Abstract:
A yo-yo includes a toy body formed by a pair of housings connected by a rotatable connecting shaft. The toy body includes a detecting unit that automatically detects the rotation of the toy body and a motor that rotates the connecting shaft on the basis of the detection result of the detecting unit. The detecting unit detects the direction of rotation of the toy body and actuates the motor to rotatingly drive the connecting shaft in the same direction as the direction of rotation of the toy body.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates generally to a yo-yo, and more particularly to a yo-yo configured to sustain selective rotation with a controllable motor system.  
         [0003]     2. Description of Related Art  
         [0004]     Generally, a traditional yo-yo includes a toy body that is formed by connecting a pair of discoid rotating bodies (housings) with a shaft body. A string is wound around the shaft body, so that when the toy body is lowered, the toy body rotates as the wound string is unwound, and when the toy body rises, the string is rewound around the shaft body due to the rotational force of the toy body. Thus, the yo-yo is an instrument of play that can repeatedly move up and down.  
         [0005]     However, the rotation of the toy body reaches a maximum speed at the lowermost end, and sometimes if the rotational force becomes weak, the string cannot be rewound around the shaft body and the yo-yo cannot be made to rise and return to the user when the toy body is left as it is, so that youngsters and beginners who cannot successfully control the timing at which to make the yo-yo rise to rewind the string become unable to continuously play with the yo-yo because the rotation becomes too slow. A yo-yo that can improve the rotational force has been proposed. In this type of yo-yo, paths are symmetrically formed in the diameter direction of hollow disc bodies, a weight and a spring body are disposed in the respective paths, and the weight moves to an outer peripheral side to counter the spring body due to the rotational force of the hollow disc bodies, whereby the center of gravity of the hollow disc bodies is moved to the outer peripheral side and the rotational force is increased (see, Japanese Patent Application Laid-Open Publication No. 11-114232).  
         [0006]     Although the aforementioned yo-yo can increase the rotational force and somewhat prolong the time period of rotation in comparison to a conventional yo-yo, the rotational force still ends up decreasing and the yo-yo can fail to arrive at a fundamental solution to the problem that conventional yo-yos have.  
         [0007]     Thus there remains a problem, particularly with young children and inexperienced users that has not been adequately addressed in the prior art.  
       SUMMARY OF THE INVENTION  
       [0008]     It is an object of the present invention to provide an improved electromechanical yo-yo that solves the above-described problem by forcibly causing a connecting shaft to rotate in the same direction as the direction of rotation of the toy body and which can easily be manipulated by youngsters and beginners.  
         [0009]     In order to solve the above-described problem, a yo-yo according to the present invention comprises a toy body that includes a pair of housings and a rotatable connecting shaft that connects the pair of housings. The toy body includes a detecting unit that detects the rotation of the toy body, and an electric motor that rotates the rotatable connecting shaft on the basis of the detection result of a detecting unit. The detecting unit detects the direction of rotation of the toy body and can actuate the motor to rotatingly drive the rotatable connecting shaft in the same direction as the direction of rotation of the toy body.  
         [0010]     The detecting unit preferably comprises fixed contacts disposed inside the pair of housings, two movable contacts that come into selective contact with the fixed contacts, and switch members that cause one of the two movable contacts to come into contact with the fixed contacts, the movable contacts being pivoted in the same direction as the direction of rotation of the toy body due to the inertial force of the switch members per se and centrifugal force generated by the rotation of the rotating bodies.  
         [0011]     According to the invention, when the toy body rotates, the detecting unit detects the rotation and direction of rotation of the toy body, and the motor automatically rotates on the basis of the detection result so that the rotation of the toy body is sustained. Thus, the rotational force of the toy body is forcibly sustained and is not damped, whereby the invention can provide a yo-yo that can be enjoyed by youngsters and beginners.  
         [0012]     Additionally, the movable contacts are selectively brought into contact with the fixed contacts by the switch members that are pivoted by the inertial force of the switch members and centrifugal force generated by the rotation of the toy body. Each of the switch members comprises a weight member and the motor can cause the toy body to selectively rotate in the rotate in a clockwise or a counter-clockwise direction. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings.  
