Abstract:
An adjustable jump rope apparatus allows easy and quick adjustment of the jump rope length by inserting and threading the jump rope through grooves around a ball-shaped bearing member, and then attaching the end of the jump rope to the body of the jump rope with a clip. The ball-shaped bearing member is rotatably retained within a hollow handgrip. Undoing the clamp and sliding the rope in either direction allows for a quick and easy jump rope length adjustment. A removable support structure enables the addition/removal of incremented weights to and fixes and supports the weights inside each hollow handgrip, thereby providing a weighted jump rope or even a dumbbell when a jump rope is not attached. Weight distribution is even as the weights extend substantially the entire length of the handgrip. The support structure also simultaneously assists in retaining the ball-shaped bearing member within the handgrip.

Description:
TECHNICAL FIELD 
     The invention generally relates to the field of exercise or sports equipment. More specifically, it relates to a high performance jump rope apparatus whereby adjusting jump rope length, inserting a different jump rope and adding or removing weight is easily and quickly accomplished. 
     BACKGROUND OF THE INVENTION 
     Jumping rope enhances endurance, strength, quickness, coordination and balance. More and more people who enjoy exercising are jumping rope, because it allows maximum conditioning and calorie consumption in a relatively short exercise bout. The natural benefits of jumping rope have become so well known, that fitness clubs offer jump rope conditioning courses to meet the needs of a fast, fun and efficient cardiovascular workout. In fact, jumping rope has become so popular that competitive rope jumping is a sport all to its own. 
     Originally a rope user would use a plain unadorned rope. Such a rope was prone to becoming excessively twisted and was sometimes hard on the hands. Later simple handles were attached to the ends of the jump rope partly to alleviate these problems; however such a design and construction still led to twisting and lagging of the rope in relation to the hands during use due to the fixed connection between the rope and the handle. 
     Eventually, a jump rope having wooden handles and a ball bearing assembly, fit into a recess in each handle, was disclosed in U.S. Pat. No. 4,293,125 to Hinds. The ball bearing assembly was intended to uncouple the rope from the handle to avoid twisting and lagging. However, such structures were generally too expensive, and too difficult to disassemble and replace or repair. Hinds taught using cylinder shaped jump rope handles containing a hemispherical or funnel-shaped socket in which a small ball was movably retained. The rope passed through the center of the small ball, and the rope was then fixed inside the handle by a knot. This design, despite marked improvements in functionality (decreased rope twisting and lagging), had the drawback that adjustment of the jump rope length was cumbersome and time consuming because the device had to be disassembled by pulling the small ball through the rear end of each handle. This delay negatively affects athletes training for maximum aerobic capacity, especially when various length or weighted ropes are necessary to accomplish their training needs optimally. Further, such rope-adjusting difficulties and time delays also hamper jump ropes used in a gym or fitness club setting, as equipment that is too difficult or time consuming to adjust often goes unused. 
     U.S. Pat. No. 4,079,932 to Schuentz also discloses a length adjusting means. Rope adjustment is accomplished by inserting the jump rope tail end through an opening in the jump rope handle and looping the rope back towards the running portion of the rope, and tying the tail to the running portion. U.S. Pat. No. 4,637,606 to Hunn discloses a ring member secured to a bearing on a jump rope handle that is further connected to a hook or eye attached to a jump rope. Various length jump ropes can be attached to the handles ring members, or a jump rope can be permanently fixed at a desired length via a rope clamp. This design only works with ropes of fixed lengths thus entailing additional costs to purchase multiple ropes if different lengths are needed. Finally, U.S. Pat. No. 5,478,297 to Dennis, Jr. teaches inserting a cord through either of two receiving holes attached to a handle, whereby the cord is then adjusted by means of a cord clamp. The excess rope resides inside one of two parallel passages in a free-spinning bearing spindle inside each of the handles. Despite a relatively simple mechanism for adjusting or changing desired ropes or rope lengths, this invention is still prone to twisting or lagging when the rope makes an obtuse angle with the long axis of the spindle. 
