Abstract:
A wrist exercise includes a casing rotatably receiving a rotor therein. The casing defines slots that are aligned in pair. The rotor has axially aligned rotation shafts respectively and rotatably received in holes defined in the casing for rotatably supporting the rotor inside the casing. A drive roller is mounted to one of the rotation shafts. A drive bar is partially and movable received in the casing through the aligned slots to drivingly engage the drive roller whereby by forcibly pulling the drive bar out of the casing, the drive roller is caused to drive an initial rotation of the rotor with a high rotational speed.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates to a wrist exerciser, and in particular to the initial actuation of the wrist exerciser. 
   2. The Related Art 
   Wrist exercisers comprising a hollow casing inside which a spherical rotor is rotatably supported are known for exercising wrist-related muscles and for rehabilitation purposes. An example of the wrist exerciser is shown in U.S. Pat. No. 5,800,311. The operation of the wrist exerciser starts with actuating and driving the rotor to have the rotor rotating in high speed with great torque. A player that plays the wrist exerciser then uses his or her wrist and palm muscles to maintain the rotation of the rotor. This exercises the palm and wrist muscles of the player. In this respect, the initial actuation of the rotor is of importance. 
     FIG. 10  of the attached drawings shows a conventional wrist exerciser, generally designated with reference numeral A. The wrist exerciser A comprises a spherical rotor A 1  rotatably mounted inside a spherical, hollow casing comprised of an upper hemi-spherical casing member A 2  and a lower hemi-spherical casing member A 3  mating each other. A circumferential groove A 11  is defined in an outer surface of the rotor A 1  and substantially extends along a great circle of the sphere of the rotor A 1 . A radially extending hole A 12  is defined in the groove A 11 . A circular opening A 21  is defined in the upper casing member A 2  for the extension of a rope B therethrough. An end of the rope B that extends into the casing through the opening A 21  is put into the hole A 21  of the rotor A 1 . The rope B is then partially wrapped around the rotor A 1  within the groove A 11 . Pulling the rope B off the rotor A 1  through the opening A 21  of the upper casing member A 2  causes an initial rotation of the rotor A 1 . 
   Since the opening A 21  is small compared to the player&#39;s hand, it is difficult to wrap the rope B around the rotor A 1  in a very tight manner. Thus, when the rope B is quickly pulled off the rotor A 1 , the force that pulls the rope B off the rotor A 1  may cause deviation of the rope B from the desired moving direction and thus leading to lose of control of the rotor A 1  and failure of initial rotation. 
   In addition, since there must be an opening A 21  defined in the casing for the extension of the rope B, surface integration of the spherical casing cannot be maintained, causing undesired adverse effect on the playing of the wrist exerciser A. The opening A 21  may cause potential risks to the player&#39;s finger if the player accidentally puts his or he finger into the casing through the opening A 21  and hit by the rotor A 1  that is rotating in high speed. 
   Thus, it is desired to have a wrist exerciser having an actuating device for overcoming the above problems. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to provide a wrist exerciser having an actuating device that can be readily operated with no failure in initially starting the wrist exerciser. 
   Another object of the present invention is to provide a wrist exerciser comprising a casing having no large opening for the extension of a driving rope whereby damage caused by accidentally placing a finger into the casing by the player can be effectively eliminated. 
   A further object of the present invention is to provide a wriest exerciser comprising an actuating device that requires no large opening defined in a casing of the wrist exerciser for retaining the surface integration of the casing. 
