Patent Publication Number: US-2023147755-A1

Title: Weight Plate

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 17/089,338, filed Nov. 4, 2020, which claims priority to U.S. Provisional Application No. 62/930,423, filed Nov. 4, 2019, which prior applications (including the Appendix filed with Application No. 62/930,423) are incorporated by reference herein in their entireties. 
    
    
     FIELD OF THE INVENTION 
     This disclosure relates to weight plates for use in weightlifting exercises, and more specifically to weight plates with features for reducing noise and/or vibration when the weight plate is dropped from an elevated position. 
     BACKGROUND 
     Weightlifting exercises are performed in a large variety of different settings, including large gyms, small gyms, homes, among many other locations. Such settings may be located in an area where loud noise is a potential issue, such as within a home or residential area or close to another business. Weight plates are one of the most frequently used types of weightlifting equipment. In some exercises, barbells weighted with weight plates are dropped from a height to the ground, such as from waist height, shoulder height, head height, etc., and such dropping can create significant noise. There is a need for providing a weight plate that reduces the noise emitted when dropping the weight plates from a height, while also retaining plate durability and safety. 
     The present disclosure is provided to address this need and other needs in existing weight plates. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings. 
     BRIEF SUMMARY 
     Aspects of the disclosure relate to a weight plate that includes an outer body formed of a first material and an inner body formed of a second material having a larger density and lower flexibility than the first material. The outer body includes an inner section having an annular shape with a passage extending axially through the inner section and configured to receive an elongated member therethrough, the inner section having a first axial thickness, a middle section having an annular shape and positioned radially outward of the inner section, the middle section including first and second outer surfaces on opposite axial sides of the outer body, with a second axial thickness defined between the first and second outer surfaces, and an outer section having an annular shape and positioned radially outward of the middle section and forming an outer radial periphery of the weight plate, where the outer section has a third axial thickness. The first axial thickness and the third axial thickness are greater than the second axial thickness. The inner body is contained within the inner section of the outer body. The middle section has a plurality of recesses extending axially inward from the first and second outer surfaces through a portion of the second axial thickness, and the plurality of recesses include a plurality of first-shaped recesses having a first peripheral shape with a first number of sides and a plurality of second-shaped recesses having a second peripheral shape that is different than the first peripheral shape and with a second number of sides that is different from the first number of sides. Each of the first-shaped recesses on the first outer surface is axially aligned with another of the first-shaped recesses on the second outer surface to form a pair of first-shaped recesses separated by a first inner wall, and each of the second-shaped recesses on the first outer surface is axially aligned with another of the second-shaped recesses on the second outer surface to form a pair of second-shaped recesses separated by a second inner wall. 
     According to one aspect, the outer body surrounds the inner body on at least both axial sides and an outer radial side thereof. 
     According to another aspect, the inner body is formed of a single piece, and the outer body is molded around the inner body as a single piece. 
     According to a further aspect, the plurality of recesses further include a plurality of third-shaped recesses having a third peripheral shape that is different from the first peripheral shape and the second peripheral shape and a third number of sides that is different from the first number of sides and the second number of sides. 
     According to yet another aspect, the first-shaped recesses each have a first perimeter defined at the first or second outer surface and a first volume, and the second-shaped recesses each have a second perimeter defined at the first or second outer surface that is different from the first perimeter and a second volume that is different from the first volume. 
     Additional aspects of the disclosure relate to a weight plate that includes a first section having an annular shape with a passage extending axially through the first section and configured to receive an elongated member therethrough, and a second section having an annular shape and positioned radially outward of the first section, where the second section includes first and second outer surfaces on opposite axial sides of the weight plate with an axial thickness defined between the first and second outer surfaces. The second section has a plurality of first recesses each extending axially inward from the first outer surface partially through the axial thickness of the second section to a first end recessed from the first outer surface, and a plurality of second recesses each extending axially inward from the second outer surface partially through the axial thickness of the second section to a second end recessed from the second outer surface. Each of the first recesses is axially aligned with one of the second recesses to form an aligned pair of recesses, such that an inner wall separates the first and second recesses of each aligned pair of recesses and defines the first and second ends of the first and second recesses of each aligned pair of recesses. 
