Patent Document

BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention generally relates to a bicycle rim for a bicycle wheel. More specifically, the present invention relates to a bicycle rim, which is configured to improve the roundness of the bicycle wheel when the spokes are placed under tension between the rim and the hub. 
     2. Background Information 
     Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has also become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One particular component of bicycles, which has been extensively redesigned over the past years, is the bicycle wheel. Bicycle wheels are constantly being redesigned to be lightweight and more aerodynamic in design as well as to be simple to manufacture and assemble. 
     There are many different types of bicycle wheels, which are currently available on the market. Most bicycle wheels have a hub portion, a plurality of spokes and an annular rim. The hub portion is attached to a part of the frame of the bicycle for relative rotation. The inner ends of the spokes are coupled to the hub and extend outwardly from the hub to the rim. The annular rim is coupled to the outer ends of the spokes and has an outer portion for supporting a pneumatic tire thereon. Typically, the spokes of the bicycle wheel are thin metal wire spokes that are placed under tension. Each end of the hub is provided with a flange that is used to couple the spokes to the hub. In particular, holes are provided in the hub flanges. The wire spokes are usually bent on their inner end and provided with a flange that is formed in the shape of a nail head. The inner ends are supported in the holes in the hub flanges. The outer ends of the spokes typically are provided with threads for engaging spoke nipples, which secure the outer ends of the wire spokes to the rim. In particular, the spoke nipples have flanges, which engage the interior surface of the rim. Alternatively, the spokes may be reversed, with the outer end having the nail head and the inner end having the threads for engaging the spoke nipples, which secure the inner ends of the wire spokes to the hub. 
     Typically, conventional spokes are attached to either the inner edge or the lateral side portions of the rim. Thus, the amount of force that can be applied to the rim by the spokes depends mainly upon the thickness of the inner edge of the rim or the lateral side portions of a rim. In order to accommodate the stress from the spokes, the inner edge of the rim can be made thicker. However, making the rim thicker increases the weight of the rim. 
     In recent years, wheels have been designed with reinforcing members arranged on the outer ends of the spokes to aid in disbursing the stress concentrated on portions of the rim. Such a wheel is disclosed in Shimano&#39;s U.S. Pat. No. 6,126,243. This wheel (i.e., rim, and spoke combination) is very strong, lightweight, and relatively simple and inexpensive to manufacture. 
     Generally speaking, the spokes in the bicycle wheel must be applied with a certain amount of tension in order to provide rigidity and trueness to the wheel. In conventional style wheels with thirty-two or more spokes, the tension applied on any one spoke is not very great. Moreover, the spokes pull the rim relatively evenly because the spoke attachment holes in the rim are fairly close together. 
     However it is desirable in the bicycle industry to have as few spokes as possible. One problem with reducing the number of spokes is the concentrated stress applied to the rim. In other words, if fewer spokes are used, the stress on the rim by each spoke becomes increasingly larger. Therefore, the spokes in the wheel with fewer number of spokes pull the rim with greater force at each attachment point. This typically causes greater deformation of the rim at the spoke attachment points than the remaining sections of the rim. Thus, the wheel after being assembled may not be truly round. In other words, the outer peripheral edge of the rim can be deformed into a somewhat polygonal shape. For example, bicycle wheels have been produced with sixteen spoke attachment portions with a pair of spoke attachment portions being positioned very close to each other. When tension is applied to the spokes, the rim is deformed from a substantially perfectly round shape to a polygonal shape after assembly of the wheel. 
     In view of the above, there exists a need for a bicycle rim that overcomes the above-mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide a rim in which tensioning of the spokes produces a bicycle wheel with improved the roundness. 
     Another object of the present invention is to provide a rim that can be manufactured without substantially increasing the cost of manufacture. 
     Yet another object of the present invention is to provide a rim that can be utilized with a low number of spokes. 
     The foregoing objects can basically be attained by providing a bicycle rim that comprises first and second annular side portions, an inner annular portion, an outer annular tire attachment portion and a plurality of circumferentially spaced spoke openings. The inner annular portion is disposed radially inwardly of the first and second annular side portions and disposed axially between the first and second annular side portions. The outer annular tire attachment portion is disposed axially between the first and second annular side portions. The tire attachment portion has non-circular outer peripheral edges arranged about a center axis of the rim. The circumferentially spaced spoke openings are formed in at least one of the following: the inner annular portion or the first and second annular side portions. The non-circular outer peripheral edges have first radii extending from the center axis of the rim and passing through the spoke openings that are larger than second radii of the non-circular outer peripheral edges passing midway between selected circumferentially adjacent pairs of the spoke openings. 
