Patent Publication Number: US-6910991-B2

Title: Stationary bike

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a stationary bike, and more particularly to a stationary bike controlling a display content appearing on a screen. 
   2. Description of the Background Art 
   Conventional stationary bikes are disclosed, for example, in U.S. Pat. No. 4,512,567 and U.S. Pat. No. 6,561,952. 
   U.S. Pat. No. 4,512,567 discloses an exercise bike having a variable resistor and a generator for outputting an electrical signal indicative of a state of a handlebar or pedal operation, which is reflected in movements in a video game. Here, the handlebar is connected to the variable resistor through a gear or the like. 
   U.S. Pat. No. 6,561,952 discloses a stationary bike using a monitor display or the like to allow users to feel virtual operations as if they are on a real road. The stationary bike has a mechanism including a shade plate having openings sandwiched between two circuit boards for limiting light to be transmitted and a sensor for detecting the light thereby detecting a rotation angle of a handlebar. 
   The stationary bikes as mentioned above, however, have the following problems. 
   The stationary bikes in the conventional examples as described above can detect and output a rotation angle of a handlebar. 
   The conventional examples, however, do not disclose a restoring mechanism that allows a handlebar to return to the vicinity of an initial position (a forward direction), of itself. Therefore, this stationary bike sometimes involves difficulty in handlebar operations during its operation. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to provide a stationary bike facilitating a handlebar operation. 
   In accordance with the present invention, a stationary bike controlling a display content appearing on a screen includes: a body; a handlebar rotatably attached to the body, a control unit for controlling the display content appearing on the screen; and a restoring mechanism restoring the handlebar to an initial position. 
   Therefore, a stationary bike facilitating a handlebar operation can be obtained. 
   Preferably, the stationary bike described above further includes: a handlebar rotation angle detector detecting a rotation angle of the handlebar; a pedal connected to the body; a speed signal generator generating a speed signal in accordance with the rotation speed of the pedal; and a brake signal generator generating a brake signal. The control unit preferably includes a controller receiving a signal from the handlebar rotation angle detector, the speed signal generator- and the brake signal generator for being reflected in the display content on the screen. 
   Therefore, the handlebar, pedal and brake operation can be reflected in the display content on the screen, thereby-giving a feel close to a real operation of a bicycle. 
   Preferably, the stationary bike described above further includes: a rotary shaft rotating in connection with a rotating motion of the handlebar; and a tubular member accommodating the rotary shaft. The restoring mechanism includes a coil spring wound around an outer circumference of the rotary shaft, a first securing portion securing one end of the coil spring to the rotary shaft, and a second securing portion securing the other end of the coil spring to the tubular member. 
   Therefore, the restoring mechanism in a compact structure can be obtained. 
   Preferably, an angle between an installation plane where the body is installed on a horizontal plane and a shaft center of the rotary shaft is at least 68° and at most 73°. 
   This angle allows the user to operate the handlebar most conveniently. This angle employed in the stationary bike described above can facilitate the handlebar operation of the bike. 
   Preferably, the handlebar rotation angle detector has a driving shaft driven to rotate by the rotary shaft. The rotary shaft has a connecting member having a first groove portion receiving the driving shaft for connecting the rotary shaft to the driving shaft and a pin attached to the rotary shaft and extending in a direction orthogonal to the first groove portion. The connecting member includes a second groove portion receiving the pin in a rotatable manner. A spacer formed of an elastic member is arranged between the connecting member and the driving shaft. 
   Here, the rotation of the pin means rolling of the pin in the second groove portion. 
   Therefore, deflection at the tip end of the rotary shaft on the side of the handlebar rotation angle detector during the handlebar operation can be absorbed. As a result, the handlebar rotation angle can readily be detected. 
   Preferably, the stationary bike described above includes a stopper mechanism for limiting a rotation angle of the handlebar. 
   Therefore, an adequate handlebar operation can be performed. 
   As described above, in accordance with the present invention, the handlebar can be operated easily during the operation of the stationary bike. 
