Abstract:
Implementations of the present invention relate to devices, systems, and methods for the safe and efficient use of exercise equipment and, in particular, weight training equipment. A locking hub for weight training equipment may include a first hub and second hub, the first hub and second hub having a sleeve located therebetween. The first hub and/or second hub may hold one or more pads adjacent the sleeve. Rotation of the sleeve relative to the first hub and/or the second hub may compress the one or more pads to force the pads radially inward against a weight bar, substantially restricting movement of the locking hub relative to the weight bar.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     N/A 
     BACKGROUND OF THE DISCLOSURE 
     Free weights provide weight resistance during strength training exercises. For example, a strength training device or system may include a bar having a grip in the center and weight loading areas on either side of the grip. A user may load one or more weight plates onto the weight loading areas to increase the weight of the bar. The user may load the weight plates onto the bar such that there is an equal weight distribution on either side of the grip. An equal weight distribution will minimize the torque placed on the bar and balance the bar during the weight training exercises. Lateral movement of the weight plates before and/or during the exercise may make the bar more difficult for a user to control during the exercise and may create additional risks to the user, individuals in the vicinity, or surrounding objects. 
     In a fitness center or gym, the space between exercise equipment may be limited. A poorly-controlled bar and/or weights may create a hazard to the user or other individuals in the gym. In the case of commercial gyms, the increased risk created by a poorly-controlled bar and/or weights may, in turn, increase liability for the gym. 
     Bar clamps are often used to restrict the lateral movement of weight plates on a bar. The bar clamps may be added to either end of the bar near or abutting the weight plates. The bar clamps may be, for example, a spring clamp that a user may expand to slide over the end of the bar, place adjacent the weight plates, and then release to allow the spring clamp to constrict onto the bar. Other clamps commonly used to restrict the lateral movement of weights on a bar include screw clamps. A user may slide a screw clamp over the end of the bar, place it next to the weights, and then tighten a screw in the clamp that secures the claim in place on the bar. Both screw and spring bar clamps are separate components from the bar and from the weight plates that must be completely removed from and replaced on the bar to remove or change weight plates. These bar clamps are also stored separately between usages of the bar and weight plates. However, the complete removal of the bar clamps from the bar each time a user removes or changes the weight plates increases the chance that the bar clamps may be lost or broken. Additionally, to save costs and reduce clutter, gyms typically have a limited number of bar clamps available for use. Given the limited number of bar clamps, users often do not take the time to locate them if they are not readily available at the station at which the user is loading his or her weights. Additionally, bar clamps and spring clamps can become stiff, thereby making them difficult for users to properly place and secure on the bar. Further, users who are performing sets of exercises successively with minimum rest time between sets, commonly referred to as performing “super sets,” often do not use bar or spring clamps because they increase the time required to change the weights in between sets. In view of these and other limitations of conventional screw and spring clamps, a need exists for an improved device and system for limiting the lateral movement of weights on a bar. 
     BRIEF SUMMARY OF THE DISCLOSURE 
     This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify specific features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. 
     In a first non-limiting embodiment, a locking hub includes a first and second hub, each hub having an outer axial surface and an inner axial surface, and sharing a longitudinal axis. The first hub includes extensions that may interlock with extensions on the second hub when inserted into a sleeve. An axial bore extends through the first hub, second hub, and the sleeve along the longitudinal axis. The sleeve is rotatable relative to the first hub and second hub, and the sleeve has an inner radial surface and an outer radial surface. At least a first portion of the inner radial surface has a first radius relative to the longitudinal axis and at least a second portion of the inner radial surface has a second radius relative to the longitudinal axis. The first radius is greater than the second radius. The locking hub also includes at least one pad between the sleeve and the first hub or the second hub. The at least one pad has a compressed state and a relaxed state. The at least one pad is in the compressed state when rotationally aligned with the second portion of the sleeve and in the relaxed state when rotationally aligned with the first portion of the sleeve. 