     According to one aspect, the first and second recesses of each aligned pair of recesses have identical sizes and shapes. In one configuration, the plurality of first recesses and the plurality of second recesses each include a plurality of first-shaped recesses having a first shape and a plurality of second-shaped recesses having a second shape that is different from the first shape, where each first-shaped recess of the plurality of first recesses is axially aligned with one of the first-shaped recesses of the plurality of second recesses, and each second-shaped recess of the plurality of first recesses is axially aligned with one of the second-shaped recesses of the plurality of second recesses. In a further configuration, the plurality of first recesses and the plurality of second recesses each further include a plurality of third-shaped recesses having a third shape that is different from the first shape and the second shape, and wherein each third-shaped recess of the plurality of first recesses is axially aligned with one of the third-shaped recesses of the plurality of second recesses. 
     According to another aspect, each of the first recesses and each of the second recesses extend through less than half of the axial thickness of the second section. 
     According to a further aspect, the weight plate further includes a third section having an annular shape and positioned radially outward of the second section and forming an outer radial periphery of the weight plate. In one configuration, the third section has a greater axial thickness than the second section. 
     According to a still further aspect, the weight plate further includes an inner body having a larger density than a material forming the first and second outer surfaces, wherein the inner body is contained within the inner section. 
     According to yet another aspect, the second section is positioned immediately radially outward of the first section and is adjacent to the first section. 
     Further aspects of the disclosure relate to a weight plate including a first section having an annular shape with a passage extending axially through the first section and configured to receive an elongated member therethrough, and a second section having an annular shape and positioned radially outward of the first section, where the second section includes first and second outer surfaces on opposite axial sides of the weight plate with an axial thickness defined between the first and second outer surfaces. The second section has a plurality of recesses extending axially inward from at least one of the first and second outer surfaces through at least a portion of the second axial thickness, and the plurality of recesses comprise a plurality of first-shaped recesses having a first peripheral shape with a first number of sides and a plurality of second-shaped recesses having a second peripheral shape that is different than the first peripheral shape and with a second number of sides that is different from the first number of sides. 
     According to one aspect, the first peripheral shape is a first polygonal shape, and the second peripheral shape is a second polygonal shape, and the first and second polygonal shapes each comprise a plurality of flat, planar sides that extend axially inward and are joined by a plurality of corners defined therebetween. 
     According to another aspect, the plurality of recesses further includes a plurality of third-shaped recesses having a third peripheral shape that is different from the first peripheral shape and the second peripheral shape and a third number of sides that is different from the first number of sides and the second number of sides. 
     According to a further aspect, the first-shaped recesses extend axially inward from both of the first and second outer surfaces, and the second-shaped recesses extend axially inward from both of the first and second outer surfaces. In one configuration, each of the first-shaped recesses on the first outer surface is axially aligned with another of the first-shaped recesses on the second outer surface to form a pair of first-shaped recesses separated by a first inner wall, and each of the second-shaped recesses on the first outer surface is axially aligned with another of the second-shaped recesses on the second outer surface to form a pair of second-shaped recesses separated by a second inner wall. 
     According to yet another aspect, the first-shaped recesses each have a first volume and the second-shaped recesses each have a second volume that is different from the first volume. 
     According to a still further aspect, the first-shaped recesses each have a first perimeter defined at the first or second outer surface, and the second-shaped recesses each have a second perimeter defined at the first or second outer surface that is different from the first perimeter. 
     Still further aspects of the disclosure relate to a weight plate including an outer body formed of a first material and an inner body formed of a second material having a larger density and lower flexibility than the first material. The outer body includes a first section having an annular shape with a passage extending axially through the first section and configured to receive an elongated member therethrough, and a second section having an annular shape and positioned radially outward of the first section, where the second section includes first and second outer surfaces on opposite axial sides of the outer body, with an axial thickness defined between the first and second outer surfaces, and a plurality of recesses extending axially inward from at least one of the first and second outer surfaces through at least a portion of the axial thickness. The inner body is contained within the first section of the outer body, such that the outer body surrounds the inner body on at least both axial sides and an outer radial side thereof. The weight plate further includes a hub surrounding the passage, where the hub is engaged with an inner radial side of the inner body. 
