Patent Publication Number: US-2023146167-A1

Title: Weightlifting disc with a reinforcement device

Description:
TECHNICAL FIELD 
     The invention considers a weightlifting disc to be used on a bar. 
     BACKGROUND ART 
     Earlier, weightlifting discs were made as solid metal disc plates, but nowadays weightlifting discs normally are made of a soft material like rubber or other elastomeric material with a central hub. Competition weights as well as training discs are normally made of rubber or other elastomeric compositions with high durability and are provided with a metal hub. The elastomeric (soft) material is used to absorb the shock and deceleration when a weightlifter drops or bumps the weights against the floor, which results in a better sound dampening and shock absorption. The metal hub provides a longer lifetime of the weight disc since there is deformation (tensioning) of the soft material around the center hole of the disc when dropped on the floor repeatedly. 
     The metal hub is of course positive for the lifetime of the disc, but yet there is a problem with the strength of the weight disc over time. One problem with these “soft” discs with a metal hub (or other hard material) is that the available area for distribution of a shock force between the metal hub and the surrounding softer disc, when the barbell with the weight disc is dropped on the floor, is limited to the interaction surface between the hub and the disc. This means that a great impact force acts on a small area of the soft weightlifting disc material which results in a tension peak at the impact area and a local deformation of the material, which is negative for the lifetime of the weightlifting disc. Over time, this also results in a gap between the hub and the disc part. 
     Thus, there is a need of an improved strength of a weightlifting disc to lengthen the lifetime of a weightlifting disc of elastomeric material. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to address at least some of the problems and issues outlined above. It is possible to achieve these objects and others by a weightlifting disc as defined in the attached independent claims. 
     According to an aspect of the invention, a reinforced weightlifting disc to be arranged on a bar is disclosed. The weightlifting disc comprises a disc part of elastomeric material, wherein the disc part comprises an outer edge and an inner edge, wherein the inner edge is arranged close to a center of the disc part and the outer edge of the disc part is distal from the center of the disc part. The weightlifting disc further comprises at least one reinforcing device, arranged into the disc part circumferentially around the center, between the outer edge and the inner edge of the disc part, wherein the reinforcing device is arranged at a distance from the inner edge of the disc part such as elastomeric material is arranged between the inner edge of the disc part and the reinforcing device. 
     By this design, an impact force transferred from the floor via the disc part to the bar, is spread out over a large area via the circumferentially arranged reinforcing device. Further, by that the reinforcing device is arranged into the disc part at a distance from the inner edge (radially seen) such as elastomeric material is arranged between the inner edge and the reinforcing device, a dampening effect is disclosed as well as that the impact force in a certain part/direction is distributed to a larger area of the reinforcing device and further to the disc part before it reaches the bar. The risk of crack formation in the elastomeric material (rubber) is significantly reduced due to the force distribution and the risk of an increase of the gap between a hub part (if applicable) and the elastomeric disc part is significantly reduced. By that, the form of the disc is kept over time and tests show that the lifetime of the weightlifting disc of elastomeric material is significantly lengthened. Another aspect is that the individual disc part may be thinner such as more discs may be applied on the bar. No prior art solution provides a weightlifting disc with all these advantages. 
     According to an embodiment, the reinforcing device is substantially ring-shaped. Such a solution provides a good distribution of impact forces between the disc part and the bar, wherein the forces are circumferentially distributed around substantially the whole disc part, i.e. in all directions before the transfer to the bar. 
     According to an embodiment, the reinforcing device comprises spaced holes arranged to accommodate elastomeric material of the outer disc part. By having a number of holes distributed around the reinforcing device, which holes are arranged to accommodate elastomeric material, the transfer area available for distributing and take care of an impact force via the reinforcing device and disc part is greatly increased compared to a solid reinforcing device. Further, the reinforcing device gets good contact with the elastomeric material without the need of any pretreatment of the surfaces of the reinforcing device, which normally is needed when for example moulding different materials together; like metal and rubber for example. 
     According to an embodiment, the weightlifting disc further comprises a hub part arranged at the center of the disc part, wherein the disc part substantially surrounds the hub part when the hub part is arranged at the center of the disc part. The hub part is arranged to be attached at the inner edge of the disc part; and the hub part comprises a center hole for receiving a bar, A hub part, preferably made of metal, provides a complement to the reinforcing device because it also provides a transfer of an impact force from the disc part, via the hub part and further to the bar, Since there is elastomeric material between the inner edge of the disc part and the reinforcing device, there is elastomeric material between the reinforcing material and the hub part, which is positive as described above. The hub part may also be attach to the sides of the disc part, at least close to the inner edge of the disc part, which means that the hub part may serve both as a sleeve through the weightlifting disc, arranged to be in contact with the bar, by the attachment to the inner edge, and further as a reinforcement due to the contact with a part of the sides around the center of the disc. 
