Abstract:
A magnetic assembly is provided for a bicycle monitoring device. The magnetic assembly includes a magnetic device that mounts on a special spoke of a wheel. This magnetic device has a housing with a magnet secured thereto. The housing has a spoke-receiving recess that receives the spoke. The housing can be secured to the spoke within the spoke-receiving recess via a snap-fit or an elastic fit. In one embodiment, the spoke-receiving recess of the housing has a projection that engages a concavity form in the connecting portion of the spoke. In another embodiment, the spoke-receiving recess of the housing has a concavity that engages a projection form on the connecting portion of the spoke. The magnetic device communicates with a sensing device, which is coupled to a portion of the bicycle that is adjacent to a wheel of the bicycle. A display unit that is mounted on handlebars of the bicycle displays the speed information obtained from the sensing device.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention generally relates to a magnetic assembly for a bicycle monitoring device. More specifically, the present invention relates a magnetic assembly which includes a magnetic device that mounts on a special spoke of a wheel such that the magnetic device remains in a predetermined location on the spoke. 
     2. Background Information 
     It is an advantage for modem cyclists to know how fast they are going. This is true in both non-competitive and competitive cycling. To that end, speedometer devices for bicycles have become commercially popular. Early forms of these devices had various mechanical disadvantages. One source of difficulty was the means by which the speedometer device sensed that the wheel had rotated. Many speedometers attached a counting device that protruded from the spoke, and would advance a gear or a counter every time the wheel rotated. But these devices were not reliable and subject to breakdown, bending, stiffening, and shifting loose from the appropriate position. This led to inductive-type sensors, which did away with the requirement of actual contact between spoke-attachment and sensor. But these were not always reliable either, due to magnets weakening, slippage on the spoke, tools required for installation, inability to sustain a satisfactory level of tightness, and other reasons. 
     In view of the above, there exists a need for a magnetic assembly which 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 magnetic assembly that is relatively easy to install on a spoke such that the magnetic device does not rotate or move longitudinally along the axis of the spoke. 
     Another object of the present invention is to provide a magnetic device that is inexpensive to manufacture. 
     Another object of the present invention is to provide a magnetic device that can be installed in one step. 
     Another object of the present invention is to provide a magnetic device that requires no tools for installation. 
     Another object of the present invention is to provide a magnetic device that can be used with spokes of a variety of circular cross-sections. 
     The foregoing objects basically can be obtained by providing a magnetic assembly for a bicycle monitoring device. The magnetic assembly includes a spoke and a magnetic housing. The spoke has a first end, a second end and a connecting portion extending between the first and second ends. The magnetic housing has a spoke-receiving recess with a pair of opposed side walls spaced apart by a first predetermined distance to retain the spoke therebetween. Either the spoke or the housing has a projection extending therefrom and the other of the spoke or the housing has a concavity for engaging the projection when the spoke is located within the spoke-receiving recess. 
     The foregoing objects basically can be obtained by providing a spoke is provided for attaching a magnetic housing thereto. The spoke includes a first attachment end, a second attachment end and a connecting portion. The first attachment end is configured and adapted to be coupled to a corresponding structure of a hub. The second attachment end is configured and adapted to be coupled to a corresponding structure of a rim. The connecting portion extends between the first and second ends. The connecting portion is with a concavity. This spoke is used with a magnetic device having a spoke-receiving recess having a complementary projection. 
     In accordance with one aspect of the present invention, a spoke is provided for attaching a magnetic housing thereto. The spoke includes a first attachment end, a second attachment end and a connecting portion. The first attachment end is configured and adapted to be coupled to a corresponding structure of a hub. The second attachment end is configured and adapted to be coupled to a corresponding structure of a rim. The connecting portion extends between the first and second ends. The connecting portion is provided with a projection. This spoke is used with a magnetic device having a spoke-receiving recess having a complementary concavity. 