     According to one aspect, the first material is or contains one or more polymer materials, and the second material is or contains one or more metallic materials. 
     According to another aspect, the inner body is formed of a single piece, and the outer body is molded around the inner body as a single piece. 
     According to a further aspect, the hub is integrally formed as part of the inner body and is formed of the second material. 
     According to yet another aspect, the ratio of a mass of the inner body to a mass of the outer body may vary by the weight of the weight plate. As one example, the weight plate may have a weight of 25 pounds, and this ratio is from 0.42 to 0.78. As another example, the weight plate may have a weight of 35 pounds, and this ratio is from 0.84 to 1.56. As a further example, the weight plate may have a weight of 45 pounds, and this ratio is from 0.77 to 1.43. 
     Yet additional aspects of the disclosure relate to a weight plate that includes a first section having an annular shape with a passage extending axially through the first section and configured to receive an elongated member therethrough, and a second section having an annular shape with a circular inner periphery and a circular outer periphery and positioned radially outward of the first section, where the second section includes first and second outer surfaces on opposite axial sides of the weight plate with an axial thickness defined between the first and second outer surfaces. The second section has a plurality of recesses extending axially inward from the first and second outer surfaces at least partially through the axial thickness of the second section. The axial thickness of portions of the second section surrounding the recesses is constant between the inner periphery and the outer periphery. A total volume occupied by the plurality of recesses between the first and second outer surfaces is from 20% to 30% of a total volume of solid material in the second section between the inner periphery and the outer periphery. In another configuration, the total volume occupied by the plurality of recesses between the first and second outer surfaces is from 22-28% of the total volume of solid material in the second section between the inner periphery and the outer periphery. In a further configuration, the total volume occupied by the plurality of recesses between the first and second outer surfaces is about 25% of the total volume of solid material in the second section between the inner periphery and the outer periphery. 
     According to one aspect, the plurality of recesses includes a plurality of first recesses each extending axially inward from the first outer surface partially through the axial thickness of the second section to a first end recessed from the first outer surface, and a plurality of second recesses each extending axially inward from the second outer surface partially through the axial thickness of the second section to a second end recessed from the second outer surface. In one configuration, each of the first recesses is axially aligned with one of the second recesses to form an aligned pair of recesses, such that an inner wall separates the first and second recesses of each aligned pair of recesses and defines the first and second ends of the first and second recesses of each aligned pair of recesses. In another configuration, the first and second recesses of each aligned pair of recesses may have identical sizes and shapes. 
     According to another aspect, the weight plate further includes a third section having an annular shape and positioned radially outward of the second section and forming an outer radial periphery of the weight plate, where the third section has a greater axial thickness than the second section. In one configuration, the second section is positioned immediately radially outward of the first section and is adjacent to the first section, and the third section is positioned immediately radially outward of the second section and is adjacent to the second section, such that the third section extends from the second section to the outer radial periphery of the weight plate. 
     According to a further aspect, each of the plurality of recesses has a constant shape along an entire axial length of the respective recess. 
     Further aspects of the disclosure relate to a weight plate including a weight plate body having an outer periphery, a first outer surface and a second outer surface on opposite axial sides of the weight plate body, and a passage extending axially through the weight plate body and configured to receive an elongated member therethrough, where the first surface and the second surface extend from the passage radially outward to the outer periphery, and a plurality of recesses extending axially inward from the first and second outer surfaces at least partially through the axial thickness of the second section. A total volume occupied by the plurality of recesses between the first and second outer surfaces is from 6% to 13% of a total volume of solid material in the weight plate between the passage and the outer periphery. 