     According to an embodiment, the inner edge of the disc part comprises at least a protruding part which protrudes radially towards the center of the disc part, wherein the protruding part is arranged to be attached to the hub part. The protruding part is arranged as a protruding lip which is arranged around the inner edge of the disc part and thus extends towards the center of the weightlifting disc. The protruding part increases the distance between the reinforcing device and the inner edge of the disc part and if a hub is arranged at the inner edge, it increases the transferring area between the hub part and the disc part and provides a good fixation between the disc part and the hub part since the protruding part may be pressed between the two halves of the hub part, if the hub part is designed in that way. 
     According to an embodiment, the reinforcing device is made of metal, Preferably the metal is cast iron, which is a robust material well suited for the purpose, but other materials like steel, light metals like aluminium or the like may be used. 
     According to an embodiment, the reinforcing device is made of plastic. A plastic material provides a cost efficient solution for providing a reinforced weightlifting disc. 
     According to an embodiment, the reinforcing device and the disc part are moulded together to a unit such as the elastomeric material of the disc part encloses the reinforcing device. 
     In yet an embodiment, the hub part comprises two halves connectable to each other, wherein at least the inner edge of the disc part is arranged to be pressed between the two halves of the hub part when they are connected to each other. Such a solution is very good since the two halves so to speak clamps the disc part (and the protruding part if applicable) from both sides whereby a solid and robust attachment of the hub part is achieved as well as large area for transfer of the sudden impact force from a drop of the barbell with the assembled weightlifting discs. The two halves may preferably extend radially a distance from the center, which is enough to “enclose” at least a part of the disc part in which the reinforcing device is arranged, which by that is arranged with at least a part (nearest the inner edge) between the two halves. 
     According to an embodiment, the reinforcing device comprises a substantially cylindrical inner ring, a substantially cylindrical outer ring and an annular body connecting the inner ring and the outer ring. The reinforcing device looks more or less like a rim of a wheel, wherein the rings and annular body may have equal or different widths. For example, the outer ring may be wider than the inner ring or vice versa and the annular body may be thinner or wider than the outer ring and/or the inner ring. If the reinforcing device comprises holes, these may be arranged in any of the inner ring, the outer ring and the annular body. The ring-shaped reinforcing device is easy to manufacture the continuous ring-shape is very good for taking care of the impact force and distribute it along the reinforcing device and further to the disc part. 
     According to an embodiment, the annular body of the reinforcing device comprises a plurality of holes circumferentially distributed along the annular body and transverse the annular body. The holes are arranged to accommodate the elastomeric material of the disc part, and since the weightlifting device preferably is produced by moulding the reinforcing device and the disc part together to one unit, the reinforcing device transfers a shock force very well to the elastomeric material and over a large area, which is very positive for the lifetime of the weightlifting disc By that the holes are filled with elastomeric disc material, the material in the holes act as transverse beams in cooperation with the reinforcing device. The solution is very strong compared to prior art solutions. The holes are also positive since the reinforcing device do not need any pretreatment to make it stick to the elastomeric material, which otherwise would be needed. 
     According to an alternative embodiment compared to the one above, the annular body of the reinforcing device comprises a plurality of partitions extending between the inner ring and the outer ring, wherein the plurality of partitions together or with at least one of the inner ring or the outer ring forms the holes of the reinforcing device. In this embodiment, the annular body looks and function like a framework connected to the inner and outer ring. 
     According to an embodiment, the hub part comprises an insert arranged in the center hole of the hub part. The insert may be in plastic or in metal, but most preferred is a plastic insert. The insert acts as a vibration dampener and a silencer between the bar and the hub and the insert may be moulded to the hub/hub parts or may be a loose or pressed in place in the hub. 
     Further possible features and benefits of this solution will become apparent from the detailed description below. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The solution will now be described in more detail by means of exemplary embodiments and with reference to the accompanying drawings, in which: 
         FIG.  1    is an exploded view of a weightlifting disc according to the invention. 
