Patent Publication Number: US-8968165-B2

Title: Structure for securing weight plates

Description:
The invention relates to structure for securing weight plates on a long weight rod grasped by both hands, on a dumbbell with a short weight rod or on a holder bar of exercise equipment or a rack, and to a weight plate for this kind of plate securing structure. 
     In high-quality weight rods, the two ends onto which the weight plates are placed are rotatably supported. To prevent the weight plates from falling off the rod, it is necessary to mount clamping locks, or even to screw nuts onto the rod. Since this entails considerable expense and loss of time, many athletes use the weight rods without securing them, thus running the attendant risks. 
     Depending on how they are embodied, weight rods weigh approximately 5 kg to 25 kg, for instance 5.5 kg, 7 kg, 17 kg, and so on. Thus there is not necessarily an integer weight number. If the weight rods are set down on the floor, it is difficult to replace weight plates of the same size as each other, since that would require lifting the weight rod by at least a few millimeters. 
     In fitness clubs, most of the weight rods are stored on support posts near bench presses, squat racks, and so forth. When weight plates are removed in order to change weights, the weight plates are initially not lifted; instead, they are simply pulled off the weight rod, so that only then does one have to bear the weight of the plates. In this way, the weight plates are sometimes unloaded from one side of the weight rod so far that it falls off the support post. 
     For securing weight plates, it is the object of the invention to form a long weight rod, a dumbbell with a short weight rod or a holder bar of exercise equipment or a rack and the associated weight plates in such a way that for avoiding the aforementioned risks, a lock is no longer required. 
     The above object is attained according to the invention by a structure for securing weight plates in which the weight rod or holder bar is provided with at least one circumferentially extending groove, and each weight plate is provided with a bore that on the bore wall has at least one radial protrusion that extends in the circumferential direction and is to be made to engage the groove, and the diameter of the bore at the protrusion is greater than the diameter of the weight rod or of the holder bar axially beside the groove. 
     The advantage of the invention is that the weight plates, as soon as they are placed on the weight rod or the holder bar, enter axially into positive engagement and cannot then fall, even if the weight rod is in a tilted position. 
    
    
     
       Some exemplary embodiments of the invention will be described below in detail. In the drawings: 
         FIG. 1  shows a side view of the end region of a weight rod, with a plurality of grooves that extend all the way around, their outer edges being partly chamfered, and an axial cross section through the middle region of a weight plate placed on the weight rod; 
         FIG. 2  shows a side view of an end region of a weight rod, with transverse grooves extending over only the upper part of the circumference, and an axial cross section through the middle region of a weight plate while it is being put on the rod; 
         FIG. 3  is a radial cross section through the arrangement shown in  FIG. 2 ; 
         FIG. 4  shows a side view of a weight rod with several weight plates on its end regions, lying on a support post. 
         FIG. 5  shows a side view of a weight rod with an end region that is eccentrically rotatably supported and provided with transverse grooves extending over the upper part of the circumference, and an axial cross section through the middle region of two weight plates placed on the weight rod; 
         FIG. 6  shows a side view of a concentrically rotatably supported end region of a weight rod, which region is connected to an adjusting weight that has an eccentric center of mass; 
         FIG. 7  is a radial cross section through an end region, supported rotatably on the weight rod and connected in a manner fixed against relative rotation to an adjusting weight plate that has an eccentric center of mass, the end region having transverse grooves extending over the upper part of the circumference, and in the rotary angle position shown, the center axis of the adjusting weight plate is aligned with the center axis of weight plates that are to be made to engage the transverse grooves; 
         FIG. 8  schematically shows both an upright rack member, having two holder bars for weight plates of different weights, and a piece of exercise equipment with two holder bars for receiving the weight plates; 
         FIGS. 9 and 10  show an axial cross section and a side view of an axial half of a hard plastic ring that can be inserted into a bore, which has been machined without a protrusion, in a weight plate of the kind shown in  FIG. 1  or  FIG. 2 , in order to line the bore and to form the protrusion; 
         FIGS. 11A and 11B  show a side view and a radial cross section of a weight rod with an adjusting weight in the form of a foot supporting the weight plates with a predetermined distance above the floor; 
         FIGS. 12A and 12B  show a side view and a radial cross section of a weight rod with a modified foot for supporting the weight plates with a predetermined distance above the floor, and 
         FIG. 13  shows a side view of a suspended dumbbell hanging on a rope. 
     
