Patent Application
20190308446
The present disclosure is generally directed to a bicycle rim, and more particularly, to a clincher tire attachment of a composite bicycle rim.
A traditional bicycle wheel may include a rim formed of extruded metals or other materials that are bent and bonded into a circular shape having consistently shaped cross sections. Recently, other materials, such as advanced carbon fiber reinforced composites, that can be manipulated into shape while soft and then set into a substantially rigid form, have been used in the manufacture of bicycle rims, which may be formed into circular shapes through non-extrusion based processes. Carbon fiber reinforced advanced composites may, for example, be used.
A method for manufacturing a carbon clincher bicycle wheel relies on the stacking of individual layers, or plies, of carbon fiber sheets to form structures such as a tire retaining portion of the rim. The carbon fiber sheets may be pre-impregnated with a resin or other matrix material, which undergoes a curing process to form a hardened rim. When the cured plies of carbon fiber sheets are loaded due to pressure from a tire on the wheel, particularly at a bead retention portion of the rim, a high short beam shear stress results within the stack of plies. In some circumstances, outward deflection of the vertical tire-retaining portion and resulting high interlaminar shear stresses in the rim cross-section causes the composite structure to delaminate along fiber-resin interfaces within the cured matrix.
In order to address the high short beam shear stress that results from loading due to pressure from the tire on the wheel, the number of plies within the stack may be increased. This, however, adds mass, weight, and cost for the carbon clincher bicycle wheel, and manufacturing of the carbon clincher bicycle wheel is more time consuming and complex. Also, positioning additional mass at the outer perimeter of the wheel rim to provide the increased number of plies may be disadvantageous. Added mass at the outer perimeter of the wheel rim, a location distal from the wheel hub, increases an amount of energy or power needed to accelerate or decelerate rotation of the wheel.
Also, in traditional composite clincher rims the interlaminar failure of the tire retaining portion may be further exaggerated within a bead retention portion of the tire retaining portion due to discontinuous fibers being used around and through the clincher hook portion. The discontinuous fibers provide an easier path for the delamination to migrate from a weaker part of the clincher hook portion, all the way through the laminate stack, resulting in compromise of the tire retaining portion (e.g., a tire retention vertical wall).
In one example, a rim for a bicycle wheel is provided. The rim includes a radially outer tire engaging portion having a first tire retaining portion and a second tire retaining portion spaced apart from the first tire retaining portion. The rim also includes a first sidewall, the first tire retaining portion extending from the first sidewall. The rim also includes a second sidewall spaced apart from the first sidewall, the second tire retaining portion extending from the second sidewall, the first sidewall and the second sidewall extending radially inward of the radially outer tire engaging portion. The first tire retaining portion includes a first tire retaining section, the first tire retaining section including a first set of layers of a first composite material forming a first outer wall and a second set of layers of a second composite material forming a first tire retaining wall opposite the first outer wall.
In one example, a rim for a bicycle wheel is made of a composite material and includes a radially outer tire engaging portion having a first tire retaining portion and a second tire retaining portion spaced apart from the first tire retaining portion. The rim also includes a first sidewall. The first tire retaining portion extends from the first sidewall. The rim includes a second sidewall spaced apart from the first sidewall. The second tire retaining portion extends from the second sidewall. The first sidewall and the second sidewall extend radially inward of the radially outer tire engaging portion. The first tire retaining portion includes a first tire retaining section. The first tire retaining section includes a first outer wall and a first tire retaining wall opposite and spaced apart from the first outer wall. The second tire retaining portion includes a second tire retaining section. The second tire retaining section includes a second outer wall and a second tire retaining wall opposite and spaced apart from the second outer wall. The first outer wall, the first tire retaining wall, the second tire retaining wall, and the second outer wall include layers of the composite material. The layers of the composite material are continuous from the first outer wall to the second outer wall, through the first tire retaining wall and the second tire retaining wall.
