Abstract:
Dumbbells that interconnect or stack upon each other without the need for a storage rack. The dumbbells include a top engagement member and a bottom engagement member, where the top engagement member is configured and shaped to accommodate and mate with the bottom engagement member. The top engagement member is preferably a protrusion having a generally flat face and a sloping sidewall, and the bottom engagement member is preferably a recess having a generally flat base and a sloping sidewall. The dumbbells may interconnect or stack flush with one another to form a column.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 61/028,202 filed on Feb. 13, 2008, the entire contents of which is expressly incorporated by reference herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to the field of exercise and weight training equipment, and more specifically, to dumbbells. 
       BACKGROUND OF THE INVENTION 
       [0003]    Dumbbells are commonly used for exercise and weight training in health clubs and home gyms. Small dumbbells, typically no more than ten pounds each, have generally spherical or cylindrical ends connected by a narrower handgrip portion. These dumbbells are often stored in horizontal or vertical racks, where the racks include saddles or similar structures for receiving the generally spherical or cylindrical ends. While these racks may be appropriate for gyms and health clubs, where large numbers of dumbbells are stored and displayed, they are typically unwieldy, expensive and unnecessary for a homeowner or retail location that needs to store or display a smaller number of dumbbells. As an alternative to a costly, space-consuming rack, the homeowner or retail store may simply lay the dumbbells on the floor. Because of their generally spherical ends, however, the dumbbells may roll, creating a potentially dangerous condition. There is a need in the art, therefore, for improved methods of storing dumbbells safely and without the need for a storage rack. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention provides a dumbbell comprising two enlarged weight members at either end of a more narrow handle, where each of the weight members comprises a top surface with a top engagement member and a bottom surface with a bottom engagement member, and where the top engagement member and bottom engagement member have complementary shapes, enabling the top engagement member to accommodate and mate with the bottom engagement member of a second dumbbell. In a preferred embodiment, the weight members are generally cylindrical or spherical. 
         [0005]    In preferred embodiments the top engagement member is a protrusion located at the approximate center of the top surface of each of the weight members and the bottom engagement member is a recess located at the approximate center of the bottom surface of each of the weight members. In a preferred embodiment, the top surface, the bottom surface, the protrusion and the recess are all generally elliptical, although in other embodiments, all may be generally circular or have any other regular or irregular shape. In a preferred embodiment, the protrusion comprises a generally flat face, and the recess comprises a generally flat base, although in other embodiments, the protrusion may comprise a generally convex face, and the recess may comprise a generally concave base. 
         [0006]    In additional embodiments, the present invention provides a pair of dumbbells, where each dumbbell comprises two enlarged weight members at either end of a handle, where each of the weight members comprises a top surface with a first engagement member and a bottom surface with a complementary second engagement member, and where the first engagement member of the first dumbbell accommodates and mates with the second engagement member of the second dumbbell, such that the first dumbbell is capable of stacking horizontally upon the second dumbbell. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. 
           [0008]      FIG. 1  is a perspective view of a top and front face of a dumbbell of according to the present invention; 
           [0009]      FIG. 2A  is a front view of the dumbbell of  FIG. 1 ; 
           [0010]      FIG. 2B  is a front view of the top engagement member of the dumbbell of  FIG. 1 ; 
           [0011]      FIG. 2C  is a front view of the bottom engagement member of the dumbbell of  FIG. 1 ; 
           [0012]      FIG. 3  is a top view of the dumbbell of  FIG. 1 ; 
           [0013]      FIG. 4  is a perspective view of a bottom and front face of the dumbbell of  FIG. 1 ; 
           [0014]      FIG. 5  is a bottom view of the dumbbell of  FIG. 1 ; 
           [0015]      FIG. 6  is a perspective view of a top and front face of a pair of interconnecting or stackable dumbbells according to the present invention; 
           [0016]      FIG. 7  is a front view of the pair of interconnecting or stackable dumbbells of  FIG. 6 ; 
           [0017]      FIG. 8  is a perspective view of a bottom and front face of the pair of interconnecting or stackable dumbbells of  FIG. 6 ; 
           [0018]      FIG. 9A  is a top view of a pair of interconnecting or stackable dumbbells according to the present invention; 
           [0019]      FIG. 9B  is a side outline view of the pair of interconnecting or stackable dumbbells of  FIG. 9A , from the perspective of section A-A; and 
           [0020]      FIG. 9C  is a detail view of the interconnection of the pair of interconnecting or stackable dumbbells shown in  FIG. 9B . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    The disclosed invention provides an interconnecting or stackable dumbbell, such that a plurality of interconnecting or stackable dumbbells may be arranged in a column without the use of a storage rack. The structure of the dumbbell of the disclosed invention also functions to prevent an individual dumbbell from rolling and creating a potentially dangerous condition. Each of the interconnecting or stackable dumbbells of the disclosed invention is configured with complementary top and bottom engagement members, such that the top engagement member of a first dumbbell accommodates and mates with the bottom engagement member of a second dumbbell, and the top engagement member of the second dumbbell accommodates and mates with the bottom engagement member of a third dumbbell, and so on, to form a column. Note that the dumbbells are not limited to any particular weight, and dumbbells of different weights may be stacked together. 
