Abstract:
An audio amplifier unit for a bicycle audio system includes audio amplifier circuitry and a rechargeable battery powering the audio amplifier circuitry which are housed in a weather resistant housing sized to be received and retained within a bicycle water bottle holder. Electrical connections are provided for connecting the amplifier circuitry to a personal audio device and at least one external speaker.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to audio systems for use on bicycles, and in particular to a battery powered audio amplifier unit for such an audio system which is sized and shaped to fit in the water bottle holder of a bicycle. 
         [0003]    2. Description of the Related Art 
         [0004]    It is common practice for bicyclists to listen to music while riding. This is often done using a personal audio device such as a portable compact disc or tape player, a radio, a satellite radio, an mp3 player (such as an ipod®), or the like. These devices are normally carried on the user&#39;s person (such as in a pocket or clipped to a belt) and equipped with headphones through which the user listens to music. A problem with listening to such devices while riding is that the use of headphones tends to blocks other sounds and makes it difficult for the bicyclist to hear approaching automobile traffic and other safety hazards. 
         [0005]    A solution to this problem would be to provide speakers mounted on the bicycle through which a rider could hear music from a personal audio player. This would allow the bicyclist to hear music from the personal audio player while not blocking his or her ears and preventing reception of other sounds. Personal audio players, however, do not typically produce enough power to drive speakers larger than those found in standard headphones. In order to use larger speakers, an audio amplifier must be connected between the personal audio device and the speakers. An amplifier requires a power source. 
         [0006]    Power sources have been previously mounted on bicycles for operating lighting systems for riding at night. These include generators driven by one of the bicycle&#39;s wheels and various types of batteries. Batteries are often mounted inside the same housing as the light source. Some batteries for lighting systems have been sized and shaped so as to resemble a water bottle and to fit into a standard water bottle holder or “water bottle cage” provided on many bicycles. For example, Nite Rider Technical Lighting Systems of San Diego, Calif. manufactures and sells rechargeable water bottle batteries for use with its lighting systems. A water bottle battery similar to those known for use with lighting systems could be used to power an audio amplifier, however there still remain the problems of mounting an amplifier on the bicycle, protecting the amplifier from the elements, and providing electrical connections to the speakers, personal audio device, and battery. 
         [0007]    If an audio amplifier is to be mounted on a bicycle, it needs to be protected from the elements in a weatherproof housing. It needs to be securely connected to the bicycle so that it does not work loose and/or become lost while riding, however it is preferably easily removable so that when a rider leaves his or her bicycle, the amplifier (as well as other components of the audio system) can be taken along and not left at risk to thievery. The electric connections from the amplifier to the speakers, personal audio device and battery need to either remain attached as the system is removed from the bicycle, or need to be easily reconnected so that reinstallation of the system on the bicycle is not overly complicated or time-consuming. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention comprises an audio amplifier unit for a bicycle audio system. The unit includes audio amplifier circuitry and a rechargeable battery powering the audio amplifier circuitry which are housed in a weather resistant housing sized to be received and retained within a bicycle water bottle holder. Electrical connections are provided for connecting the amplifier circuitry to a personal audio device and at least one external speaker. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0009]      FIG. 1  is a perspective view of a bicycle audio system including a water bottle amplifier unit according to the present invention with elements of the system shown mounted on a bicycle handlebar. 
           [0010]      FIG. 2  is a perspective view of the water bottle amplifier unit of  FIG. 1  showing the amplifier mounted in a water bottle holder located on a frame member of a bicycle. 
           [0011]      FIG. 3  is exploded side elevational view of the water bottle amplifier unit. 
           [0012]      FIG. 4 . is a circuit diagram showing exemplary amplifier circuitry which may be included in the water bottle amplifier unit. 
           [0013]      FIG. 5  is a circuit diagram showing audio signal processing circuitry for the water bottle amplifier unit. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]    As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
         [0015]    Certain terminology will be used in the following description for convenience in reference only and will not be limiting. For example, the words “upwardly,” “downwardly,” “rightwardly,” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the embodiment being described and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof and words of a similar import. 
         [0016]    Referring to the drawings in more detail, the reference number  1  generally designates a water bottle audio amplifier unit according to the present invention. As best seen in  FIGS. 3 and 4 , the unit  1  includes audio amplifier circuitry  3  and a battery or battery pack  5  providing power to the amplifier circuitry  3 . The amplifier circuitry  3  and battery  5  are both mounted inside a housing  7  which is sized and shaped to fit into a standard bicycle water bottle cage or holder  9 , as shown in  FIG. 2 . 
         [0017]    A water bottle holder  9  is a common accessory for a bicycle and is generally used to hold a bottle of drinking water (not shown). A common location for mounting a water bottle holder  9  is on a frame member  11  of a bicycle, which is located within easy reach of a bicyclist positioned astride the bicycle. It is believed that a common standard diameter for bicycle water bottles is 74 mm (2.9 in) and that the majority of water bottle holders  9  are designed to accept and retain water bottles which are generally cylindrical and have a diameter of somewhere between approximately 2.5 to 3.5 inches. 