In one example, a wheel for a bicycle includes a central hub configured for rotational attachment to the bicycle, and a plurality of spokes attached to the central hub and extending radially outward from the hub. The plurality of spokes consist of a number of spokes. The wheel also includes a rim. The rim includes a radially outer tire engaging portion having a first tire retaining portion and a second tire retaining portion spaced apart from the first tire retaining portion. The rim also includes a first sidewall. The first tire retaining portion extends from the first sidewall. The rim includes a second sidewall spaced apart from the first sidewall. The second tire retaining portion extends from the second sidewall. The first sidewall and the second sidewall extend radially inward of the radially outer tire engaging portion. The rim also includes a radially inner portion disposed along an inner circumference of the rim. The plurality of spokes are attached to the radially inner portion of the rim. The radially outer tire engaging portion includes layers of the composite material. The layers of the composite material are continuous from the first tire retaining portion to the second tire retaining portion, such that the layers of the composite material are continuous around and through the radially outer tire engaging portion.
In one example, the composite material is a carbon fiber based material and/or fibers of the composite material are carbon fibers.
In one example, a bicycle rim includes a first outer wall and a first tire retaining wall, and/or a second outer wall and a second tire retaining wall, respectively, and the first outer wall and the first tire retaining wall, and/or the second outer wall and a second tire retaining wall are separated by only air. In another example, the first outer wall and the first tire retaining wall, and/or the second outer wall and a second tire retaining wall are separated by a foam.
Objects, features, and advantages of the present invention will become apparent upon reading the following description in conjunction with the drawing figures, in which:
The present disclosure provides examples of rims and wheels that solve or improve upon one or more of the above-noted and/or other disadvantages with prior known rims and wheels. The disclosed rims may include tire retaining portions with layers of composite material that are continuous from an outer wall to at least an opposite tire retaining wall. In other words, the layers of composite material are unbroken through one or both clincher hooks of the tire retaining portion. Exposed layer ends at the clincher hooks are thus eliminated or reduced, which eliminates or reduces crack initiation and propagation at ply interfaces through the tire retaining portion. The tire retaining portion may include two discrete walls (i.e. an outer wall and tire retaining wall) formed of layers of composite material (e.g., the continuous layers of composite material) spaced apart by a distance.
The space between the two discrete walls may be filled by a substance having a lower density than the composite material, such as air, a foam, or other materials. The tire retaining portion of the rim may be wider than known composite material tire retaining portions, providing additional structure for tire retention. A significant advantage of the disclosed rims is that the rim is stronger with less material usage compared to the prior art composite rims due to the layers of composite material being continuous through the tire retaining portion. Other advantages of the disclosed rims are that the rim weighs less, has a more advantageous distribution of mass, and is less expensive to manufacture compared to the prior art composite rims.
Turning now to the drawings,
While the illustrated bicycle 50 depicted in
The drivetrain 58 has a chain 10 and a front sprocket assembly 72, which is coaxially mounted with a crank assembly 74 having pedals 76. The drivetrain 58 also includes a rear sprocket assembly 78 coaxially mounted with the rear wheel 56 and a rear gear change mechanism, such as a rear derailleur 80.
As is illustrated in
The rear derailleur 80 may be a wireless, electrically actuated rear derailleur mounted or mountable to the frame 52, or frame attachment, of the bicycle 50. The electric rear derailleur 80 has a base member 86 (e.g., a b-knuckle) that is mounted to the bicycle frame 52. A linkage 88 has two links L that are pivotally connected to the base member 86 at a base member linkage connection portion. A movable member 90 (e.g., a p-knuckle) is connected to the linkage 88 at a movable member linkage connection portion. A chain guide assembly 92 (e.g., a cage) is configured to engage and maintain tension in the chain. Other gear changing systems, such as mechanically or hydraulically controlled and/or actuated systems may also be used.
In operation, the chain 10 is routed around one of the rear sprockets (e.g. G1-G11). An upper segment of the chain 10 extends forward to the front sprocket assembly 72 and is routed around one of the front sprockets F1. A lower segment of the chain 10 returns from the front sprocket assembly 72 to the tensioner wheel and is then routed forward to the guide wheel. A guide wheel directs the chain 10 to the rear sprockets (e.g. G1-G11). Lateral movement of the cage plate 93, tensioner wheel, and guide wheel may determine the lateral position of the chain 10 for alignment with a selected one of the rear sprockets (e.g. G1-G11).