     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 with a monitoring device mounted thereto in accordance with the present invention; 
     FIG. 2 is a partial front perspective view of a magnetic device mounted on a flat spoke in accordance with a first embodiment of the present invention; 
     FIG. 3 is a partial rear perspective view of the magnetic device illustrated in FIG. 2, while mounted on a flat spoke; 
     FIG. 4 is a front elevational view of the housing of the magnetic device illustrated in FIGS. 2 and 3; 
     FIG. 5 is a rear elevational view of the housing of the magnetic device illustrated in FIGS. 3-4; 
     FIG. 6 is an end elevational view of the housing of the magnetic device illustrated in FIGS. 2-5; 
     FIG. 7 is a front elevational view of a flat spoke that is used with the magnetic device illustrated in FIGS. 2-6; 
     FIG. 8 is a side elevational view of the flat spoke illustrated in FIG. 7; 
     FIG. 9 is a partial front perspective view of a magnetic device mounted on a flat portion of a spoke in accordance with a second embodiment of the present invention; 
     FIG. 10 is a partial rear perspective view of the magnetic device illustrated in FIG. 9, while mounted on the flat portion of the spoke; 
     FIG. 11 is an end elevational view of the housing of the magnetic device illustrated in FIGS. 9 and 10; 
     FIG. 12 is a partial perspective view of a portion of the spoke that is used in the second embodiment of the present invention; 
     FIG. 13 is a front elevational view of a magnetic device in accordance with a third embodiment of the present invention; 
     FIG. 14 is a rear elevational view of the housing of the magnetic device illustrated in FIGS. 13; 
     FIG. 15 is an end elevational view of the housing of the magnetic device illustrated in FIGS. 13 and 14; 
     FIG. 16 is a front elevational view of a spoke that is used with the magnetic device illustrated in FIGS. 13-15; 
     FIG. 17 is a side elevational view of the spoke illustrated in FIG. 16; 
     FIG. 18 is a front elevational view of a magnetic device in accordance with a fourth embodiment of the present invention; 
     FIG. 19 is a rear elevational view of the housing of the magnetic device illustrated in FIGS. 18; 
     FIG. 20 is an end elevational view of the housing of the magnetic device illustrated in FIGS. 18 and 19; 
     FIG. 21 is a front elevational view of a spoke that is used with the magnetic device illustrated in FIGS. 18-20; 
     FIG. 22 is a side elevational view of the spoke illustrated in FIG.  21 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring initially to FIG. 1, a bicycle  10  is illustrated with a monitoring device  12  mounted thereon in accordance with the present invention. Bicycles and their various components are well known in the art, and thus, bicycle  10  and its various components will not be discussed or illustrated in detail herein except for the components that relate to the present invention. In other words, only monitoring device  12  and the components of bicycle  10  relating thereto will be discussed and/or illustrated herein. 
     Bicycle  10  basically includes a frame  14 , a pair of wheels  16  and handlebar  17 . The bicycle frame  14  has handlebar  18  movably attached thereto for turning front wheel  16 . Each of the wheels  16  are conventional wheels that are rotatably coupled to frame  14  in a conventional manner. Each of the wheels  16  has a hub  18 , a plurality of spokes  19  and a rim  20 . Spokes  19  of each of the wheels  16  extend between hub  18  and rim  20 . While the hubs  18  for the wheels  16  are different in the front and rear wheels, these differences are not important to this invention. 
     Spoke  19  has first attachment end  21 , second attachment end  22  and a connecting portion  23  extending therebetween. First attachment end  21  can be adapted to be coupled to the corresponding structure of the hub  18 . First attachment end  21  is threaded as shown in FIGS. 7 and 8. Second attachment end  22  has a head  27  in the shape of a bent nail head as shown in FIG.  6 . Second attachment end  22  can be adapted to be coupled to rim  20  of wheel  16 . However, flat spoke  19  can be reversed, so that first attachment end  21  is coupled to rim  20 , and second attachment end is coupled to hub  18 . Connecting portion  23  has a non-circular cross-sectional, preferably substantially elliptical cross-section. 