    
    
     The simplest version is shown in  FIG. 1 . Grooves  14  (plunge cuts) are cut into the end regions  10  of the weight rod  12  by turning. A weight plate  16 , which in its central bore is provided with a protrusion  17  extending all the way around and fitting into the grooves  14 , is simply slipped onto the rod  10 ,  12  and then lowered. Via the protrusion  17 , the weight plate  16  catches on a groove  14  of the rod  10 ,  12  and can no longer slip off the rod. 
     The spacings of the centers of the grooves correspond to the thicknesses of the weight plates  16 . All the weight plates  16  are of the same thickness. As an alternative, in  FIG. 5  narrower grooves  14  are shown, with two grooves  14  provided for one large weight plate  16  and one groove  14  provided for one small weight plate  16 . Even narrower grooves  14  can be selected as well. 
     The weight plate receptacle in the end region  10  of the weight rod  12  shown in  FIG. 1  is not rotatable relative to the grip region of the weight rod. In this weight rod  12 , the weight plates  16  cannot be changed particularly easily, because over the entire circumference they repeatedly catch on the grooves  14 . This problem is alleviated if, as shown on the right-hand side of  FIG. 1 , the edges of the lands  15  between the grooves  14  are chamfered. This makes it easier to change the weight plates  16 . 
     In  FIGS. 2 and 3 , the grooves  14 , in the form of turned plunge cuts, are created around an eccentric center axis  18 , shifted downward, on only the upper half of the circumference of the end region  10  of the weight rod  12 . To change the weights, the weight plate  16  is lifted until it touches the lower, smooth half  11  of the circumference of the end region  10 , and then, in the position shown in  FIGS. 2 and 3 , it can be pulled off or slipped on without catching on anything. 
     The problem of falling off a support post  20 , shown for instance in  FIG. 4 , when the weight plates  16  are being unloaded from only one side is solved as well. Once the weight rod  12  on the support post  20  has already been largely unloaded on one side, and the next weight plate  16  is lifted in order to set it down, the now lightweight end of the rod  12 , on the right in  FIG. 4 , swivels upward, so the next weight plate  16  cannot come loose from the grooves  14  and be removed. Thus it is possible to feel that the rod  12  is about to fall, in time to prevent that from happening. 
     If the grooves  14  are provided only at the top, as shown in  FIGS. 2 and 3 , then if possible they should always stay at the top. For that purpose, in  FIG. 5  the plate holder bar  10 ′ that forms the end region  10  is supported rotatably via a rotary bearing  22  and is eccentrically offset from the grip region of the weight rod  12  by the amount x. By the weight of the holder bar  10 ′ itself and the weight of the weight plates  16  slipped onto it, the holder bar  10 ′ always drops downward into the position shown in  FIG. 5 , in which the grooves  14  are located at the top. 
     In  FIG. 6 , the weight holder bar  10 ′ is aligned with the central longitudinal axis of the weight rod  12 . This bar  10 ′ is likewise supported rotatably on the grip region of the rod  12  and is connected, in a manner fixed against relative rotation, to an eccentrically mounted adjusting weight  24 . The mass of this weight  24  drops downward and rotates the weight holder bar  10 ′ in such a way that the grooves  14  are at the top. The adjusting weight  24  can be embodied arbitrarily, but its center of mass must be located opposite the grooves  14 . It is possible to combine the eccentricity x of  FIG. 5  and an adjusting weight  24  with an eccentric center of mass in accordance with  FIG. 6  for turning and maintaining the grooves  14  in the position at the top side of the weight holder bar  10 ′. 
     In  FIG. 7 , the adjusting weight  24  is in the form of a circular plate with an eccentric center of mass and is likewise solidly connected to the holder bar  10 ′ that is supported concentrically on the weight rod  12  by ball bearings  26 . However, in the position shown, in which the grooves  14  are located at the top, the center point of the adjusting weight plate  24  is a few millimeters below the center of the weight rod  12  and of the holder bar  10 ′. The eccentricity is preferably the same as the plunge-cut depth of the grooves  14 , plus the difference in the radii of the central hole in the weight plates at the protrusion  17  and of the holder bar  10 ′ at the lands  15  (corresponding to the small gap between protrusion  17  and land  15  in  FIG. 2 ). On these preconditions, the adjusting weight plate  24  and the weight plates  16  are seated concentrically on the end regions  10  of the weight rod  12 . The horizontal center line of the adjusting weight plate  24  and of the weight plates  16  that are seated on the holder bars  10 ′ is identified in  FIG. 7  by reference numeral  28 . The horizontal center line of the holder bar  10 ′ and of the grip region of the weight rod  12  is shown at  30 . The spacing between the two center lines  28  and  30  amounts to only approximately 4 mm and is not visually obvious. The eccentricity of the center of mass of the adjusting weight plate  24  is achieved, in the exemplary embodiment of  FIG. 7 , by means of a relatively large recess  32  in the plate, extending over approximately half the circumference, which makes this half of the circumference lighter in weight than the solid half of the circumference shown at the bottom in  FIG. 7 . Thus the embodiment of  FIG. 7  is a combination of an eccentricity of the total weight  16  (x=distance between 28 and 30) and an eccentric adjusting weight  24 . 
