Abstract:
An exercise barbell comprises a pair of rings connected by a pair of curved bars. The rings rotatably support handle members. Extensions of the bar on the exterior of the two rings support crescent-shaped weights which conform to the outer diameter of the ring and to one another. The weights are relatively flat so the entire apparatus lies in a single plane. A straight bar connecting the opposed sides of the two rings supports a sliding weight which may be moved to one side of the bar or the other to allow asymmetrical exercises.

Description:
RELATED APPLICATION 
   This application claims priority of U.S. Provisional Patent Application Ser. No. 60/547,590 filed Feb. 25, 2004, and U.S. Provisional Patent Application Ser. No. 60/564,671, filed Apr. 21, 2004 which are incorporated herein by reference. 

   FIELD OF THE INVENTION 
   This invention relates to a barbell for exercise purposes such as weightlifting and more particularly to such exercise apparatus which includes means for supporting a number of weights on both ends of the apparatus and includes rotatable handgrips, a sliding counterweight supported on a central bar, and rectangular curved weights which may be supported on the ends of the apparatus. 
   BACKGROUND OF THE INVENTION 
   Barbells are commonly used to perform a variety of exercises including curling and weightlifting, and it has been proposed to provide rotating handgrips for use in such apparatus so that the user&#39;s grip may be accommodated in any position and is not restricted to an angle parallel to the axis of the device. In particular, U.S. Pat. Nos. 3,384,370; 4,618,183; 4,629,184; 5,334,113; 6,022,300 and Re. 33,218 all disclose barbell arrangements having handgrips which are rotatably supported so that their angle relative to the bar may be adjusted. 
   One problem associated with prior art barbells resides in the fact that if the bar is to resist the bending forces imposed when the bar is lifted with weights on the end, it must be formed of a strong and relatively heavy material. The weight of this bar imposes a minimum weight on the exercise apparatus even without any end weights. Another problem is that the use of disk-like end weights creates problems in storage and transportation of a barbell with the associated weights. 
   Another problem associated with conventional barbells, with or without rotatable handgrips, is that it is inconvenient and awkward to provide a greater weight on one end than the other in order to impose asymmetrical stresses on the user&#39;s muscles during exercise. 
   SUMMARY OF THE INVENTION 
   These problems are addressed by our invention, which is disclosed in detail subsequently, and which provides a weightlifting apparatus including a pair of spaced outer rings which support rotatable handgrips and, in a preferred embodiment of the invention, are connected to one another by a supporting structure constituting a pair of intermediate bars each connected at its opposite ends to the opposed edges of the two rings which support the rotatable handles. The connecting bars are preferably curved and joined to the rings so as to present their curved surfaces externally of the barbell and their opposed concave surfaces facing one another. These connecting bars do not extend beyond lines tangent to the two handle supporting rings so that the bars will not hit the user&#39;s body during exercise. The connecting bars are preferably formed of tubular steel so that they may have a lower weight collectively than the single conventional longitudinal bar of a barbell. While the connecting bars of the present invention are preferably curved, in other embodiments of the invention they could be formed of straight sections, sections with an intermediate bend projecting outwardly or elliptical sections. 
   Each of the outer rings rotatably supports an inner ring having an outer diameter complementary to the inner diameter of the outer ring. The bearing surface between the inner diameter of the outer ring and the outer diameter of the inner ring may either be frictional or may be equipped with anti-friction bearings such as ball bearings, roller bearings, or the like. Alternatively, low friction materials such as nylon may be coated on the contacting surfaces. Each inner ring is bisected with a grip handle so that the inner ring may be rotated to any convenient position within the outer ring by forces exerted on the handles. 
   This construction provides a very strong, lightweight, rigid exercise apparatus. 