     In this embodiment, as seen in FIGS. 7 and 8, spokes  19  are so-called flat or aerodynamic spokes. Spokes  19  differ from round spokes in that they have a substantially elliptical cross-section, where that cross-section has rounded ends. The cross-sectional length of flat spoke  19  is preferably around 2.75 millimeters. Flat spokes  19  are aligned along hub  18  of wheel  16  so as to decrease wind resistance. This decrease in wind resistance is due to the flattened surface of spoke  19  which lies in the same center plane as wheel  16 . Thus, flat spokes  19  are very desirable in bicycle riding. 
     Monitoring device  12  is adapted to be fixedly coupled to frame  14 , handlebar  17  and one of the spokes  19  of one of the wheels  16 . In this first embodiment, monitoring device  12  is especially designed for mounting on spoke  19  that has a portion with a non-circular cross-section. 
     The monitoring device  12  basically includes four parts. In particular, monitoring device  12  basically includes a display unit  24 , a wire  25 , a sensor  26  and a magnetic device  28 . All of the parts are basically conventional parts that are well known in the bicycle art, except for magnetic device  28  which is the subject of the present invention. Therefore, the display unit  24 , wire  25  and sensor  26  will not be discussed or illustrated in detail herein. One example of a prior art monitoring device is disclosed in U.S. Pat. No. 5,264,791, which is assigned to Cat Eye Incorporated. This U.S. patent is hereby incorporated herein by reference for the purpose of understanding one particular use of the magnetic device  28  in accordance with the present invention. Accordingly, display unit  24  mentioned above can be of the type mentioned in this U.S. Pat. or any other prior art device. Similarly, the sensor  26  can be a reed switch or any other type of magnetic sensor that is known in the art. 
     Magnetic device  28  basically includes a magnet  30  and housing  32 . Housing  32  is integrally formed as a one-piece unitary member, preferably of lightweight material. For example, housing  32  can be molded as a one-piece, unitary member from plastic types of materials that can accomplish the essence of the present invention. Housing  32  can also be referred to as a bracket assembly. Housing  32  can alternatively be made of magnetic or magnetized material, and thus, eliminate the need for a separate magnet  30 . For example, housing  32  can be constructed of a plastic material with magnetic particles embedded therein. In any case, the construction of the material for housing  32  of magnetic device  28  is preferably lightweight. Magnetic device  28  should have a magnetism that is strong enough to operate sensor  26  without difficulty during rotation of wheel  16 . 
     Housing  32  has a body portion  34  and two retaining portions  36  extending from body portion  34 . Body portion  34  can be cylindrical in shape. Housing  32  is preferably constructed of a lightweight material such as a resilient plastic. Housing  32  should be of a resilient material to releasably couple spoke  19  thereto. Body portion  34  has a cylindrical cavity  37  for holding magnet  30 , with two semi-circular flanges  38  formed at the open end of cavity  37 . Semi-circular flanges  38  are arranged to receive a portion of spoke  19  therebetween when housing  32  is completely installed on one of the spokes  19 , and are molded in such a way as to be less likely to break off during handling of housing  32 . 
     The two retaining portions  36  are integrally formed with body portion  34  and extend in opposite directions from body portion  34 . In other words, retaining portions  36  are integrally formed with body portion  34  as a one-piece, unitary member. Retaining portions  36  are channel-shaped to form a spoke-receiving recess  39 . Each of the retaining portions  36  has a bottom wall  40  and two side walls  42 . 
     Each bottom wall  40  of each retaining portion  36  has an aperture  43  for decreasing weight of housing  32 , and increasing flexibility. The two side walls  42  and bottom wall  40  extend outward from body portion  34 . Side walls  42  are substantially parallel to each other and also extend substantially perpendicular to the bottom wall  40 . Side walls  42  are spaced apart from each other by a predetermined distance B except along detents  48 . 