     As jump rope handles were developed to allow various rope adjustments and enhance speed and smoothness of rotation, a means for adding weight to the handles became desirable to increase the cardiovascular work out, and to strengthen user&#39;s upper body. Schuentz (U.S. Pat. No. 4,079,932) discloses a jump rope having hollow shell handles that allows water or sand to be added to create a weighted handle. Other jump rope inventions disclose attaching weights to one or both ends of each jump rope handle as in a patent to Donohue (U.S. Pat. No. 4,647,037). Another design even connected a jump rope to a set of hand weights as disclosed in a patent to Grant (U.S. Pat. No. 4,787,624). All such designs limit the users abilities to manipulate the weights in the jump rope handles, have uneven weight placement, and/or require significant time to adjust the weights. These designs generally do not allow a comfortable and natural handgrip feeling when weights are added to the jump rope handgrips. 
     U.S. Pat. No. 4,157,827 to Winston teaches using a hollow body member with an access opening to a storage compartment for holding exercise weights. A plug is inserted after removal or insertion of a weight to maintain the structure of the jump rope handle. This invention uses soft plastic handles, which may require the user to grip the handles tightly in order to keep the inserted weights stable. 
     U.S. Pat. No. 4,778,173 to Joutras also discloses a jump rope that allows inserting a weight into the end of a handle body portion; however this invention provides no support means for fixing the weight to prevent the weight from rotating or jarring inside the handle. Further, an extra hand guard and a screw down cap present the user with a somewhat complicated means of securing the weights. 
     U.S. Pat. No. 5,054,772 to Winston discloses a jump rope handle that allows a weight to be inserted; however, a rope length adjusting means is not simultaneously provided. Further, like the Jountras patent, no means is provided for supporting the weight to prevent the weight from rotating or jarring inside the handle. 
     Thus, prior art in the inventive field teaches complicated and time consuming means for adjusting jump rope handle weight or jump rope length. Further, many disclosures require the use of separate ropes or weight securing means that can allow the weights to become loose. 
     It is therefore desirable to produce a jump rope apparatus that allows a user to quickly and easily adjust jump rope length externally, without having to open the jump rope handgrips. 
     It is also desirable to produce a jump rope apparatus that allows the addition or removal of finely incremented weights that are supported within the handgrips. 
     It is also desirable to produce a jump rope apparatus that contains a readily removable and adjustable bearing to eliminate rope twisting. 
     It is further desirable to produce a jump rope apparatus whereby the jump rope can be easily changed to allow weighted or speed ropes of varying lengths to be easily attached. 
     It is also desirable to produce a jump rope apparatus, wherein the handles can readily be used without a rope for practice purposes or as hand weights for exercise. 
     SUMMARY OF THE INVENTION 
     The present invention satisfies the above-described need by providing a jump rope apparatus wherein each tail or end of a jump rope is: 1) inserted into a channel cut into the base of a ball-shaped bearing member; 2) passes through a groove cut into the head of the bearing member; 3) exits through a second channel to emerge from the bearing member parallel to the remaining or running portion of the rope; and 4) is attached thereto. The ball-shaped bearing member is rotatably retained within a hollow handgrip member. A support structure enables the addition and removal of weights and removably fixes and supports the weights inside each handgrip member. The support structure also removably retains the ball-shaped bearing member inside the handgrip member and tensions the bearing member against a frictionless bearing surface inside each handgrip to allow the bearing member and the attached jump rope to easily rotate in relation to the handgrip. A spring-loaded cap holds the weights and the support structure in a stable and relatively fixed position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a perspective drawing of an entire jump roper of the present invention with the rope mostly shown in phantom; 
