Dumbbell and Manufacturing Method

Abstract

A dumbbell includes a handle member and two weight heads connected to opposite ends of the handle member. The heads each have a passage extending partially or completely therethrough to receive the ends of the handle member. In one configuration, the passages extend through the heads, and each head includes bevels around the inner and outer end openings of the passage. The heads in this configuration are connected to the handle member by welding, including weld beads formed within the bevels between the head and the handle member, at least partially around the corresponding end openings. A manufacturing method for a dumbbell may include providing or forming the handle member, casting the heads, and connecting the heads to the handle member by welding of this type.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a nonprovisional of, and claims priority to, U.S. Provisional Application No. 63/713,799, filed Oct. 30, 2024, which prior application is incorporated by reference herein in its entirety.

TECHNICAL FIELD

This disclosure relates to dumbbells for weightlifting, and more specifically to dumbbell constructions that use multiple pieces joined together, such as via casting onto an existing handle member.

BACKGROUND

Dumbbells having various configurations are known in the art of weightlifting equipment, and may be manufactured using a variety of different techniques, including various casting, molding, and machining techniques and combinations of such techniques. One such manufacturing method is by casting dumbbell heads onto a previously-formed handle. However, dumbbells manufactured using this technique typically have a rough and unfinished look. Other manufacturing techniques may produce dumbbells having aesthetic or structural concerns, or may present manufacturing inefficiencies.

The present disclosure is provided to address this need and other needs in existing dumbbells and manufacturing techniques for the same. 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

General aspects of the present disclosure relate to dumbbells using cast weight heads that are connected to a separately manufactured handle member or handle assembly, structures for such connections, and methods of manufacturing the same.

Aspects of the disclosure relate to a dumbbell that includes a handle member having a center portion having a cylindrical shape and configured for gripping by a user, a first end portion extending from the center portion to a first distal end of the handle member, and a second end portion extending from the center portion to a second distal end of the handle member, such that the center portion is located between the first and second end portions, and a first head and a second head connected to the first and second end portions, respectively, of the handle member to provide weight to the dumbbell for use in a weightlifting exercise. The first head has a first inner side facing toward the center portion of the handle member, a first outer side facing away from the center portion of the handle member, and a first passage extending through the first head and having a first inner end opening on the first inner side and a first outer end opening on the first outer side. The first head also has a first inner bevel on the first inner side extending around the first inner end opening of the first passage and a first outer bevel on the first outer side extending around the first outer end opening of the first passage. The second head has a second inner side facing toward the center portion of the handle member, a second outer side facing away from the center portion of the handle member, and a second passage extending through the second head and having a second inner end opening on the second inner side and a second outer end opening on the second outer side. The second head also has a second inner bevel on the second inner side extending around the second inner end opening of the second passage and a second outer bevel on the second outer side extending around the second outer end opening of the second passage. The first end portion of the handle member is received in the first passage of the first head and extends through the first passage from the first inner side to the first outer side, and the first end portion of the handle member is connected to the first head by welding. This welding includes a first inner weld bead extending at least partially around the first inner end opening between the first inner bevel of the first head and the first end portion of the handle member and a first outer weld bead extending at least partially around the first outer end opening between the first outer bevel of the first head and the first end portion of the handle member. The second end portion of the handle member is received in the second passage of the second head and extends through the second passage from the second inner side to the second outer side, and the second end portion of the handle member is connected to the second head by welding. This welding includes a second inner weld bead extending at least partially around the second inner end opening between the second inner bevel of the second head and the second end portion of the handle member and a second outer weld bead extending at least partially around the second outer end opening between the second outer bevel of the second head and the second end portion of the handle member.

According to one aspect, the first inner weld bead extends completely around the first inner end opening, the first outer weld bead extends completely around the first outer end opening, the second inner weld bead extends completely around the second inner end opening, the second outer weld bead extends completely around the second outer end opening. In one configuration, the first inner weld bead, the first outer weld bead, the second inner weld bead, and/or the second outer weld bead may completely fill the respective corresponding bevels.

According to another aspect, the first end portion and the second end portion of the handle member have cylindrical shapes. In one configuration, the center portion, the first end portion, and the second end portion of the handle member have equal diameters. In an alternate configuration, the center portion of the handle member has a larger diameter than the first end portion and the second end portion, and the handle member has step changes in diameter between the center portion and the first end portion and between the center portion and the second end portion.