   In embodiments of the invention which will be subsequently disclosed in detail, the supporting structure for the rings includes a central straight bar, preferably formed of tubing, connecting the two rings at their points of closest separation, midway between the two outer connecting bars. A relatively small weight is slidingly supported on this central bar so that when the bar is tipped in one vertical direction or the other, the weight will slide toward the downward end. Thus the bar may be weighted in an asymmetrical manner so that the work exerted by the exerciser is greater on the side with the weight than the opposite side. This allows the exerciser to provide higher forces to one muscle group than another and allows shifting of the weights between exercises. Thus, asymmetrical stresses may be imposed to exercise the oblique muscles and related groups. 
   Prior art barbells typically employ disk-shaped weights. In one embodiment of the present invention the weights to be secured on supporting extensions on the outer sides of the two outer rings are elongated rectangles, preferably crescent-shaped and curved to a radius similar to the rings so that the innermost weight can rest against the ring and the outermost weights curve around the inner weights. The rectangles extend parallel to the rings to give the entire bar, with the associated weights, a narrow profile for storage or transportation. 
   The exercise device of the present invention is useful for a wide variety of exercises. In particular:
         1. The biceps may be exercised by lifting and rotating with the handle parallel to the central axis;   2. The triceps may be exercised by lifting and rotating with the handles perpendicular to the central axis;   3. The trapezius muscles may be exercised with grips on the end of either curved connecting bar;   4. Pushups may be performed with hands on the handle perpendicular to the central axis; and   5. A normal bench press may be performed with the correct support angles safely because the double connecting bar lies on the chest rather than creating the danger of a single conventional bar hitting the thorax.       

   It is contemplated that a version of the present invention may be produced without extending weight supporting sections on the outer sides of the two rings. This version would provide a single weight for exercise and would be useful for lower strength individuals, and some females, as well as being more compact for storage and transportation than the version with the extending weight supporting sections. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects, advantages and applications of the present invention will be made apparent by the following detailed description of preferred embodiments of the invention. The description makes reference to the accompany drawings in which: 
       FIG. 1  is a perspective view of a person using a first embodiment of the barbell for exercising, illustrating, in phantom lines, the alternative positions for imposing asymmetrical forces on the muscles; 
       FIG. 2  is a top perspective view of the preferred embodiment of our invention carrying several crescent-shaped weights; 
       FIG. 3  is a fragmentary perspective view of the embodiment of  FIG. 2  supporting conventional disc-shaped weights; 
       FIG. 4  is an exploded view of a preferred embodiment of our invention; and 
       FIG. 5  is a perspective view of an alternative embodiment of the invention without end bars for supporting additional weights. 
       FIG. 6  is a perspective view of an alternative embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1–4 , a preferred embodiment of our exercise apparatus comprises a pair of outer rings  10  and  12 , preferably formed of tubular steel, aluminum or another rigid material. The rings  10  each have a number of tapped holes  14 , formed in regular intervals about their perimeter for securing inner rotatable rings in a manner which will be subsequently described. 
   The two outer rings  10  and  12  are joined to one another by a pair of curved, tubular, connecting bars  16  and  18 . The ends of the bars are welded, or otherwise secured to spaced points on the perimeter of the outer rings  10  and  12 . A straight center bar  20 , which is preferably rectangular in cross-section, extends intermediate the two curved connecting bars  16  and  18  and also has its ends secured to the outer perimeter of the two rings  10  and  12  midway between the points of connection of the bars  16  and  18 . The connecting bar  20  may be solid or tubular. The bars  16 ,  18  and  20  are connected to the rings  10  and  12  so that the rings, as well as their connecting bars, all lie in a common plane. The lengths of the bars  16 ,  18  and  20  are preferably such that the centers of the two rings  10  and  12  are separated by approximately 10–15 inches, which represents a comfortable distance for gripping the exercise apparatus. 