     FIG. 1B is a close up view of one of the handgrips of the jump rope of FIG. 1A to show the attachment of the rope to the ball-shaped bearing member; 
     FIG. 1C is a different view of the handgrip of FIG. 1B showing the rope exiting from the ball-shaped bearing member; 
     FIG. 2A is an exploded view of the handgrip and bearing member of FIG. 1B; 
     FIG. 2B is a close up section through the handgrip at the point indicated by “ 2 B in FIG. 2A; 
     FIG. 2C is a close up section through the handgrip at the point indicated by “ 2 C in FIG. 2A; 
     FIG. 3A is a longitudinal section of the handgrip of FIG. 1B along the plane  3 A— 3 A; 
     FIG. 3B is a view of the handgrip of FIG. 1B as seen from the plane  3 B— 3 B; 
     FIG. 3C is a view of the handgrip of FIG. 1B as seen from the plane  3 C— 3 C; 
     FIG. 4 is a view of the handgrip of FIG. 1C as seen from the plane  4 — 4 ; 
     FIG. 5A is a close up view of the bottom end of the handgrip of FIG. 1; 
     FIG. 5B is close up of the locking member opened to show the close ended groove; 
     FIG. 5C is a close up of the locking member; and 
     FIG. 5D is a longitudinal section of the locking member showing both grooves with the rope tail and running portion of the rope in position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates to creating an adjustable jump rope apparatus by first inserting a jump rope tail end through a bottom end opening and then a top end opening of a handgrip, by next inserting the jump rope end into an opening in a ball-shaped bearing member, passing the jump rope tail end through an opening in the bearing member and through a groove cincturing a top end of the ball-shaped bearing member, and then back through the opening. Next a locking mechanism is used to attach the jump rope tail end that has been looped through the ball-shaped bearing member to a point along the running portion of the same jump rope to set the desired length of the rope. Then one, pulls the jump rope (now attached to the ball-shaped bearing member) back through the top end of the handgrip until the ball-shaped bearing member is resting against and articulates with a surface inwardly protruding from the bottom end of the handgrip. Finally, a removable support structure is inserted into a receiving structure located inside the handgrip, wherein the bottom end of the removable support member  26  bears a cup-shaped cage  27  for trapping the ball-shaped bearing member  20  in a low friction mode inside and against the retaining surface  17  of the handgrip opening  16 . Elongate weights can be optionally inserted into the support structure, and the top end opening closed by affixing a spring-loaded cap. 
     EXAMPLE 
     To create the adjustable jump rope apparatus  10  described above, the jump rope  12  of the adjustable jump rope apparatus can be made of any low friction, aerodynamic, densely weighted, or faster spinning jump rope (known as a speed rope) material such as metal (steel), cotton, polyester or leather, however a preferred embodiment utilizes nylon because it is durable and inexpensive, and can easily support the attachment of protective beads  12   a  that increase the weight of the jump rope while providing an anti-tangling and anti-friction effect and protecting the jump rope. Further, it is also possible to attach a jump rope having heavier or lighter protective beads  12   a , or to add or subtract various weighted protective beads  12   a  in order to increase or decrease the work required to swing the jump rope. The jump rope end or tail is inserted through an opening in a ball-shaped bearing member  20 , and then fed around a groove cut in a top portion of the surface of the ball-shaped bearing member  20 , and then back out parallel to the entering rope. The jump rope end can be pulled out of the same opening in the ball-shaped bearing member  20 , or, in an alternate embodiment, pulled out through a separate opening located near the initial opening. The jump rope end normally bears a metal ferrule or sleeve, not unlike the aglets or tips on shoelaces that facilitate passing the laces through the eyelets. The metal ferrule or sleeve prevents the end of the jump rope from unraveling or fraying and makes it easier to thread the rope end through the ball-shaped bearing member  20  and helps retain the tail in a clamping device as explained below. It is also possible to incorporate plastic or other rigid materials, or use a coating to protect the end of the jump rope. 