According to a further aspect, the first inner side and the first outer side of the first head have curved surfaces, and the first head further has a first cylindrical peripheral surface extending between the first inner side and the first outer side. Similarly, the second inner side and the second outer side of the second head have curved surfaces, and the second head further has a second cylindrical peripheral surface extending between the second inner side and the second outer side. In one configuration, the handle member has a first distal end and a second distal end, the first distal end is substantially flush with the first outer side and is curved to match a curvature of the first outer side, and the second distal end is substantially flush with the second outer side and is curved to match a curvature of the second outer side. In another configuration, the first head and the second head are formed by casting a metallic material to near net shape. As noted herein, the first inner weld bead, the first outer weld bead, the second inner weld bead, and the second outer weld bead may extend completely around the respective corresponding end openings. Further, the first end portion and the second end portion of the handle member may have cylindrical shapes, and/or the center portion of the handle member may be knurled over at least a portion of a length thereof.

Additional aspects of the disclosure relate to a dumbbell having any combination of the features, aspects, and configurations disclosed above, as well as alternate combinations of features. For example, according to some aspects, the handle member may have endpieces and/or bolsters as described herein for further engagement with the heads, and/or the passages may extend from the inner end openings partially through the heads.

Further aspects of the disclosure relate to a method of manufacturing a dumbbell, which may have any combination of the features, aspects, and configurations disclosed above. In one embodiment, the method includes providing a handle member, and connecting a first head and a second head to the handle member, such that the handle member, the first head, and the second head form the dumbbell, and the first head and the second head are configured to provide weight to the dumbbell for use in a weightlifting exercise. The handle member has a center portion having a cylindrical shape and configured for gripping by a user, a first end portion extending from the center portion to a first distal end of the handle member, and a second end portion extending from the center portion to a second distal end of the handle member, such that the center portion is located between the first and second end portions. The first head and the second head are cast to near net shape from a metallic material. The first head has a first inner side facing toward the center portion of the handle member, a first outer side facing away from the center portion of the handle member, and a first passage extending through the first head and having a first inner end opening on the first inner side and a first outer end opening on the first outer side, and the first head also has a first inner bevel on the first inner side extending around the first inner end opening of the first passage and a first outer bevel on the first outer side extending around the first outer end opening of the first passage. The second head has a second inner side facing toward the center portion of the handle member, a second outer side facing away from the center portion of the handle member, and a second passage extending through the second head and having a second inner end opening on the second inner side and a second outer end opening on the second outer side, and the second head also has a second inner bevel on the second inner side extending around the second inner end opening of the second passage and a second outer bevel on the second outer side extending around the second outer end opening of the second passage. The first and second end portions of the handle member are inserted into and through the first passage of the first head and the second passage of the second head, respectively, such that the first end portion extends through the first passage from the first inner side to the first outer side, and the second end portion extends through the second passage from the second inner side to the second outer side. The first and second end portions of the handle member are connected to the first head by welding. This welding includes forming a first inner weld bead extending at least partially around the first inner end opening between the first inner bevel of the first head and the first end portion of the handle member and a first outer weld bead extending at least partially around the first outer end opening between the first outer bevel of the first head and the first end portion of the handle member. This welding also includes forming a second inner weld bead extending at least partially around the second inner end opening between the second inner bevel of the second head and the second end portion of the handle member and a second outer weld bead extending at least partially around the second outer end opening between the second outer bevel of the second head and the second end portion of the handle member. After welding, a smoothing operation is conducted on at least one of the first inner weld bead, the first outer weld bead, the second inner weld bead, and the second outer weld bead, using a material removal technique. In one embodiment, the handle member may be manufactured, such as by machining a metallic component.

According to one aspect, the first inner weld bead extends completely around the first inner end opening, the first outer weld bead extends completely around the first outer end opening, the second inner weld bead extends completely around the second inner end opening, the second outer weld bead extends completely around the second outer end opening. In one configuration, the first inner weld bead completely fills the first inner bevel, the first outer weld bead completely fills the first outer bevel, the second inner weld bead completely fills the second inner bevel, and the second outer weld bead completely fills the second outer bevel.