         FIG.  2   a    is a front view of the weightlifting disc of  FIG.  1   , 
         FIG.  2   b    is a section view of the weightlifting disc of  FIG.  2     a.    
         FIG.  3   a    is a front view and  FIG.  3   b    is a section view of an insert of the weightlifting disc of  FIG.  1   . 
         FIG.  3   c    is a section view and  FIG.  3   d    is a front view of a first half of a hub part of the weightlifting disc of  FIG.  1   . 
         FIG.  3   e    is a front view and  FIG.  3   f    is a section view of a second half of a hub part of the weightlifting disc of  FIG.  1   . 
         FIG.  4   a    is a side view of a disc part of the weightlifting disc of  FIG.  1   . and  FIG.  4   b    is a section view of the disc part of  FIG.  4     a,    
         FIG.  4   c    is a side view of a reinforcing device of the weightlifting disc of  FIG.  1   , and  FIG.  4   d    is a section view of the reinforcing device of  FIG.  4     c.    
         FIG.  4   e    is a side view of the weightlifting disc of  FIG.  1   , and  FIG.  4   f    is a section view of the weightlifting disc of  FIG.  4   e   , where the hub part is assembled to the disc part of the weightlifting disc. 
         FIG.  5   a    is a zoomed section view of the hub part of the weightlifting disc with a first type of insert mounted to the hub part. 
         FIG.  5   b    is a zoomed section view of the hub part of the weightlifting disc with a second type of insert mounted to the hub part. 
         FIG.  6   a    is a front view of an alternative reinforcing device and  FIG.  6   b    is a section view of the reinforcing device of  FIG.  6     a.    
     
    
    
     DETAILED DESCRIPTION 
     Briefly described, an improved weightlifting disc of elastomeric material and comprising a reinforcing device, is disclosed. 
       FIG.  1    shows an exploded view of a weightlifting disc  1  according to the invention. The weightlifting disc  1 , which not necessarily but more preferred is a circular disc, comprises a disc part  10  made of elastomeric material, preferably a rubber material or the like. The disc part  10  comprises an outer edge  11  and an inner edge  12 , wherein the inner edge  12  is arranged close to a center  13  of the disc part  10  and the outer edge  11  of the disc part  10  is distal from the center  13  of the disc part  10 . 
     The preferred embodiment of the weightlifting disc  10  further comprises a hub part  30  which comprises a first half  30   a  and a second half  30   b . The hub part  30  is to be arranged at the center  13  of the disc part  10 , such as the disc part  10  substantially surrounds the hub part  30  when the hub part  30  is arranged at the center  13  of the disc part  10 , The hub part  30  is arranged to be attached at the inner edge  12  of the disc part  10 , and the hub part  30  comprises a center hole  35  arranged for receiving a bar. The a first half  30   a  and a second half  30   b  of the hub  30  are connectable to each other, wherein at least the inner edge  12  of the disc part  10  is arranged to be pressed between the first and the second halves  30   a ,  30   b  of the hub part  30  when they are connected to each other. The first half  30   a  and a second half  30   b  are preferably fixedly connected to each other by means of screws  37 , The hub part  30  may comprise an insert  36 , which is to be arranged at the center hole  35  of the hub part  30 . The insert  36  is arranged as a vibration dampener and a silencer between the bar and the hub  30  and the insert  36  may be moulded to the hub/halves  30   a ,  30   b  or may be a loose or pressed in place in the hub  30 . 
       FIG.  2   a    is a front view of the complete weightlifting disc  1  comprising the hub part  30 , arranged at the center  13  of the disc part  10 . The outer edge  11  may normally have a flat or rounded surface.  FIG.  2   b    is a section view at the center of the weightlifting disc  1 , indicated by the dotted line and arrows.  FIG.  3   a    is a front view and  FIG.  3   b    is a section view of the insert  36  mentioned above.  FIG.  3   c    is a section view and  FIG.  3   d    is a front view of the first half  31   a  of the hub part  30  and  FIG.  3   e    is a front view and  FIG.  3   f    is a section view of a second half  30   b  of a hub part  30 . 