   A pair of inner rings  22  and  24  which have outer diameters slightly smaller than the inner diameters of the rings  10  and  12 , are secured within the outer rings by opposed pairs of retaining plates  28 ,  30 ,  32  and  34 . The retaining plates  28 ,  30 ,  32  and  34  have a number of screw holes  36  formed through their thickness. The retaining rings may be secured to the opposed faces of the outer rings  10  and  12  with screws  31 , to capture the inner rings  22  and  24  between them. Inner rings  22  and  24  make a loose fit within the inner diameters of the outer rings  10  and  12 . Each of the inner rings  22  and  24  has a cylindrical grip member  38  and  40 , preferably with a serrated surface, extending diametrically across the respective ring. 
   A metal weight  42  is slidably supported on the straight connecting bar  20 . The fit is such that it may easily slide from one side to the other, as the bar is appropriately inclined. In  FIG. 1 , the weight  42  is shown at the end toward the right arm of the exerciser  50  and shown in phantom at a position adjacent to his left arm. In the embodiment of  FIGS. 1 through 4 , weight supporting, rectangular cross-section extensions  52  and  54 , are fixed to the outer rings  10  and  12  respectively, at points diametrically opposed to the points where the center connecting bar  20  joins those rings. 
   A plurality of weights may be supported on each extension  52  and  54  in the manner of a conventional barbell.  FIGS. 1 and 3  illustrate crescent-shaped weights formed in accordance with the present invention.  FIG. 3  illustrates several conventional disc-shaped weights  60  secured on a bar end  52  and retained by a conventional spring clip  62 . 
   Another novel aspect of the present invention resides in the use of crescent-shaped weights  64 A,  64 B, and  64 C, rather than the conventional disc-shaped weights  60 . These crescent-shaped weights preferably have a thickness similar to the thickness of outer rings  10  and  12  and have central holes which allow them to be supported on the extensions  52  and  54 . They may be retained with conventional spring slips  62 . When equipped with the crescent-shaped weights, the exercise apparatus has a relatively flat profile and my be conveniently stored or packaged. The crescent-shaped weight  64 A has a concave surface with a diameter that approximates that of the outer ring so it slightly extends around the outer ring. The weights  64 B and  64 C have concave surfaces which allow them to closely nestle the convex surfaces of the larger weights. 
   The crescent-shaped weights provide a number of advantages over conventional weightlifting bars which may be equipped with disc-shaped weights with central holes that fit over an extending bar such as the bar  52  in addition to the resulting compact configuration and ease of storage. Disc-shaped weights tend to rotate during exercise resulting in forces that destabilize the conventional exercises that may be performed by the bar. The crescent-shaped weights lock into one another to prevent rotation. Additionally, the crescent-shaped weights minimize the length of the exercise bar and thus lower force moments which tend to cause the bar to twist during use. Finally, disc-shaped weights tend to make contact with the user&#39;s elbows during many exercises, particularly trapezius pulls involving grabbing the center of the bar with both hands and lifting towards the chin. Since the crescent-shaped bars do not extend out of the plane of the weightlifting apparatus, they do not create such interference. 
   The embodiment of the invention illustrated in  FIG. 5  does not have the weight supporting extensions  52  and  54  which form part of the first embodiment of the invention. Rather, the exercise apparatus simply consists of the rings and their rotatable handles and the associated connecting bars and the sliding weight. 
   In alternative embodiments of the invention, an anti-friction bearing could be used to support the inner rings  22  and  24  within the outer rings  10  and  12 . This might be a ball bearing or a roller bearing. Alternatively, the engaging surfaces of one of the elements could be coated with an anti-friction material. 
   Alternate physical arrangements also might be employed for securing the inner rings  22  and  24  within the outer rings  10  and  12 , as opposed to the retaining plates illustrated in the drawings. 
   The use of connecting bars  16 ,  18  and  20  which are preferably tubular, gives the weightlifting apparatus a rigidity without the weight of conventional barbells. 
   In an alternative embodiment to the invention, the center bar  20  and its supporting sliding weight  42  could be omitted so as to only allow for symmetrical exercises. 
   As illustrated in  FIG. 1 , by inclining the bar in one direction or another, asymmetrical forces would be imposed on the exerciser&#39;s muscles while using the bar for otherwise conventional exercises.