Abstract:
A device for exercising the abdominal and other core muscles of a user comprises a rotatable base having a central opening therein, and a bar removably insertable into the opening. The bar may comprise two or more separable segments and may have provide for the attachment and removal of weights to provide resistance to a user. Also disclosed is a method of exercising using such a device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application incorporates by reference and claims the priority of U.S. provisional patent application No. 61/060,300, filed Jun. 10, 2008. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to the field of exercise devices, especially exercise devices for the abdominal and other core muscles. 
       BACKGROUND OF THE INVENTION 
       [0003]    In the field of exercise devices, inventors have developed devices for use in exercising a user&#39;s abdominal and other core muscles. Inventors have employed various devices that allow the user to exercise the abdominal and other core muscles through relative motion of the user&#39;s upper body and lower body, including bending motions and twisting motions. 
         [0004]    Of the mechanisms used to allow exercise by a twisting motion, some mechanisms provide a rotating base on which the user may stand and twist the upper body and lower body relative to each other from side to side. Some such mechanisms provide fixed handles that may be gripped by the user while standing on a rotating base, as disclosed in U.S. Pat. No. 7,118,519 to Slowinski, U.S. Pat. No. 4,305,579 to Rice, and U.S. Pat. No. 5,433,690 to Gilman. A contrary approach is disclosed in U.S. Pat. No. 4,249,727 to Dehan, which discloses a mechanism in which the user stands on a fixed base and moves a bar mounted to the base in a ball-and-socket fitting so as to provide resistance against the user when the user attempts to move the bar. In addition, an exercise device has been sold consisting of a rotatable base on which the user may stand and rotate the user&#39;s upper body relative to the upper body, but with no handle or bar for gripping by the user. 
       SUMMARY OF THE INVENTION 
       [0005]    The exercise device disclosed herein is an exercise device that works the abdominal and other core muscles, including the lower back and obliques. The device includes two principal parts: a rotatable base having a central opening, and a bar removably insertable into the central opening. The user exercises by standing on the rotatable base and inserting the bar into the central opening, which is sized to accept the bar. The user twists so that his or her upper body moves relative to his or her lower body; while doing so with the bar inserted in the central opening, the user may use the bar to aid balance or to aid the relative twisting of the upper and lower body. The user may also remove the bar from the central aperture and use movement while carrying the weight of the bar to provide additional resistance for exercising the user&#39;s upper body, including the rear deltoids, upper back, and legs by providing additional weight to resist the user&#39;s movements. 
         [0006]    Optionally the bar may include a plurality of segments that may be connected or separated as needed for various exercises. One example of such a bar may include a first connectable bar segment and a second connectable bar segment that are releasably coupled and thus may be separated. The lengths and weights of the bar segments may be essentially identical or may differ significantly. Bar segments that are relatively close in length and weight are preferred for allowing the user to hold one bar segment in each hand; bar segments that differ significantly in length or weight allow the user to use only one bar segment or the other to provide a desired weight and length for exercising. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0007]    The invention is best understood from the following detailed description when read with the accompanying drawings. 
           [0008]      FIG. 1  shows a base and a bar removably inserted into the central aperture according to an illustrative embodiment of the invention. 
           [0009]      FIG. 2  shows an assembly view of a base and a bar according to an illustrative embodiment of the invention. 
           [0010]      FIG. 3A  shows a bar according to an illustrative embodiment of the invention in a connected state, and  FIG. 3B  shows the same bar in a disconnected state. 
           [0011]      FIG. 4  shows a base and a bar removably inserted into the central aperture according to an illustrative embodiment of the invention. 
           [0012]      FIG. 5  is a partial cross-sectional view of the bar shown in  FIG. 4 . 
           [0013]      FIG. 6  shows an illustrative embodiment of a base according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    An illustrative embodiment of the exercise device  10  according to the invention includes two principal parts, as shown in  FIG. 1  and  FIG. 2 : a rotatable base  20  having a central opening  23 , and a bar  50  equipped with hand grips  21 A and  21 B (preferably of rubber or other elastic material) removably insertable into the central opening. The rotatable base  20  includes a lower base section  22  that rests upon an exercise surface. The rotatable base  20  also includes an upper base section  24  rotatably mounted on the lower base section  22 . The rotation of the upper base may be provided by conventional ball bearings captured in races. 