     As can be seen in  FIG.  2   b    the first and second halves  30   a ,  30   b  of the hub part  30  are mounted to the disc part  10  from a respective side of the disc part  10  and are fixedly attached to each other by screws  37 , which are screwed from the first half  30   a  in direction to the second half  30   b  of the hub part  30 , The insert  36  is in this embodiment a plastic cylinder fitted in the center hole  35  of the hub part  30 . A reinforcing device  20  is arranged into the disc part  10 , circumferentially around the center  13  of the disc part  10 , between the outer edge  11  and the inner edge  12  of the disc part  10 , The reinforcing device  20  and the disc part  10  are moulded together to a unit such as the elastomeric material (rubber) of the disc part  10  encloses the reinforcing device  20 , such as the reinforcing device  20  is totally enclosed into the elastomeric material. For further information about the reinforcing device, please see description below relating to  FIG.  4   a - f    and  FIG.  5   a   - b.    
     The insert  36  preferably is a plastic cylinder like the insert  36  visible in  FIG.  3   a - b   . According to an alternative embodiment the insert  36  may have an outer flange (see  FIG.  5   b   ) which flange then extends radially outwards a short distance from the cylinder body and by that rests at an outside of the halves  30   a ,  30   b  of the hub part  30 . 
     The first and second halves  30   a ,  30   b  of the hub part  30 , which are visible in  FIG.  3   c - f   , preferably are disc-shaped metal hubs with a center hole  35 , which halves as mentioned above, are connectable to each other on opposite sides of the disc part  10 , such as the inner edge  12  of the disc part  10  is pressed between the first and the second halves  30   a ,  30   b  of the hub part  30  when they are connected to each other. The halves  30   a ,  30   b  are preferably screwed together by screws  37 . 
       FIG.  4   a    is a side view of the disc part  10  and  FIG.  4   b    is a section view of the disc part  10  of  FIG.  4   a    in a section indicated by the dotted line and arrows. In the figures, the hub part  30  is not assembled to the disc part  10 . As can be seen in the section in  FIG.  4   b    the reinforcing device  20  is arranged circumferentially around the center  13  of the disc part  10 , between the outer edge  11  and the inner edge  12  of the disc part  10 , such as the reinforcing device  20  is totally enclosed into the elastomeric material of the disc part  10 , As mentioned above, the reinforcing device  20  and the disc part  10  are moulded together to one unit. The inner edge  12  of the disc part  10  comprises a protruding part  12   a , which protrudes radially towards the center  13  of the disc part  10 , and the protruding part  12   a  is arranged to be attached to the hub part  30 , i.e, the protruding part  12   a  is to be pressed between the first and second half  30   a ,  30   b  of the hub part  30 , when the hub part  30  is mounted to the center  13  of the disc part  10 , which may be seen in  FIG.  4     f.    
       FIG.  4   c - d    show the reinforcing device  20  in a side view respective a section view along the dotted line and indicated by the arrows in  FIG.  4   c   . The reinforcing device  20  according to this preferred embodiment is ring-shaped and comprises a cylindrical inner ring  21 , a cylindrical outer ring  22  and an annular body  23 , which connects the inner ring  21  and the outer ring  22 . In the preferred embodiment, the outer ring  22  is slightly wider than the inner ring  21  and the annular body  23  has a tapered extension from the wider outer ring  22  to the narrower inner ring  21 . The annular body  23  of the reinforcing device  20  comprises a plurality of holes  25  circumferentially distributed spaced apart along the circular extension of the annular body  23  and which holes  25  are transverse relative the annular body  23 . The holes  25  are arranged to accommodate elastomeric material of the outer disc part  10  such as, when the reinforcing device  20  and the disc part  10  are moulded to one piece, the elastomeric material fills the holes  25 . By that, the total contact area between the elastomeric material of the disc part  10  and the reinforcing device  20  is very large, and the area for transferring impact forces between the disc part  10  and the reinforcing device  20  is thereby large. When moulding elastomeric material like rubber and incorporating another material into the mould, like the reinforcing device  20 , the surface of the incorporated material normally must be pretreated to get a “grip” between the incorporated device and the rubber, but because of the transverse holes  25  in the annular body  23  of the reinforcing device  20 , this is not necessary since the holes  25  provide a very good grip such as the reinforcing device  20  stays into the mould and “grips” the elastomeric material (rubber) in a very god way. Further, the ring-shape of the reinforcing device  20 , with the inner ring  21  and outer ring  22 , is very effective when taking care of impact forces since the “continuous” rings  21 ,  22  distributes the force better compared to if the rings were not continuous. The reinforcing device  20  is preferably made of metal or of plastic material. 