According to another aspect, the first inner side and the first outer side of the first head have curved surfaces, and the first head further has a first cylindrical peripheral surface extending between the first inner side and the first outer side. Additionally, the second inner side and the second outer side of the second head have curved surfaces, and the second head further has a second cylindrical peripheral surface extending between the second inner side and the second outer side. In one configuration, the handle member has a first distal end and a second distal end, the first distal end is substantially flush with the first outer side and is curved to match a curvature of the first outer side, and the second distal end is substantially flush with the second outer side and is curved to match a curvature of the second outer side. Additionally, in one configuration, the smoothing step may further include smoothing at least one of the first distal end of the handle member, the second distal end of the handle member, the first outer side of the first head, and the second outer side of the second head using the material removal technique, such that the first distal end, the first outer weld bead, and the first outer side form a first smooth surface, and such that the second distal end, the second outer weld bead, and the second outer side form a second smooth surface. The first inner weld bead, the first outer weld bead, the second inner weld bead, and the second outer weld bead may extend completely around the respective corresponding end openings.

Further aspects of the disclosure relate to method of manufacturing a dumbbell having any combination of the features, aspects, and configurations disclosed above, as well as alternate combinations of features. For example, according to some aspects, the heads may be cast in-place on the handle member by inserting one the ends of the handle member into a mold and casting the respective head in place on the handle member.

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 front view of one embodiment of a dumbbell according to aspects of the present disclosure;

FIG. 2 is a side view of the dumbbell of FIG. 1;

FIG. 3 is a cross-section view taken along lines 3-3 of FIG. 2;

FIG. 4 is a front view of a handle member of the dumbbell of FIG. 1;

FIG. 5 is a perspective view of the handle member of FIG. 4;

FIG. 6 is a front view of another embodiment of a dumbbell according to aspects of the present disclosure;

FIG. 7 is a cross-section view of the dumbbell of FIG. 6, taken along lines 7-7 of FIG. 8;

FIG. 8 is a side view of the dumbbell of FIG. 6;

FIG. 9 is a cross-section view of a head of the dumbbell of FIG. 6, taken along lines 9-9 of FIG. 10;

FIG. 10 is a side view of the head of the dumbbell of FIG. 6;

FIG. 11 is a front view of a handle member of the dumbbell of FIG. 6;

FIG. 12 is a magnified cross-section view of a portion of the dumbbell of FIG. 6, showing welding connections;

FIG. 13 is a front view of another embodiment of a dumbbell according to aspects of the present disclosure;

FIG. 14 is a perspective view of a handle member of the dumbbell of FIG. 13;

FIG. 15 is a front view of the handle member of FIG. 14;

FIG. 16 is a cross-section view of the dumbbell of FIG. 13; and

FIG. 17 is a cross-section view of one embodiment of a method of manufacturing a dumbbell, according to aspects of the present disclosure.

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.

General aspects of the present disclosure relate to a dumbbell 10 that includes a handle assembly 13 including at least a handle member 20, and two heads 11, 12 connected to the handle member 20, such that two opposed end portions 21, 22 of the handle member 20 are each received within one of the two heads 11, 12, and the end portions 21, 22 of the handle member 20 extend at least partially through the respective heads 11, 12. The heads 11, 12 are configured to function as weights for use in a weightlifting exercise by a user gripping the handle member 20, and the sizes of the heads 11, 12 may therefore vary based on the desired weight of the dumbbell 10. Typically, the two heads 11, 12 are equal or substantially equal in weight, size, and shape, and may be symmetrically shaped with respect to a center plane (CP) extending transversely through the center of the handle member 20. As used herein, the terms “inward,” “inner,” “outward,” and “outer” are defined relative to the center plane (CP), unless otherwise specified. Generally, each of the heads 11, 12 has an inner side 14 facing inward with respect to the center plane (CP) of the dumbbell 10 and an outer side 15 facing outward with respect to the center plane (CP). Each of the heads 11, 12 may have a peripheral surface 16 located between the inner and outer sides 14, 15 to define an outer periphery of the heads 11, 12. The heads 11, 12 in this embodiment are made from a heavy material, such as an iron or steel alloy, or another metal. The heads 11, 12 may be cast onto the ends of the handle member 20 in one embodiment, and for this purpose, the heads 11, 12 are made from a material with suitable casting qualities, such as cast iron. It is understood that the heads 11, 12 may be coated with one or more additional materials in some embodiments, which may include a rubber or other polymer material in one embodiment.