     Preferably, the weight of the adjusting weight plates  24  is selected such that the total weight of the weight rod is a round number, such as 10, 15, 20, or 25 kg. It is favorable if the outer diameter of the adjusting weight plates  24  is equal to or a little bit greater than that of the largest weight plate  16  provided. Even on a weight rod  12  that is resting on the floor, weight plates  16  of equal size can then easily be slipped on and removed, since each needs to be lifted only slightly, one at a time, and then lowered. If the weight rod  12  with the weight plates  16  is set down on the floor, it likewise tends to orient itself in such a way that the grooves  14  are at the top. 
     As  FIG. 8  shows, the proposed means for securing weight plates can also be used for designing the holder bars  34  and  36  of upright rack members  38  or of pieces of exercise equipment  40 . In such applications, even if the holder bars  34 ,  36  are used for receiving many weight plates  16 , they can be designed more simply than the ends of weight rods, since there is no danger that they can become tilted so that the weight plates  16  would slide off. It therefore suffices if, in the example of the holder bar  34 , there is a single groove  14  before the free end, or in the example of the holder bar  36 , a groove  14  extending over almost the entire length of the holder bar extends to just before the free end of the holder bar. The holder bars  34  and  36  can be brought into alignment, so that the weight plates can be slipped from one holder bar  34 ,  36  to another across a relatively small intermediate spacing. 
     In terms of view to their expense and for the sake of their holding their value, it is recommended that the weight plates  16  be made of steel, with a straight through bore in the center. These steel plates are encased in a coating of rubber or a rubberlike plastic, and this casing extends toward the central bore by approximately 2 to 3 mm. In the bore, two rings  42  of the type shown in  FIGS. 9 and 10  are then put together in mirror symmetry and are screwed together axially in such a way that the flange  44  shown is in each case located axially on the outside. After assembly, the rings  42 , joined together by four screws, form the protrusion  17 , shown in  FIGS. 1 and 2 , of the weight plate  16 . In a weight plate  16  that is 20 mm wide, for example, the protrusion  17  has a width of 16 mm, for example. Each ring  42  contributes to this with its width of 8 mm each. The flanges  44  are located on the face ends of the steel core of the weight plate  16 ; at the edge of the bore, this steel core is not encased in rubber. The rings  42  are under greater mechanical stress than the casing. They are therefore made of a hard, wear-resistant plastic. 
       FIG. 11A , B show an embodiment with an adjusting weight  24  (another one is at the other end of the weight rod  12 ) having a second function. It does not only contribute to rotate the weight holder bar  10 ′ in such a way that the grooves  14  are at the top, as described in connection with  FIG. 6 , but when dropped downward also serves as foot  25  on which the weight rod  12  can be placed on a floor. It is so long that in this position there is a distance between the weight plates  16  and the floor so that it is easy to remove or exchange weight plates without having to lift the weight rod. As mentioned before, additionally the rotatable weight holder bar  10 ′ could be mounted eccentrically on the grip portion of the weight rod  12 . 
     A similar embodiment is shown in  FIG. 12  A, B. It is a modification of  FIG. 7  insofar as a disk  24 ′ on the side of its center of mass is formed as a foot  25 ′ with a greater radius having its center  25 ″ offset in relation to the longitudinal axis  30  of the weight rod  12  to the opposite side of the foot  25 ′. The foot  25 ′ provides an adjusting weight  24  with an eccentricity of the mass which can be enlarged in accordance with  FIG. 7 . In addition to this function the circular plate  24 ′ with the round foot  25 ′ allows for placing the weight rod  12  on the floor while keeping the weight plates  16  above the floor so that they also can be removed or exchanged without having to lift the weight rod. 
     As can be seen from  FIGS. 11B and 12B  the feet  25  and  25 ′ are inclined or curved so that their ends are on a greater radius in relation to the longitudinal axis of the weight rod  12  than their middle portion and point upward. This has the effect that when lowering the weight rod  12  to the floor the ends of the feet  25 ,  25 ′ do not cause damage and after placing the weight rod  12  on the floor there is a tendency to roll the feet into their normal position shown in  FIGS. 11B and 12B . In order to ensure that the grooves  14  are always located at the top of the weight holder bar  10 ′ the latter is mounted rotatably and eccentrically on the weight rod  12  and is fixedly connected to the foot disk  24 ′. 
       FIG. 13  shows one dumbbell of a pair of dumbbells, each being suspended at the lower end of a rope  45  hanging from a gallows-like piece of exercise equipment. The lower end of the rope  45  is fixed to a bridge-like connecting member  46  that bridges the grip of the short weight rod  12  of the dumbbell. Both, the connecting member  46  and the end regions  10 ′ are freely rotatable in relation to the grip portion of the dumbbell. In the hanging position shown in  FIG. 13  the connecting member  46  is vertically above the short weight rod  12  and the weight of the weight plates  16  turns the eccentrically mounted end portions  10 ′ into the rotary angle position in which the grooves  14 , extending over only a portion of the circumference, are located on the top. When weight plates  16  of a dumbbell of  FIG. 13  are exchanged its weight rod  12  normally will be more or less tilted but the means described above for securing the weight plates  16  on the weight rod prevent their falling off the end regions  10 ′. Straightening plates  48  assist because they hold the adjacent weight plates  16  exactly in a position transverse to the longitudinal axis of the weight rod  12  even if it is more tilted than 45°.