       FIG.  4   e    is a side view of the weightlifting disc  1  of  FIG.  1   . and  FIG.  4   f    is a section view of the weightlifting disc  1  of  FIG.  4   e    at a position indicated by the dotted line and arrows, and where the hub part  30  is assembled to disc part  10  of the weightlifting disc  1 . The section of  FIG.  4   f    shows how the hub part  30  is arranged at the center  13  of the disc part  10 , such as the disc part  10  substantially surrounds the hub part  30 . As mentioned above, the hub part  30  comprises the center hole  35  arranged for receiving a bar and the first half  30   a  and the second half  30   b  of the hub  30  are connected to each other, wherein at least the protruding part of the inner edge  12  of the disc part  10  is pressed between the halves  30   a ,  30   b  of the hub part  30 . The hub part  30  is preferred to be a metal hub with a circular design and since the hub part  30  is in contact with the bar (not visible), the force from a drop of the barbell on the ground is transferred from the disc part  10  to the hub  30 . But due to the reinforcing device  20 , a substantial part of the force is transferred to the reinforcing device  20 , which distributes the force over a large area before it is transferred to the hub  30 , and the force at the contact surface between the hub part  30  and the bar by that is very low compared to if no reinforcing device would be arranged into the disc part  10 , as in prior art. 
       FIG.  5   a    is a zoomed section view of the hub part  30  of the weightlifting disc  1  with a first type of insert  36  mounted to the hub part  30 . The section shows how the holes  25  of the reinforcing device  20  is filled with the elastomeric material of the disc part  10 , and how the outer ring  22  and the inner ring  21  of the reinforcing device  20  is enclosed into the elastomeric material. The inner edge  12  of the disc part  10  is arranged such as the inner ring  21  of the reinforcing device  20  is arranged at a distance a from the inner edge  12  of the disc part  10 , such as elastomeric material is arranged between the inner edge  12  of the disc part  10  and the reinforcing device  20 . The first half  30   a  and the second half  30   b  of the hub part  30  are fixedly attached to each other by screws  37  such as the inner edge  12  and its protruding part  12   a  is pressed between the halves  30   a ,  30   b , wherein the hub part  30  is very robust attached to the disc part  10  and wherein there is elastomeric material between the hub  30  and the reinforcing device  20 , The latter is shown to be very positive due to dampening characteristics and the total lifetime of the elastomeric weightlifting disc  1 , Further, the insert  36  in the form of the cylinder-shaped insert  36  presented in  FIG.  3   a - b   , is attached in the center hole  35  of the hub part  30 . The insert  36  may be in plastic or in metal, but most preferred is a plastic insert  36 . The insert  36  acts as a vibration dampener and a silencer between the bar and the hub part  30  and the insert  36  may be moulded to the hub/hub parts  30   a ,  30   b  or may be a loose or pressed in place in the hub part  30 . 
       FIG.  5   b    is a zoomed section view of the hub part  30  of the weightlifting disc  1  with a second type of insert  36  mounted to the hub part  30 . This second type is an alternative insert  36  which has an outer flange which extends radially outwards a short distance from the cylinder body and by that rests at an outside of the respective halves  30   a ,  30   b  of the hub part  30 . The first and second halves  30   a ,  30   b  may be arranged with a recess to accommodate the flange of the insert  36  as may be seen in the figure. 
       FIG.  6   a    shows a front view of an alternative reinforcing device  20  and  FIG.  6   b    shows a section view of the reinforcing device of  FIG.  6   a   . This type has the same functionality as the one described above ( FIG.  4   c - d   ) and is also ring-shaped and comprises a cylindrical inner ring  21 , a cylindrical outer ring  22  and an annular body  23 , which connects the inner ring  21  and the outer ring  22 . In the preferred embodiment, the outer ring  22  is slightly wider than the inner ring  21  and the annular body  23  has a tapered extension, at least partly, from the wider outer ring  22  to the narrower inner ring  21 . The annular body  23  comprises a plurality of partitions  23   a , which extends between the inner ring  21  and the outer ring  22  in different directions and thereby forms a “pattern”, such as the plurality of partitions  23   a  together or with the inner ring  21  and/or the outer ring  22  forms the holes  25  of the reinforcing device  20 . The holes  25  have the same function as described above. 
     Although the description above contains a plurality of specificities, these should not be construed as limiting the scope of the concept described herein but as merely providing illustrations of some exemplifying embodiments of the described concept. It will be appreciated that the scope of the presently described concept fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the presently described concept is accordingly not to be limited, Reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural and functional equivalents to the elements of the above-described embodiments that are known to those of ordinary skill in the art are expressly incorporated herein and are intended to be encompassed hereby.