     The handgrips  14  of the preferred invention are cylindrically shaped with a slightly larger top end circumference  14   a  and a slightly narrower bottom end circumference  14   b . Moving from the top of a handgrip  14  towards its bottom end, the handgrip  14  bottles down into a neck before slightly expanding again at its bottom-most end  14   b . The shape just described is not essential but makes the handgrip better fit the user&#39;s hands. The handgrips  14  can be made from any material that can support individual and fitness club use, but in preferred embodiments, the handgrips are made of polypropylene or ABS (acrylonitrile-butadiene-styrene) plastic. Other materials plastic materials and materials such as wood or metal are also functional in the present invention. In one embodiment, the handgrip is formed in a mold, which includes raised gripping structures that spiral slightly and longitudinally cover a substantial length of each handgrip  14 . The raised gripping structures can be made advantageously of any soft or spongy materials such as neoprene, or they can also be formed from harder material such as polypropylene or ABS plastic. One embodiment of the gripping structures Uses Santoprene® (thermoplastic elastomer or TPE). The raised gripping devices allow the user to tactilely or visually find the handgrips&#39; sweet spot during use. This provides the user with a secure, soft and giving grip that is very comfortable, and easy to hold, and allows the user rapidly to locate the optimal gripping position. 
     The ball-shaped bearing member  20  which receives the covered jump rope tail is substantially globular, however other shapes (i.e., elliptical) that allow a low friction interaction with the bearing surface are also appropriate. In one embodiment, a cylindrical portion  20   a  protrudes from the bottom surface of the ball-shaped bearing member  20  to receive the jump rope tail. The cylindrical portion  20   a  allows the user to swings the jump rope at obtuse angles in relationship to the handgrip. In such a case, the ball-shaped bearing-member  20  swivels in relation to the handgrip  14  with the cylindrical portion  20   a  essentially tracking the rope  12 . The cylindrical portion  20   a  protects the jump rope  12  from rubbing against the circular flange  17  of the bottom end opening  16  of the handgrips  14 . The ball-shaped bearing member  20  is made from a low friction material such as Delrin® (generically known as acetal or poly-acetal); nylon and polytetrafluoroethylene because of such materials are self-lubricating, durable and low in friction. 
     Once the covered jump rope tail is inserted into the ball-shaped bearing member  20 , the jump rope cinctures the top surface of the ball-shaped bearing member  20  by way of a groove in one preferred embodiment. The jump rope is partially exposed at the top end of the ball-shaped bearing member  20  where the groove is visible and accessible. This assists the user in inserting and removing the jump rope end from the ball-shaped bearing member  20 . It is possible, however to create a ball-shaped bearing member  20  with the rope passing: 1) through channels only in the interior of the ball-shaped bearing member  20 ; 2) through external groove(s) circumnavigating the outside of the ball-shaped bearing member  20 ; or 3) through some combination thereof. Further, in one embodiment, it is also possible to utilize a ball-shaped bearing member that includes only an eyelet or small opening through which to insert the jump rope tail. In such an embodiment, the jump rope end would not ‘horseshoe’ around the ball-shaped bearing member  20 , as it would merely be inserted into, around, and then back out of the eyelet (being retained by a structure within the bearing member). 
     Once the jump rope end is threaded through, around, and back out of the ball-shaped bearing member  20 , a locking member  24  is clamped to the jump rope to fix the jump rope&#39;s length and to keep the rope inserted into the bearing member  20 . In one embodiment locking member  24  is a more or less rectangular structure that contains: 1) two side-by-side, but oppositely facing grooves separated by an inner wall that allow the removable placement of the covered jump rope tail and the jump rope running portion within; and 2) two hinge doors (one for each groove) that enclose the covered jump rope tail and the jump rope running portion within the two grooves. A variety of locking member  24  clips or clamps can be used in the present invention. It is preferable that the structure selected allows ready removal for adjustment of the rope but is proof against accidental removal. 
