Patent Publication Number: US-8118717-B1

Title: Dumbbell with rotatable weights

Description:
BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention relates to a dumbbell, and more particularly, to a dumbbell with rotatable weights on two ends of the bar so as to exercise muscles of the users. 
     (2) Description of the Prior Art 
     A conventional dumbbell is shown in  FIG. 1  and generally includes a bar  10  with two weights  11  on two ends of the bar  10 , wherein the weights  11  each are a circular disk-like weight, spherical weights or polygonal disk-like weights. However, the use of the dumbbell is simply and boring, the dumbbell is held at the bar and moves the arms up and down. Only the muscles of the arms are exercised and this cannot be satisfied by most of the users who want to exercise more muscles of the body. 
     The present invention intends to provide a dumbbell which is designed to overcome the shortcomings of the conventional dumbbell and can exercise more muscles. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a dumbbell and includes a bar, an axle, two 
     weights and two cover. The bar includes a holding portion and two enlarged reception members connected to two ends of the bar. The axle extends through a passage of the bar and each reception member has a space for reception of the weight. Each weight includes a ridge and a weight body, the ridge is connected between the axle and the weight body. The two covers are respectively connected to the reception members to cover the two respective spaces. 
     When the dumbbell is operated, the weights are rotatable and generate eccentric force to swing the dumbbell and the swinging action of the dumbbell is transferred to the user&#39;s body to vibrate and exercise the user&#39;s body. There are different ways to operate the dumbbell to train the user to keep balance which provides more interest to the user. 
     Each of the weights can be composed of multiple identical plates so that the user can optionally use desired weights. 
     The weight body of each weight is a curved body and the ridge is connected to a middle of the concaved inside of the weight body so that each weight is an anchor-like weight which has an off-center weight center to the dumbbell to have better swinging feature. 
     The weights can be made into different ponds for the user to choose. 
     The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view to show a conventional dumbbell; 
         FIG. 2  is an exploded view to show the dumbbell of the present invention; 
         FIG. 3  is a cross sectional view of the dumbbell of the present invention; 
         FIG. 4  is an exploded view to show the second embodiment of the dumbbell of the present invention; 
         FIG. 5  is a cross sectional view of the dumbbell in  FIG. 4  of the present invention; 
         FIG. 6  is an exploded view to show the third embodiment of the dumbbell of the present invention; 
         FIG. 7  is an end cross sectional view of the dumbbell of the present invention, and 
         FIGS. 8 to 11  show different ways of operation of the dumbbell of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIGS. 2 and 3 , the dumbbell of the present invention comprises a bar  20 , two bearings  30 , an axle  40 , two C-clips  50 , two weights  60 , two washers  70 , two nuts  80  and two covers  90 . The bar  20  includes a holding portion  21  and two enlarged reception members  22  connected to two ends of the bar  20 . The bar  21  has a passage  23  axially defined therethrough and each reception member  22  has a space  25  defined therein which opens outward. The space  25  communicates with the passage  23  and the passages  23  communicates with two bearings  24  located at two ends of the passage  23 . Each of the two reception members  22  has outer threads  26 . The two bearings  30  are located in the bearing spaces  24   
     The axle  40  rotatably extends through the passage  23  and two ends of the axle  40  extend through the two bearings  30  and are located in the spaces  25  of the two reception members  22 . The axle  40  includes two grooves  41  respectively located close to two ends thereof and each end of the axle  40  has a notch  42  defined therein. A threaded rods  43  extends from each end of the axle  40 . 
     The four C-clips  50  are engaged with the four grooves  41  and two C-clips  50  located close to the middle of the axle  40  are in contact with two respective outsides of the two bearings  30 , and a distance is defined between the two inside C-clips  50  and the two outside C-clips  50 . 
     The two weights  60  fixed to the two ends of the axle  40  and each weight  60  includes a ridge  61  and a weight body  62 . The ridge  61  is connected between the axle  40  and the weight body  62 . Each of the ridges  61  has a tubular portion  63  to which the axle  40  is connected. Each tubular portion  63  has a protrusion  64  which is engaged with the notch  42  when the axle  40  is inserted into the tubular portion  63 . The two outside C-clips  50  are in contact with the two respective insides of the two tubular portions  63 . The weight body  62  of each weight  60  is a curved body and the ridge  61  is connected to the middle of the concaved inside of the weight body  62  such that each weight  60  is an anchor-like weight. 
     The two washers  70  are mounted to the two threaded rods  43  and cooperated with the two C-clips  50  to restrict the two weights  60  on the two ends of the axle  40 . The two nuts  80  are threadedly mounted to the two threaded rods  43  and secure the two washers  70 . 
     The two covers  90  each have inner threads  91  so that the two covers  90  are threadedly mounted to the outer threads  26  of the reception members  22 . The two covers  90  can also be secured to the reception members  22  by way of high-frequency welding. 
     As shown in  FIGS. 4 and 5 , the second embodiment of the present invention is similar to the first embodiment and the differences are that each of the weights  60  is composed of multiple identical weight plates  65 , and the two ends of the axle  40  each have a first surface  42   a , and each of the ridges  61  has a tubular portion  63  to which the axle  40  is connected. Each tubular portion  63  has a second surface  64   a  which is matched with the first surface  42   a  when the axle  40  is inserted into the tubular portion  63 . Therefore, the users can choose desired number of the weight plates  65 . After use, multiple tubular portions or washers (not shown) can be mounted to the axle  40  to secure and position the weight plates  65  on the axle  40 . In this embodiment, the number of the weight plates  65  is six. 
     As shown in  FIG. 6 , the third embodiment of the present invention is similar to the first embodiment and the difference is that the weights  60  can be made to include different weight for the users to choose. 
     When the user holds the bar  20  and operates the dumbbell, the two weights  60  in the spaces  25  are rotated about the axle  40  as shown in  FIG. 7 . The rotation of the two weights  60  generates eccentric force to swing the dumbbell and the swinging action is transferred to the user&#39;s body so that the muscles of the user&#39;s body slightly shake and are exercised. There are several ways to operate the dumbbell as shown in  FIGS. 8 to 11 . The anchor-like weight bodies  62  generate larger eccentric force and train the user to keep balance. 
     As shown in  FIG. 8 , the user holds the bar  20  by one hand to arrange the dumbbell horizontally and the hand holding the dumbbell move right and left or back and forth repeatedly to let the weights  60  to rotate. 
     As shown in  FIG. 9 , the user holds the bar  20  by one hand to arrange the dumbbell upright and the hand holding the dumbbell move right and left or back and forth repeatedly to let the weights  60  to rotate. 
     As shown in  FIG. 10 , the user holds the two bars  20  by two hands and 
     arranges the dumbbells upright, and the hands holding the dumbbells move right and left or back and forth repeatedly to let the weights  60  to rotate. 
     As shown in  FIG. 11 , the user holds the two covers  90  by two hands and two hands operate the dumbbells right and left or back and forth repeatedly to let the weights  60  to rotate. 
     While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.