The bicycle 50 may include one or more bicycle control devices mounted to handlebars 68. The bicycle control devices may include one or more types of bicycle control and/or actuation systems. For example, the bicycle control devices may include brake actuation systems to control the front brake 60 and/or the rear brake 62, and/or gear shifting systems to control the drivetrain 58. Other control systems may also be included. For example, the system may be applied, in some embodiments, to a bicycle where only a front or only a rear gear changer is used. Also, the one or more bicycle control devices may also include suspension and/or other control systems for the bicycle 50.
The front wheel 54 and/or the rear wheel 56 of the bicycle 50 may include a tire 120, attached to a radially outer tire engaging portion of a rim 122. As shown in
The rim 122 provides structure for attachment of the spokes 124 to the rim 122 at a receiving portion of the rim 122, proximate to the spoke receiving surface 132. As such, the spoke receiving surface 132 is part of a spoke engaging portion 136 of the rim 122. In an embodiment, the spoke receiving surface 132 and the spoke engaging portion 136 may be separate parts and/or portions of the rim 122. For example, the spokes 124 may pass through the spoke receiving surface 132, and the structure for attachment to the rim 122 may be provided proximate to the tire engaging portion 130. In one example, the rim 122 is formed by carbon-fiber reinforced advanced composite. The rim 122 may, however, be formed of other materials and/or material combinations. In one example, carbon-fiber reinforced advanced composite forms a one-piece unitary rim of a singular collection of carbon-fiber layers including the tire engaging portion 130, two sidewalls, and the spoke engaging portion 136. Although as described herein spokes are referenced for attaching the rim 122 to the central hub 126, those skilled in the art will know that other attachment methods may be utilized such as advanced composite blades or full disc extending from the central hub 126 to rim 122. Other configurations may also be provided.
The front wheel 54 and the rear wheel 56 may include rims 122 configured for any size wheel. In an embodiment, the rims 122 are configured for use in wheels conforming to a 700 C (e.g. a 622 millimeter diameter clincher and/or International Standards Organization 622 mm) bicycle wheel standard.
The front wheel 54 and the rear wheel 56 may rotate about the central hub 126 in either direction. For example, as shown in
In one example, the tire engaging portion 130, the spoke engaging portion 136, the first sidewall 140, and the second sidewall 142 are formed of a single piece construction. The rim 122 may be formed of a single material having thin walls (e.g., layers of composite sheets). At least a portion of the rim 122 may have walls having a constant thickness. In one example, the tire engaging portion 130, the spoke engaging portion 136, the first sidewall 140, and/or the second sidewall 142 is a separate part and attached to the other parts of the rim 122. Specific areas and/or positions of the walls of the rim 122 may be thicker or thinner based on structural requirements of the rim 122.
The rim 122 also includes an optional support 146 (e.g., a base plate). At least a portion of the support 146 may be shaped and/or sized to conform to the tire engaging portion 130, the first sidewall 140, and/or the second sidewall 142. The support 146 may be made of any number of materials including, for example, a carbon-fiber reinforced composite, a metal such as aluminum, or other materials. The support 146 extends across the axial width 144 of the rim, such that the support abuts both the first sidewall 140 and the second sidewall 142. The support 146 may be physically connected to the tire engaging portion 130, the first sidewall 140, and/or the second sidewall 142 in any number of ways including, for example, with an adhesive, via press fit, or the support 146 is molded with the tire engaging portion 130. The support 146 may, for example, tie the first sidewall 140 and the second sidewall 142 together and/or may provide support for braking if the bicycle 50 includes rim brakes.
Referring to
The first tire retaining portion 150 includes a first tire retaining section 154 and a first protrusion 156 (e.g., a first bead retaining structure). The first tire retaining section 154 includes a first outer wall 158 and a first tire retaining wall 160 opposite and spaced apart from the first outer wall 158. The first protrusion 156 extends generally between the first outer wall 158 and the first tire retaining wall 160 and may extend inward toward the tire engaging portion 130. For example, the first protrusion 156 extends from the first outer wall 158 to the first tire retaining wall 160. In one example, the first protrusion 156 extends from the first tire retaining wall 160, towards the second tire retaining portion 152. At least a portion of the first protrusion 156 may extend inward toward the tire engaging portion 130 and form any number of shapes including, for example, a first hook 161.