     In FIG. 5, the locking member  24  is shown with one groove  37  that has one open end and one closed end. This groove  37  and its respective hinge door  38  allow the covered jump rope tail  13  to be retained within. The jump rope tail  13 , covered by a ferrule  13   a , rests against the groove&#39;s closed end with the ferrule  13   a  being too large to pass through a constriction  39 —thus, the tail  13  is captured within the locking member  24 . A groove  41  enclosed by the other hinge door  42  has two open ends, allowing the running portion of the jump rope to pass completely through the locking member  24 . Once the jump rope tail  13  and the jump rope running portion are placed in their desired positions within their respective grooves, a user simple presses them down into the grooves to fix them in place, and each door is then hinged over its respective groove and snapped closed, thereby removably fixing the jump rope tail  13  and jump rope running portion. 
     For example, temporarily attaching the jump rope end and the jump rope to the locking member  24  is accomplished in a preferred embodiment by: unsnapping and opening the hinge door  38  covering the one closed ended groove  37  of the locking member  24 ; placing the jump rope tail against the closed end of that groove and then pushing the jump rope end down so that the ferrule  13   a  is retained by the constriction  39  and then closing that hinge door  38 , thereby completely capturing the jump rope tail  13 . The other hinge door  42  located on the opposite side of the locking member  24  is opened and the steps described above are repeated; however, this time the running portion of the jump rope (the portion of the jump rope that has not passed through the ball-shaped bearing member  20 ) is captured by teeth or similar structures within the groove  41 , which has both its ends open, thereby allowing the jump rope to enter and exit the locking member  24 . This simplifies removing the jump rope to use the handgrips separately, changing the jump rope, or adjusting the length of the jump rope. Ease of changing ropes makes it simple to remove the rope and practice with the handles alone. 
     Jump rope length adjustment is especially easy, as a user does not have to disassemble the handgrip. The user simply: 1) unhinges the door  42  capturing the running portion; 2) move the locking member  24 , with the covered jump rope tail  13  captured within, along the running portion of the rope until the desired jump rope length is achieved; and then 3) (if there are beads on the rope, first separate the beads at the desired location) closes the hinge door  42  to reattach the locking member  24  to the running portion. Obviously, the running portion of the rope is fed through the bearing member  20  so that the length of the rope on the tail end is increased or decreased as desired. The locking member  24  can be made of any material that will sufficiently and durably immobilize the jump rope, however a plastic such as polypropylene that exhibits the “living hinge” property is preferred. 
     It is possible to use other locking member designs including locking devices of various configurations such as a two-sided locking member having both side-by-side grooves with two open ends. Such a design allows the jump rope end to dangle outside the locking member. In another embodiment, it is also possible to make a locking member  24  that has one hinge door covering two grooves. 
     In a one embodiment, the jump rope tail and the jump rope running portion, now fixed to the ball-shaped bearing member and the locking member  24 , are pulled back through the top end  14   a  of the handgrip  14  until the ball-shaped bearing member  20  is caught and retained by an inward facing chamfered surface  17  that protrudes from the bottom end  14   b  of the handgrip  14 . In another embodiment, however it is possible to snap the ball-shaped bearing member  20  into an inward facing socket, thereby eliminating the need to insert the jump rope end completely through the handgrip  14  to attach it to the ball-shape bearing member  20 . This can facilitate an even quicker and easier means of changing jump ropes. In either embodiment, the chamfered surface provides a bearing surface that allows a low friction interaction with the ball-shaped bearing member  20 . The inward facing chamfered surface can be made of any material that will sufficiently retain the ball-shaped bearing member  20  while maintaining a low friction interaction. However, like the handgrip, a polypropylene or ABS plastic is used when making a preferred embodiment due to its durability and relatively inexpensive production costs. As will be apparent to one of skill in the art, a low friction interaction can best be attained by maintaining a sufficient difference in hardness between the ball-shaped bearing member  20  and the retaining flange  17 . Further, in a one embodiment, the inward facing chamfered surface or flange  17  is integral with the handgrip  14  and is formed by the same mold. However, it is also possible to create the handgrip  14  by attaching a separately formed flange  17 . In another embodiment, the flange  17  does not have to be continuous. The flange can be comprised of a plurality of separate flanges, attached or formed at spaced apart points within the inner surface of the handgrip bottom opening  16 . 