     The foregoing objects can also basically be attained by a method of forming a bicycle wheel comprising the steps of: forming a non-circular bicycle rim having a non-circular outer periphery arranged about a center axis of the rim; attaching a bicycle hub to the non-circular bicycle rim by a plurality tension spokes; and tightening the tension spokes to place the tension spokes under tension and deform the rim inwardly in a generally radial direction to become more circular. 
     These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring now to the attached drawings which form a part of this original disclosure: 
     FIG. 1 is a side elevational view of a bicycle having front and rear wheels in accordance with the present invention; 
     FIG. 2 is a side elevational view of the front bicycle wheel illustrated in FIG. 1 in accordance with the present invention; 
     FIG. 3 is an edge elevational view of the front bicycle wheel with the bicycle rim illustrated in FIG. 1 and 2 in accordance with the present invention; 
     FIG. 4 is an enlarged, partial side elevational view of the bicycle hub assembly used with the bicycle rim illustrated in FIGS. 1-3 in accordance with the present invention, with a portion of the hub body broken away for purposes of illustration; 
     FIG. 5 is an exaggerated side elevational view of the bicycle rim illustrated in FIGS. 1-4 in accordance with the present invention, prior to the tensioning of the spokes to produces the bicycle wheel with improved the roundness; 
     FIG. 6 is an enlarged, partial side elevational view of the bicycle rim illustrated in FIGS. 1-5 in accordance with the present invention, with a pair of spokes coupled thereto; 
     FIG. 7 is a partial, enlarged cross sectional view of the bicycle rim illustrated in FIGS. 1-6 in accordance with the present invention as seen along section line  7 — 7  of FIG. 5; 
     FIG. 8 is a partial, enlarged cross sectional view of the bicycle rim illustrated in FIGS. 1-7 in accordance with the present invention as seen along section line  8 — 8  of FIG.  5  and with a spoke coupled thereto; 
     FIG. 9 is a side elevational view of the rear bicycle wheel illustrated in FIG. 1 in accordance with the present invention; 
     FIG. 10 is an edge elevational view of the rear bicycle wheel with the bicycle rim illustrated in FIGS. 1 and 9 in accordance with the present invention; 
     FIG. 11 is an enlarged, partial side elevational view of the bicycle hub assembly used with the bicycle rim illustrated in FIGS. 1,  9  and  10  in accordance with the present invention, with a portion of the hub body broken away for purposes of illustration; 
     FIG. 12 is an exaggerated side elevational view of a bicycle rim in accordance with a second embodiment of the present invention, prior to the tensioning of the spokes to produces the bicycle wheel with improved the roundness; 
     FIG. 13 is an enlarged, partial cross sectional view of the bicycle rim illustrated in FIG. 12 in accordance with the second embodiment of the present invention as seen along section line  13 — 13  of FIG. 12; 
     FIG. 14 is an enlarged, partial cross sectional view of the bicycle rim illustrated in FIG. 12 in accordance with the second embodiment of the present invention as seen along section line  14 — 14  of FIG. 12; 
     FIG. 15 is a side elevational view of the rear bicycle wheel in accordance with a third embodiment of the present invention; 
     FIG. 16 is an exaggerated side elevational view of the bicycle rim illustrated in FIG. 15 in accordance with the third embodiment of the present invention, prior to the tensioning of the spokes to produces the bicycle wheel with improved the roundness; 
     FIG. 17 is a side elevational view of the rear bicycle wheel in accordance with a fourth embodiment of the present invention; and 
     FIG. 18 is an exaggerated side elevational view of the bicycle rim illustrated in FIG. 17 in accordance with the fourth embodiment of the present invention, prior to the tensioning of the spokes to produces the bicycle wheel with improved the roundness. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring initially to FIG. 1, a bicycle  10  is illustrated with a pair of bicycle wheels  12  and  13  in accordance with the present invention. The bicycle wheels  12  and  13 , as discussed below, are designed such that after assembly, the wheels  12  and  13  are more round than conventional wheels with similar spoking arrangements. The bicycle  10  basically has a frame  14  with front and rear wheels  12  and  13  rotatably coupled thereto. A conventional drive train  15  is operatively coupled the rear wheel  13  for propelling the bicycle  10 . A front fork  17  is coupled between the frame  14  and the front wheel  12  in a conventional manner. The front wheel  12  is turned by turning a handlebar  18 , which is fixedly coupled to the front fork  17 . The rear wheel  13  is rotatably coupled to a rear portion of the frame  14 . The frame  14  also has a seat  19  adjustably coupled to frame  14 . 