The second tire retaining portion 152 includes a second tire retaining section 162 and a second protrusion 164 (e.g., a second bead retaining structure). The second tire retaining section 162 includes a second outer wall 166 and a second tire retaining wall 168 opposite and spaced apart from the second outer wall 168. The second protrusion 164 extends generally between the second outer wall 166 and the second tire retaining wall 168 and may extend inward toward the tire engaging portion 130. For example, the second protrusion 164 extends from the second outer wall 166 to the second tire retaining wall 168. In one example, the second protrusion 164 extends from the second tire retaining wall 168, towards the first tire retaining portion 150. At least a portion of the second protrusion 164 may extend inward toward the tire engaging portion 130 and form any number of shapes including, for example, a second hook 169.
As illustrated in
The radially outer tire engaging portion 130 also may include a well 172 positioned between the first tire retaining portion 150 and the second tire retaining portion 152 of the rim 122. The well 172 provides a volume into which the beads 170 of the tire 120 may be placed when the tire 120 is being attached to the rim 122. As the tire 120 is inflated, the beads 170 of the tire 120 move away from each other until the beads 170 interact with the first tire retaining portion 150 and the second tire retaining portion 152, respectively. As shown in
In an embodiment, the radially outer tire engaging portion 130 also includes ridges 174 (e.g., bead bumps; a first bead bump 174a and a second bead bump 174b) on opposite sides of the well 172, respectively. A first shelf 176 (e.g., a first bead shelf) extends between the first tire retaining wall 160 and the first bead bump 174a, and a second shelf 178 (e.g., a second bead shelf) extends between the second tire retaining wall 168 and the second bead bump 174b. In one embodiment, curved transition regions 177 extend between the first shelf 176 and the first tire retaining wall 160, and the second shelf 178 and the second tire retaining wall 168, respectively. The bead bumps 174 are positioned on opposite sides of the well 172, respectively, and are raised relative to the first shelf 176 and the second shelf 178, respectively. The bead bumps 174 help retain the tire 120 on the rim 122 if the tire 120 loses pressure.
As illustrated in
The rim 122 may be made of any number of materials including, for example, a carbon fiber reinforced polymer (CFRP) composite. Other materials may be used. Again referring to
In the example shown in
Referring to
In the example shown in
The maximum distances D, D2 between the first outer wall 158 and the first tire retaining wall 160 of the first tire retaining section 154, and the second outer wall 166 and the second tire retaining wall 168 of the second tire retaining section 162, may be the same in both the first tire retaining section and the second tire retaining section. In an embodiment, the maximum distances between the first outer wall 158 and the first tire retaining wall 160 of the first tire retaining section 154 may be different than the maximum distances between the second outer wall 166 and the second tire retaining wall 168 of the second tire retaining section 162.
The tires 120 for particular bicycles may require less air pressure compared to road bicycle. For example, the tires 120 for road bicycles may require a tire pressure of 80 to 130 psi or more, while the tires 120 for mountain bicycles may require a tire pressure of only 25 to 35 psi. Referring to the example shown in
In the example shown in
Referring to the examples shown in
Referring to
In one example, at least the tire engaging portion 130, the first sidewall 140, and the second sidewall 142 are formed with the stack 200 of the continuous layers 202 of the CFRP. More or less of the rim 122 may be formed with the stack 200 of continuous layers 202 of the CFRP. In one example, the layers 202 of the composite material extend and are continuous from at least the first sidewall 140, through the first tire retaining portion 150. In an embodiment the continuous layers 202 extend to the first shelf 176, and at least part of the well 172. The layers 202 of composite material may be continuous through the entire first protrusion 156. The layers 202 of the composite material may also extend through the remainder of the well 172, the second shelf 178, the second tire retaining portion 152, and at least a portion of the second sidewall 142. The layers 202 of composite material are thus continuous through the entire second protrusion 164. In other words, the layers 202 of the composite material extend through the entire radially outer tire engaging portion 130 (e.g., the first tire retaining portion 150 and the second tire retaining portion 152) and through at least portions of the first sidewall 140 and the second sidewall 142, respectively.