     In a second non-limiting embodiment, a system may include a locking hub, a weight plate, and a weight bar. The locking hub includes a first and second hub, each having an outer axial surface and an inner axial surface, and sharing a longitudinal axis. The first hub includes extensions that may interlock with extensions on the second hub when inserted into a sleeve. The inner axial surfaces of the two hubs oppose one another and the sleeve is located between the hubs. An axial bore extends through the first hub, second hub, and the sleeve along the longitudinal axis. The sleeve is rotatable relative to the first hub and second hub, and the sleeve has an inner radial surface and an outer radial surface. At least a first portion of the inner radial surface has a first radius relative to the longitudinal axis and at least a second portion of the inner radial surface has a second radius relative to the longitudinal axis. The first radius is greater than the second radius. The locking hub also includes at least one pad between the sleeve and the first hub or the second hub. The at least one pad has a compressed state and a relaxed state. The at least one pad is in the compressed state when rotationally aligned with the second portion and in the relaxed state when rotationally aligned with the first portion. The weight plate may be connected to the sleeve or may be integrally formed with the sleeve, such that the inner radial surface of the sleeve is the inner radial surface of the weight plate. The bar has a grip portion, a weight portion, and a weight stop located between the grip portion and weight portion. The weight stop has a stop outer axial surface toward the weight portion with one or more bar engagement features. The bar engagement features may be connected to the outer axial surface and configured to engage with the one or more first engagement features of the locking hub. 
     In yet another non-limiting embodiment, a method of use of a locking hub as described herein includes providing a locking hub according to the present disclosure in an unlocked state and positioning the locking hub on a bar or other object extending through an axis of the locking hub. The method includes rotating a first hub of the locking hub relative to a sleeve and compressing a pad against the bar or other object and thereby restricting or substantially preventing lateral movement of the locking hub relative to the bar or other object. 
     Additional features of embodiments of the disclosure will be set forth in the description which follows. The features of such embodiments may be realized by means of the instruments and combinations particularly pointed out in the appended claims. These and other features will become more fully apparent from the following description and appended claims, or may be learned by the practice of such exemplary implementations as set forth hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to describe the manner in which the above-recited and other features of the disclosure can be obtained, a more particular description will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. For better understanding, the like elements have been designated by like reference numbers throughout the various accompanying figures. While some of the drawings may be schematic or exaggerated representations of concepts, at least some of the drawings may be drawn to scale. Understanding that the drawings depict some example embodiments, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
         FIG. 1  is a perspective view of a locking hub, according to one or more embodiments disclosed herein; 
         FIG. 2  is a perspective exploded view of a locking hub, according to one or more embodiments disclosed herein; 
         FIG. 3  is a cross-sectional end view of a locking hub in a locked position, according to one or more embodiments disclosed herein; 
         FIG. 4  is a cross-sectional end view of a locking hub in an unlocked position, according to one or more embodiments disclosed herein; 
         FIG. 5  is an end view of a locking hub including engagement features, according to one or more embodiments disclosed herein; 
         FIG. 6  is a side view of a locking hub including engagement features, according to one or more embodiments disclosed herein; 
         FIG. 7  is a perspective view of two locking hubs including engagement features that are engaged, according to one or more embodiments disclosed herein; 
         FIG. 8  is a perspective cutaway view of a locking hub having a visual indicator in an unlocked position, according to one or more embodiments disclosed herein; 
         FIG. 9  is a perspective cutaway view of a locking hub having a visual indicator in a locked position, according to one or more embodiments disclosed herein; 
         FIG. 10  is a perspective cutaway view of a free weight system including a locking hub, according to one or more embodiments disclosed herein; and 
         FIG. 11  is a flowchart depicting a method of use of a locking hub according to one or more embodiments disclosed herein. 
     
    
    
     DETAILED DESCRIPTION 
     One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, some features of an actual embodiment may be described in the specification. It should be appreciated that in the development of any such actual embodiment, as in any engineering or design project, numerous embodiment-specific decisions will be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one embodiment to another. It should further be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     One or more embodiments of the present disclosure may generally relate to securing an object about a bar located therethrough. More particularly, one or more embodiments of the present disclosure may relate to securing weight plates on exercise equipment. 