     Since the parts of the bicycle  10  are well known in the art, the parts of the bicycle  10  will not be discussed or illustrated in detail herein, except as they are modified in accordance with the present invention. Moreover, various conventional bicycle parts such as brakes, derailleurs, additional sprockets, etc., which are not illustrated and/or discussed in detail herein, can be used in conjunction with the present invention. 
     Turning now to FIGS. 2-8, the front wheel  12  basically includes the front bicycle hub  20 , a plurality of outwardly extending spokes  22  and an annular rim  24  with a pneumatic tire  26  coupled thereto in a conventional manner. In the illustrated embodiment, the front wheel  12  has sixteen spokes  22  extending generally in a radial direction between the front hub  20  and the annular rim  24 . Of course, it will be apparent to those skilled in the art from this disclosure that the front wheel  12  can have fewer or more spokes  22  than illustrated without departing from the present invention, if needed and/or desired. 
     The rim  24  is constructed of a substantially rigid material, such as those materials, which are well known in the art. For example, the rim  24  can be constructed of any suitable metallic material, such as plated steel, stainless steel, aluminum, magnesium or titanium, as well as other non-metallic materials, such as a carbon fiber composite, which can be utilized for a bicycle wheel. The rim  24  is relatively conventional, except for their shape. As discussed below in more detail, the rim  24  has a generally octagonal shape prior to assembly as seen in FIG.  5 . This octagonal shape of the rim  24  is design to improve the roundness of the wheel due to the deformation caused by the spokes  22 . Basically, the spokes  22  are under placed under tension during assembly, which in turn causes the rim  24  to deform radially inwardly as explained below in more detail. 
     Still referring to FIGS. 2-4 and  6 - 8 , the general construction of the front wheel  12  will now be described in more detail to better understand the present invention. The front hub  20  is a well known hub in the art. Thus, the hub  20  will not be discussed or illustrated in detail herein. Moreover, it will be apparent to those skilled in the art that the construction of the hub  20  can be modified from the hub illustrated herein without departing from the scope of the present invention. Moreover, the front hub  20  is designed to have sixteen tangentially arranged spokes  22 . However, it will be apparent to those skilled in the art from this disclosure that the hub  20  can be designed for tangential and/or radial spokes with more or fewer spokes as needed and/or desired. 
     Basically, the front hub  20  has a tubular body  30  with a pair of end mounting flanges  32  for mounting spokes  22  thereto. Each end flange  32  has four spoke attachment points or members with a pair of spoke holes  34  formed in each of the spoke attachment members for coupling the spokes  22  thereto. The tubular body section  30  rotatably supports an axle  36  therein about a center axis of rotation A by a pair of bearing assemblies (not shown). Each of the spoke holes  34  preferably has a step shaped configuration for attaching the spokes  22  thereto. 
     As mentioned above, the number and shape of the spoke attachment points of the end flanges  32  will depend on the number of spokes and their shapes. Accordingly, it will be apparent to those skilled in the art from this disclosure that other types and shapes of hubs can be utilized in connection with the present invention. 
     Each of the spokes  22  has an outer end portion  40 , a center middle portion  42  and an inner end portion  44 . The outer end portions  40  are in the shape of spoke heads that are coupled to the rim  24  by reinforcement members or washers  48 . The reinforcement washers  48  are designed to disperse the stress applied to the rim  24  by the spokes  22 . Of course, the present invention can be carried out without the use of reinforcement members as illustrated herein, as needed and/or desired. 