   The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view showing a stationary bike in use in accordance with one aspect of the present invention. 
       FIG. 2  is a side view showing the stationary bike in accordance with one aspect of the present invention. 
       FIG. 3  is an enlarged side view showing a handlebar part in the stationary bike in accordance with one aspect of the present invention. 
       FIG. 4  is an enlarged partial cross-sectional side view showing the handlebar part in the stationary bike in accordance with one aspect of the present invention. 
       FIG. 5  is a partial cross-sectional view taken along V—V in  FIG. 4 . 
       FIG. 6  is a cross-sectional view taken along VI—VI in  FIG. 4 . 
       FIG. 7  is an enlarged cross-sectional side view showing a connection portion between a shaft and a variable resistor in the stationary bike in accordance with one aspect of the present invention. 
       FIG. 8  is a cross-sectional side view showing an upper spacer shown in  FIG. 7 . 
       FIG. 9  is a cross-sectional side view showing a lower spacer shown in  FIG. 7 . 
       FIG. 10  is a front view of the upper spacer shown in  FIG. 7 . 
       FIG. 11  is a top view of the lower spacer shown in  FIG. 7 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   In the following, an embodiment of a stationary bike in accordance with the present invention will be described with reference to  FIGS. 1 to 11 . 
   A stationary bike in accordance with the embodiment of the present invention is a fixed bike providing a virtual operation of a bicycle with a display content on a screen being controlled. It is noted that the stationary bike is used in a variety of usages such as games, exercise, and the like. 
   A stationary bike in accordance with the present embodiment includes a body, a handlebar rotatably attached to the body, a control unit for controlling a display content on a screen, and a restoring mechanism restoring the handlebar to an initial position. 
   Therefore, during the operation of the stationary bike, the user hardly makes a forcedly sharp turn or the user easily returns the handlebar that is turned to the left or right to the vicinity of an initial position (a forward direction). Moreover, even if the user releases the handlebar, the handlebar that is turned to the left or right returns to the vicinity of the initial position, of itself. As a result, the handlebar can easily be operated. 
   The embodiment of the present invention will now be described in detail with reference to the figures. 
     FIG. 1  is a perspective view showing an exemplary use of the stationary bike in accordance with the embodiment of the present invention. 
   Referring to  FIG. 1 , a stationary bike  1  includes a body  2 , a front leg  3  and a back leg  4  supporting body  2 , a pedal  5  attached to body  2 , a saddle  7  attached to body  2  through a seat post  6 , a handlebar post  8 , and a handlebar  9  rotatably attached to body  2  through handlebar post  8  and a tubular member  10 . 
   The tubular member contains a not-shown rotation sensor (a handlebar rotation angle detector) detecting a rotation angle of handlebar  9 . This rotation sensor may include, for example, a variable resistor. Body  2  contains speed sensor  2 A (a speed signal generator) generating a speed signal in accordance with the rotation speed of the pedal  5 . Handlebar  9  is provided with a brake button  11  (a brake signal generator) generating a brake signal. Controller  12  is connected to the rotation sensor, the speed sensor and brake button  11  described above as well as a game machine body  13  through a not-shown connecting line, for receiving a signal from the rotation sensor, speed sensor and brake button  11  and outputting the signal to game machine body  13 . The signal transmitted to game machine body  13  is displayed on a monitor  14  (a screen). Therefore, the handlebar operation, pedal operation and brake operation are reflected in the display content on monitor  14 , so that the user can enjoy a game using stationary bike  1 . 
   Monitor  14  can display a vision of an operator in an operation of a bicycle, thereby providing a virtual operation with stationary bike  1 . In this case, monitor  14  can give a display in such a manner that the bike travels in the direction to which the handlebar is turned, or the landscape flows fast toward the back as if the bike is accelerated by pedaling fast, or as if the bike is decelerated by pushing the brake button. 
   It is noted that controller  12  is provided with a speed sensitivity adjuster and a handlebar sensitivity adjuster. The monitor display therefore can properly respond to the pedal operation or the handlebar operation. 