         [0022]      FIG. 1  is a perspective view of a top and front face of a preferred embodiment of the dumbbell  10  of the present invention,  FIG. 2A  is a front view of the dumbbell  10  shown in  FIG. 1 , and  FIG. 3  is a top view of the dumbbell  10  shown in  FIG. 1 . 
         [0023]    With further reference to  FIG. 1 , in a preferred embodiment, dumbbell  10  is a semi-rigid, hollow plastic vessel that is preferably filled with a mixture of sand, iron chips and concrete, and permanently sealed with plug  12  after filling. The weight of dumbbell  10  can be adjusted by varying the substance and/or volume of material used to fill the dumbbell  10 . In alternate embodiments, dumbbell  10  can be filled with a mixture of sand and iron chips, ball bearings, or other relatively flowing substance. In additional embodiments, plug  12  may be removable by the user, and the dumbbell  10  may be filled with water or sand. 
         [0024]    As shown in  FIGS. 1 ,  2 A, and  3 , in a preferred embodiment, dumbbell  10  includes two generally cylindrical weight members  11  connected by a narrower handle grip portion  13 . Each of the weight members  11  includes a top engagement member  16  positioned on a top surface  15  of weight member  11 . 
         [0025]      FIG. 2B  is a front view of the top engagement member  16  of dumbbell  10 . As shown in  FIGS. 1 ,  2 A,  2 B, and  3 , in a preferred embodiment, top engagement member  16  is a protrusion comprising a generally flat face  18  and a sidewall  17  between the face  18  and the top surface  15 . In alternate embodiments, face  18  may have a generally convex shape. 
         [0026]    As shown in  FIG. 3 , top surface  15 , and top engagement member  16  are preferably generally elliptical in shape, although in other embodiments, top surface  15  and top engagement member  16  may have other shapes, including but not limited to generally circular, rectangular, square, or any other regular or irregular shape. Further, as shown in  FIGS. 1 ,  2 A, and  3 , top engagement member  16  is preferably located at the approximate center of top surface  15 . 
         [0027]    With reference to  FIGS. 2A and 2B , in a preferred embodiment, sidewall  17  slopes such that the diameter of top engagement member  16  at face  18  is smaller than the diameter of top engagement member  16  at top surface  15 . In alternate embodiments, sidewall  17  may be generally vertical relative to face  18  and top surface  15 . 
         [0028]      FIG. 4  is a perspective view of a bottom and front face of the dumbbell  10  of the present invention, and  FIG. 5  is a bottom view of the dumbbell  10  shown in  FIG. 1 . 
         [0029]    As shown in  FIGS. 4 and 5 , in a preferred embodiment, each of the weight members  11  of dumbbell  10  includes a bottom engagement member  26  positioned on a bottom surface  25  of weight member  11 . 
         [0030]      FIG. 2C  is a front view of the bottom engagement member  26 . As shown in  FIGS. 2A ,  2 C,  4 , and  5 , in a preferred embodiment, bottom engagement member  26  is a recess comprising a generally flat base  28  and a sidewall  27  located between the base  28  and the bottom surface  25 . Bottom engagement member  26  and top engagement member  16  have complementary shapes, enabling top engagement member  16  to accommodate and mate with bottom engagement member  26 . In alternate embodiments, where face  18  of top engagement member  16  has a generally convex shape, base  28  of bottom engagement member  26  has a generally concave shape, to accommodate and mate with top engagement member  16 . 
         [0031]    As shown in  FIG. 5 , bottom surface  25 , and bottom engagement member  26  are preferably generally elliptical in shape, to accommodate and mate with top engagement member  16 . In other embodiments, bottom surface  25  and bottom engagement member  26  have the same shapes as top surface  15  and top engagement member  16 , respectively, including but not limited to generally circular, rectangular, square, or any other regular or irregular shape, such that bottom engagement member  26  accommodates and mates with top engagement member  16 . Further, as shown in  FIGS. 4 and 5 , bottom engagement member  26  is preferably located at the approximate center of bottom surface  25 . 
         [0032]    With reference to  FIGS. 2A and 2C , in a preferred embodiment, sidewall  27  slopes such that the diameter of bottom engagement member  26  at base  28  is smaller than the diameter of bottom engagement member  26  at bottom surface  25 . In alternate embodiments, sidewall  27  may be generally vertical relative to base  28  and bottom surface  25 . 
         [0033]      FIG. 6  is a perspective view of a top and front face of a pair of interconnecting or stackable dumbbells  20  according to a preferred embodiment of the invention.  FIG. 7  is a front view of the pair of interconnecting or stackable dumbbells  20  shown in  FIG. 6 , and  FIG. 8  is a perspective view of a bottom and front face of the pair of interconnecting or stackable dumbbells shown in  FIG. 6 . Each of the dumbbells  10  in the pair of dumbbells  20  includes a top engagement member  16  and bottom engagement member  26 , as described above. As shown in  FIGS. 9A ,  9 B and  9 C, top engagement member  16  is configured to accommodate and mate with bottom engagement member  26 , such that one dumbbell  10  interconnects with or stacks upon a second dumbbell  10 . 
         [0034]    The claims should not be read as limited to the described order or elements unless stated to that effect. Therefore, all embodiments that come within the scope and spirit of the following claims and equivalents thereto are claimed as the invention.