FR2816548A1 - Bicycle wheel rim for tubeless tyre has two ends of rim member joined and sealed by insert of deformable material, liquid or paste - Google Patents

Abstract

The wheel rim is made from a curved member with a hollow section and transverse bridge, with its two ends joined together by an insert (52) of a deformable material such as an elastomer or a liquid or paste which seals the bridge and at least part of the side walls above it, and at the same time acts as a holder for the tyre inflating valve (53). A recess (51) is machined in at least one end of the rim for the joint. The wheel rim is made from a curved member with a hollow section and transverse bridge, with its two ends joined together by an insert (52) of a deformable material such as an elastomer or a liquid or paste which seals the bridge and at least part of the side walls above it, and at the same time acts as a holder for the tyre inflating valve (53). A recess (51) is machined in at least one end of the rim for the joint, which can be fixed in place by vulcanization adhesion or welding, and it is also used to support a pair of connecting pins.

Description

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Method for manufacturing a bicycle rim intended for mounting without an inner tube and rim obtained by implementing the method
The invention relates to a method of manufacturing a bicycle rim intended for tubeless mounting of the tire. It also relates to the rim obtained by the implementation of the method.

 Traditionally, a rim is produced from a profile bar, for example made of aluminum alloy.

 The bar is bent to form one or more turns, then it is cut to have one or more open rings of length equal to the circumference of the rim.

 The two ends of the ring are assembled to close the ring and form the final rim.

 Several assembly techniques are known, which depend on the section of the profile and the use of the rim.

 In particular, it is known to assemble the two ends of a rim by means of a sleeve or needles which are fitted or held by force in the two ends. Patent application FR 2 733 459 describes an assembly by means of an expandable sleeve. US Patent 5,470,133 relates to an assembly by needles.

 Another technique consists in welding the ends of the rim by flashing, then in machining the internal and external burr of the weld. Patent application FR 2 693 672 describes this assembly technique.

 This last welding assembly technique lends itself well to the production of a rim intended for mounting the tire without an inner tube and without a rim tape. Indeed, the welding ensures perfect continuity of the upper deck and the two wings of the rim.

 The problem arises of making a rim for mounting without an inner tube from a rim whose ends are not welded. Indeed, with traditional assembly techniques, the two ends of the rim are only applied against each other, and necessarily leave a space through which air may escape.

 An object of the invention is to propose a method of constructing a rim whose ends are not welded and which is moreover suitable for mounting a tubeless tire.

 According to the method of manufacturing the rim, a curved ring is formed having a box section which comprises at least one upper bridge and wings forming an annular channel provided for mounting the tire, and the two ends of which face each other. -vis that we assemble by an assembly technique other than welding.

 The method is characterized by the fact that an element foreign to the ring made of deformable material or else in a liquid or pasty state is attached to the two ends of the ring in order to seal the upper wall of the ring in an airtight manner. upper deck and at least the lower part of the inner wall of the wings at the junction of the two ends.

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 The rim according to the invention comprises a curved ring having a box section which comprises at least one upper bridge and wings, and the two ends of which are assembled by an assembly technique other than welding. It is characterized by the fact that an element foreign to the ring of deformable material or else in the liquid or pasty state seals airtight the upper wall of the upper deck and at least the lower part of the inner wall of the wings at the junction of the two ends.

 The invention will be better understood by referring to the description below and to the attached drawings which are attached to it.

 Figure 1 illustrates a first embodiment of the invention.

 Figure 2 is a sectional view of the ring of Figure 1.

 Figure 3 shows a side view of the ring of Figure 1 at its two ends, after assembly.

 Figure 4 relates to an alternative embodiment.

 FIG. 5 shows another variant implementation of the invention.

 Figure 6 shows a side view of the two ends of the ring of Figure 5 after assembly.

 Figure 7 relates to another alternative embodiment of the invention.

 FIG. 8 is a side view of the two ends of the ring of FIG. 7.

 FIG. 9 illustrates another embodiment of the invention.

 FIG. 10 relates to another embodiment of the invention.

 Figure 11 shows a side view of the two ends of the ring of Figure 10 after assembly.

 Figure 12 illustrates another embodiment of the invention.

 FIG. 13 shows in perspective one of the ends of the ring of FIG. 12.

 Figure 14 relates to an alternative embodiment of the invention.

 FIG. 15 represents in perspective one end of the ring of FIG. 14.

 FIG. 16 illustrates another variant implementation of the invention.