         [0015]    Preferably the lower base section  22  and the upper base section  24  are round, generally flat pieces; and in some embodiments the upper base section  24  is a round, generally flat piece about 41 to 46 centimeters or about 16 to 18 inches in diameter, with the height of the base being about 3.8 cm or about 1.5 inches. The rotatable base  20  has a central opening  23  in its upper surface with a bar releasably inserted therein. The bar  50  fits within the opening  23  so that the bar may be moved relative the rotatable base  20 . The bar  50  or the opening  23  (or both) may be fitted with a rubber or other conformable surface; this may take the form of a thimble-shaped insert or boot  30 , preferably of rubber or other elastic material, placed within the opening  23 . The opening  23  is formed in the upper surface of the upper base section  24  and is a depression of sufficient depth to aid the user in maintaining the position of the bar  50  in the depression if so desired for a particular exercise. The upper base section  24  may be mounted on the lower base section  22  by means of conventional bearings and races and is secured to the lower base section by bolt  34  and nut  32 , or alternatively means of clips or screws, to prevent the upper base section  24  from separating from the lower base section  22 . In the embodiment illustrated in  FIG. 1  and  FIG. 2 , the bolt  34  and nut  32  are augmented by washer  36  and spacer  38 . Optionally bearings and races are supported by frame  26 . Optionally lower base section  22  has a ribbed pattern and includes circular channels  23 A,  23 B, and  23 C in which bearings from frame  26  will run. Optionally the lower base section  22  may include a support frame for supporting a plurality of bearings for rotatably supporting the upper base section on the lower base section. Optionally the top surface of base  20  is topped by contoured rubber pad  28 . 
         [0016]    The user may exercise by placing the rotatable base  20  on an exercise surface, standing on the rotatable base  20 , and inserting the bar  50  into the central opening  23 . The user twists his or her upper body and lower body relative to one another; while doing so with the bar  50  inserted in the central opening  23 , the user may use the bar  50  to aid balance or to aid the relative twisting of the upper and lower body. The user may also remove the bar  50  from the central aperture  23  and use movement of the bar  50  to provide additional exercise for user&#39;s upper body. 
         [0017]    Optionally, as shown in  FIGS. 3A and 3B , a bar  90  may comprise a first releasably coupled bar segment  92  and a second releasably coupled bar segment  94 , with the coupling device comprising a spring-loaded protruding button  96  that mates with an aperture  98  to fasten the two segments together. Also optionally, the bar  90  may include hand grips  91 A and  91 B. The bar segments  92  and  94  may in other embodiments be connected by other means. Optionally, as shown in  FIG. 4  and  FIG. 5 , male threaded coupling  76  at one end bar segment  72  is fitted to a corresponding threaded coupling  78  of bar segment  74 . Optionally and again as shown in  FIG. 4  and  FIG. 5 , the bar  70  may include additional weights  80  and  82 , which are circular disks each having a central aperture allowing them to be slipped over male threaded coupling  76  and secured between bar segments  72  and  74 . The lengths and weights of the bar segments  72  and  74  may be essentially identical or may differ significantly. For example, each bar segment may be about 76 cm to 100 cm or about 2.5 to 3 feet in length, with a total assembled bar length of about 150 to 200 cm or about 5 to 6 feet. A first bar segment may weigh about 0.9 kilograms or 2 pounds and be supplied with a second bar segment weighting about 2.3 kg or about 5 pounds. Bar segments that are relatively close in length and weight are preferred for allowing the user to hold one bar segment in each hand; bar segments that differ significantly in length or weight allow the user to use only one bar segment or the other to provide a desired weight and length for exercising. 
         [0018]    Optionally the device may include a conventional timer or calorie counter of the type that calculates a number of calories burned based on the user&#39;s weight and elapsed exercise time. Optionally, the device may include a counter that displays the number of “twists” or movements completed by the user. If a timer, calorie counter, or other counter is provided, a display  65 , as shown in  FIG. 4 , or a display  125 , as shown in  FIG. 6 , may be mounted on the base or elsewhere. 
         [0019]    Preferably the upper base section  22  and the lower base section  24  are constructed from aluminum, plastic, or other sturdy material, with the upper surface of the upper section having a surface providing some traction for the feet of the user, such as provided by use of a friction material such as rubber pad  28  shown in  FIG. 1  and  FIG. 2 , or by use of protrusions, depressions, grooves, as shown in  FIG. 6 , or other contours formed on the surface. 
         [0020]    An alternative embodiment of a base  120  is shown in  FIG. 6 . In that embodiment, opening  123  could have a depth of less than 1.3 cm, or about 0.5 inches. 
         [0021]    While the invention has been described by illustrative embodiments, additional advantages and modifications will occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to specific details shown and described herein. Modifications may be made without departing from the spirit and scope of the invention. For example, modifications may be made to the weight or length of bar segments, to the size of the rotatable base sections; to the mechanism used to support the upper base section on the lower base section or to couple those two sections together; and to the materials of construction. Accordingly, it is intended that the invention not be limited to the specific illustrative embodiments, but be interpreted within the full spirit and scope of the appended claims and their equivalents.