   In this way, the handlebar, pedal and brake operation can be reflected in the display content on the screen, thereby giving a feel close to a real operation of a bicycle. 
   Game machine body  13  may be a general-purpose game machine that is commonly used. Controller  12  is provided with buttons corresponding to the pedal, brake and handlebar operations. The user can enjoy games and the like only with controller  12 , game machine body  13  and monitor  14 . 
     FIG. 2  is a side view of stationary bike  1 , and  FIG. 3  is an enlarged view around handlebar  9 . 
   Referring to  FIGS. 2 and 3 , it is preferable that an angle (θ  1  in  FIGS. 2 and 3 ; a caster angle) between an installation plane where body  2  is installed on the horizontal plane and a shaft center of a shaft (rotary shaft) of handlebar  9  is at least 68° and at most 73°. 
   In an operation of a two-wheeled vehicle, the caster angle (θ  1 ) at which the handlebar operation is most convenient is approximately 70°. The caster angle set at the aforementioned range can facilitate the handlebar operation of stationary bike  1 . 
   The angle (θ  2  in  FIG. 2 ) between the installation plane where body  2  is installed on the horizontal plane and the shaft center of seat post  6  is approximately 74°. 
   Seat post  6  has a variable length, and the height (H1 in  FIG. 2 ) from the center of rotation of pedal  5  to the saddle can be adjusted to suit the figure of the user of stationary bike  1 . 
     FIG. 4  is an enlarged partial cross-sectional side-view around handlebar  9 .  FIG. 5  shows a partial cross section taken along V—V (only the inside of tubular member  10 ) in  FIG. 4 . It is noted that in  FIG. 4  handlebar  9  is not shown. 
   Referring to  FIGS. 4 and 5 , shaft  15  that is inserted into a head tube  15 A and serves as a rotary shaft rotating in connection with the rotating motion of handlebar  9  is provided inside tubular member  10 . 
   The restoring mechanism for handlebar  9  as described above is configured with a coil spring  16  wound around the outer circumference of shaft  15 , a hook  16 A (a first securing portion) securing one end of coil spring  16  to shaft  15 , and a hook  16 B (a second securing portion) securing the other end of coil spring  16  to tubular member  10 . 
   Hook  16 A is engaged with a bolt  17 A secured to shaft  15 , and hook  16 B is engaged with a bolt  17 B secured to tubular member  10 . 
   In the configuration described above, when handlebar  9  is rotated, the end portion of coil spring  16  on the hook  16  B side is fixed by tubular member  10  while the end portion on the hook  16 A side is moved with the rotation of shaft  15 . Accordingly, torque acts on coil spring  16 , and a restoring force forcing handlebar  9  to return to the initial position acts on shaft  15  as the counteraction against the torque. In this way, the restoring mechanism as described above can be obtained. This configuration allows a counter-force (restoring force) to act on the handlebar in proportion to the turning angle of the handlebar, thereby resulting in a smooth handlebar operation during a game operation. 
   It is noted that the first and second securing portions are not limited to the structure such as hooks  16 A and  16 B and may be structured such that the both end portions of coil spring  16  are directly connected to shaft  15  and tubular member  10 , respectively, by welding or the like. 
   Although the restoring mechanism may be structured, for example, such that tubular member  10  is connected to body  2  by an elastic member outside tubular member  10 , the structure using the coil spring as described above allows the restoring mechanism to be accommodated inside tubular member  10 , resulting in a compact structure. In addition, the tubular member can protect the coil spring, and the life of the apparatus can therefore be prolonged. 
   The handlebar rotation angle detector may include, for example, a variable resistor  19 . Variable resistor  19  is secured to tubular member  10  with an attachment  18  and has a driving shaft  19 A connected to shaft  15  with an upper spacer  20  interposed as a connecting member. With this configuration, a rotation amount of driving shaft  19 A that rotates along with the rotation of handlebar  9  is measured by variable resistor  19 , so that the rotation amount of handlebar  9  can be measured. The detected rotation amount is output as an electrical signal through an output terminal  19 B. 