     The straight center portion  42  of each spoke  22  is located radially inwardly of its respective outer end portion  40 , and its respective inner end portion  44  is located radially inwardly of its respective center portion  42 . The inner end portions  44  are coupled to the front hub  20  utilizing spoke nipples  46  in a conventional manner. Preferably the outer end portion  40 , the center portion  42  and the inner end portion  44  are constructed as a unitary, one-piece member with the spoke nipples  46  threadedly coupled to the inner end portion  44  of each of the spokes  22  for connection to the hub  20 . 
     As best seen in FIGS. 6 and 8, the outer end portions  40  of the spokes  22  have a bent section  40   a  with an enlarged head  40   b  at the free end of the bent section  40   a . The bent section  40   a  has a circular cross-section of a predetermined diameter or width. The head  40   a  has a larger diameter or width to secure the spoke  22  to the rim  24  via the reinforcement washer  48 . The center portions  42  and the inner end portions  44  each have a circular or elliptical cross-section. Of course, it will be apparent to those skilled in the art from this disclosure that the entire length of the spokes  22  can be substantially uniform along its entire cross-section, if needed and/or desired. It will also be apparent to those skilled in the art that constant cross-section spokes can be utilized or spokes with varying cross-sections can be utilized as needed and/or desired. 
     Referring again to FIG. 4, the inner end portions  44  of the spokes  22  are threaded for receiving the conventional spoke nipples  46  thereon. More specifically, the inner end portions  44  of the spokes  22  are inserted through one end of the bores  34  of the hub  20 , and then the spoke nipples  46  are inserted through the other end of the bores  34 . The headed or flanged portion of the spoke nipples  46  engage an internal abutment surface of the bore  34  to fixedly secure inner end portions  34  of the spokes  22  to the hub  20 . Accordingly, the spokes  22  can be tightened in a substantially conventional manner between the hub  20  and the rim  24  such that the spokes  22  are placed under tension. In other words, when the spokes  22  are placed under tension, the spokes  22  apply a radially inwardly directed force on the rim  24  at various points on the rim  24 . These tension forces of the spokes  22  cause the rim  24  to deform inwardly at the points where the spokes  22  are coupled to the rim  24  as discussed below. 
     Referring now to FIGS. 5,  7  and  8 , the rim  24  is a so-called deep rim in which the rim&#39;s radial height is greater than the rim&#39;s radial width. Of course, it will be apparent to those skilled in the art from this disclosure that other types of rims can be utilized in connection with the present invention without departing from the scope of the present invention. The rim  24  is designed to secure the tire  26  thereto in a conventional manner. In particular, in this embodiment, the rim  24  is a “clinchers” type of rim. It will be apparent to those skilled in the art from this disclosure that the rim can be a “tubular” type of rim in which the tire  26  is fastened thereto by rim cement. In other words, the rim  24  can have other shapes to accommodate other types of tire arrangements as needed and/or desired without departing from the scope of the present invention. 
     As seen in FIG. 5, the rim  24  has a substantially octagonal shape. It should be noted that this substantially octagonal shape is exaggerated in FIG. 5 for the purposes of illustration. Of course, the precise shape of the outer periphery of the rim  24  will depend upon the number of spokes  22  being utilized and/or their arrangements. In this embodiment, there are eight pairs of spokes  22  such that tension from the spokes  22  is concentrated at eight points on the rim  24 . Thus, the rim  24  can be divided into sixteen rim areas or sections  24   a  and  24   b . More specifically, the rim  24  has eight spoke attachment areas  24   a  and eight non-spoke attachment areas  24   b  that are located between the spoke attachment areas  24   a . The outer peripheral edges of the spoke attachment areas  24   a  have a first radii R 1  extending from the center axis A of the rim  24 , while the outer peripheral edges of the non-spoke attachment areas  24   b  have second radii R 2  extending from the center axis of the rim. The first radii R 1  of the spoke attachment areas  24   a  are larger than the second radii R 2  of the non-spoke attachment areas  24   b , since the tension from the spokes  22  deforms the spoke attachment areas  24   a  in a generally radially inward direction. Thus, the tension of the spokes  22  deforms the rim  24  such that the spoke attachment areas  24   a  move radially inwardly so that the radii of the spoke attachment areas  24   a  substantially match the non-spoke attachment areas  24   b  as compared to a round conventional rim that has a circular outer peripheral edge prior to deformation by the tension of the spokes. For example, a round conventional rim (circular prior to assembly) will typical have the radii of the rim varying in length from about 0.4 mm to about 0.6 mm depending on the tension in the spokes. In the rim  24  of the present invention, the radii of the rim  24  will only vary about 16 mm in length to produce a more round wheel. 