     Side walls  42  have detents  48  for holding and securing flat spoke  19  via a snap-fit. Preferably, each side wall  42  has two detents  48  that are longitudinally spaced apart from each other along spoke-receiving recess  35 . Each detent  48  has a curved outer surface  52  for inserting flat spoke  19 . Each detent  48  also has an inner retaining surface  54 . Side walls  42  and detents  48  form an opening  46  through which flat spoke  19  can be inserted beneath detents  48 . Each retaining portion  36  is flexible so that it can move slightly outwardly to expand the spoke-receiving recess  39  as flat spoke  19  passes into opening  46 . The opposing detents  48  are separated from each other by a predetermined distance C. 
     Bottom wall  40 , side walls  42 , and the two detents  48  together form a spoke receiving recess  39 . This spoke-receiving recess  39  has a cross-sectional shape of an oval or racetrack, with rounded ends  56 , as shown in FIG.  6 . Spoke-receiving recess  39  preferably has a length between approximately 10 millimeters and 30 millimeters, preferably around 18 millimeters. 
     After the flat portion of spoke  19  is initially inserted into spoke-receiving recess  39 , housing  32  is then rotated about the axis of flat spoke  19 , so that the rounded ends  56  match up with rounded ends of spoke  19 . This matching up of surfaces, in combination with inner retaining surface  54  of detent  48 , acts to snap-fit spoke  19  into spoke-receiving recess  50 . Alternatively, housing  32  can be made of a more elastic material, so that detents  48  could become optional, and the snap-fit is replaced by an elastic fit as in a subsequent embodiment discussed below. 
     The bottom wall  40  is spaced from inner retaining surfaces  54  by a predetermined distance A. It is an important feature of this invention that, as shown in FIG. 6, distance A be less than distance B, so that housing  32  will more accurately fit the shape of spoke  19 . This results in housing  32  not rotating about the axis of the spoke  19 , and also orients housing  32  to activate sensor  26 . 
     As shown in FIG. 6, opening  46  (distance C) is smaller than spoke-receiving recess  39  (distance B). This contributes to the snap-fit of housing  32  around the flat portion of spoke  19 . Also, housing  32  will have a reduced tendency to work loose from the flat portion of spoke  19 , and will remain in place more effectively. 
     During installation, housing  32  is pressed against spoke  19 . At first, detents  48  resist the centerward motion of flat spoke  19 , but being made of flexible plastic, can yield to a slight degree. Also, each detent  48  has a curved outer surface which assists in the flat portion of spoke  19  passing through opening  46 . While the installer exerts pressure on housing  32  during installation, detents  48  are forced radially outward from the center axis of spoke-receiving recess  39 . After the flat portion of spoke  19  passes by detents  48 , side walls  42  spring back to return to their original positions. In doing so, inner retaining surfaces  54  engage the flat portion of spoke  19  to hold spoke  19  against the bottom wall  40  of the spoke-receiving recess  39  with a slight pressing force. Thus, housing  32  is frictional retained on spoke  19  to substantially prevent longitudinal movement of magnetic device  12  along the longitudinal axis of spoke  19 . 
     Because housing  32  is snap-fitted, secured by detents  48  applying continual pressure, and very light in weight, no further securing means, such as a screw or a cover, is necessary. Another advantage is that housing  32  is less likely than conventional art to rotate out of position during use, because rounded ends of spoke-receiving recess  39  can more effectively grip rounded ends of flat spoke  19 . Also, because of its snap-fit characteristics, housing  32  can be can be installed in one step, and requires no tools for installation. 
     SECOND EMBODIMENT 
     Referring now to FIGS. 9-12, a magnetic device  128  is illustrated in accordance with another embodiment of the present invention. In view of the similarities between this embodiment and the prior embodiment, this embodiment will not be discussed or illustrated in detail. Rather, it will be apparent to those skilled in the art from this disclosure that the most of the parts and descriptions of the prior embodiments also apply to the similar or identical parts of this embodiment. 
     In a second embodiment, housing  132  is constructed of an elastic material, and detents  148  are optional. The term “elastic” as used hereinafter can include materials with some plastic deformation. In any event, the elastic material should substantially return to its initial form or state after being deformed. Thus, magnetic device  128  can be repeatedly installed, removed, and reinstalled, without significantly affecting the shape of housing  132 . 