     According to one aspect, the weight plate body has an axial thickness defined between the first outer surface and the second outer surface, and the plurality of recesses includes a plurality of first recesses each extending axially inward from the first outer surface partially through the axial thickness of the weight plate body to a first end recessed from the first outer surface, and a plurality of second recesses each extending axially inward from the second outer surface partially through the axial thickness of the weight plate body to a second end recessed from the second outer surface. In one configuration, each of the first recesses is axially aligned with one of the second recesses to form an aligned pair of recesses, such that an inner wall separates the first and second recesses of each aligned pair of recesses and defines the first and second ends of the first and second recesses of each aligned pair of recesses. In another configuration, the first and second recesses of each aligned pair of recesses have identical sizes and shapes. 
     According to another aspect, the weight plate body includes a first section having an annular shape with the passage extending axially through the first section, a second section having an annular shape and positioned radially outward of the first section, and a third section having an annular shape and positioned radially outward of the second section and forming an outer radial periphery of the weight plate. In one configuration, the third section has a greater axial thickness than the second section, and the plurality of recesses are formed in the second section. 
     According to a further aspect, each of the plurality of recesses has a constant shape along an entire axial length of the respective recess. 
     Other aspects of the disclosure relate to a weightlifting apparatus including a weight mount connected to a gripping member, such as a barbell or dumbbell, with one or more weight plates as described herein mounted on the weight mount. 
     Still other aspects of the disclosure relate to a method of manufacturing a weight plate as described herein, including providing an inner body made at least partially from a first material and molding an outer body in connection with, and optionally at least partially surrounding, the inner body. The outer body may be made from a second material that is more flexible and less dense than the first material of the inner body. 
     Other features and advantages of the disclosure will be apparent from the following description taken in conjunction with the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To allow for a more full understanding of the present disclosure, it will now be described by way of example, with reference to the accompanying drawings in which: 
         FIG.  1    is a perspective view of one embodiment of a weight plate according to aspects of the disclosure; 
         FIG.  2    is a front view of the weight plate of  FIG.  1   ; 
         FIG.  3    is a rear view of the weight plate of  FIG.  1   ; 
         FIG.  4    is a cross-section view of the weight plate of  FIG.  1   ; 
         FIG.  5    is a perspective view of another embodiment of a weight plate according to aspects of the disclosure; 
         FIG.  6    is a cross-section view of the weight plate of  FIG.  5   ; 
         FIG.  7    is a perspective view of another embodiment of a weight plate according to aspects of the disclosure; 
         FIG.  8    is a cross-section view of the weight plate of  FIG.  7   ; 
         FIG.  9    is a perspective view of a section of the weight plate of  FIGS.  1 - 4   ; and 
         FIG.  10    is a plan view of one embodiment of a weightlifting apparatus in the form of a barbell having weight plates as shown in  FIGS.  1 - 4    engaged with the barbell. 
     
    
    
     DETAILED DESCRIPTION 
     While this invention is susceptible of embodiments in many different forms, there are shown in the drawings and will herein be described in detail example embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated. In the following description of various example structures according to the invention, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various example devices, systems, and environments in which aspects of the invention may be practiced. It is to be understood that other specific arrangements of parts, example devices, systems, and environments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. 
       FIGS.  1 - 4    illustrate an example embodiment of a weight plate  10  according to aspects of the present disclosure, which includes a hub  12  defining a passage  14 , an inner body  16 , and an outer body  18  extending radially and/or axially outward of the inner body  16 . The hub  12  and the passage  14  are configured for mounting the weight plate  10  as known in the art, such as by receiving a portion of a barbell or other weight mount therein for use in a weightlifting exercise.  FIG.  10    illustrates a weightlifting apparatus  40  in the form of a barbell, which includes two weight mounts  42  in the form of barbell sleeves  46  connected to opposite ends of a gripping member  44  in the form of a bar  48 , with two weight plates  10  as shown in  FIGS.  1 - 4    removably mounted on each of the barbell sleeves  46 . Each of the barbell sleeves  46  is inserted through the passage  14  of the weight plate  10  in this configuration. Additionally, barbell collars  50  are engaged with each of the barbell sleeves  46  to hold the weight plates  10  in place. 