       FIG. 1  is a perspective view of an embodiment of a locking hub  100 . The locking hub  100  may include a first hub  102  and a second hub  104 . The first hub  102  and second hub  104  may have a sleeve  106  located therebetween. The first hub  102  and/or second hub  104  may be made of and/or include various materials including metals, plastics, ceramics, or combinations thereof. In an embodiment, the first hub  102  and/or second hub  104  may be made of and/or include a metal such as steel alloys, aluminum alloys, titanium alloys, other alloys, other metals, or combinations thereof. In another embodiment, the first hub  102  and/or second hub  104  may be made of and/or include a plastic such as a molded or machined thermoplastic such as styrenic block copolymers, elastomeric alloys, thermoplastic polyurethanes, thermoplastic copolyesters, or thermoplastic polyamides; or thermosetting polymer such as polyurethane, fiberglass, or resins. The first hub  102  and/or second hub  104  may have one or more pads  108  contained therein. The pads  108  may be made of and/or include a molded or machined thermoplastic such as styrenic block copolymers, elastomeric alloys, thermoplastic polyurethanes, thermoplastic copolyesters, or thermoplastic polyamides. 
     The first hub  102  and/or second hub  104  may include one or more retention members  110 . The retention members  110  may be connected to a surface of the first hub  102  and/or second hub  104 . In another embodiment the retention members  110  may be integrally formed with the first hub  102  and/or second hub  104 . In an embodiment, the retention members  110  may extend from an inner axial surface of the first hub  102  and/or second hub  104 . In another embodiment, the retention members  110  may be connected to or integrally formed with a radial surface of the first hub  102  and/or second hub  104  and extend axially. The retention members  110  may limit movement of the pads  108  relative to the retention members  110  and, therefore, limit movement of the pads  108  relative to the first hub  102  and/or second hub  104 . 
     The retention members  110  may limit movement of the first hub  102  and second hub  104  relative to one another. In some embodiments, the retention members  110  may include mating features  109  located thereon. The mating features  109  may allow the retention members  110  to engage with and lock to one or more complimentary features  111  on another retention member  110 . For example, the retention members  110  may include a plurality of complimentary features  111  at various axial positions relative to the locking hub  100  such that the locking hub  100  may have a variable length such that it may accommodate varying lengths of a sleeve  106 . The adjustable length of locking hub  100  allows the locking hub  100  to be used with weight plates of varying thicknesses. The mating features  109  may engage with the complimentary features  111  by a press fit, a snap fit, a friction fit, an adhesive, a material bond, one or more threads, or combinations thereof. In other embodiments, the mating features  109  may engage with and lock to complimentary features  111  located on other components, such as a first hub  102  and/or second hub  104 . 
       FIG. 2  is an exploded view of a locking hub  200 .  FIG. 2  depicts the relative position of the components of the locking hub  200 . A sleeve  206  is located between a first hub  202  and second hub  204 . The first hub  202  and/or second hub  204  may include one or more retention members  210 . In some embodiments, the first hub  202  may include three retention members  210  and the second hub  204  may include three retention members  210 . Each retention member  210  may align with and/or be associated with a pad  208 . Each pad  208  may include a body  212  and wings  214 . In some embodiments, the body  212  and wings  214  may be integrally formed with one another. For example, in the depicted embodiment, the body  212  and wings  214  are injection molded as a continuous piece. The pad  208  may include a textured surface  216  such that a surface of the body  212  and/or wings  214  may have an increased coefficient of friction relative to an untextured surface. 
     The body  212  of the pad  208  may align with a channel  220  in the retention member  210 . In some embodiments, the body  212  may protrude from the channel  220 . In other embodiments, the body  212  may be flush with a surface of the retention member  210  or recessed with the channel  220 . The wings  214  of the pad  208  may be aligned with and/or contact one or more sloped surfaces  218  of the retention member  210 . The sloped surface  218  may be curved and/or substantially planar. The sloped surface  218  may have a portion that forms an angle with a surface of the associated retention member  210  in a range having upper and lower values including 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, or any value therebetween. For example, the sloped surface  218  may have a portion that forms an angle with a surface of the associated retention member  210  in a range between 20° and 70°, between 30° and 60°, or between 35° and 55°. The sloped surfaces  218  may apply a radial force to the pad  210  to limit or, in some instances, prevent movement of the pad  210  in a radial direction relative to the sleeve  206 . The sloped surfaces  218  may apply a lateral force to the pad  210  to limit or, in some instances, prevent movement of the pad  210  in a lateral and/or rotational direction relative to the sleeve  206 . 
