Rotary dumbbell

Abstract

A rotary dumbbell of the present invention includes a handle, and two pairs of wheels and weight devices pivoted on opposite ends of the handle for rotation. Each of the wheels has a center pivoted on the handle and is unadjustable in a radial direction thereof that the wheels centrally rotate. Each of the weight devices is adjustable in a radial direction thereof that the weight devices may eccentrically rotate. The dumbbell further includes two pairs of covers to hold the weight devices and the wheels respectively. Therefore, user may get an extra loading because of the eccentric rotation of the weight devices when he/she shakes the dumbbell. The dumbbell may be used as a roller to train abdominal muscles while the wheels serve the function of rollers.

1 . A rotary dumbbell, comprising:
 a handle;   two wheels pivoted on opposite ends of the handle for free rotation; and   two weight devices pivoted on the opposite ends of the handle for free rotation;   wherein each of the wheels has a center pivoted on the handle and is unadjustable in a radial direction thereof to have a central rotation;   wherein each of the weight devices is adjustable in a radial direction thereof to have an eccentric rotation.   
     
     
         2 . The rotary dumbbell as defined in  claim 1 , further comprising an axle pivoted on the handle for free rotation, wherein the axle has two connecting portions at opposite ends, and the connecting portions extend out of the opposite ends of the handle to connect the wheels and the weight devices respectively. 
     
     
         3 . The rotary dumbbell as defined in  claim 2 , wherein the weight device has an elongated adjusting slot extending in the radial direction, and the axle passes through the adjusting slot of the weight device that the weight device is moved along the adjusting slot. 
     
     
         4 . The rotary dumbbell as defined in  claim 1 , further comprising two pairs of first covers and second covers, between each pair of which the wheel and the weight device are provided. 
     
     
         5 . The rotary dumbbell as defined in  claim 4 , wherein the first cover has a plurality of posts to be inserted into holes on the wheel that the first cover rotates along with the wheel. 
     
     
         6 . The rotary dumbbell as defined in  claim 4 , wherein the first cover has a cavity to receive the end of the handle therein. 
     
     
         7 . The rotary dumbbell as defined in  claim 4 , wherein the second cover has a cavity with a hole at a bottom thereof, and a fastener is inserted into the hole of the second cover to be connected to the handle. 
     
     
         8 . The rotary dumbbell as defined in  claim 1 , wherein the wheel has a case and at least a weight member received in the case, and the weight member is evenly distributed in the case. 
     
     
         9 . The rotary dumbbell as defined in  claim 8 , wherein the case has a box and a lid, and the box has posts to be inserted into holes of the weight member when the weight member is put in the box, and the lid covers the box with screws screwed into the posts of the box through the lid. 
     
     
         10 . The rotary dumbbell as defined in  claim 1 , wherein the weight device has a case and at least a weight member received in the case, and the weight member is unevenly distributed in the case. 
     
     
         11 . The rotary dumbbell as defined in  claim 10 , wherein the case has a region without the weight member, and an elongated adjusting slot is provided on the region. 
     
     
         12 . The rotary dumbbell as defined in  claim 11 , wherein the adjusting slot extends in the radial direction with an end at a center of the case. 
     
     
         13 . The rotary dumbbell as defined in  claim 11 , wherein the adjusting slot extends in the radial direction with an end distal to a center of gravity of the weight member. 
     
     
         14 . The rotary dumbbell as defined in  claim 1 , wherein the wheel has a diameter the same as that of the weight device. 
     
     
         15 . A rotary dumbbell, comprising:
 a handle; and   two weight devices pivoted on opposite ends of the handle for free rotation;   wherein each of the weight devices has a case and at least a weight member received in the case, and the weight member is unevenly distributed in the case.   
     
     
         16 . The rotary dumbbell as defined in  claim 15 , wherein the case has a region without the weight member, and an elongated adjusting slot is provided on the region and extends in a radial direction, and the handle has an connecting portion engaged with the adjusting slot that the weight device is adjustable in the adjusting slot. 
     
     
         17 . The rotary dumbbell as defined in  claim 16 , wherein the adjusting slot has an end at a center of the case. 
     
     
         18 . The rotary dumbbell as defined in  claim 16 , wherein the adjusting slot has an end distal to a center of gravity of the weight member. 
     
     
         19 . The rotary dumbbell as defined in  claim 15 , further comprising a pair of wheels pivoted on the opposite end of the handle, and the wheels and the weight devices have the same rotation axis.