     FIG. 6  shows a cross section taken along VI—VI in  FIG. 4 . 
   Tubular member  10  includes a stopper portion  10 A (a stopper mechanism) limiting the rotation angle of handlebar  9 . 
   Stopper portion  10 A is formed by cutting and denting a part of tubular member  10 . This stopper portion  10 A interferes with bolt  17 A secured to shaft  15  to limit the rotation of shaft  15 . In  FIG. 6 , for example, shaft  15  can rotate by an angle of θ  3  from the initial position to either side. Most preferably, θ  3  is approximately 50°. 
   The configuration described above allows a moderate handlebar operation during the operation of stationary bike  1 . 
   In the following, a structure of a connection portion between shaft  15  and variable resistor  19  will be described in more detail with reference to  FIGS. 7–11 . 
     FIG. 7  is an enlarged view showing the aforementioned connection portion. As shown in  FIG. 7 , shaft  15  has upper spacer  20  (a connecting member) and a pin  22 , through which driving shaft  19 A of variable resistor  19  is connected to shaft  15 . With this configuration, driving shaft  19 A is driven to rotate by shaft  15 , and the handlebar rotation angle can be detected by variable resistor  19 . A lower spacer  21  formed, for example, of an elastic member such as rubber is arranged-between upper spacer  20  and driving shaft  19 A. 
     FIGS. 8–11  are exploded views showing upper and lower spacers  20  and  21 .  FIGS. 8 and 9  show the cross-sectional side views of the upper and lower spacers  20  and  21 , respectively,  FIG. 10  shows a front view of upper spacer  20  as seen from the direction orthogonal to the direction of  FIG. 8 , and  FIG. 11  is a top view of lower spacer  21 . 
   As shown in  FIGS. 7 ,  8  and  10 , upper spacer  20  has a groove portion  20 A (a first groove portion) receiving driving shaft  19 A and a groove portion  20 B (a second groove portion) receiving pin  22  in such a manner that it can be rotated (rolled). The first and second groove portions are provided in the directions orthogonal to each other. 
   As shown in  FIGS. 7 ,  9  and  11 , lower spacer  21  has an opening  21 A through which driving shaft  19 A is inserted. Lower spacer  21  with driving shaft  19 A of variable resistor  19  being inserted is fitted into groove portion  20 A of upper spacer  20 . 
   Handlebar  9  rotates about the shaft center (the up/down direction in  FIG. 7 ) of shaft  15  and driving shaft  19 A. Here at the tip end of shaft  15  on the side of variable resistor  19 , a certain amount of margin (play) is preferably provided with respect to the rotation about the axis in the forward/backward direction as well as the right/left direction in  FIG. 7 . 
   On the other hand, in the configuration described above, deflection caused by the rotation about the axis in the right/left direction in  FIG. 7  can be absorbed by upper spacer  20  rotating about pin  22 , and deflection caused by the rotation about the axis in the forward/backward direction in  FIG. 7  can be absorbed by lower spacer  21  being elastically deformed. 
   As described above, in accordance with the present embodiment, the deflection at the tip end of shaft  15  on the variable resistor  19  side during the handlebar operation can be absorbed. As a result, an improper force is not exerted on driving shaft  19 A of variable resistor  19 , and the handlebar rotation angle can properly be detected, thereby improving the reliability of the detection result. Additionally, the life of the apparatus can be prolonged. 
   Although, in the present embodiment, in order to provide a virtual operation of a bicycle using a stationary bike, pedal  5  is used as an accelerator and brake button  11  is used as a brake, the accelerator and the brake are not limited thereto. Alternatively, the accelerator may employ a throttle system that virtually accelerates the bike by rotating a grip portion  9 A of handlebar  9 , and the brake may employ a brake lever structure attached to handlebar  9 . In this case, stationary bike  1  can be used to perform a virtual operation of a motor cycle having a prime mover. 
   Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.