   To achieve the above objects, in accordance with the present invention, there is provided a wrist exercise comprising a casing rotatably receiving a rotor therein. The casing defines slots that are aligned in pair. The rotor has axially aligned rotation shafts respectively and rotatably received in holes defined in the casing for rotatably supporting the rotor inside the casing. A drive roller is mounted to one of the rotation shafts. A drive bar is partially and movable received in the casing through the aligned slots to drivingly engage the drive roller whereby by forcibly pulling the drive bar out of the casing, the drive roller is caused to drive an initial rotation of the rotor with a high rotational speed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be apparent to those skilled in the art by reading the following description of preferred embodiments thereof, with reference to the attached drawings, in which: 
       FIG. 1  is a perspective view of a wrist exerciser constructed in accordance with a first embodiment of the present invention; 
       FIG. 2  is an exploded view of the wrist exerciser of the present invention; 
       FIG. 3  is a perspective view of a rotor and a support ring that are movably mounted inside a casing of the wrist exerciser of the present invention; 
       FIG. 4  is a cross-sectional view of the wrist exerciser of the present invention; 
       FIG. 5  is a cross-sectional view of an actuating device of the wrist exerciser of the present invention; 
       FIG. 6  is a cross-sectional view showing an actuating device of the wrist exerciser constructed in accordance with a second embodiment of the present invention; 
       FIG. 7  is a cross-sectional view showing an actuating device of the wrist exerciser constructed in accordance with a third embodiment of the present invention; 
       FIG. 8  is a cross-sectional view showing an actuating device of the wrist exerciser constructed in accordance with a fourth embodiment of the present invention; 
       FIG. 9  is a perspective view of a wrist exerciser constructed in accordance with a fifth embodiment of the present invention; and 
       FIG. 10  is a perspective view of a conventional wrist exerciser. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With reference to the drawings and in particular to  FIGS. 1–4 , a wrist exerciser constructed in accordance with the present invention, generally designated with reference numeral  100 , comprises a casing having a substantially spherical shape and comprising upper and lower casing members  10 ,  20  mating each other to define an interior space (not labeled) therebetween. If desired, the upper and lower casing members  10 ,  20  may be movable relative to each other A spherical rotor  30  is rotatably supported and received in the interior space. Slots  11 ,  12 , preferably elongated in a circumferential direction, are defined in the upper and lower casing members  10 ,  20  and substantially aligned with each other. 
   A support ring  40  is mounted between the upper and lower casing members  10 ,  20  and defines diametrically opposite holes  41 . The rotor  30  comprises a substantially spherical body having axially aligned rotation shafts  32  on opposite sides thereof for being rotatably received in the holes  41  of the support ring  40  whereby the rotor  30  is rotatably supported by the support ring  40  within the interior space of the casing. A drive roller  33 , constituting partly an actuating device of the wrist exerciser  10 , is mounted to one of the rotation shafts  32 . The roller  33  may have any desired form, such as a toothed wheel as shown in  FIGS. 3 and 5 . This will be further described. 
   If desired, light emitting elements  31 , such as light emitting diodes, may be mounted to a circuit board attached to the rotor  30 . When the rotor  30  rotates, the light emitting elements  31  are energized and give off light. 
   The actuating device of the wrist exerciser further comprises a box  42  mounted to the support ring  40  at a position corresponding to the drive roller  33  of the rotor  30  and substantially aligned with the slots  11 ,  21  defined in the upper and lower casing members  10 ,  20 . The box  42  defines a channel (not labeled) extending in a direction substantially normal to the support ring  40 . A partition  422  is mounted inside the channel of the box  42  to divide the channel into two separated passages  423 . The partition  422  may comprise a single board or alternatively, the partition  422  is comprised of two separated but aligned boards. 
   The box  42  defines, in an inner side wall thereof, an opening  421  large enough to accommodate the drive roller  33  as well as the rotation shaft  32 . Thus, the drive roller  33  is located inside the box  42  and between the two passages  423  as shown in  FIG. 5 . 
   A drive bar  50  has a length sufficient to extend through the slots  11 ,  21  of the upper and lower casing members  10 ,  20  and the box  42  as particularly shown in  FIG. 4 . The drive bar  50  is drivingly engageable with the drive roller  33  whereby operating the drive bar  50  causes the roller  33  to drive an initial rotation of the rotor  30 . In the embodiment illustrated in  FIGS. 1–5 , the roller  33  is a toothed wheel and corresponding thereto, the drive bar  50  comprises a rack  51  engageable with the toothed wheel  33 . A pull ring  52  is formed on a remote end of the drive bar  50  for player&#39;s pulling the drive bar  50 . 
   To operate, the drive bar  50  is put into the casing through the slots  11 ,  21  of the upper and lower casing members  10 ,  20  and extends through one of the passages  423  of the box  42  with the rack  51  engages the toothed wheel  33 . Forcibly pulling the drive bar  50  out of the casing through the slots  11 ,  21  of the upper and lower casing members  10 ,  20 , as indicated by arrow of  FIG. 5 , causes the drive roller  33  to drive the rotor  30  to rotate. Thus, an initial rotation of the rotor  30  with a high speed and great torque is realized. The slots  11 ,  21  are preferably arranged along a circular path to ensure that the box  42  can always be aligned with one of the slot pairs  11 ,  21  for next operation. 