         [0018]    Referring to  FIG. 1 , the unit  1  is for use with a personal audio device  13  (such as a portable compact disc or tape player, a radio (including a satellite radio), an mp3 player (such as an ipod®), or the like, and a pair of speakers  15 , which may be, for example mounted in speaker housings  16  on a handlebar  17  of a bicycle. The unit  1  accepts an audio signal from the personal audio device  13 , amplifies the signal, and passes the signal to the speakers  15  where it is emitted as sound. In combination, the personal audio device  13 , amplifier unit  1 , speakers  15 , speaker housings  16 , and associated wiring, comprise a bicycle audio system  19 . The audio system  19  may also include a mount  21  located on the handlebar  17  for supporting and retaining the personal audio device  13 . 
         [0019]    The speaker housings  16  and mount  21 may be removably mounted on the handlebar  17  using quick-disconnect mounting rings  23  which allow them to be easily removed from the bicycle. Mounting rings  23  of this type are sold by Nite Rider Technical Lighting Systems of San Diego, Calif. The housings  16  each receive, for example, a respective 2 inch speaker  15 . 
         [0020]    As best seen in  FIG. 3 , the housing  7  is preferably shaped like a common bicycle water bottle and includes a bottom portion  25  and a top portion  27 . The bottom portion  25  includes a generally cylindrical outer wall  29 , an open top  31  and closed bottom  33 . The outer wall  29  includes an annular upper edge  35  encircling the open top  31  and internal threads  37  are formed in the wall  29  proximate the open top  31 . The top portion  27  of the housing  7  forms a closure member for the open top  31  of the bottom portion  25  and includes a downwardly extending cylindrical flange  39  having external threads  41  engageable with the internal threads  37  of the bottom portion  25  to connect the top portion  27  to the bottom portion  25 . The downwardly extending cylindrical flange  39  defines an opening  43  into an upper cavity  45  of the housing  7  inside the top portion  27 . 
         [0021]    A radially outwardly extending annular flange  47  is formed on the top portion  27  above the cylindrical flange  39 . An elastomeric sealing gasket  49  is captured between the annular flange  47  and the upper edge  35  of the bottom portion  25  to form a water-tight seal when the top portion  27  is installed onto the bottom portion  25 . 
         [0022]    The amplifier circuitry  3  is mounted on an integrated circuit board  51  which is sized and shaped to be received within the housing  7 , and preferably to be received through the opening  43  such that the circuit board  51  can be positioned inside the upper cavity  45 , inside the top portion  27 . An example of acceptable amplifier circuitry  3  is shown in  FIG. 4  and includes a Texas Instruments® TPA3004D2 12 W stereo audio power amplifier chip  53 . It is to be understood, however, that the present invention is not to be limited to any particular amplifier circuitry  3 . In general, the circuitry  3  includes speaker outputs  55  and  57  for left and right speakers  15 , respectively, as well as signal inputs  59  for receiving an audio signal from the personal audio device  13  and a power input  61  for receiving D.C. (direct current) from the battery  5  (negative to ground). 
         [0023]    Referring again to  FIG. 1 , the speaker outputs  55  and  57  are connected to the respective speakers  15  by speaker wiring  62 . The signal input  59  receives the audio signal through input wiring  63  having a plug  65  for insertion into a headphone jack  67  of the personal audio device  13 . As shown in  FIG. 5 , the input wiring  63  may be connected to signal processing circuitry  68 , which is in turn connected to the signal input  59 . 
         [0024]    Referring to  FIG. 3 , the wiring  62  and  63  extends outwardly from the housing  7  through an opening  69 . The opening  69  is sealed around the wiring  62  and  63  by a waterproof grommet  71 . 
         [0025]    The battery  5  comprises a plurality of rechargeable cells  73 , which may be, for example, Nickel Cadmium (NiCad) cells. The size and number of cells  73  are selected to meet the power requirements of the circuitry  3 . For example, the TPA3004D2 has a supply voltage requirement of 8.5 to 18 volts, and the battery  5  is shown as comprising eleven 1.5 volt cells  73  in series, producing a combined 16.5 volts. The battery  5  is received inside the housing  7  and preferably within the bottom portion  25 . 
         [0026]    The battery  5  is connected to the power input  61  of the amplifier circuitry  3  by a power lead  75  controlled by an on/off switch  77  extending through the housing  7 . A power LED (light emitting diode)  79  visible from outside the housing  7  is energized when the switch  77  is in the on position. 
         [0027]    It is to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown. For example, although the amplifier unit  1  has been described and depicted herein as being cylindrical and sized to fit within the most common type of water bottle holder  9  which is designed to receive and retain a cylindrical water bottle, it is to be understood that the present invention could be adapted to fit in most any type of water bottle holder  9  and configured in different geometries.