       FIGS. 3 and 4  show cross-section views of locking hubs  300 ,  400 , respectively. The cross-sectional view of locking hub  300  in  FIG. 3  depicts the locking hub  300  in a locked state. The locking hub  300  may have a locked state and an unlocked state. A sleeve  306  located between a first hub (not shown) and a second hub  304  has more than one inner radius. In particular, the sleeve  306  may include a one or more unlocked recesses  322  and one or more locked recesses  324  in an inner radial surface  326 . The one or more unlocked recesses  322  may be a portion of the inner radial surface  326  having a first radius. The one or more locked recesses  324  may be a portion of the inner radial surface  326  having a second radius. The first radius may be greater than the second radius. 
     In other embodiments, the sleeve  306  may include one or more protrusions (not shown) extending radially inward from the inner radial surface  326  such that a first portion of the inner radial surface  326  has a first radius, and a second portion of the inner radial surface  326  has a second radius. In yet other embodiments a combination of both protrusions (not shown) and recesses  322  and/or  324  may be used to create varying radii for the inner radial surface  326 . The body  312  of the pad  308  may include one or more recesses (not shown). The recesses in the body  312  may complimentarily mate with the protrusions on the inner radial surface  326  when in the locked and/or unlocked position. The protrusions in the inner radial surface  326  may apply a force to the pads  308  when not aligned with the one or more recesses in the body  312  such that the pads are in a compressed state. When aligned with the one or more recesses in the body  312 , the one or more protrusions may apply less or substantially no force to the pads  308  such that the pads may be in a relaxed state. 
       FIG. 3  shows a pad  308  in a compressed state. In a compressed state, the sleeve  306  may be rotated relative to the locking hub  300  such that at least one of the locked recesses  324  is substantially aligned with a body  312  of a pad  308 . Each pad  308  may be at least partially within a retention member  310 . The radial inner surface  326  of the sleeve  306  may apply a force to the pad  308  radially inward. The sloped surfaces  318  of the retention member  310  may apply a force to the pad  308  having a component radially outward and a component toward the body  312 . The pad  308  may compress at least partially due to the force applied by the sloped surface  318 . The pad  308  may compress and extend through the channel  320  of the retention member  310 . The channel  320  may be open and allow the pad  308  to extend beyond a surface of the retention member  310  such that the pad  308  may engage another object, such as a weight bar as will be described in relation to  FIG. 10 , and apply a frictional force thereto to limit motion of the locking hub  300  relative to the object. The body  312  of the pad  308  may include one or more relief cuts  328  in a surface thereof. The relief cuts  328  may facilitate preferred compression of a portion of the pad  308  against another, such as a bar. For example, the relief cuts  328  may be longitudinal cuts in a surface of the body  312  that allow for more lateral compression (i.e., perpendicular to the longitudinal cuts) than compression in another direction relative to the body  312 . 
     In other embodiments, the sleeve  306  may include unlocked recesses  322  and have a constant radius of the inner radial surface  326  therebetween. For example, the sleeve  306  may not include locked recesses  324 . In such an embodiment, the inner radial surface  326  may apply a force radially inward against the pads  308  such that the pads  308  may be in a compressed state. The unlocked recesses  322  may be distributed evenly about the circumference of the inner radial surface  326  of the sleeve. The unlocked recesses  322  may, therefore, provide one or more unlocked positions of the locking hub  300  in which the sleeve  306  is oriented at one or more predetermined positions relative to the first hub  302  and/or second hub  304 . All other positions of the sleeve  306  relative to the first hub  302  and/or second hub  304  may result in the locking hub  300  being in a locked state. 
       FIG. 4  shows a pad  408  in a relaxed state. In a relaxed state, a sleeve  406  of a locking hub  400  rotated relative to a first hub (not shown) and a second hub  404  such that at least one of the unlocked recesses  422  of the radial inner surface  426  is substantially aligned with a body  412  of the pad  408 . The unlocked recess  422  may have a radius that is larger than that of a locked recess  424 . When in a relaxed state, the pad  408  may be in an uncompressed or less compressed state relative to a pad in a compressed state. One or more relief cuts  428  may expand when a radially inward force on the pad  408  is reduced or removed. The expansion of the relief cuts  428  may encourage a preferred lateral expansion of the body  412  against the sloped surfaces  418  of the retention members  410 . The expansion of the body  412  against the sloped surface  418  of the retention member  410  may urge the pad  408  toward the sleeve  406 . In some embodiments, a portion of the pad  408  may protrude from the channel  420 . In other embodiments, a portion of the pad  408  may extend from the channel  420  and the body  412  may be flush with or recessed from radial inner surface of the retention members  410 . 