 Figure 17 relates to another embodiment of the invention.

 Figure 18 shows in longitudinal section the two ends of the ring of the previous figure.

 Figure 19 shows another variant implementation of the invention.

 Figure 20 relates to a variant.

 FIG. 21 illustrates another embodiment of the invention.

 FIG. 1 shows the two ends 2 and 3 of a ring 1. In a known manner, the ring 1 is formed from a profile bar which is curved according to turns, which are then cut transversely.

 In section, the ring has for example the box shape shown in FIG. 2, with an upper bridge 5, a lower bridge 6, side walls 7 and 8 which are extended by wings 9 and 10. The upper bridge and the wings form an annular channel which is intended to receive

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 the tire. At the end of the wings there are hooks or hooks 11 and 12 which help to hold the tire in place.

 Preferably, as described in patent application EP 893 280, the upper bridge has an upper wall formed in a narrow and deep central groove 13, bordered by two beads 15 and 16 which then descend towards the foot of the wings 9 and 10.

 As described in the aforementioned patent application, for mounting without an inner tube, the central groove facilitates the fitting of the tire and the primary inflation, that is to say the first phase of inflation. Beyond a certain inflation pressure, the tire beads cross the beads and press against the fenders.

 Preferably also, the lower deck comprises means for hooking the spokes, and the upper deck has no drilling except that provided for the valve. For example, as described in patent application EP 818 328, the lower bridge is pierced by a fluoperimentation technique so as to form chimneys. The chimneys are tapped, and the shelves are hung by means of hollow screws. In this way, the spokes are hooked and adjusted in tension without having to drill the upper deck.

 However, the construction of the rim is not limiting. In particular, the upper deck could be drilled to mount the spokes according to the traditional technique. The holes could then be closed by plugs, a rim tape, or any other suitable means.

 According to the illustrated embodiment, the profile of the ring 1 has at the upper deck two corridors 19, 20 of circular section. In known manner, needles 21a and 21b are force-fitted into the lanes 19 and 20 at the two ends of the ring so as to assemble them end to end.

 According to the invention, before the fitting operation, a seal 22 is interposed between the faces 23 and 24 of the ends of the ring. The seal is made of an elastically deformable material. For example, it is made of elastomer. TRI is preferably relatively hard in order to be able to withstand the pressure between the two ends of the ring which results from the subsequent tensioning of the spokes. In section, the joint has the same shape as the profile of the ring. Preferably, however, the seal has an outer contour which is slightly set back relative to the outer contour of the faces 23 and 24. The seal 22 has two perforations 25 and 26 for the passage of the needles.

 The thickness of the joint is relatively small, for example of the order of a few tenths of a millimeter. The seal 22 is pinched between the two faces 23 and 24 during the force fitting of the needles. By deforming under the effect of pinching, it provides a seal between the two ends of the rim, in particular at the level of the upper channel of the tire, that is to say at the upper wall of the upper bridge and the internal wall of the wings.

Externally, the seal is flush or slightly recessed with respect to the outer wall of the rim, in particular at the level of the outer surfaces of the fenders which form the braking surfaces.

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 In this regard, preferably, as is already the practice, the braking walls of the rim are machined subsequently so that they are well level, including at the junction of the two ends.

 As a variant, the seal 22 could be produced with a central metallic core, for example made of aluminum alloy, and on each side of this core a thin elastically deformable layer, for example of elastomer which is assembled to the core by any suitable means , for example by vulcanization, adhesion, bonding, welding or other. This gives better resistance of the elastomeric layers.

 Figure 4 relates to an alternative embodiment. According to this variant, the two needles 27 and 28 are pre-mounted on the seal 30. Under these conditions, in addition to its sealing function, the seal acts as a support for the needles at the time of the fitting operation.

 According to Figure 5, the seal 32 is thicker than in the previous cases, for example its thickness is of the order of 1 centimeter, and, it is shaped to follow the rounding of the ring.

As in the previous case, it has hands 33 and 34, but it is an optional function. A valve 35, which is in fact the tire inflation valve, is mounted on the seal, that is to say that it crosses its lower and upper bridges 37 and 38 and that it opens at the upper wall of the bridge. superior. The valve mechanism is of a known type, for example of the Schrader or Presta type. Advantageously, the seal is overmolded on the valve so as to form a one-piece assembly with it. As in the previous cases, the seal 32 is disposed between the ends 39 and 40 of the ring, it is pinched between the ends, which achieves sealing at this level. The presence of the valve at the joint avoids having to pierce the rim and bring back a valve later.