     The hub  12  may have flanged and/or beveled ends  20  in order to ease insertion of a barbell or other weight mount. The inner body  16  is positioned radially outward of the hub  12 , and the inner radial side of the inner body  16  may be engaged with or connected to the hub  12  in one embodiment. The hub  12  is formed as a separate piece from the inner body  16  in  FIGS.  1 - 4   , but may be integrally formed as part of the inner body  16  in another embodiment. It is understood that the hub  12  and the inner body  16  may be formed of the same material in this configuration. The hub  12  may be designed for durability and low friction properties. In one embodiment, the hub  12  may be formed of stainless steel. 
     The inner body  16  is formed of a metal, e.g., cast iron or steel in one embodiment, and is configured to provide mass to the weight plate  10 . The inner body  16  may be formed of a different material or materials in other embodiments, and it is understood that the material(s) forming the inner body  16  may have a greater density than the material forming the outer body  18 . The inner body  16  is completely encased by the hub  12  and the outer body  18  in the embodiment of  FIGS.  1 - 4   , and the outer body  18  surrounds the inner body  16  in both the outer radial direction and the axial direction, i.e., on the outer radial side and both axial sides of the inner body  16 . In another embodiment, the inner body  16  may be partially or completely exposed on the axial faces, such that the outer body  18  surrounds the inner body  16  radially but not axially. It is understood that if the hub  12  is part of the inner body  16 , then a portion of the inner body  16  including at least the hub  12  may be exposed. 
     In one embodiment, the outer body  18  includes at least two sections  22 ,  24 ,  26  that are radially disposed with respect to each other. These sections  22 ,  24 ,  26  may be referred to as a first section, a second section, a third section, etc. The outer body  18  in the embodiment of  FIGS.  1 - 4    includes three sections: an inner section  22  that surrounds and contains the inner body  16 , a middle section  24  positioned immediately radially outward of the inner section  22 , and an outer section or outer rim  26  positioned immediately radially outward of the middle section  24  and forming the outer periphery of the weight plate  10 . In the embodiment of  FIGS.  1 - 4   , the axial thickness of the weight plate  10  is greatest at the outer rim  26  and smallest at the middle section  24 . This is illustrated in  FIG.  4   , where the thickness T 1  at the outer section  26  and the thickness T 4  at the inner section  22  are both greater than the thickness T 2  at the middle section  24 . The thickness T 1  of the outer section  26  and the thickness T 4  at the inner section  22  may be equal in one embodiment, or one of the inner section  22  or the outer section  26  may have a slightly greater thickness than the other. In the embodiments of  FIGS.  1 - 8   , the thickness T 1  of the outer section  26  is greater than the thickness T 4  of the inner section  22 . The transitions  28  between the inner, middle, and outer sections  22 ,  24 ,  26  are beveled or gradual. Each of the sections  22 ,  24 ,  26  may have a constant axial thickness T 1 , T 2 , T 4  over the substantial entirety thereof (i.e., between the inner and outer periphery thereof), such as in the embodiment of  FIGS.  1 - 4   . It is understood that the “constant axial thickness” is defined by the general contour of the outer surfaces  31 ,  33  of the plate  10  or a section thereof. Accordingly, a section may be considered to have a “constant axial thickness” and still have slight variations, such as the thickness variations caused by the raised letters and numbers on the inner section  22  in  FIGS.  1 - 4   . Additionally, a section may be considered to have a “constant axial thickness” despite the presence of numerous recesses  30  as disclosed herein, if the thickness defined by the outer surfaces  31 ,  33  (i.e., the material surrounding the recesses  30 ) is constant. In another embodiment, the outer body  18  may include only two sections, including an inner section  22  and an outer section  24 ,  26  positioned radially outward of the inner section  22 , such that the inner section  22  has a constant axial thickness and the outer section  24 ,  26  has a constant axial thickness that is larger or smaller than the axial thickness of the inner section  22 . In a further embodiment, the outer body  18  may include more than the three sections  22 ,  24 ,  26  illustrated in  FIGS.  1 - 4   , such that the outer body  18  has more than one middle section. 