     In this preferred embodiment, the spoke attachment areas  24   a  extend for approximately 20°, while the non-spoke attachment areas  24   b  extend along an arc of approximately 25°. While the non- spoke attachment areas  24   b  are shown as relatively straight tubular sections, it will be apparent to those skilled in the art from this disclosure that the non-spoke attachment portions can be slightly curved. In any event, the rim  24  is constructed such that its outer periphery has a non-circular outer periphery arranged about the center axis A of the rim  24  such that by tightening the spokes  22  the rim  24  is deformed inwardly in a generally radial direction to become more circular. More specifically, the tightening of the spokes  22  results in the rim  24  having first radii R 1  at the spoke attachment areas  24   a  that are larger than second radii R 2  at the non-spoke attachment areas  24   b . In other words, the spoke attachment areas  24   a  are areas of high deformation, while the non-spoke attachment areas  24   b  are areas of low deformation. In contrast, a conventional rim is initially substantially circular, and thus, the spoke attachment areas will be deformed inwardly in a generally radial direction to become less circular. In other words, in a conventional rim, the spoke attachment areas have smaller radii than the radii of the non-spoke attachment areas. 
     Referring again to FIGS. 7 and 8, the rim  24  is an annular member that has an outer annular outer tire attachment portion  50 , a pair of annular spoke attachment or side portions  52  and an inner annular portion  54 . The outer annular portion  50  extends between the annular spoke attachment portions  52  and is adapted to receive a pneumatic tire  26  thereon. The general shape of the cross-sectional profile of the rim is illustrated and discussed in U.S. Pat. No. 6,283,557, issued on Sep. 4, 2001 and assigned to Shimano, Inc. Thus, the cross-sectional profile of the rim  24  will not be discussed and/or illustrated in detail herein. 
     Preferably, the outer annular portion  50  of the rim  24  has a substantially “U-shaped” cross-section adapted to receive a clincher type pneumatic tire  26 . The outer annular portion  50  of the rim includes first and second clincher attachment flanges  56  with first and second annular beads  57 . The outer peripheral edges of the beads  57  define the outer peripheral edges of the rim  24 . The inner radially facing surfaces of the beads  57  have an annular contour that is identical to the outer peripheral edge of the rim  24 , except that the inner radially facing surfaces of the beads  57  have smaller radii than the outer peripheral edges of the rim  24 . 
     The rim  24  is preferably constructed utilizing conventional manufacturing techniques for producing bicycle rims. More specifically, the rim  24  of the illustrated embodiment is initially formed as an extruded tube that is shaped to form a somewhat octagon shape as seen in FIG.  5 . The ends of the tube are welded together along a weld or seam  53  to form a continuous annular, tubular member. 
     In this embodiment, the annular spoke attachment portions  52  face in substantially opposite axial directions, and include a plurality of spoke openings  58 . In this illustrated embodiment, eight spoke openings  58  are formed on each of the annular spoke attachment portions  52  to form first and second sets of spoke openings  58 . More specifically, the first spoke openings  58  on the first annular spoke attachment portions  52  are equally space apart in the circumferential direction. Likewise, the second spoke openings  58  on the second annular spoke attachment portion  52  are evenly spaced apart in the circumferential direction. In this embodiment, the first spoke openings  58  are circumferentially offset by a few degrees from the second spoke openings  58 . Thus, the spoke openings  58  are located in the spoke attachment areas  24   a  of the rim  24 . 
     Turning now to FIGS. 9-11, the rear wheel  13  is basically identical to the front wheel  12 , except for the rear bicycle hub  20 ′. Thus, the parts of the rear wheel  13  that are identical to the parts of the front wheel  12  will be given the same reference numerals as the parts of front wheel  12 . In other words, the rear wheel  13  includes the identical rim  24  as the front wheel  12  with sixteen spokes  22  extending generally in a radial direction between the rear hub  20 ′ and the annular rim  24 . In view of the similarity between the front and rear wheels  12  and  13 , the descriptions of the parts of the rear wheel  13  that are identical to the parts of the front wheel  12  have been omitted for the sake of brevity. 