 Alternatively, as in the previous case, the seal could be formed by a central metal core which carries the valve, and on each side an attached deformable layer, for example made of elastomer.

 According to another variant, the needles have a shoulder zone in their middle part of width slightly less than the thickness of the joint 32. The compression of the joint 32 is controlled by the abutment of the ends 39 and 40 against the shoulder of the needles . It is also possible to machine by contoumage in numerical control.

 The construction shown in Figures 7 and 8 is relatively close to that of Figure 1. The difference is that the seal 42 provides sealing on only part of the surface of the ends 43 and 44 of the rim. As can be seen in FIG. 8, one of the ends of the rim, in this case the end 44 is machined to create a housing 45 of uniform depth. The housing 45 extends at the level of the upper bridge, at least at the upper part of its thickness, that is to say that at least the upper wall of the bridge has been machined.

Laterally, the housing goes up along the internal face of the wings 47 and 48, and in the illustrated embodiment, it stops just below the hooks. Preferably, the housing starts only part of the thickness of the fenders, on the inside of the tire channel.

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 Advantageously, the machining of the housing can be carried out using a cylindrical cutter with a diameter slightly less than the width of the rim at the level of the wings.

 The seal 42 has an external shape which matches the cross section of the housing. Its thickness is however greater than the depth of the housing. As in the previous case, the seal is made of elastomer, therefore elastically compressible. When the needles 49 and 50 are fitted, the seal is compressed until the non-machined part of the end 44 comes into contact with the other end 43.

 The advantage of this construction method is that the compression of the seal is controlled, that is to say that it depends on the difference between the thickness of the seal and the depth of the housing. At the junction of the two ends, the braking surfaces come in continuity with each other as for a traditional rim. In addition, there is a metal-to-metal contact at both ends which resists compression well resulting from the tensioning of the spokes.

 The seal 42 seals the tire channel. Indeed, it is pinched between the upper walls of the upper decks and the inner face of the wings.

 Although the seal does not extend to the top of the wings, the seal was found to be acceptable. It is believed that an acceptable seal can be obtained as soon as the seal covers the base of the wings. Under these conditions, the seal is made with the beads of the tire.

 According to the variant of Figure 9, the housing 51 is machined to a greater depth. The seal 52 is also thicker, and it is crossed by a valve 53 which opens at the upper wall of the seal. The end of the rim which has been machined has at the level of the lower bridge an opening 54 provided to receive the base of the valve.

 As in the previous case, the seal 52 has a thickness slightly greater than the depth of the housing 51. When the two ends of the rim are assembled, the seal is compressed in a controlled manner until the two ends of the rim come into contact.

 According to the variants of Figures 10 and 11, an insert carrying the needles and the valve is interposed between the two ends of the ring. The insert comprises a main body 55 which is for example made of a profile of the same material and of the same section as the ring. The two bridges of the insert are crossed by the inflation valve. The body 55 has two housings, one at each of the ends, which open onto the upper surface of the bridge and which rise along the internal face of the wings. Deformable seals 56 and 57, for example made of elastomer, are placed in the housings of the body. These joints have a thickness slightly greater than the depth of machining of the housings. During assembly, the non-machined part of the body bears against each of the ends of the ring, and the seals 56 and 57 seal the tire mounting channel, that is to say at the upper wall of the upper deck and the inner wall of the wings over at least the lower part of their height.

 Figures 12 and 13 relate to an alternative embodiment according to which a material, for example polymerizable, is injected into the box at the two ends. For example, as can be seen in Figure 12, a partition 58.59 is introduced at

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 the interior of the box at each of the ends 60 and 61 of the ring, so as to close off the box.

 One of the ends, for example the end 61 has for example at the lower deck an orifice 62 which opens into the box between the two partitions 58, 59 and which is provided for the injection of a material into the liquid or pasty state that hardens or polymerizes. The material in question is, for example, an epoxy or thermosetting type resin, possibly loaded with reinforcing fibers. Once hardened, the material forms a kind of sleeve 64.

 Preferably, one of the ends of the ring is machined at the upper bridge and along at least part of the height of the wings in a recess 63 to form with the walls opposite the other end a fine slot into which the resin is introduced. At the upper wall of the upper deck, the slot can be temporarily blocked on the inside of the tire channel with an adhesive or a pad or the like which is removed once the polymerization or hardening has sufficiently started. Thus, the injected material will have penetrated into the thickness of the upper bridge and of the wings, and it will have formed the seal at the level of the tire mounting channel.