     One or more of the locked recesses  424  and/or one or more of the unlocked recessed  422  may include a curved surface relative to the radial inner surface  426 . In an embodiment, one or more of the locked recesses  424  and/or one or more of the unlocked recessed  422  may be radially symmetrical relative to the sleeve  406  such that the pad  408  will expand and preferentially rest substantially centered in one or more of the locked recesses  424  and/or one or more of the unlocked recessed  422 . In such an embodiment, the sleeve  406  may be rotated relative to the first hub and/or second hub  404  in either rotational direction (i.e., clockwise and counterclockwise). A force applied between the pads  408  and the sleeve  406  may be substantially equal in either direction. In another embodiment, one or more of the locked recesses  424  and/or one or more of the unlocked recessed  422  may be radially asymmetrical relative to the sleeve  406  such that compression of the pad  408  may be more gradual and/or easier when moving the sleeve  406  and pad  408  relative to one another in a first direction when compared to moving the sleeve  406  and the pad  408  relative to one another in a second direction. One or more of the locked recesses  424  and/or one or more of the unlocked recessed  422  being radially asymmetrical may create a tactile feel for a user that there is a preferred rotational direction for entering and/or exiting a locked and/or unlocked state of the locking hub  400 . 
       FIG. 5  is an exterior side view of a locking hub  500 . The locking hub  500  may include an axial bore  530  having a longitudinal axis  532  therethrough. The locking hub  500  may include first hub  502  having one or more engagement features  534 . The one or more engagement features  534  may be spaced evenly about a circumference of the first hub  502 . The one or more engagement features  534  may be separated by one or more engagement spaces  536  spaced evenly about the circumference of the first hub  502  and alternatingly with the engagement features  534 . In other embodiments, the engagement features  536  may be spaced or otherwise located unevenly about the circumference of the first hub  502 . It should be understood that while the engagement features  534  and the associated engagement spaces  536  are described and depicted in relation to the first hub  502 , the engagement features  534  and the associated engagement spaces  536  may also be located on a corresponding second hub as shown in  FIG. 6 . 
       FIG. 6  depicts a locking hub  600  having a first hub  602  and a second hub  604 . The first hub  602  may have a plurality of engagement features  634  and engagement spaces  636 . The second hub  604  may have a plurality of engagement features  634  and engagement spaces  636 . The first hub  602  may have an outer axial surface  638  and an inner axial surface  640 . The engagement features  634  and engagement spaces  636  may be located on the outer axial surface  638  and the inner axial surface  640  may be proximate and/or abutting a sleeve  606 . Similarly, the second hub  604  may have an outer axial surface  638  and an inner axial surface  640 . The engagement features  634  and engagement spaces  636  may be located on the outer axial surface  638  and the inner axial surface  640  may be proximate and/or abutting a sleeve  606 . 
     As shown in  FIG. 6 , the first hub  602  and second hub  604  may be similar or identical. In some embodiments, the first hub  602  and second hub  604  of the locking hub  600  may be substantially rotationally aligned. For example, the engagement features  634  of the first hub  602  may be substantially rotationally aligned (i.e., may fall along a common longitudinal line) with the engagement features  634  of the second hub  604 . In other embodiments, the first hub  602  and second hub  604  may not be similarly rotationally aligned. For example, the engagement features  634  of the first hub  602  may substantially align with the engagement spaces  636  of the second hub  604 . In yet other embodiments, the engagement features  634  of the first hub  602  and second hub  604  may not align with any feature or space on the first hub  602  and/or second hub  604 . 
       FIG. 7  depicts a pair of locking hubs  700 - 1 ,  700 - 2  engaged with one another. In an embodiment, a first locking hub  700 - 1  and a second locking hub  700 - 2  may be similar or identical to one another. For example, first locking hub  700 - 1  may share all components with second locking hub  700 - 2 , such that first locking hub  700 - 1  and/or second locking hub  700 - 2  may engaged in the described fashion with any number of similar locking hubs a user may use. 