A number of benefits result from the use of the continuous layers 202 of the composite material to form, for example, the radially outer tire engaging portion 130. The rim 122 may be designed with these benefits in mind. For example, the fibers of the stack 200 of continuous layers 202 of the composite material perform well in tension, particularly along a primary strength orientation. For example, to take advantage of this property, the first sidewall 140 and the first outer wall 158 and the first tire retaining wall 160 of the first tire retaining section 154, and the second sidewall 142 and the second outer wall 166 and the second tire retaining wall 168 of the second tire retaining section 162, respectively, may be straight to keep the fibers within the layers 202 of the composite material straight (e.g., in line with directions in which the first sidewall 140, the first outer wall 158, the first tire retaining wall 160, the second sidewall 142, the second outer wall 166, and the second tire retaining wall 168 extend, respective) and in tension. As another example, the use of the continuous layers 202 of the composite material through the first protrusion 156 and the second protrusion 164 provides a stronger rim compared to the prior art, as the layers 202 of the composite material are not cut and stacked to form the width of the tire retaining portions or the first protrusion 156 (e.g., including the first hook 161) or the second protrusion 164 (e.g., including the second hook 169), as done in the prior art. This reduces the number of exposed, or otherwise unconstrained, layer ends, which also eliminates the crack initiation at ply interfaces that may occur around a fiber retention portion of the first hook and the second hook of the prior art.
In an embodiment, a rim for a bicycle wheel is provided. The rim includes a radially outer tire engaging portion having a first tire retaining portion and a second tire retaining portion spaced apart from the first tire retaining portion. The rim also includes a first sidewall, the first tire retaining portion extending from the first sidewall. The rim also includes a second sidewall spaced apart from the first sidewall, the second tire retaining portion extending from the second sidewall, the first sidewall and the second sidewall extending radially inward of the radially outer tire engaging portion. In an embodiment, the first tire retaining portion includes a first tire retaining section, the first tire retaining section including a first set of layers of a first composite material forming a first outer wall and a second set of layers of a second composite material forming a first tire retaining wall opposite the first outer wall. In an embodiment, such as that illustrated with respect to
In an embodiment, the first set of layers is spaced apart from the second set of layers by a substance having a lower density than the composite material. The substance may be any material having a lower density than the composite material, such as air or a foam material.
In an embodiment, the second tire retaining portion includes a second tire retaining section, the second tire retaining section including a third set of layers of composite material forming a second outer wall and a fourth set of layers of composite material forming a second tire retaining wall opposite and spaced apart from the second outer wall, and wherein the third set of layers is spaced apart from the fourth set of layers by the substance having a lower density than the composite material.
In an embodiment, the radially outer tire engaging portion, the first sidewall, and the second sidewall are formed of a same composite material, for example layers of the same composite material.
The illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The illustrations are not intended to serve as a complete description of all of the elements and features of apparatus and systems that utilize the structures or methods described herein. Many other embodiments may be apparent to those of skill in the art upon reviewing the disclosure. Other embodiments may be utilized and derived from the disclosure, such that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. Additionally, the illustrations are merely representational and may not be drawn to scale. Certain proportions within the illustrations may be exaggerated, while other proportions may be minimized. Accordingly, the disclosure and the figures are to be regarded as illustrative rather than restrictive.
While this specification contains many specifics, these should not be construed as limitations on the scope of the invention or of what may be claimed, but rather as descriptions of features specific to particular embodiments of the invention. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.
Similarly, while operations and/or acts are depicted in the drawings and described herein in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that any described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.
One or more embodiments of the disclosure may be referred to herein, individually and/or collectively, by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any particular invention or inventive concept. Moreover, although specific embodiments have been illustrated and described herein, it should be appreciated that any subsequent arrangement designed to achieve the same or similar purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all subsequent adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, are apparent to those of skill in the art upon reviewing the description.
The Abstract of the Disclosure is provided to comply with 37 C.F.R. § 1.72(b) and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all of the features of any of the disclosed embodiments. Thus, the following claims are incorporated into the Detailed Description, with each claim standing on its own as defining separately claimed subject matter.
It is intended that the foregoing detailed description be regarded as illustrative rather than limiting and that it is understood that the following claims including all equivalents are intended to define the scope of the invention. The claims should not be read as limited to the described order or elements unless stated to that effect. Therefore, all embodiments that come within the scope and spirit of the following claims and equivalents thereto are claimed as the invention.