 The ends of the rim are retained by needles as in the previous case.

 As a variant, FIGS. 14 and 15 show ends 65 and 66 of a rim assembled using a sleeve 67 which is force-fitted at each end of the ring. Under the junction between the two upper deck parts, the sleeve has a cavity 68 which communicates with the outside via a duct 69. The duct opens to the outside, for example at an opening 70.

 As in the previous case, a hardenable or polymerizable material 71 is introduced in the liquid or pasty state into the cavity 68 through the conduit 69. Preferably also, one of the ends of the ring is machined at the level of the bridge upper and wings to form with the other end a slit into which the curable material is introduced.

 According to the variant of FIG. 16, a valve 72 is integrated in the sleeve 73. The valve is housed in openings 74 and 75 of the upper and lower bridges which are made in half at each of the ends of the rim.

 The sleeve 73 comprises on each side of the valve two blocks 78 and 79 which have in section the same shape as the casing of the rim and which are designed to be force fitted at each end of the ring. The two blocks are joined by a beam 80 which supports the valve. Once the assembly has been carried out, a hardenable or polymerizable material is injected between the two blocks, for example through a bore 81 made in the side wall of the box.

 Many variants of the sleeve construction are possible.

 For these three modes of implementation, in addition to the sealing function, the material if it is hardenable contributes to strengthening the connection of the two ends of the rim.

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 According to the embodiment shown in FIGS. 17 and 18, the two ends of the rim are machined so as to form, at the level of the upper bridge and wings, for one a mortise 82 and for the other a tenon 83. A l 'assembly these elements are glued and then nested one inside the other.

 This assembly of the two ends can be reinforced by needles or a sleeve. The rim profile is determined accordingly.

 Other forms of machining could be carried out, the aim being to favor between the ends of the assembly surfaces which are situated in a plane other than the transverse plane.

 According to the embodiment of FIG. 19, at the junction of the two ends, the upper wall of the upper deck and the inside of the wings are covered with a self-adhesive film 85 which is airtight. The film 85 can be protected by a protective film 86.

The thickness of the film 85 is chosen to be sufficiently small so as not to create at its periphery a local deformation of the tire capable of letting air escape. Preferably, the film is slightly stretchy to perfectly match the shape of the wall of the channel.

 According to FIG. 20, at the junction of the two ends, the tire channel is lined with a piece 87 of thin thickness which matches the shape of the tire channel, and which is assembled for example by gluing to the ring. Given its small thickness, the part 87 is flexible.

According to the mode of construction shown, the part 87 supports the valve which passes through circular openings 88 and 89 made in the two bridges and half at each end 90 and 91 of the rim. Optionally, the upper wall of the upper bridge is machined to a depth corresponding to the thickness of the part 87 so as not to create any additional thickness in this area. According to a variant, the two end edges of the part 87 are chamfered so as to have a progressive reduction in its thickness.

 FIG. 21 relates to another variant of implementation. According to this variant, the internal wall of the tire channel is coated, at the junction of the two ends 93 and 94 with a liquid or pasty product such as a paint or a rubberized coating or the like 95 which, penetrating into the junction line at both ends, provides air tightness. To improve the behavior of the product, it is preferable to make a chamfer at both ends of the rim in the area where the product is deposited.

 Of course, this description is given for information only, and other implementations of the invention could be adopted without departing from the scope thereof.

 In particular, the invention also applies to the construction of rims which are provided for another mode of braking than by friction of pads on the sides of the rim.

In particular, rims intended for disc braking could be produced. In this case the problem of continuity of the lateral surfaces of the rim poses no particular problem.

Claims (24)

