Abstract:
A hand weight with a central grip area and contoured opposing weight portions at the ends so as to convey a “Z”-shaped profile. The asymmetry of the hand weight results in a shape that is more open to accommodate a larger range of hand sizes and to more comfortably fit into the hand for a variety of holds. The shape of the end portions also results in an overall shape that is less obstructive of movements since it has a narrower profile when rotated appropriately. One of the ends is configured with a flat section to enable the weight to be positively and stably set on a flat surface and prevent rolling.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to exercise equipment and more particularly, to a hand weight for general fitness use providing resistance to movement. 
     2. Background of the Invention 
     Hand weights are used to provide weight based resistance to movement to increase the intensity of exercise. Hand weights are used in strength building, toning, shaping and firming exercises, as well as to increase the cardiovascular intensity of running or walking. Activities such as weight training, aerobics, toning and any fitness instruction, whether group or personal, may require weight. Fixed weight hand weights range from one-half pound up to 20 pounds or more for a set, generally in half pound or one pound increments. For toning, sculpting and firming exercises, three, five and eight pound hand weights are commonly used. Whatever the weight, hand weights typically have a center bar with cylindrical weights at the ends to provide an H-shaped profile. Some have weights at the ends which are polygonal in cross-section. The conventional shape of hand weights reduces the effective gripping area of the center bar, and the protruding weights at the ends of the bar can obstruct free movement during exercise. 
     As expected of a generally cylindrical shape, a conventional hand weight is symmetrical with respect to a vertical plane extending through a center line, about a horizontal plane extending through a center line, and symmetrical about a longitudinal axis. The longitudinal axis of a conventional hand weight at rest typically coincides with a horizontal axis. 
     One of the objects of the invention is to provide a hand weight that provides an increased effective gripping area to accommodate a larger range of hand sizes. Another one of the objects of the invention is to provide a hand weight with a shape that is more open and less obstructive than traditional weights. 
     Conventional cylindrical hand weights also tend to roll around easily and increase the possibility of mishaps from the equipment which can lead to injury. Yet another object of the invention is to provide a hand weight designed to prevent accidental rolling and potential injury. 
     SUMMARY 
     In accordance with the present invention, a hand weight has a central grip area and weight portions at the ends but is asymmetrical with respect to both horizontal and vertical planes, and a longitudinal axis. Each end is flared out and its contours extend beyond the central grip area only on one side. The two ends are flared and contoured in opposite directions so as to convey a “Z”-shaped profile to the weight. The asymmetry of the hand weight results in a shape that is more open to accommodate a larger range of hand sizes. The effective gripping area of the weight extends further than the corresponding area of a conventional weight with an H-shaped profile. In contrast to conventional hand weights, the longitudinal axis of the hand weight of the present invention is angled with respect to the horizontal. The central grip portion of the hand weight is overlaid with material to enhance the grip and reduce the likelihood of slipping when wet. 
     The asymmetry and the shape of the end portions also results in an overall shape that is less obstructive of movements since it has a narrower profile when rotated appropriately. This is especially advantageous for toning and firming exercises where stability and form are important, and in which the hand weight is held close and passes close to the body during repetitions. 
     In addition to the advantages of the asymmetrical design when the hand weight is gripped in the traditional way, i.e., generally parallel to the floor, the present invention also provides a more comfortable and ergonomic feel when the hand weight is held in other ways. For example, for some exercises, it is desired to hold the hand weight generally perpendicular to the floor by ringing the forefinger and thumb and hanging the weight from that ring such that the flared end portion of the weight rests mostly on just those two fingers. The smoothly contoured, asymmetrical end portions more comfortably fit within the user&#39;s hand when the weight is held in this manner as compared to typical cylindrically shaped weights. The same holds true with regard to other ways of gripping the hand weight. 
     To ensure that the hand weight does not accidentally roll, one of the ends is configured with a flat section to enable the weight to be positively and stably set on a flat surface. 
     Other configurations, features and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the following claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views. In the drawings: 
         FIG. 1  is a side elevational view of a hand weight in accordance with the present invention. 
         FIG. 2  is a top plan view thereof. 
         FIG. 3  is an end elevational view thereof. 
         FIG. 4  is a cross-sectional view taken along line  4 - 4  of  FIG. 1 . 
         FIG. 5  is a side elevational view like  FIG. 1  marked with reference lines and planes. 
         FIG. 6  is a top plan view like  FIG. 2  marked with reference lines and planes. 
         FIG. 7  is an end elevational view like  FIG. 3  marked with reference lines and planes. 
         FIG. 8  is an elevational view of a conventional cylindrical hand weight. 
         FIG. 9  is an end elevational view of a conventional cylindrical hand weight. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-7 , hand weight  10  comprises a central grip area  12  and integrally formed weight portions  14 ,  16  at the ends. For clarity of description various directional adjectives such as “top” and “bottom” and “left” and “right” will be used herein with respect to the orientation of hand weight  10  as illustrated in the drawings. It will be understood that these adjectives refer to the hand weight at rest on a stable surface as illustrated, and may not apply to the hand weight&#39;s orientation while being used. The x, y and z reference lines and planes marked in  FIGS. 4-7  also refer to the illustrated orientation, although the longitudinal axis L of the body of hand weight  10  is a self-contained reference regardless of orientation. 
