the opening being created by a plurality of tabs 303. For example, but not limited to, the connector 30 comprises six tabs 303, arranged along the circumference of the sliding end 301 and belonging to the body of the connector 30. The tabs 303 and the sliding end 301 are not fixed together, allowing the sliding end 301 to slide in the lengthwise direction of the tabs 303, i.e. along the longitudinal axis x. The space between the different tabs 303 can be filled by the sliding end 301, the sliding end 301 then having shoulders of material 3011 housed between the tabs 303 and thus blocking the rotation of the sliding end 301. The sliding end 301 therefore having a surplus of material forming teeth 3011, making it possible to fill these spaces, the sliding end 301 then taking the overall shape of a toothed wheel, that is to say comprising teeth 3011, the tabs 303 being inserted between the teeth of the toothed wheel 301.

[0079] When the sliding end 301 slides towards the inside of the connector 30, that is to say when the sliding end 301 approaches the end 305 following screwing of the screw, the tabs 303 are pushed towards the outer wall 304 of the connector 30, thanks to the fact that the tabs have a thickness which increases as they approach the end 305. In other words, the tabs 303 are thinner at their end, that is to say at the level of the sliding end 301 when it is unscrewed, and are increasingly thicker as they approach the end 305.

[0080] By being pushed towards the outer wall 304 of the connector 30, the tabs 303 reduce the opening 302 that they form with the outer wall 304. This opening 302 is adapted to receive an element made of bistable composite material in its unrolled state SI, or two elements made of bistable composite material nested as in [Fig. 10], in their unrolled states SL. For this, the opening 302 has a diameter close to or equal to the diameter of the nested element or elements that it receives, and a thickness sufficient to accommodate the thickness of the nested element or elements.When the connector 30 receives an element or elements nested in the opening 302, and when the screw is screwed in, the sliding end 301 approaches the end 305, the tabs 303 are pushed back towards the outer wall 304, thus reducing the thickness of the opening 302 and tightening the tabs against the nested element or elements present in the opening 302. The nested element or elements are then held in the opening 302 and therefore in the connector 30. To remove the nested element or elements from the connector 30, it is sufficient to unscrew the screw at the end 305 and remove the nested element or elements from the connector 30.

[0081] The connector 30 may form one or more end(s) of one or more connector(s) among the connectors 23, 23' 24, 25, 25' and 28, for example all the ends of all the connectors 23, 23' 24, 25, 25' and 28. The different ends thus formed by connectors 30 can be held together by a connector body, for example by welding or injection molding or three-dimensional printing, to form the complete connectors 23, 23' 24, 25, 25' and 28 as described above. The connector 30 has for example a length D of between 30 and 50 millimeters, preferably 40 millimeters.

[0082] Another aspect of the invention relates to a bicycle comprising the bicycle frame according to the invention. Such a bicycle is for example a balance bike, that is to say a bicycle not comprising a means for driving the wheels or a crankset. A bicycle according to the invention then comprises a bicycle frame according to the invention and at least two wheels, a saddle and a handlebar connected to a front wheel attachment fork. A bicycle according to the invention may further comprise a crankset included in a wheel drive system.

Claims

1.

2.

3. Claims Bicycle frame (2,2') comprising at least one first (20) element made of bistable composite material, the first element (20) comprising at least one first end (201) adapted to be in an unrolled state (SI) or in a rolled-up state (S2), in which: - in the unrolled state (SI) the first end (201) is self-supporting and takes a stable elongated shape along a first axis (x) and has a slot (F) of predefined width (Ll) along its length along the first axis (x), - in the wound state (S2) the slot (F) has a width greater (LF) than the predefined width (Ll) and the first end (201) is wound around a second axis (y) extending transversely to the first axis (x), - the first end (201) is adapted to pass from the wound state (S2) to the unwound state (SI) in a reversible manner, the bicycle frame (2,2') further comprising at least one first connector (23,23',24,25,25',28) adapted to connect the first element (20) to at least one second element of the bicycle frame (2,2') when the first end (201,202) of the first element (20) is in the unrolled state (SI). Bicycle frame (2,2') according to the preceding claim, wherein the first element (20) forms a part of the bicycle frame (2,2') among: - An upper tube (20), - An oblique tube (21), - A seat tube (22), - A guy line (26), - A rear base (27). Bicycle frame (2,2') according to one of the preceding claims, wherein the second element (21) comprises a first end (211) made of bistable composite material adapted to be in an unrolled state (SI) or in a wound state (S2) and the connector (23,23',24,25,25',28) comprises at least: - a first end (231) adapted to receive the first end (201) of the first element (20) and - a second end (232) adapted to receive the first end (211) of the second element (21).