     The rear hub  20 ′ is a well known hub in the art. Thus, the rear hub  20 ′ will not be discussed or illustrated in detail herein. Moreover, it will be apparent to those skilled in the art that the construction of the rear hub  20 ′ can be modified from the hub illustrated herein without departing from the scope of the present invention. Moreover, the rear hub  20 ′ is designed to have sixteen tangentially arranged spokes  22 . However, it will be apparent to those skilled in the art from this disclosure that the rear hub  20 ′ can be designed for tangential and/or radial spokes with more or fewer spokes as needed and/or desired. 
     Basically, the rear hub  20 ′ has a tubular body  30 ′ with a pair of end mounting flanges  32 ′ for mounting spokes  22  thereto. Each end flange  32 ′ has four spoke attachment points or members with a pair of spoke holes  34 ′ formed in each of the spoke attachment members for coupling the spokes  22  thereto. The tubular body section  30 ′ rotatably supports an axle  36 ′ therein about a center axis of rotation A by a pair of bearing assemblies (not shown). Each of the spoke holes  34 ′ preferably has a step shaped configuration for attaching the spokes  22  thereto. The axle  36 ′ has a freewheel  38 ′ that supports a sprocket assembly  39 ′ (FIG.  1 ). 
     It will be apparent to those skilled in the art from this disclosure that the number and shape of the spoke attachment points of the end flanges  32 ′ will depend on the number of spokes  22  and their shapes. Accordingly, it will be apparent to those skilled in the art from this disclosure that other types and shapes of hubs can be utilized in connection with the present invention. 
     Second Embodiment 
     Referring now to FIGS. 12-14, a rim  124  is illustrated in accordance with a second embodiment of the present invention. The rim  124  can be utilized with spokes  22  and either the front hub  20  or the rear hub  20 ′ to form either a front wheel or a rear wheel as needed and/or desired. The rim  124  is a tubular type of rim. The rim  124  is substantially identical to rim  24 , discussed above, except that rim  124  does not include clincher attachment flanges. In view of the similarities between the first embodiment and the second embodiment, the second embodiment will not be discussed or illustrated in detail herein. Rather, it will be apparent to those skilled in the art from this disclosure that the description of the first embodiment applies to the description of the second embodiment, except for the attachment of the tire thereto. 
     As seen in FIG. 12, the rim  124  has a substantially octagonal shape that is the same as the rim  24 , discussed above. It should be noted that this substantially octagonal shape is exaggerated in FIG. 12 for the purposes of illustration. Of course, the precise shape of the outer periphery of the rim  124  will depend upon the number of spokes being utilized and/or their arrangements. 
     In this embodiment, there are eight pairs of spokes such that tension from the spokes is concentrated at eight points on the rim  124 , similar to the first embodiment. Thus, the rim  124  can be divided into sixteen rim areas or sections  124   a  and  124   b . More specifically, the rim  124  has eight spoke attachment areas  124   a  and eight non-spoke attachment areas  124   b  that are located between the spoke attachment areas  124   a . The outer peripheral edges of the spoke attachment areas  124   a  have a first radii R 1  extending from the center axis A of the rim  124 , while the outer peripheral edges of the non-spoke attachment areas  124   b  have second radii R 2  extending from the center axis of the rim  124 . The first radii R 1  of the spoke attachment areas  124   a  are larger than the second radii R 2  of the non-spoke attachment areas  124   b , since the tension from the spokes  122  deforms the spoke attachment areas  124   a  inwardly in a generally radially direction. Thus, the tension of the spokes deforms the rim  124  such that the spoke attachment areas  124   a  move radially inwardly so that the radii of the spoke attachment areas  124   a  substantially match the non-spoke attachment areas  124   b  as compared to a conventional rim that has a circular outer peripheral edge prior to deformation by the tension of the spokes. In any event, the rim  124  is constructed such that its outer periphery has a non-circular outer periphery arranged about the center axis A of the rim  124  such that by tightening the spokes the rim  124  is deformed inwardly in a generally radial direction to become more circular. More specifically, the tightening of the spokes results in the rim  124  having first radii R 1  at the spoke attachment areas  124   a  that are larger than second radii R 2  at the non-spoke attachment areas  124   b . In other words, the spoke attachment areas  124   a  are areas of high deformation, while the non-spoke attachment areas  124   b  are areas of low deformation. In contrast, a conventional rim is initially substantially circular, and thus, the spoke attachment areas will be deformed inwardly in a generally radial direction to become less circular. In other words, in a conventional rim, the spoke attachment areas have smaller radii than the radii of the non-spoke attachment areas. 