     Top and bottom surfaces of central grip area  12  are provided with grip enhancing pads  18 . Weight portions  14 ,  16  are formed to protrude on opposing sides of central grip area  12  such that hand weight  10  has a “Z”-shaped profile,  FIG. 1 . Weight portion  14  protrudes downward in  FIG. 1  from central grip area  12 , and weight portion  16  protrudes upward. The protrusion each have a tip  14   a ,  16   a  and a seat  14   b ,  16   b . Tips  14   a  and  16   a  extend outward from central grip area  12  while seats  14   b  and  16   b  are flush with central grip area  12 . A view of end portion  16  from the end,  FIG. 3 , shows that tip  16   a  is narrower in cross-section than seat  16   b  thereby lending a generally triangular shape to end portion  16 . End portion  14  is similarly shaped. 
     Because tips  14   a  and  16   a  are formed on opposing sides of the hand weight, when hand weight  10  is set on a flat surface as illustrated, tip  14   a  and seat  16   b  face downward and contact the surface. For convenience of description this will be referred to as the “rest” position. Longitudinal axis L of hand weight  10  extends through the comers of seats  14   b  and  16   b , as illustrated in  FIG. 5 , and is therefore angled relative to the horizontal axis x at an angle θ. Angle θ is preferably greater than 1°, and is approximately 9° in the illustrated embodiment. Each end surface of hand weight  10  extending along line V in  FIG. 5  is also angled relative to the x axis at an angle α which is preferably greater than 90°, and is approximately 116° in the illustrated embodiment. This of course means that the end surfaces are also angled from the vertical y axis. The opposing relationship of the protrusions and the resulting angled body of hand weight  10  with respect to the horizontal lends the present invention the “Z”-shaped profile. 
     Typical prior art hand weights have weight protrusions that are equally distributed at the ends of the central bar to lend an “H”-shaped profile to the weight at rest,  FIGS. 8 and 9 . Since the larger cylinders of the weighted ends are axially aligned with the cylinder of the central bar, a longitudinal axis A is horizontal at rest and therefore coincides with or is parallel to the x-axis. The end surfaces of the weight protrusions of the prior art weight are vertical. The axially aligned cylinders of the prior art weights are also symmetrical about the x-axis, i.e., the overall shape is a surface of revolution since the surface can be generated by rotating a two-dimensional curve about the x-axis. In the illustrated example, the two-dimensional curve would be the top half of the “H”-shape in  FIG. 8  rotated about the x-axis. In mathematical terms, for all surfaces of revolution, the resulting surface is said to have azimuthal symmetry. 
     In contrast, hand weight  10  has a more complex shape and is azimuthally asymmetric as there is no two-dimensional curve that could be rotated about an axis to result in this shape. Compared to the traditional dumbbell shape, the opposing protrusion configuration of the present invention provides more clearance for certain movements, particularly those close to the body. 
     In addition to azimuthal asymmetry, and in contrast to prior art weights, hand weight  10  is asymmetric with respect to other references. One way of describing the contrasts in symmetry is with respect to various planes defined by the xyz axes through a geometric centerpoint C of both the present invention and the prior art weight. The prior art weight,  FIGS. 8-9 , is symmetric with respect to all three planes: with respect to the xy plane through centerpoint C, with respect to the xz plane through centerpoint C, and the yz plane through centerpoint C. In contrast, hand weight  10  of the present invention is symmetric only with respect to the xy plane through centerpoint C. This symmetry is best seen in  FIG. 6 . Otherwise, hand weight is asymmetric with respect to the xz plane and the yz plane through centerpoint C. As noted above, this asymmetry is due to the opposing configuration of the weight protrusions and the angled body of the weight. In summary, hand weight  10  is asymmetrical with respect to all references except for the xy plane. Asymmetry with respect to the horizontal x axis, the longitudinal L axis, the xz plane and the yz plane provide result in the unique shape of hand weight  10 . This resulting shape provides the needed weight resistance with an open design that accommodates a larger range of hand sizes and added clearance and comfort. 
     As seen in the cross-sectional view,  FIG. 4 , the center of the central grip portion has a generally circular shape. As described herein protrusions  14 ,  16  have generally triangular end profiles with the end surfaces canted at an angle α with respect to the horizontal. All of the transition surfaces between the central grip area and the weight protrusions are contoured to lend hand weight  10  a sleek and smooth overall appearance. These surface contours also provide a comfortable, ergonomic feel to the hand weight for any manner of hold and use. This is particularly true of holds other than a traditional grasp around the central grip area, such as when the user holds only an end either in the palm of the hand or hanging from ringed thumb and forefinger. 
     In keeping with the contours of the weight, each grip enhancing pad  18  has a contoured outer boundary as seen in  FIG. 6 . Hand weight  10  is formed with recesses for attaching pads  18  such that the outer surfaces are substantially flush and smooth. Pads  18  can be made of an array of thermoplastic resins. Attachment can be done in any suitable manner. The material for hand weight  10  is preferably a cast metal, but an iron or other material filled plastic can also be used as the core material. The surface can be polished, textured or treated with coatings or colors. 
     As recounted in the Background section, prior art cylindrical hand weights are prone to rolling and increasing the chance of injury. The asymmetric shape of hand weight  10  in and of itself prevents the likelihood of the weight rolling around. To positively set hand weight  10  on a flat surface, one of the tips is provided with a flattened area. As best seen in  FIG. 1 , tip  14   a  has a flattened area  20  which together with seat  16   b  enables hand weight  10  to be set stably on a flat surface. 
     While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that may more embodiments and implementations are possible that are within the scope of the invention.