         [0014]      FIG. 1  is a perspective view of a yo-yo according to the invention;  
         [0015]      FIG. 2  an exploded perspective view of the yo-yo;  
         [0016]      FIGS. 3A  to  3 C are explanatory views of the internal configuration of the yo-yo and explanatory views of the operational mode thereof;  
         [0017]      FIG. 4  is a block diagram describing the electrical configuration of the yo-yo;  
         [0018]      FIG. 5  is a cross-sectional view describing a transmission mechanism of the yo-yo; and  
         [0019]      FIGS. 6A  to  6 D are explanatory views of the use mode of the yo-yo. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]     Reference will now be made in detail to the preferred embodiments of the invention which set forth the best mode contemplated to carry out the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention.  
         [0021]      FIG. 1  shows an example of an electromechanical yo-yo according to the present invention. The yo-yo comprises a toy body  4 , which is formed by connecting a pair of discoid rotating bodies (housings)  1  and  2  with a connecting shaft  3 , and an elongated flexible member such as a string  5  fixed, one end thereof, to the connecting shaft  3  connecting the rotating bodies  1  and  2 . The other end of the string is held by the user. Similar to a conventional yo-yo, the yo-yo is configured so that one can play with the yo-yo by lowering and raising the toy body  4  to repeatedly unwind and rewind the string  5 .  
         [0022]      FIG. 2  shows an exploded perspective view of the yo-yo of the present invention. The rotating body  1  is configured by a case  6  and a cover  7 , and the rotating body  2  is configured by a case  8  and a cover  9 . The covers  7  and  9  are respectively fixed to the cases  6  and  8  with screws  10 .  
         [0023]     Connecting shaft housing portions  13  and  14  are formed in centers of the cases  6  and  8  so as to protrude towards back surface sides thereof. Convex-concave portions  15  are provided to enhance a releasable catching and retention of the string  5  and are formed at outer respective sides of the facing surfaces of the connecting shaft housing portions  13  and  14  to form a releasable catch assembly operatively positioned against the connecting shaft  3 .  
         [0024]     Struts  19 , to which are fitted a battery housing  16 , magnet retainers  17  and a motor housing  18 , are formed at an inner side of the case  6 . A detecting unit  20  that can detect the direction of rotation of the toy body  4 , a motor  21 , a transmission mechanism  22  that transmits the rotation of the motor  21  to the connecting shaft  3 , and a secondary battery  23  are housed inside the case  6 .  
         [0025]     The detecting unit  20  comprises a first detecting assembly  20   a  and a second detecting assembly  20   b  that are disposed at symmetrical positions around the connecting shaft  3  inside the case  6 .  
         [0026]     The first detecting assembly  20   a  is configured by a fixed contact  25  disposed in close contact with an inner peripheral wall of the case  6 , two movable contacts  26  and  27  disposed facing the fixed contact  25 , and an actuator weight member  28  that constitutes a switch member and can selectively actuate the movable contacts  26  and  27 . The second detecting assembly  20   b  is configured by a fixed contact  30  disposed in close contact with the inner peripheral wall of the case  6 , two movable contacts  31  and  32  disposed facing the fixed contact  30 , and an actuator weight member  33  that constitutes a switch member and can selectively actuate the movable contacts  31  and  32 .  
         [0027]     As shown in the block diagram of  FIG. 4 , the fixed contacts  25  and  30  are respectively connected to input terminals  21   a  and  21   b  of the motor  21 . The movable contacts  26  and  31  and the movable contacts  27  and  32  respectively symmetrically disposed around the center of the case  6  are electrically connected, and the movable contacts  26  and  27  and the movable contacts  31  and  32  are connected to a positive terminal  23   a  and a negative terminal  23   b  of batteries  23 .  
         [0028]     Each of the weight members  28  and  33 , which constitutes the switch member, is configured by a substantially square rod-shaped magnetic material, such as steel, whose ends are formed in circular arcs. Spindles  35  and  36  attached to the case  6  are passed through shaft holes  28   a  and  33   a  formed in rear ends of the weight members  28  and  33 , so that the weight members  28  and  33  can pivot around spindles  35  and  36 . When the toy body  4  is not rotating, as shown in  FIG. 3A , the weight members  28  and  33  are in a stationary state where they are attracted, towards the center of the case  6 , by the magnets  37  retained in the magnet retainers  17  formed in the case  6 . When the toy body  4  rotates, the weight members  28  and  33  will rotate in the same direction as the direction of rotation of the toy body  4  to try to stay in that position due to an inertial rotational force, and are pushed against the movable contacts due to that centrifugal force (see  FIGS. 3B and 3C ).  