     The outer body  18  may be formed of a single material and/or a single piece in one embodiment. In the embodiment of  FIGS.  1 - 4   , the outer body  18  is molded around the inner body  16  and formed of a rubber material. The material of the outer body  18  may be relatively soft, to provide sound and vibration damping and impact absorbing properties, such as having a hardness of 50-80 Shore A. In another embodiment, the material of the outer body  18  may be a rubber material having a hardness of 70-90 Shore A, which provides sound and vibration damping and impact absorbing properties. An ethylene propylene diene monomer (EPDM) rubber may be used as the rubber material of the outer body  18  in one embodiment. 
     The middle section  24  of the outer body  18  in  FIGS.  1 - 4    includes a plurality of recesses  30  extending inward from opposed front and rear surfaces  31 ,  33 . The recesses  30  in this embodiment are generally equal in depth but have different sizes and shapes. The recesses  30  may have multiple different polygonal shapes having different numbers of sides in one embodiment. In one embodiment, the recesses  30  may include “groups” of recesses all having the same shapes and/or the same number of sides. For example, the recesses  30  may include at least first-shaped recesses  30 A having a first shape, size, volume, surface perimeter, and/or number of sides and second-shaped recesses  30 B having a second shape, size, volume, surface perimeter, and/or number of sides, and may further include third-shaped recesses  30 C having a third shape, size, volume, surface perimeter, and/or number of sides, or potentially additional recess groups. In the embodiment of  FIGS.  1 - 4   , the recesses include small triangular recesses  30 A all having the same shape, size, volume, surface perimeter, and number of sides, mid-sized quadrilateral recesses  30 B all having the same shape, size, volume, surface perimeter, and number of sides, and large pentagonal recesses  30 C all having the same shape, size, volume, surface perimeter, and number of sides, each with rounded corners. These recesses  30  may be considered first-shaped recesses  30 A, second-shaped recesses  30 B, and third-shaped recesses  30 C as described herein, and these groups are identified in  FIGS.  2 - 3   . In other embodiments, other shapes of recesses  30  having different numbers of sides may be used, including single-sided recesses (e.g., circle, ellipse), two-sided recesses (e.g., pointed oval), and/or recesses having more than five sides. Each recess  30  in  FIGS.  1 - 4    has a constant shape, e.g., the same peripheral size and shape, along its entire axial length/depth, and this size and shape is the same as the surface shape and perimeter, i.e., the shape and perimeter defined at the surface  31 ,  33  of the plate  10 . 
     As shown in  FIGS.  2 - 3   , the recesses  30  on both the front and rear surfaces  31 ,  33  have identical shapes and arrangements, such that each recess  30  on the front surface  31  is aligned with an identically sized and shaped recess  30  extending inward in the opposite direction from the rear surface  33 . As shown in  FIGS.  1 - 4   , the recesses  30  are arranged such that each of the front and rear surfaces  31 ,  33  has first-shaped (triangular) recesses  30 A, second-shaped (quadrilateral) recesses  30 B, and third-shaped (pentagonal) recesses  30 C distributed thereon in identical patterns. In this configuration, each first-shaped recess  30 A on the front surface  31  is axially aligned with a first-shaped recess  30 A on the rear surface  33 , each second-shaped recess  30 B on the front surface  31  is axially aligned with a second-shaped recess  30 B on the rear surface  33 , and each third-shaped recess  30 C on the front surface  31  is axially aligned with a third-shaped recess  30 C on the rear surface  33 . These opposed recesses  30  are separated by inner walls  32  as shown in  FIG.  4   , and the inner walls  32  may all be of equal thickness T 3  in one embodiment. Each recess  30  in  FIGS.  1 - 4    has a plurality of generally flat walls or sides  35  extending inwardly from the outer surface  31 ,  33 , which are arranged to intersect at angles to each other. The intersections between the walls  35  are formed by rounded corners in  FIGS.  1 - 4   . The recesses  30  may have a variety of different depths in other embodiments, such that the inner walls  32  have different axial thicknesses T 3 . Viewed another way, the middle section  24  may be considered to include a plurality of interconnected raised areas or ridges  34  extending between the outer rim  28  and the inner section  22 . In other embodiments, the arrangements of the recesses  30  may be different, and may not be identical or symmetrical. In a further embodiment, some or all of the recesses  30  may be formed as passages that extend completely through the middle section  24 , from the front surface  31  to the rear surface  33 . The configuration of the recesses  30  in the middle section  24  provides additional sound and vibration damping and impact absorbing properties. 