4. Bicycle frame (2,2') according to claim 3 according to which each end (231,232) of the connector (23,23',24,25,25',28) comprises at least one clamping means adapted to hold in the connector (23,23',24,25,25',28) the end of the element that the connector receives when the clamping means is tightened.

5. Bicycle frame (2,2') according to one of the preceding claims, wherein the first element (20) comprises a second end (202) and is adapted to pass entirely from the wound state (S2) to the unwound state (SI) in a reversible manner, the bicycle frame (2,2') comprising a second connector (24) configured to connect the second end (201) of the first element (20) to a third element (22).

6. Bicycle frame (2, 2') according to one of the preceding claims comprising: - A slant bar (21), - A seat bar (22), - A connector (24) adapted to connect the slant bar (21) to a steering socket (243) adapted to receive an assembly comprising a handlebar and a fork for fixing a front bicycle wheel, - A connector (25, 25') adapted to connect the slant bar (21) and the seat bar (22) and comprising mounting means (253) of a crankset of a bicycle drive system, - A connector (23, 23') adapted to connect the seat bar (22) to a means for receiving a bicycle saddle (233), the slant bar (21) and the seat bar (22) each being formed by at least one element made of bistable composite material adapted to be in the unrolled state (SI) or in the wound state (S2) reversibly.

7. Bicycle frame (2,2') according to claim 6 further comprising an upper bar (20) formed by at least one element of bistable composite material adapted to be in the unrolled state (SI) or in the wound state (S2) reversibly, the connector (24) adapted to connect the slash bar (21) to the head tube (243) being further adapted to connect the top bar (20) to the slash bar (21) and to the head tube (243), and the connector (23, 23') adapted to connect the seat bar (22) to the receiving means of a bicycle saddle (233) being further adapted to and connect the top bar (20) to the seat bar (22) and to the receiving means of the bicycle saddle (233).

8. Bicycle frame (2,2') according to one of claims 6 or 7 according to which at least one bar among the oblique bar (21) and / or the saddle bar (22) is formed by two elements made of bistable composite material adapted to be in the unrolled state (SI) or in the rolled up state (S2) reversibly, the two elements being fitted into each other so as to no longer have an open slot (F).

9. Bicycle frame (2,2') according to one of claims 6 to 8 further comprising: - Two assemblies each comprising: • A seat stay (26), • A rear chainstay (27), - Each assembly comprising a means of association with respectively one side of a rear bicycle wheel, each seat stay (26) and each rear chainstay (27) being formed by at least one element made of bistable composite material adapted to be in the unrolled state (SI) or in the wound state (S2) in a reversible manner.

10. Bicycle frame (2,2') according to claim 9 according to which each seat stay (26) and each rear chain stay (27) is formed by two elements made of bistable composite material adapted to be in the unrolled state (SI) or in the wound state (S2) reversibly, the two elements being fitted into each other so as to no longer have an open slot (F).

11. Bicycle frame (2,2') according to one of the preceding claims according to which the bistable composite material comprises a first substrate prestressed in the elongated stable form, and a plurality of prestressed fibers extending along the second axis (y) in the wound state (S2), the plurality of fibers being under tension in the wound state (S2), the fibers being chosen from carbon fibers and / or glass fibers, the substrate being made of a material chosen from a plastic and / or a metal.

12. Bicycle frame (2,2') according to one of the preceding claims, wherein each connector (23,23',24,25,25',28) is made of at least one material chosen from a thermoplastic elastomer and / or a metal.

13. Bicycle frame (2,2') according to one of the preceding claims wherein each connector (23,23',24,25,25',28) is manufactured by three-dimensional printing or by injection molding.

14. Bicycle comprising the bicycle frame according to any one of the preceding claims and: - A front wheel, - A rear wheel, - A handlebar, - A fork for fixing the front wheel.

15. A bicycle according to claim 14 further comprising a wheel drive system comprising a crankset.

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