     The first locking hub  700 - 1  and/or second locking hub  700 - 2  may each have a first hub  702 - 1 ,  702 - 2  and a second hub  704 - 1 ,  704 - 2 , respectively. In the depicted embodiment, the first hub  702 - 1 ,  702 - 2  and a second hub  704 - 1 ,  704 - 2  may be identical and/or interchangeable (e.g., first locking hub  700 - 1  may be inverted without altering the function of the first locking hub  700 - 1 ) and, therefore, it should be understood that “first hub” and “second hub” are merely used as directional indicators relative to depicted positions. The first locking hub  700 - 1  may engage with the second locking hub  700 - 2 . Engagement features  734 - 1  of the first locking hub  700 - 1  may engage with the engagement features  734 - 2  of the second locking hub  700 - 2 . In the depicted embodiment, the engagement features  734 - 1  of the first locking hub  700 - 1  may substantially mate with the engagement spaces  736 - 2  of the second locking hub  700 - 2 . The engagement features  734 - 2  of the second locking hub  700 - 2  may substantially mate with the engagement spaces  736 - 1  of the first locking hub  700 - 1 . 
     The interlocking engagement of the locking hubs  700 - 1 ,  700 - 2  may facilitate the locking/unlocking of the hubs  700 - 1 ,  700 - 2 . For example, the interlocking engagement of the locking hubs  700 - 1 ,  700 - 2  may rotationally fix the first hub  702 - 1  of the first locking hub  700 - 1  with the second hub  704 - 2  of the second locking hub  700 - 2 . While the first hub  702 - 1  of the first locking hub  700 - 1  is engaged with the second hub  704 - 2  of the second locking hub  700 - 2 , the second locking hub  700 - 2  may be moved into a locked state and/or an unlocked state without a user manually fixing the position of the first hub  702 - 2  and/or second hub  704 - 2  (e.g., when a plurality of locking hubs are aligned and engaged in series when on a weight bar as will be described in more detailed in relation to  FIG. 10 ). 
       FIGS. 8 and 9  are cutaway views of locking hubs  800 ,  900  that include visual indicators  842 ,  942  to indicate when the locking hub  800 ,  900  is in a locked state and/or an unlocked state. As shown in  FIG. 8 , the locking hub  800  may include a visual indicator  842 . In some embodiments, the visual indicator  842  may include an opening and a pattern, color, light, other selectable visual cue, or combinations thereof visible through the opening. In other embodiments, the visual indicator may include a pattern, color, light, display, readout, or other selectable visual cue located on a surface of the locking hub. In  FIG. 8 , the locking hub  800  is depicted in an unlocked state with a pad in a relaxed state flush with and/or recessed within a surface of a retention member  810 . A first visual cue  844  may be visible in the visual indicator  842  when the locking hub  800  is in an unlocked state. 
     As shown in  FIG. 9 , a second visual cue  946  may be visible through a visual indicator  942  when a locking hub  900  is in a locked state. A pad  908  may be in a compressed state and protrude from a retention member  910  when the second visual cue  946  is visible through the visual indicator. For example, the first visual cue  844  in  FIG. 8  and the second visual cue  946  in  FIG. 9  may be located on a sleeve (not shown). When the sleeve is moved relative to the visual indicator  842 ,  942 , the first visual indicator  844  and the second visual indicator  946  may move with the sleeve, becoming selectively visible in association with the relative position of the sleeve. The relative position of the sleeve may at least partially determine whether the pad  908  is in a compressed or relaxed state and, hence, whether the locking hub  900  is in a locked or unlocked state. The visual indicator  942  may thereby provide a visual indication as to the state of the locking hub  900 . 
       FIG. 10  depicts a system  1050  including a locking hub  1000  located between a weight plate  1048  and a weight bar  1052 . The weight bar  1052  may include a weight portion  1054  and a grip portion  1056 . A user may load weight plates  1048  onto the weight portion  1054  of the weight bar  1052  prior to a weight training exercise while the locking hub  1000  is in an unlocked state. The weight bar  1052  may include a weight stop  1058  that is positioned between the grip portion  1056  and the weight portion  1054 . The weight stop  1058  may include one or more bar engagement features  1060  and/or bar engagement spaces  1062  on an outer axial surface thereof. The bar engagement features  1060  may be configured to engage with the engagement features  1034  and/or engagement spaces  1036  of the locking hub  1000 . 