 CLAIMS 1-Method of manufacturing a rim according to which a curved ring is formed having a box section which comprises at least one upper bridge (5) with an upper wall, and wings (9,10) with an internal wall forming an annular channel provided for mounting the tire, and the two ends (23,24, 39,40, 43,44, 90,91) are opposite which are assembled by an assembly technique other than welding, characterized in that an element (22.30, 32.42, 52.55, 64.71, 73.85, 87.93) foreign to the two ends of the ring is attached 'ring of deformable material or in a liquid or pasty state to seal airtight the upper wall of the upper deck and at least at the lower part of the inner wall of the wings at the junction of the two ends.  2-A method according to claim 1, characterized in that there is interposed between the two ends of the ring a seal (22.30, 32.42, 52) which comprises at least one layer of elastically deformable material.  3-A method according to claim 2, characterized in that the seal (32,52) is the support of the inflation valve.  4-A method according to claim 2, characterized in that one machines at least one end of the ring a housing (45, 51) for the joint.  5-A method according to claim 1 wherein the two ends of the ring are assembled by means of force-fitted needles, characterized in that the seal (30,32) supports the two needles during the operation of fitting.  6-A method according to claim 1, characterized in that one inserts between the two ends of the rim an insert (55) having a seal (56,57) elastically deformable at each of its ends.  7-A method according to claim 1, characterized in that one injects into the box locally at the junction of the two ends a material (64, 71) in the liquid or pasty state intended to harden or polymerize.  8-A method according to claim 1 wherein the two ends of the ring are assembled by a sleeve (67) force-fitted at both ends, characterized in that a cavity (68) is positioned in the sleeve beforehand. the junction of the two ends, into which is injected after fitting a material in the liquid or pasty state which is intended to harden or polymerize.  9-A method according to claim 1, characterized in that at least the upper bridge and the lower part of the wings, one end of the ring is machined according to a mortise (82), the other end of the ring according to a tenon (83), and that the two ends are assembled by fitting the tenon into the mortise, with the addition of an adhesive.  10-A method according to claim 1, characterized in that after assembly of the two ends, at the junction of the two ends, the upper wall of the upper bridge and at least the lower part of the inner wall of the wings are covered with a film sticker (85). <Desc / Clms Page number 9>  11-A method according to claim 1, characterized in that one lines the upper wall and at least the lower part of the inner wall of the wings of a flexible shaped piece (87) which matches the inner shape of the wall upper of the upper deck and at least the lower part of the inner wall of the wings, and which is glued.  12-A method according to claim 1, characterized in that at the junction of the two ends, the upper wall of the upper bridge and at least the lower part of the inner wall of the wings are coated with a liquid or pasty product (95) intended to penetrate into the junction line of the two ends.  13-Bicycle rim formed by a ring having a box section which comprises at least one upper bridge (5) with an upper wall and wings (9,10) with an internal wall, and the two ends of which (23,24 , 39.40, 43.44, 88.89, 90.91) are assembled by an assembly technique other than welding, characterized in that an element (22.30, 32.42, 52.55 , 64.71, 73.85, 87.93) foreign to the ring of deformable material or in a liquid or pasty state airtightly closes the upper wall of the upper bridge and at least at the part bottom of the inner wall of the wings at the junction of the two ends.  14-rim according to claim 13, characterized in that a seal (22.30, 32.42, 52.55) comprising at least one layer of elastically deformable material is interposed between the two ends of the ring.  15-Rim according to claim 14, characterized in that the seal (32,52) is the support of an inflation valve (35,53).  16-Rim according to claim 14, characterized in that a housing (45,51) is machined at at least one end of the ring for the seal (42,52).  17-rim according to claim 13 wherein the two ends of the ring are assembled by means of force-fitted needles, characterized in that the seal (30,32) is the support of the two needles.  18-Rim according to claim 13, characterized in that an insert (55) having a seal (56,57) elastically deformable at each of its ends is interposed between the two ends of the rim.  19-rim according to claim 13, characterized in that a material (64,71) in the liquid or pasty state intended to harden is injected into the box locally at the junction of the two ends.  20-rim according to claim 13 wherein the two ends of the ring are assembled by a sleeve (67) force-fitted at both ends, characterized in that the sleeve has a cavity (68) positioned at the junction of the two ends , into which is injected a material in the liquid or pasty state which is intended to harden or polymerize.  21-rim according to claim 13, characterized in that at least the upper bridge and the lower part of the wings, one end of the ring has a mortise (82), <Desc / Clms Page number 10>  the other end of the ring has a tenon (83), and that the tenon is fitted into the mortise with the addition of an adhesive.  22-rim according to claim 13, characterized in that the upper wall of the upper deck and at least the lower part of the inner wall of the wings are covered with a self-adhesive film (85).  23-rim according to claim 13, characterized in that the upper wall and at least the lower part of the inner wall of the wings are upholstered with a flexible shaped piece (87) which matches the internal shape of the upper wall of the bridge upper and at least the lower part of the inner wall of the wings, and which is glued.  24-rim according to claim 13, characterized in that at the junction of the two ends the upper wall of the upper bridge and at least the lower part of the inner wall of the wings are coated with a liquid or pasty product (95) provided to enter the line joining the two ends.