   With reference to  FIG. 6 , which shows a second embodiment of the wriest exerciser in accordance with the present invention. The second embodiment wrist exerciser is substantially the same as the first embodiment wrist exerciser. Thus, parts or members of the second embodiment wrist exerciser that are identical or similar to the parts or members of the first embodiment wrist exerciser bear the same reference numerals and will not be described again for simplicity. As shown in  FIG. 6 , the drive roller that is embodied as a toothed wheel  33  in the first embodiment is now embodied in the form of a friction roller in the second embodiment and is designated with reference numeral  33 ′ for distinction. An example of the friction roller  33 ′ is a rubber roller. Corresponding to the friction roller  33 ′, the drive bar that is embodied in the form of a rack in the first embodiment is now replaced by a bar having a high friction surface and is designated with reference numeral  50 ′. An example of the friction bar  50 ′ is a rubber bar or a bar having a rubber-made surface layer to form a frictional engagement with the friction roller  33 ′. Similar to the first embodiment, forcibly pulling the drive bar  50 ′ as indicated by the arrow of  FIG. 6  causes the roller  33 ′ to drive the initial rotation of the rotor  30 , by means of frictional engagement, rather than the toothed engagement in the first embodiment. 
   With reference to  FIG. 7 , which shows a third embodiment of the wriest exerciser in accordance with the present invention. The third embodiment wrist exerciser is substantially the same as the first embodiment wrist exerciser. Thus, parts or members of the third embodiment wrist exerciser that are identical or similar to the parts or members of the first embodiment wrist exerciser bear the same reference numerals and will not be described again for simplicity. As shown in  FIG. 7 , an additional toothed wheel  424  is rotatably supported in the box  42  and arranged between the toothed wheel  33  and the rack  51  of the drive bar  50 . Forcibly pulling the drive bar  50  as indicated by the arrow of  FIG. 7  causes the additional toothed wheel  424  to rotate and the rotation is transmitted to the rotor  30  via the toothed wheel  33 . Thus, pulling the drive bar  50  will eventually cause the roller  33  to drive the initial rotation of the rotor  30 . 
   The arrangement of the additional toothed wheel  424  allows for different torque in causing the initial rotation of the rotor  30 . This can be done by making use of additional toothed wheel  424  of different specification that provides different ratio of diameters between the toothed wheels  424 ,  33 . 
   With reference to  FIG. 8 , which shows a fourth embodiment of the wriest exerciser in accordance with the present invention. The fourth embodiment wrist exerciser is substantially the same as the second embodiment wrist exerciser. Thus, parts or members of the fourth embodiment wrist exerciser that are identical or similar to the parts or members of the second embodiment wrist exerciser bear the same reference numerals and will not be described again for simplification of the description. As shown in  FIG. 8 , an additional friction roller  424 ′ is rotatably supported in the box  42  and arranged between the friction roller  33  and the friction layer of the drive bar  50 ′. Forcibly pulling the drive bar  50 ′ as indicated by the arrow of  FIG. 8  causes the additional friction roller  424 ′ to rotate and the rotation is transmitted to the rotor  30  via the friction roller  33 ′. Thus, pulling the drive bar  50 ′ will eventually cause the roller  33 ′ to drive the initial rotation of the rotor  30 . 
   Similar to the third embodiment, the arrangement of the additional friction roller  424 ′ allows for different torque in causing the initial rotation of the rotor  30 . This can be done by making use of additional friction roller  424 ′ of different diameter that provides different ratio of diameters between the friction rollers  424 ′,  33 ′. 
     FIG. 9  shows a wrist exerciser constructed in accordance with a fifth embodiment of the present invention. The fifth embodiment wrist exerciser is substantially the same as the first embodiment wrist exerciser. Thus, parts or members of the fifth embodiment wrist exerciser that are identical or similar to the parts or members of the first embodiment wrist exerciser bear the same reference numerals and will not be described again for simplicity. As shown in  FIG. 9 , a counter  22  is mounted to the lower casing member  20  of the casing of the wrist exerciser  100 . The counter  22  provides counting for the turns of rotation of the rotor  30 . 
   The wrist exercise  100  of the present invention, as illustratively described with embodiments shown in  FIGS. 1–9 , allows for initial actuation by a drive bar  50 ,  50 ′ extending through small slots  11 ,  21  defined in the casing. Troublesome operation of winding a rope around the rotor is no longer required. Thus, failure of initial actuation by incorrect rope winding is eliminated. In addition, no large opening is needed. Thus, damage caused to the player&#39;s finger accidentally put into the casing through the opening is completely eliminated. 
   Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.