     Referring to FIGS. 13 and 14, the rim  124  is an annular member that has an outer annular outer tire attachment portion  150 , a pair of annular spoke attachment or side portions  152  and an inner annular portion  154 . The outer annular portion  150  is adapted to receive a pneumatic tire thereon. The general shape of the cross-sectional profile of the rim is illustrated and discussed in U.S. Pat. No. 6,234,580, issued on May 22, 2001 and assigned to Shimano, Inc. Thus, the cross-sectional profile of the rim  124  will not be discussed and/or illustrated in detail herein. Preferably, the outer annular portion  150  of the rim  124  portion is an axially curved tire cementing surface as viewed in cross section that is adapted to receive a pneumatic tire. The outer peripheral edges of the annular spoke attachment portions  152  define the outer peripheral edges of the rim  124 . The outer annular portion  150  and the annular spoke attachment portions  152  have an annular contour that is identical to the outer peripheral edge of the rim  24 , except that the outer annular portion  150  has smaller radii than the outer peripheral edges of the rim  24 . 
     Third Embodiment 
     Referring now to FIGS. 15 and 16, a rear wheel  213  is illustrated in accordance with a third embodiment of the present invention. In view of the similarities between this third embodiment and the prior embodiments, this third embodiment will not be discussed or illustrated herein. The rear wheel  213  utilizes a rim  224  that has an octagonal shape similar to FIG. 5, prior to placing the spokes  22  under tension to deform the rim  224 . Thus, the rim  224  is constructed to deform in the same manner as the first embodiment. However, the spoking arrangement of the rear wheel  213  has been changed to have radially arranged spokes on the freewheel side of the hub  220  and tangential spokes on the opposite (non-freewheel) side of the hub  220 . Thus, the rim  224  is identical to the rim  24 , discussed above, except that the spacing of the spoke holes  258  have been changed to accommodate the different spoking arrangement. Specifically, the first and second sets of spoke openings  258  are axially aligned in the rear wheel  213 . In other words, the first and second spoke openings  258  on the opposite sides of the spoke attachment portions  252  are coincident. As seen in FIG. 16, the rim  224  has an octagonal shape similar to the first and second embodiment, prior to assembly. The cross-sectional profile of the rim  224  has the same profile as the first embodiment. Of course, the rim  224  can have the same profile as the second embodiment as needed and/or desired. 
     Moreover, while the rim  224  is designed to have sixteen tension spokes  22 . However, it will be apparent to those skilled in the art from this disclosure that the rim  224  can be designed with more or fewer spokes as needed and/or desired. Also the rear wheel  213  can be designed with radially arranged spokes on the non-freewheel side of the hub  220  and tangential spokes the freewheel side of the hub  220 . 
     In this embodiment, there are eight pairs of spokes such that tension from the spokes is concentrated at eight points on the rim  224 , similar to the first embodiment. Thus, the rim  224  can be divided into sixteen rim areas or sections  224   a  and  224   b . More specifically, the rim  214  has eight spoke attachment areas  224   a  and eight non-spoke attachment areas  224   b  that are located between the spoke attachment areas  224   a . The outer peripheral edges of the spoke attachment areas  224   a  have a first radii R 1  extending from the center axis A of the rim  224 , while the outer peripheral edges of the non-spoke attachment areas  224   b  have second radii R 2  extending from the center axis of the rim  224 . The first radii R 1  of the spoke attachment areas  224   a  are larger than the second radii R 2  of the non-spoke attachment areas  224   b , since the tension from the spokes  222  deforms the spoke attachment areas  224   a  inwardly in a generally radially direction. Thus, the tension of the spokes deforms the rim  224  such that the spoke attachment areas  224   a  move radially inwardly so that the radii of the spoke attachment areas  224   a  substantially match the non-spoke attachment areas  224   b  as compared to a conventional rim that has a circular outer peripheral edge prior to deformation by the tension of the spokes. In any event, the rim  224  is constructed such that its outer periphery has a non-circular outer periphery arranged about the center axis A of the rim  224  such that by tightening the spokes the rim  224  is deformed inwardly in a generally radial direction to become more circular. More specifically, the tightening of the spokes results in the rim  224  having first radii R 1  at the spoke attachment areas  224   a  that are larger than second radii R 2  at the non-spoke attachment areas  224   b . In other words, the spoke attachment areas  224   a  are areas of high deformation, while the non-spoke attachment areas  224   b  are areas of low deformation. In contrast, a conventional rim is initially substantially circular, and thus, the spoke attachment areas will be deformed inwardly in a generally radial direction to become less circular. In other words, in a conventional rim, the spoke attachment areas have smaller radii than the radii of the non-spoke attachment areas. 