     Referring initially to FIG. 10, the magnetic device  128  can comprise a magnet  130  and housing  132 . As stated, housing  132  is constructed of a lightweight elastomeric material, having elastic properties. 
     As shown in FIG. 11, the cross-sectional length B′ of spoke-receiving recess is slightly smaller than the cross-sectional width D of the flat portion of spoke  119 . For example, length or distance B′ is approximately 2.5 millimeters and the flat portion of spoke  119  has a cross-sectional width D of approximately 2.75 millimeters. Accordingly, housing  132  elastically grips the flat portion of spoke  119 . Thus, housing  132  will remain in place more effectively. 
     Housing  132  is integrally formed as a one-piece unitary member, preferably of lightweight material. For example, housing  132  can be molded as a one-piece, unitary member from an elastomeric material that can accomplish the essence of the present invention. Housing  132  can also be referred to as a bracket assembly. Housing  132  can alternatively be made of magnetic or magnetized material, and thus, eliminate the need for a separate magnet  130 . For example, housing  132  can be constructed of an elastomeric material with magnetic particles embedded therein. Magnetic device  128  should have a magnetism that is strong enough to operate sensor  26  without difficulty during rotation of wheel  16 . 
     Housing  132  has a body portion  134  and two retaining portions  136  extending from body portion  134 . Body portion  134  can be cylindrical in shape. Housing  132  should be of a resilient material to releasably couple spoke  119  thereto. Body portion  134  has a cavity  137  for holding magnet  130 , with two semi-circular flanges  138  formed at the open end of cavity  137 . Semi-circular flanges  138  are arranged to receive a flat portion of spoke  119  therebetween when housing  132  is completely installed on one of the spokes  119 . Retaining portions  136  are channel-shaped to form a spoke-receiving recess  139 . Each of the retaining portions  136  has a bottom wall  140  and two side walls  142 . 
     Each bottom wall  140  of each retaining portion  136  has an aperture  143  for decreasing weight of housing  132 , and increasing flexibility. The two side walls  142  and bottom wall  140  extend outward from body portion  134 . Side walls  142  are substantially parallel to each other and also extend substantially perpendicular to the bottom wall  140 . Side walls  142  are spaced apart from each other by a predetermined distance B except along detents  148 . 
     Side walls  142  can optionally have detents  148  for further holding and securing flat surface of spoke  19  via an elastic fit. Preferably, each side wall  142  has two detents  148  that are longitudinally spaced apart from each other along spoke receiving recess  35 . Each detent  148  has a curved outer surface  152  for inserting spoke  119 . Each detent  148  also has an inner retaining surface  154 . Side walls  142  and detents  148  form an opening  146  through which spoke  119  can be inserted beneath detents  148 . Each retaining portion  136  is flexible so that it can move slightly outwardly to expand the spoke-receiving recess  139  as flat surface of spoke  119  passes into opening  146 . 
     Bottom wall  140  and side walls  142  and the two detents  148  together form a spoke-receiving recess  139 . This spoke-receiving recess  139  has a cross-sectional shape of an oval or racetrack, with rounded ends  156 , as shown in FIG.  11 . Spoke-receiving recess  139  preferably has a length between approximately 10 millimeters and 30 millimeters, preferably around 18 millimeters. Detents  48  are optional in this embodiment since that spoke  119  is held within spoke-receiving recess  139  by an elastic fit. 
     The bottom wall  140  is spaced from inner retaining surfaces  154  by a predetermined distance A. As shown in FIG. 11, distance A be less than distance B′, so that housing  132  will more accurately fit the shape of flat portion of spoke  119 . This prevents housing  132  from rotating about the axis of the spoke  119 , and also orients housing  132  to activate sensor  26 . 
     As shown in FIG. 11, opening  146  (distance C) is smaller than spoke receiving recess  139  (distance B′). This contributes to the elastic fit of housing  132  around flat portion of spoke  119 . Thus, housing  132  will have a reduced tendency to work loose from the flat portion of spoke  119 , and will remain in place more effectively. 