     The sizes, depths, spacing, shapes, and distribution of the recesses  30  are configured to produce a desired combination of sound and vibration reduction, bounce height, and durability when the weight plate  10  is dropped. Too great a bounce height may present safety issues, as the weight may bounce unpredictably and cause injury. In general, greater flexibility and compressibility of the material surrounding the recesses  30  (i.e., a greater proportional volume of the recesses  30  relative to the surrounding material) produces greater sound and vibration reduction, but a higher bounce height when the weight plate  10  is dropped to sustain a radial impact force, and may decrease durability. Conversely, less flexibility and compressibility of the material surrounding the recesses  30  (i.e., a smaller proportional volume of the recesses  30  relative to the surrounding material) produces less sound and vibration reduction, but a lower bounce height when the weight plate  10  is dropped to sustain a radial impact force, and may have increased durability. The desired combination of durability, bounce height, and sound/vibration reduction may be different depending on the desired use of the weight plate  10 . In one embodiment, the recesses  30  may be distributed across a section of the outer body  18  having a constant axial thickness, e.g., the middle section  24  in  FIGS.  1 - 4   , and the total volume of the recesses  30  (between the front and rear surfaces  31 ,  33 ) is from 20-30%, or from 22-28%, or about 25%, of the volume of material in the middle section  24 .  FIG.  9    illustrates the isolated middle section  24  of the outer body  18  in  FIGS.  1 - 4   , which forms the basis for these figures. In another embodiment, the total volume of the recesses  30  (between the front and rear surfaces  31 ,  33 ) is from 6-13%, or from 8-11%, or about 9.5%, of the volume of material in the entire weight plate  10 . The volume ratios of the plates  10  in  FIGS.  5 - 8    are the same as in  FIGS.  1 - 4   . It is also shown, e.g., in  FIGS.  1 - 4   , that immediately adjacent recesses on the front and rear sides  31 ,  33  have flat sides  35  that are generally parallel with the closest adjacent side  35  of each adjacent recess  30 , in order to create consistent wall thickness of the material separating the adjacent recesses  30 . This, in turn, creates consistent and predictable compression of the material surrounding the recesses  30 . 
     The weight plate  10  in  FIGS.  1 - 4    is configured as a 45 lb. weight, and the inner body  16  and the outer body  18  are dimensioned to provide this weight.  FIGS.  5 - 6    illustrate another embodiment of a weight plate  10  configured as a 25 lb. weight, and  FIGS.  7 - 8    illustrate a further embodiment of a weight plate  10  configured as a 35 lb. weight. The weight plates  10  in  FIGS.  5 - 8    are configured similarly to the weight plate  10  in  FIGS.  1 - 4   , and the features of the weight plates  10  in  FIGS.  5 - 8    will therefore not be described in detail herein, for the sake of brevity. The mass of the inner body  16  as a proportion of the overall mass of the weight plate  10  may vary depending on the target weight of the weight plate  10 . In one embodiment, the weight plate  10  may be a 45 pound weight plate (see  FIGS.  1 - 4   ), and the ratio of the mass of the inner body  16  to the mass of the outer body  18  is from 0.77 to 1.43, or from 0.94 to 1.27, or about 1.10. In another embodiment, the weight plate  10  may be a 35 pound weight plate (see  FIGS.  7 - 8   ), and the ratio of the mass of the inner body  16  to the mass of the outer body  18  is from 0.84 to 1.56, or from 1.02 to 1.38, or about 1.20. In a further embodiment, the weight plate  10  may be a 25 pound weight plate (see  FIGS.  5 - 6   ), and the ratio of the mass of the inner body  16  to the mass of the outer body  18  is from 0.42 to 0.78, or from 0.51 to 0.69, or about 0.60. 