Referring now to the drawings, and initially to FIGS. 1-5, there is shown an embodiment of a dumbbell 10 according to aspects of the present disclosure. The dumbbell 10 in FIGS. 1-5 includes a handle member 20 and two heads 11, 12 connected to the handle member 20 such that the end portions 21, 22 of the handle member 20 are received within holes or passages 17 within the two heads 11, 12 and extend partially through the two heads 11, 12. Each head 11, 12 in this embodiment has curved inner and outer sides 14, 15 and a cylindrical peripheral surface 16 between the inner and outer sides 14, 15. In this configuration, the two opposed distal ends 23, 24 of the handle member 20 are contained within the heads 11, 12, respectively. The handle assembly 13 in this embodiment has an endpiece 25 located at or near each end 23, 24, with each endpiece 25 generally having a larger outer profile than the handle member 20. The handle member 20 itself is an elongated cylinder that may be made from a metal such as stainless steel or other steel alloy, and may be manufactured by machining. The handle member 20 has a center portion 30 positioned between the two end portions 21, 22 configured for gripping by a user, and the center portion 30 may be provided with knurling (not shown) over at least part of the length thereof. The handle member 20 has a substantially constant diameter over the entire length thereof in the embodiment of FIGS. 1-5, but may have a varying diameter and/or peripheral shape over portions thereof in another embodiment.

Each endpiece 25 in FIGS. 1-5 has a body 26 defining a cavity 27 to receive a portion of the handle member 20, with a plurality of projections 28 extending radially outward from the body 26 to create a larger outer profile than the handle member 20. The cavity 27 has a smaller diameter than at least the center portion 30 of the handle member 20, and the end portions 21, 22 of the handle member 20 have reduced width/diameter portions 35 at the ends 23, 24, to be received in the cavities 27 of the endpieces 25. The projections 28 are in the form of lugs having rectangular cutouts 29 between them in the embodiment of FIGS. 1-5, and the endpiece 25 in this configuration has four projections 28 located at equal quarter-circumference positions around the perimeter of the endpiece 25. The body 26 in FIGS. 1-5 is a cylindrical tubular member defining a circular cavity 27 in the form of a passage that extends axially through the entire body 26. The endpiece 25 in FIGS. 1-5 may be formed of a rigid material, such as stainless steel or another steel alloy, and may be manufactured by machining, in various embodiments. The endpieces 25 may be fixed to the ends 23, 24 of the handle member 20 by welding or other integral joining technique in one embodiment, or by a mechanical connection technique such as set screws or interference fit, or a combination of such techniques. It is understood that the endpieces 25 being located at the ends 23, 24 of the handle member 20, as described herein, does not mean that the endpieces 25 are necessarily located at the terminal portions of the handle member 20, and the endpieces 25 may be pushed farther onto the ends 23, 24 of the handle member 20. The larger outer profile provided by the endpieces 25 permits the endpieces 25 to act as anchors to strengthen the connection between the handle member 20 and the heads 11, 12.

In other embodiments, the body 26 may be a partial tube that extends less than an entire periphery of the handle member 20, and/or the cavity 27 may not extend entirely through the body 26 axially. In another embodiment, the cavity 27 and the ends 23, 24 of the handle member 20 may have non-circular peripheries, such as square, hexagonal, triangular, etc., to form a rotation-locking engagement. In a further embodiment, the endpiece 25 may not have a body 26 and may consist entirely of projections 28 that are fixed to the ends 23, 24 of the handle member 20, such as by welding and/or partially embedding the projections 28 in the handle member 20.