     The locking hub  1000  may be located within an axial bore of the weight plate  1048 . In an embodiment, the locking hub  1000  may be connected to the weight plate  1048  by a press fit, a friction fit, an adhesive, one or more threads, a material bond, or combinations thereof such that the weight plate  1048  and a sleeve (not shown) may be rotationally fixed relative to one another. In other embodiments, the locking hub  1000  may be at least partially integrally formed with the weight plate  1048 . For example, the sleeve may be integrally formed with the weight plate  1048  and/or an inner radial surface of the weight plate  1048  may directly contact the pads (not shown) of locking hub  1000 . 
     The weight plate  1048  and locking hub  1000  may be placed on the weight portion  1054  of the weight bar  1052  such that the weight portion  1054  extends through an axial bore of the locking hub  1000  (see axial bore  530  in  FIG. 5 ). The weight plate  1048  and locking hub  1000  may be advanced on the weight portion  1054  until the locking hub  1000  contacts the weight stop  1058 . In some embodiments, the engagement features  1034  of the locking hub may engage the bar engagement features  1060  when the locking hub  1000  is adjacent the weight stop  1058 . The bar engagement features  1060  may rotationally fix the engagement features  1034  of the locking hub  1000  relative to the weight bar  1052 . A user may then rotate the weight plate  1048  relative to the weight bar  1052  until the locking hub  1000  reaches a locked state, which may be indicated by a visual indicator such as described in relation to  FIGS. 8 and 9 , or until the user feels a tactile change in the resistance of the locking hub  1000  as the pads move between unlocked and locked recesses as described in relation to  FIGS. 3 and 4 . 
     In an embodiment including a plurality of weight plates  1048  on a weight portion  1054 , an outermost weight plate  1048  may partially or substantially limit the lateral movement of one or more inner weight plates. In such an embodiment, the interlocking engagement of the plurality of locking hubs  1000  may rotationally fix all of the first and/or second hubs relative to the weight bar  1052  (as described in relation to  FIG. 7 ). The outermost weight plate  1048  may be rotated relative to the weight bar  1052  to move the locking hub  1000  to a locked state. 
     A method  1164  of use, as shown in  FIG. 11 , may include providing  1166  a locking hub according to the present disclosure in an unlocked state and positioning  1168  the locking hub on a bar or other object extending through an axis of the locking hub. The method  1164  may include rotating  1170  a first hub of the locking hub relative to a sleeve and compressing  1172  a pad against the bar or other object and thereby restricting  1174  or substantially preventing lateral movement of the locking hub relative to the bar or other object. The method  1164  may also include rotating the first hub of the locking device and relaxing the pad from the bar or other object to ease movement of the locking hub relative to the bar or other object. In doing so, a locking hub according to the present disclosure may effectively and reliably retain one or more weight plates on a weight bar with an integrated locking mechanism. 
     The articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements in the preceding descriptions. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Numbers, percentages, ratios, or other values stated herein are intended to include that value, and also other values that are “about” or “approximately” the stated value, as would be appreciated by one of ordinary skill in the art encompassed by embodiments of the present disclosure. A stated value should therefore be interpreted broadly enough to encompass values that are at least close enough to the stated value to perform a desired function or achieve a desired result. The stated values include at least the variation to be expected in a suitable manufacturing or production process, and may include values that are within 5%, within 1%, within 0.1%, or within 0.01% of a stated value. 
     A person having ordinary skill in the art should realize in view of the present disclosure that equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations may be made to embodiments disclosed herein without departing from the spirit and scope of the present disclosure. Equivalent constructions, including functional “means-plus-function” clauses are intended to cover the structures described herein as performing the recited function, including both structural equivalents that operate in the same manner, and equivalent structures that provide the same function. It is the express intention of the applicant not to invoke means-plus-function or other functional claiming for any claim except for those in which the words ‘means for’ appear together with an associated function. Each addition, deletion, and modification to the embodiments that falls within the meaning and scope of the claims is to be embraced by the claims. 
     The terms “approximately,” “about,” and “substantially” as used herein represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” and “substantially” may refer to an amount that is within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of a stated amount. Further, it should be understood that any directions or reference frames in the preceding description are merely relative directions or movements. For example, any references to “up” and “down” or “above” or “below” are merely descriptive of the relative position or movement of the related elements. 
     The present disclosure may be embodied in other specific forms without departing from its spirit or characteristics. The described embodiments are to be considered as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. Changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.