         [0029]     When the toy body  4  (case  6 ) rotates in a counter-clockwise direction, as shown in  FIG. 3B , the weight members  28  and  33  also pivot in a counter-clockwise direction around the spindles  35  and  36 , so that front ends of the weight members  28  and  33  push the movable contacts  26  and  31  against the fixed contacts  25  and  30 , and the fixed contact  25  and the movable contact  26  and the fixed contact  30  and the movable contact  31  become conductive. When the toy body  4  (case  6 ) rotates in a clockwise direction, as shown in  FIG. 3C , the weight members  28  and  33  also pivot in a clockwise direction around the spindles  35  and  36 , so that the front ends of the weight members  28  and  33  push the movable contacts  27  and  32  against the fixed contacts  25  and  30 , and the fixed contact  25  and the movable contact  27  and the fixed contact  30  and the movable contact  32  become conductive.  
         [0030]     As shown in  FIG. 5 , the transmission mechanism  22  that transmits the rotation of the motor  21  to the connecting shaft  23  is configured by a pinion gear  39  fixed to a rotating shaft of the motor  21  and a transmission gear  40 . The transmission gear  40  is configured by a first spur gear  41  that meshes with the pinion gear  39  and a second spur gear  42  that is fixed coaxial with the first spur gear  41 . Because the second spur gear  42  meshes with a gear  43  disposed around the periphery of one end of the connecting shaft  3 , the connecting shaft  3  rotates via the pinion gear  39  and the transmission gear  40  when the motor  21  rotates.  
         [0031]     As shown in  FIG. 2 , a cylindrical grove  44  around which the string  5  is wound is disposed around the center of the peripheral surface of the connecting shaft  3 . The gear  43  that meshes with the second spur gear  42  is disposed around the case  6  side end portion peripheral surface of the connecting shaft  3 . The connecting shaft  3  is sandwiched from both sides by shaft receivers  50  and  51  and is rotatably housed inside the connecting shaft housing portions of the cases  6  and  8  in a state where a hollow shaft body  52  has been inserted therethrough. A screw  54  is passed from the rear surface side of the case  6  through the shaft receiver  50 , the connecting shaft  3  and the shaft receiver  51 , and fastened with a nut  56  via a washer  55  from the rear surface side of the case  8 , whereby a state where the cases  6  and  8  are connected by the connecting shaft  3  can be created.  
         [0032]     With the cases  6  and  8  connected by the connecting shaft  3 , the batteries  23 ,  23 , the fixed contacts  25  and  30 , the movable contacts  26 ,  27 ,  31  and  32 , the weight members  28  and  33 , the magnets  37  and the transmission gear  40  ( 41 ,  42 ) are housed inside the case  6 . The motor housing  18  housing the motor  21  is fastened with screws to the struts  19 , and the cover  7  is attached thereto with screws  10 ,  10 . The cover  9  is fixed with the screw  10  after balancers  57  (see  FIG. 5 ) for balancing the entire toy body  4  have been attached to inner peripheral wall surfaces of the case  8 , whereby the yo-yo can be formed.  
         [0033]     Next, an operational mode of the yo-yo of the above-described configuration will be described.  
         [0034]     As shown in  FIG. 6A , after the string  5  has been wound in a counter-clockwise direction around the connecting shaft  3 , a person inserts his/her finger through an end portion of the string  5  tied in a ring and grips the toy body  4 . Because the toy body  4  is stationary at this time, the weight members  28  and  33  are attracted to the magnets  37  and do not act on the movable contacts, and the motor  21  is not actuated.  