     To prevent the ball-shaped bearing member  20  from sliding towards the top of the handgrip  14 , and to assist in holding the ball-shaped bearing member  20  in a low friction interaction with the inward facing chamfered surface or flange  17 , a removable support structure  26  is inserted through the opening in the top end  14   a  of the handgrip  14 . In the illustrated embodiment, the support structure  26  is “skeleton-like. By skeleton-like is meant that the support structure is a largely open framework (as is a skeleton). The openings in the framework accommodate removably inserted weights. To prevent the support structure  26  from moving about as the jump rope is used, portions  26   a  of the support structure  26  slides into a plurality (here three) of grooves or guide ways  28  on the interior surface of the handgrip  14 . In one embodiment, the guide ways are represented by a series of ridges forming grooves along the inside surface of the handgrip. The ridges run a substantial length of the inside of each handgrip, and each portion  26   a  of the removable skeleton like support structure  26  is inserted into each one of the grooves  28  formed by the ridges. One of skill in the art can readily envision a variety of other structures used to guide and position the support structure  26 . The bottom end of the support structure  26  bears a cup-shaped cage  27  for retaining the bearing member  20 . 
     The removable support structure  26  in the illustrated embodiment is trimerous, with three vanes or portions  26   a  radiating from a central point. However, any number of equal or non-equal sections can be used. The removable support structure houses the addition of removable elongate weights  30  (here wedge-shaped). The removable support structure can also be made of a polypropylene or ABS plastic, but any material that is strong and durable enough to support weights  30  within the handgrip  14  can be used. 
     Further, in the illustrated embodiment, each removable elongate weight  30  resembles a one-third piece of a pie from a top or bottom view, and an elongated rectangle from a side view; however, each weight can comprise any elongated shape that corresponds to the individual sections of the removable support structure  26  into which the weights  30  are to be inserted. An advantage of multiple sections within the skeleton-like support structure  26  is that one can gradually add or subtract weights from the support structure  26  to allow a range of users to achieve an optimal handgrip weight. The removable rod-shaped weights  30  can be made using any material that achieves a desired individual or cumulative weight. One embodiment incorporates weights made of zinc plated steel. Because the elongate weights run substantially the entire length of the handgrip  14 , the distribution of the weight is exceptionally even—thus facilitating ease of use. The variable weight features and ease of rope removal allow the handgrips to be used as exercise hand weights only. 
     The removable support structure  26  also includes a cup-shaped bottom end  27 . In the illustrated embodiment, the cup-shaped bottom end  27  is an extension of each of vanes  26   a  of the support structure  26 , wherein each vane&#39;s bottom-most end has a concave shape so that the ball-shaped bearing member  20  can be cradled within the cage  27 . The cup-shaped cage  27  also comprises a partition that separates the removable rod-shaped weights  30  from the ball-shaped bearing member  26  so that the weights  30  do not press against the bearing member  20 . The partition resembles a disk horizontally placed between the weight supporting area and the cup-shaped cage  27  of the removable support structure  26 . The partition may be made using any other shape, or piece or pieces that function to stabilize and separate the removable elongate weights  30  from the ball-shaped bearing member  26 . 
     The top-most end  14   a  of the handgrip  14  has a slightly indented or smaller circumference portion, which allows a cap  32  to be attached. The interaction of the top-most end  14   a  of the handgrip  14  and the cap  32  is a bayonet mount. The cap  32  includes a centrally located spring  34  that pushes against the central portion of the top end of the support structure  26  if no weights  30  are installed. Since the weights  30  are slightly longer than the portion of the support structure  26  into which they can be inserted, if weights  30  are inserted, the spring  34  will press on the weights  30  instead of the support structure  26 . If the cap  32  is pressed towards the handgrip  32 , the spring  34  will be depressed allowing the cap  32  to slide over the slightly indented or smaller circumference portion of the top-most end of the handgrip  14 . Twisting the closure cap clockwise engages teeth  36 , located on the inner ring surface of the closure cap, into grooves  31  located on the exterior surface of the top-most end of the handgrip  14 . The tooth and groove interaction secures the closure cap  32  against the handgrip, eventually allowing the closure cap  32  to raise slightly when the teeth  36  reaches a detent locking point at the end of the grooves. To undo the bayonet mount, a user simply pushes cap  32  against the handgrip  14  and twists the cap counter-clockwise until the teeth  36  become disengaged from the grooves and the spring releases the cap  32 . 