The handle assembly 13 in FIGS. 1-5 also includes bolsters 31 connected to the handle member 20 and located axially inward from the ends 23, 24 of the handle member 20. The bolsters 31 in this embodiment are spaced axially inward from the endpieces 25 and are partially embedded within the heads 11, 12 in the assembled dumbbell 10. The bolsters 31 also have a larger outer profile than the handle member 20 and are formed as annular members having a passage 32 receiving the handle member 20 therethrough. As with the endpieces 25, the passage 32 and the corresponding portions of the handle member 20 are circular in peripheral shape in this embodiment, but these components may have non-circular shapes (including rotational locking shapes) in other embodiments. The bolsters 31 have a circular outer periphery as well in the embodiment of FIGS. 1-5, which may be different in other embodiments. Each bolster 31 in FIGS. 1-5 has an inner surface 33 located axially inward with respect to the handle member 20 and an outer surface 34 located axially outward with respect to the handle member 20. The bolsters 31 may have at least a portion that is exposed on the inner sides 14 of the heads 11, 12, and in the embodiment of FIGS. 1-5, the inner surfaces 33 of each bolster 31 is exposed. The inner surface 33 of each bolster 31 in this embodiment has a curved contour that curves axially away from the center portion 30 of the handle member 20. When the handle assembly 13 is connected to the heads 11, 12, the curvature of the inner surface 33 (in cross-section) matches the curvature of the inner sides 14 of the heads 11, 12, to create a smooth transition between the bolsters 31 and the heads 11, 12. For example, the inner surfaces 33 of the bolsters 31 and the inner sides 14 of the heads 11, 12 may have a radius of curvature of approximately 6.660 inch in one embodiment. The outer sides 15 of the heads 11, 12 may have approximately the same radius of curvature as the inner sides 14 of the heads 11, 12 and the inner surfaces 33 of the bolsters 31 in one embodiment as well. In another embodiment, the inner sides 14 of the heads 11, 12 and/or the inner surfaces 33 of the bolsters 31 may have varying radii of curvature, and the curvatures of the inner surface 33 of the bolster 31 and the inner side 14 of the respective head 11, 12 may be approximately equal at least at the juncture between the bolster 31 and the head 11, 12. The bolsters 31 may be made from a metal such as stainless steel or other steel alloy, and may be manufactured by machining. Additionally, the bolsters 31 may be fixed to the handle member 20 by welding or other integral joining technique in one embodiment, or by a mechanical connection technique such as set screws or interference fit, or a combination of such techniques. The outer surfaces 34 of the bolsters 31 in the embodiments of FIGS. 1-5 have an inward, annular bevel 36 around the passage 32.

In a further embodiment, the handle member 20 may have a step change in diameter at the locations of the bolsters 31, with the center portion 30 having a larger diameter than the passage 32, such that the bolsters 31 abut the shoulder created by the step change in diameter.

FIGS. 6-12 illustrate another embodiment of a dumbbell 10 that includes many of the components and features of the dumbbell 10 in FIGS. 1-5. Such shared components and features are referred to herein with the same reference numbers in FIGS. 6-12 and may not be described again in detail for the sake of brevity. The dumbbell 10 in FIGS. 6-12 has a handle assembly 13 that includes a handle member 20, and does not include endpieces or bolsters as in the embodiment of FIGS. 1-5. Nevertheless, it is contemplated that the dumbbell 10 in FIGS. 6-12 may be modified to include bolsters or endpieces in other embodiments.

The dumbbell 10 in FIGS. 6-12 includes a handle member 20 and two heads 11, 12 connected to the handle member 20 such that the end portions 21, 22 of the handle member 20 are received within holes or passages 17 within the two heads 11, 12 and extend completely through the two heads 11, 12. Each head 11, 12 in this embodiment has curved inner and outer sides 14, 15 and a cylindrical peripheral surface 16 between the inner and outer sides 14, 15. The passage 17 of each head 11, 12 has an inner end opening 37 on the inner side 14 and an outer end opening 38 on the outer side 15. In this configuration, the two opposed distal ends 23, 24 of the handle member 20 are exposed at the outer sides 15 of the heads 11, 12, respectively. The ends 23, 24 of the handle member 20 may be curved to match the radius of curvature of adjacent portions of the outer side 15 of the respective head 11, 12, such as having a radius of curvature of approximately 6.660 inch in one embodiment. Additionally, the ends 23, 24 of the handle member 20 may be substantially flush with the outer side 15 of the respective head 11, 12. The handle member 20 itself is an elongated cylinder that may be made from a metal such as stainless steel or other steel alloy, and may be manufactured by machining. The handle member 20 in this embodiment has a center portion 30 positioned between the two ends 23, 24 configured for gripping by a user, and the center portion 30 may be provided with knurling (not shown) over at least part of the length thereof. The handle member 20 has a substantially constant diameter over the entire length thereof in this embodiment, but may have a varying diameter and/or peripheral shape over portions thereof in another embodiment. For example, in one embodiment, the handle member 20 may have a step change in diameter at the ends of the center portion 30, with the center portion 30 having a larger diameter than the end portions 21, 22 of the handle member 20. The heads 11, 12 in the embodiment of FIGS. 6-12 are formed with bevels 18 in the inner and outer sides 14, 15 at the inner and outer end openings 37, 38 of the passages 17. The bevels 18 extend at least partially around the inner and outer end openings 37, 38 of the passages 17 in one embodiment. The bevels 18 in the embodiment of FIGS. 6-12 extend completely around the inner and outer end openings 37, 38 of the passages 17. In this embodiment, the bevels 18 are formed as angular bevels 18 that have a frusto-conical shape, and in other embodiments, the bevels 18 may have a curved contour, and/or the heads 11, 12 may include bevels 18 only at the inner or outer end openings 37, 38 of the passages 17.