     Also, as shown in FIGS. 11 and 12, cross-sectional length of flat section of spoke  119  (distance D) is larger than distance B′. Distance D is preferably around 2.75 millimeters, and distance B′ is preferably around 2.5 millimeters. Because spoke-receiving recess  139  is smaller than spoke  119 , the elastic properties of housing  132  will cause side walls  142  to push against flat surface of spoke  119 . This will increase the gripping force of housing  132  on flat surface of spoke  119 . 
     THIRD EMBODIMENT 
     Referring now to FIGS. 13-17, a magnetic device  238  is illustrated in accordance with another embodiment of the present invention. Magnetic device  228  is designed to be used with monitoring device  12  of FIG.  1 . This third embodiment of the magnetic device  228  is substantially identical to the prior embodiments, except that a projection  257  is provided on the housing  232  and the spoke  219  is provided with a concavity  258 . For example, housing  232  can be dimensioned to have a snap fit configuration or an elastic fit configuration. Also, magnetic device  228  of this embodiment can be used with a variety of spokes, e.g., round, elliptical or flat. In view of the similarities between this embodiment and the prior embodiment, this embodiment will not be discussed or illustrated in detail. Rather, it will be apparent to those skilled in the art from this disclosure that the various parts and descriptions of the prior embodiments apply to the similar or identical parts of this embodiment. 
     Housing  232  can have magnet  230 , body portion  234 , and retaining portions  236 . Retaining portions  236  are channel-shaped to form a spoke-receiving recess  239 . Each of the retaining portions  236  has a bottom wall  240  and two side walls  242 . Bottom wall  240 , side walls  242 , and two detents  248  together form spoke-receiving recess  239 . This spoke-receiving recess  239  has a cross-sectional shape of an oval or racetrack, with rounded ends  256 , as shown in FIG.  15 . Housing  232  also has a projection  257  formed from bottom wall  240  of one of the retaining portions  236 . The projection  257  extends outward approximately 0.7 millimeters. Spoke  219  has a corresponding concave surface  258 , as shown in FIGS. 16 and 17, for accommodating projection  257 . This matching up of projection  257  to concave surface or concavity  258  acts to firther secure spoke  219  into spoke-receiving recess  239 , and prevent relative movement between spoke  219  and housing  232 . 
     FOURTH EMBODIMENT 
     Referring now to FIGS. 18-22, a magnetic device  328  is illustrated in accordance with another embodiment of the present invention. Magnetic device  328  is designed to be used with monitoring device  12  of FIG.  1 . This fourth embodiment of the magnetic device  328  is substantially identical to the prior embodiments, except that a projection  357  is provided on the spoke  319  and housing  332  is provided with a concavity  358 . For example, housing  332  can be dimensioned to have a snap-fit configuration or an elastic fit configuration. Also, magnetic device  328  of this embodiment can be used with a variety of spokes, e.g., round, elliptical or flat. In view of the similarities between this embodiment and the prior embodiment, this embodiment will not be discussed or illustrated in detail. Rather, it will be apparent to those skilled in the art from this disclosure that the various parts and descriptions of the prior embodiments apply to the similar or identical parts of this embodiment. 
     Housing  332  can have magnet  330 , body portion  334 , and retaining portions  236 . Retaining portions  336  are channel-shaped to form a spoke-receiving recess  339 . Each of the retaining portions  336  has a bottom wall  340  and two side walls  342 . Bottom wall  340 , side walls  342 , and two detents  348  together form spoke-receiving recess  339 . This spoke-receiving recess  339  has a cross-sectional shape of an oval or racetrack, with rounded ends  356 , as shown in FIG.  20 . As shown in FIGS. 21 and 22, spoke  319  also has a projection  357  formed from its surface. Housing  332  has a corresponding concave surface  358  in one of its retaining walls  336 , as shown in FIG. 20, for accommodating projection  357 . This matching up of projection  357  to concave surface or concavity  358  acts to further secure spoke  319  into spoke receiving recess  339 , and prevent relative movement between spoke  319  and housing  332 . 
     While several 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.