     In FIG. 1, an adjustable jump rope apparatus  10  incorporating the invention comprises a jump rope  12 , optionally including protective jump rope beads  12   a . The jump rope  12  also contains a covered jump rope tail  13  that is inserted completely through the bottom end handgrip opening  16  and the top end handgrip opening  18  of a handgrip  14 . A raised gripping structure  15  enables a user to visibly or physically grip the handgrip&#39;s sweet spot with ease ensuring optimum orientation of the handgrip  14 . 
     After the covered jump rope tail  13  is passed completely through the bottom end handgrip opening  16  and the top end handgrip opening  18  of the handgrip  14 , the covered jump rope tail  13  is then inserted into an opening  22  located in a cylinder  20   a  protruding from the ball-shaped bearing member  20 . The covered jump rope tail  13  is further threaded through arcuate or U-shaped groove cincturing the ball-shaped bearing member  20  until the covered jump rope tail  13  exits the opening  22  in the ball-shaped bearing member  20 . Once the covered jump rope tail  13  exits the opening  22  in the ball-shaped bearing member  20 , it may be removably fastened to any point on the running portion of the jump rope  12  via a locking member  24 . The locking member  24  captures the jump rope  12  and the covered jump rope tail  13 , and prevents the covered jump rope tail  13  from sliding out of or exiting the ball-shaped bearing member  20 . The ball-shaped bearing member  20  is now pulled back through the top end circular edge handgrip opening  18  until the ball-shaped bearing member  20  is caught by and rests in a low friction relationship against an inward facing chamfered surface or flange  17  protruding from the bottom end handgrip opening  16 . The inward facing chamfered surface  17  forms a low friction articulation with the ball-shaped bearing member  20 . 
     The removable support structure  26  is then inserted into the handgrip  14  with protruding portions  26   a  of the support member  26  sliding into receiving structures  28  that run substantially the length of the inside of the handgrip  14 . The removable support structure  26  supports and surrounds elongate weights  30  that are used to increase a user&#39;s upper body strength and/or increase workout intensity. The removable support structure  26  comprises a cup-shaped bottom end  27  and a top end  29 . The cup-shaped bottom end  27  assists in retaining the ball-shaped bearing member  20  in a low friction relationship with the inward facing chamfered surface  17 . With the locking member  24  exposed and located outside the handgrip  14 , it is also possible quickly and easily to adjust the length of jump rope  12  without opening the handgrip  14 . 
     The top end of the handgrip  14  is closed with a cap  32 . This is accomplished through the interaction of recessed grooves  31  and entry grooves  33  located around the external top of the handgrip  14 , with teeth  36  located on the inner ring surface of the closure cap  32  and a spring  34  centrally located on the interior surface of the closure cap  32 . The teeth  36  engage the recessed grooves  31  when the closure cap  32  is twisted onto the top end of the handgrip  14 . The spring  34  assists in locking the teeth  36  into the detents in the recessed groove. In addition, the spring presses against the support structure  26  or the weights  30  biasing the support structure  26  towards the ball-shaped bearing member  20  at the opposite end of the handgrip  14 . 
     The following claims are thus to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, what can be obviously substituted and what essentially incorporates the essential idea of the invention. Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope of the invention. The illustrated embodiment has been set forth only for the purposes of example and that should not be taken as limiting the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.