The heads 11, 12 may be connected to the handle member 20 in one embodiment by welding or other integral joining technique. As shown in FIG. 12, each head 11, 12 may be welded to one of the end portions 21, 22 of the handle member 20 at both the inner and outer sides 14, 15, with weld beads 42 positioned at least partially within the bevels 18. The weld beads 42 may completely fill the bevels 18 in one embodiment. These weld beads 42 may extend at least partially around the respective end openings of the head 11, 12, and in one embodiment, the weld beads 42 extend completely around each end opening. After welding, the weld bead 42 may be smoothed after welding by a material removal technique such as grinding or machining. The smoothing operation may also be applied to adjacent surfaces of the handle member 20, and/or the head 11, 12, e.g., portions of the inner and outer sides 14, 15 and/or portions of the distal ends 23, 24 of the handle member 20. The distal ends 23, 24 of the handle member 20, the outer side 15 of the head 11, 12, and the weld bead 42 at the outer end opening 38 may all form a smooth surface and/or may be substantially flush with each other after this smoothing operation.

FIGS. 13-16 illustrate another embodiment of a dumbbell 10 that includes many of the components and features of the dumbbells 10 in FIGS. 1-5 and 6-12. Such shared components and features are referred to herein with the same reference numbers in FIGS. 13-16 and may not be described again in detail for the sake of brevity.

The dumbbell 10 in FIGS. 13-16 includes a handle member 20 and two heads 11, 12 connected to the handle member 20 such that the end portions 21, 22 of the handle member 20 are received within holes 17 within the two heads 11, 12 and extend from an inner end opening 37 partially through the two heads 11, 12. Each head 11, 12 in this embodiment has curved inner and outer sides 14, 15 and a cylindrical peripheral surface 16 between the inner and outer sides 14, 15. In this configuration, the two opposed distal ends 23, 24 of the handle member 20 are contained within the heads 11, 12, respectively. The handle assembly 13 in this embodiment has an endpiece 25 located at or near each end 23, 24, with each endpiece 25 generally having a larger outer profile than the handle member 20. The endpieces 25 and the connection of the endpieces 25 to the handle member 20 in FIGS. 13-16 are substantially identical to those in FIGS. 1-5. The handle assembly 13 in FIGS. 13-16 does not include bolsters as in the embodiment of FIGS. 1-5.

The handle member 20 in FIGS. 13-16 itself is an elongated cylinder that may be made from a metal such as stainless steel or other steel alloy, and may be manufactured by machining. The handle member 20 has a center portion 30 positioned between the two end portions 21, 22 configured for gripping by a user, and the center portion 30 may be provided with knurling (not shown) over at least part of the length thereof. The handle member 20 has a substantially constant diameter over the entire length thereof in the embodiment of FIGS. 13-16, but may have a varying diameter and/or peripheral shape over portions thereof in another embodiment. The handle member 20 may have a step change in diameter at the ends of the center portion 30, with the center portion 30 having a larger diameter than the end portions 21, 22 of the handle member 20. In one embodiment, the heads 11, 12 in the embodiment of FIGS. 13-16 may be formed with bevels 18 in the inner sides 14 at least partially around the inner end openings 37 of the passages 17, similarly to the embodiment of FIGS. 6-12. The bevels 18 extend around the inner ends of the passages 17, and in one embodiment, the bevels 18 may provide room for a weld bead if the handle member 20 is welded to heads 11, 12 at the inner sides 14, 15 to provide additional reinforcement to the connection between the handle member 20 and the heads 11, 12.