         [0035]     Next, when the toy body  4  is strongly released downward, it rotates in a counter-clockwise direction and falls downward as the string  5  unwinds (see  FIG. 6A ). Because the rotation of the toy body  4  grows faster at this time, the weight members  28  and  33  are pivoted by an inertial force and a centrifugal force in the same direction as the direction of rotation of the toy body  4  (counter-clockwise direction), so that the movable contacts  26  and  31  respectively push against the fixed contacts  25  and  30  (see  FIG. 3B ). When the movable contacts  26  and  31  and the fixed contacts  25  and  30  respectively become conductive, as shown in  FIG. 4 , a current flows to the motor  21  in the direction of arrow a (called a forward current) and the motor  21  begins forwardly rotating. When the motor  21  forwardly rotates, the connecting shaft  3  rotates via the transmission mechanism  22 . Thus, the connecting shaft  3  rotates due to the rotation of the motor  21  in addition to the rotation resulting from the inertia of the toy body  4 , so that the toy body  4  can sustain its rotation. The activation of the motor is automatically performed by the controllable motor system without requiring any skill by the user.  
         [0036]     In a state where the rotation is sustained, the string  5  can still catch on the string-catching convex-concave portions  15  formed at opposing surfaces of the cases  6  and  8  when flexure is imparted to the string  5  by the user&#39;s hand movement to provide an off-axis undulation in the same manner as a conventional yo-yo and, as shown in  FIG. 6B , the toy body  4  rises upward towards the person&#39;s hand while the connecting shaft  3  rewinds the string  5  in a counter-clockwise direction. When the toy body  4  rises up to the person&#39;s hand and the person grips the toy body  4  with his/her hand, the rotation of the toy body  4  is forcibly stopped, whereby the centrifugal force acting on the weight members  28  and  33  ceases, the movable members  26  and  31  are freed because they are attracted to the magnets  37  and become stationary, the current to the motor  21  is blocked off and the motor  21  stops.  
         [0037]     Next, when the toy body  4  is strongly released downward, it rotates in a clockwise direction and falls downward as the string  5  unwinds (see  FIG. 6C ). Because the rotation of the toy body  4  grows faster at this time, the weight members  28  and  33  are pivoted by an inertial force and a centrifugal force in the same direction as the direction of rotation of the toy body  4  (clockwise direction), so that the movable contacts  27  and  32  respectively push against the fixed contacts  25  and  30  (see  FIG. 3C ). When the movable contacts  27  and  32  and the fixed contacts  25  and  30  respectively become conductive, as shown in  FIG. 4 , a current flows to the motor  21  in the direction of arrow “b” (called a reverse current) and the motor  21  begins reversely rotating. When the motor  21  reversely rotates, the connecting shaft  3  rotates via the transmission mechanism  22 . Thus, the connecting shaft  3  rotates due to the rotation of the motor  21  in addition to the rotation resulting from the inertia of the toy body  4 , so that the toy body  4  can sustain its rotation.  
         [0038]     When flexure is imparted to the string  5  in a state where the rotation is sustained, as shown in  FIG. 6D , the toy body  4  rises upward towards the person&#39;s hand while the connecting shaft  3  rewinds the string  5  in a clockwise direction. When the person grips the toy body  4  that has risen up to the person&#39;s hand with his/her hand, the rotation of the toy body  4  is forcibly stopped, whereby the centrifugal force acting on the weight members  28  and  33  ceases, the movable members  26  and  31  are freed because they are attracted to the magnets  37  and become stationary, the current to the motor  21  is blocked off and the motor  21  stops.  
         [0039]     When the toy body  4  that has returned to the person&#39;s hand is again thrown by the user, the toy body  4  rotates and falls downward and the motor  21  also begins rotating. Thus, as shown in  FIGS. 6A  to  6 D, the toy body  4  can be moved up and down, and the motor  21  rotates to sustain the rotation of the toy body  4  in accompaniment with the up and down movement of the toy body  4 . Thus, as long as the rotation of the toy body  4  is not forcibly stopped, the toy body  4  can be continuously rotated.  
         [0040]     As described above, when the toy body  4  rotates, the weight members  28  and  33  are actuated by the inertial force and centrifugal force generated from the rotational force of the toy body  4 , and the movable contacts are brought into contact with the fixed contacts to form the drive circuit of the motor  21 . Thus, the rotation of the toy body  4  can be sustained by the rotation of the motor  21 , and the toy body  4  can be manipulated without worrying about a drop in the rotational speed. Thus, a yo-yo appropriate for youngsters and beginners can be provided.  
         [0041]     Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the amended claims, the invention may be practiced other than as specifically described herein.