     The weight plates  10  in  FIGS.  1 - 8    are designed as “bumper plates” that are designed to be dropped from an elevated position, such as when a weightlifting exercise is over. The weight plates  10  in  FIGS.  1 - 8    have different weights with substantially equal outer widths (e.g., radius or diameter) and peripheral sizes (e.g., circumference), and the weight differences are achieved by increasing other dimensions of the inner and/or outer bodies  16 ,  18 , such as the axial thickness. The weight plates  10  in  FIGS.  1 - 8    all have diameters D of about 450 mm, and the radial width W of the outer rim  26  in these plates  10  is about 72 mm, as shown in  FIG.  2   . The 45 lb. weight plate in  FIGS.  1 - 4    has a maximum axial thickness T 1  (at the outer rim) of about 82 mm and a thickness T 2  in the areas surrounding the recesses  30  of about 70 mm, the 35 lb. weight plate in  FIGS.  7 - 8    has a maximum axial thickness of about 68 mm and a thickness in the areas surrounding the recesses  30  of about 56 mm, and the 25 lb. weight plate in  FIGS.  5 - 6    has a maximum axial thickness of about 59 mm and a thickness in the areas surrounding the recesses  30  of about 47 mm. The thicknesses T 3  of the inner walls  32  in the weight plates  10  in  FIGS.  1 - 8    are all approximately equal at about 6 mm, and the depths of the recesses  30  vary among the different weight plates  10 . The weight plates  10  in  FIGS.  5 - 6    have recesses  30  with depths of about 20.5 mm, the weight plates  10  in  FIGS.  7 - 8    have recesses  30  with depths of about 25 mm, and the weight plates  10  in  FIGS.  1 - 4    have recesses  30  with depths of about  32  mm. In one embodiment, the depth of each recess  30  in a weight plate  10  of any size is about 43%-46% of the axial thickness of the area surrounding the recess  30 . In another embodiment, the configurations and features described herein may be used in connection with weight plates that have unequal diameters and/or different (e.g., non-circular) peripheral shapes. In a further embodiment, the configurations and features described herein may be used in connection with fixed (non-removable) weights or weight plates, such as weights fixedly attached to the ends of a dumbbell. 
     Various embodiments of weight plates have been described herein, which include various components and features. In other embodiments, the weight plates may be provided with any combination of such components and features. It is also understood that in other embodiments, the various devices, components, and features of the weight plates described herein may be constructed with similar structural and functional elements having different configurations, including different ornamental appearances. 
     Several alternative embodiments and examples have been described and illustrated herein. A person of ordinary skill in the art would appreciate the features of the individual embodiments, and the possible combinations and variations of the components. A person of ordinary skill in the art would further appreciate that any of the embodiments could be provided in any combination with the other embodiments disclosed herein. It is understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein. Terms such as “top,” “bottom,” “front,” “back,” “side,” “rear,” and the like, as used herein, are intended for illustrative purposes only and do not limit the embodiments in any way. When used in description of a method or process, the term “providing” (or variations thereof) as used herein means generally making an article available for further actions, and does not imply that the entity “providing” the article manufactured, assembled, or otherwise produced the article. Nothing in this specification should be construed as requiring a specific three dimensional orientation of structures in order to fall within the scope of this invention, unless explicitly specified by the claims. Additionally, the term “plurality,” as used herein, indicates any number greater than one, either disjunctively or conjunctively, as necessary, up to an infinite number. Accordingly, while the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention and the scope of protection is only limited by the scope of the accompanying claims.