     Fourth Embodiment 
     Referring now to FIGS. 17 and 18, a rear wheel  313  is illustrated in accordance with a fourth embodiment of the present invention. In view of the similarities between this fourth embodiment and the prior embodiments, this fourth embodiment will not be discussed or illustrated herein. 
     The rear wheel  313  utilizes a rim  324  that has an octagonal shape similar to FIG. 5, prior to placing the spokes  22  under tension to deform the rim  324 . Thus, the rim  324  is constructed to deform in the same manner as the first embodiment. However, the spoking arrangement of the rear wheel  313  has been changed to have radially arranged spokes on the freewheel side of the hub  320  and tangential spokes on the opposite (non-freewheel) side of the hub  320 . Thus, the rim  324  is identical to the rim  24 , discussed above, except that the spacing of the spoke holes  358  have been changed to accommodate the different spoking arrangement. Specifically, the first and second sets of spoke openings  358  are arranged in groupings of three in the rear wheel  313 . As seen in FIG. 18, the rim  324  has an octagonal shape similar to the first and second embodiment, prior to assembly. The cross-sectional profile of the rim  324  has the same profile as the first embodiment. Of course, the rim  324  can have the same profile as the second embodiment as needed and/or desired. 
     Moreover, while the rim  324  is designed to have twenty-four tension spokes  22 . However, it will be apparent to those skilled in the art from this disclosure that the rim  324  can be designed with more or fewer spokes as needed and/or desired. Also the rear wheel  313  can be designed with radially arranged spokes on the non-freewheel side of the hub  320  and tangential spokes the freewheel side of the hub  320 . 
     In this embodiment, there are eight groupings of three spokes such that tension from the spokes is concentrated at eight points on the rim  324 , similar to the first embodiment. Thus, the rim  324  can be divided into sixteen rim areas or sections  324   a  and  324   b . More specifically, the rim  324  has eight spoke attachment areas  324   a  and eight non-spoke attachment areas  324   b  that are located between the spoke attachment areas  324   a . The outer peripheral edges of the spoke attachment areas  324   a  have a first radii R 1  extending from the center axis A of the rim  324 , while the outer peripheral edges of the non-spoke attachment areas  324   b  have second radii R 2  extending from the center axis of the rim  324 . The first radii R 1  of the spoke attachment areas  324   a  are larger than the second radii R 2  of the non-spoke attachment areas  324   b , since the tension from the spokes  322  deforms the spoke attachment areas  24   a  inwardly in a generally radially direction. Thus, the tension of the spokes deforms the rim  324  such that the spoke attachment areas  324   a  move radially inwardly so that the radii of the spoke attachment areas  324   a  substantially match the non-spoke attachment areas  324   b  as compared to a conventional rim that has a circular outer peripheral edge prior to deformation by the tension of the spokes. In any event, the rim  24  is constructed such that its outer periphery has a non-circular outer periphery arranged about the center axis A of the rim  324  such that by tightening the spokes the rim  324  is deformed inwardly in a generally radial direction to become more circular. More specifically, the tightening of the spokes results in the rim  324  having first radii R 1  at the spoke attachment areas  324   a  that are larger than second radii R 2  at the non-spoke attachment areas  324   b . In other words, the spoke attachment areas  324   a  are areas of high deformation, while the non-spoke attachment areas  324   b  are areas of low deformation. In contrast, a conventional rim is initially substantially circular, and thus, the spoke attachment areas will be deformed inwardly in a generally radial direction to become less circular. In other words, in a conventional rim, the spoke attachment areas have smaller radii than the radii of the non-spoke attachment areas. 
     The terms of degree such as “substantially”, “generally”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms should be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies. 
     While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing description of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

Technology Category: 7