In one embodiment, the dumbbell 10 may be manufactured by casting the heads 11, 12 directly in place on the handle member 20. FIG. 17 illustrates an example of this method used to form a dumbbell 10 as shown in FIGS. 6-12, and it is understood that such a method may be used in connection with any embodiment herein. The method includes first forming the handle member 20, such as by rolling, extruding, forging, or other metal manufacturing technique, and then machining the handle member 20 to the desired shape. The handle member 20 is then connected to the bolsters 31 and/or the endpieces 25 (if present) by first inserting the ends 23, 24 of the handle member 20 through the passages 32 in the bolsters 31 and then inserting the ends 23, 24 into and/or through the cavities 27 of the endpieces 25. The bolsters 31 and the endpieces 25 may be fixed to the handle member 20 using a technique disclosed herein, e.g., welding. Then, the ends 23, 24 of the handle member 20 are inserted into molds 40, and the heads 11, 12 are cast onto the ends of the handle member 20 (see FIG. 17). The cavity 41 of each mold 40 may be shaped to a near net shape of the respective head 11, 12, accommodating for shrinkage if necessary. Knurling may be added to the handle member 20 before or after the casting step. Welding or other integral joining technique may be applied to further strengthen the connection between the handle member 20 and the heads 11, 12, such as described herein with respect to FIG. 12. The bevels 18 may provide room for a weld bead 42 if the handle member 20 is welded to heads 11, 12 at the inner and outer sides 14, 15 to provide further reinforcement to the connection between the handle member 20 and the heads 11, 12.

In another embodiment, the heads 11, 12 may be manufactured separately from the handle member 20 with the holes 17 extending inward from the inner sides 14 through at least a portion of the thickness of the head 11, 12 (see FIG. 9), and the ends 23, 24 of the handle member 20 may be inserted into the holes 17. The heads 11, 12 may then be fixed to the handle member 20, such as by an integral joining technique (e.g., welding as shown in FIG. 12) or mechanical connection technique as disclosed herein. As discussed herein, the weld bead 42 and/or adjacent surfaces of the handle member 20 and/or the head 11, 12 may be smoothed by a material removal technique such as grinding or machining. The heads 11, 12 may be similarly manufactured using casting, such as casting to near net shape. In one embodiment, the passages 17 and/or the bevels 18 may be formed in the heads 11, 12 by casting, and in another embodiment, the passages 17 and/or the bevels 18 may be formed by post-casting processing, such as drilling/machining or other material removal technique(s). It is understood that some configurations of the handle assembly 13, such as those having enlarged endpieces 25 fixed to the handle member 20, may not be suitable for insertion into pre-formed heads 11, 12, or may require modification of the process.

Various embodiments of dumbbells and components thereof have been described herein, which include various components and features. In other embodiments, the dumbbells 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 dumbbells described herein may be constructed with similar structural and functional elements having different configurations, including different ornamental appearances.

The embodiments of dumbbells and manufacturing methods described herein provide benefits and advantages over existing products. For example, the structure of the handle assembly provides a handle with a high quality materials, performance, and aesthetics, which can be used with heads formed using an efficient manufacturing process such as casting. As another example, the connection and assembly techniques described herein provide a more secure connection between the handle assembly and the heads. As a further example, the use of bolsters and/or bevels at the surfaces of the heads provides an aesthetic appearance that is cleaner and more attractive than is typically achieved by cast dumbbell heads. Still other benefits and advantages are readily recognized by those skilled in the art.

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. The terms “top,” “bottom,” “front,” “back,” “side,” “rear,” “proximal,” “distal,” and the like, as used herein, are intended for illustrative purposes only and do not limit the embodiments in any way. 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. 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. The term “approximately” or “substantially” as used herein implies a variation of up to 10% of the nominal value or property modified by such term, or up to 10% of a midpoint value of a range modified by such term. “Integral joining technique,” as used herein, means a technique for joining two pieces so that the two pieces effectively become a single, integral piece, including, but not limited to, irreversible joining techniques such as welding, brazing, soldering, or the like, where separation of the joined pieces cannot be accomplished without structural damage thereto. 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.

Claims

1. A dumbbell comprising:

a handle member having a center portion having a cylindrical shape and configured for gripping by a user, a first end portion extending from the center portion to a first distal end of the handle member, and a second end portion extending from the center portion to a second distal end of the handle member, such that the center portion is located between the first and second end portions;

a first head connected to the first end portion of the handle member, the first head having a first inner side facing toward the center portion of the handle member, a first outer side facing away from the center portion of the handle member, and a first passage extending through the first head and having a first inner end opening on the first inner side and a first outer end opening on the first outer side, wherein the first head has a first inner bevel on the first inner side extending around the first inner end opening of the first passage and a first outer bevel on the first outer side extending around the first outer end opening of the first passage; and

a second head connected to the second end portion of the handle member, the second head having a second inner side facing toward the center portion of the handle member, a second outer side facing away from the center portion of the handle member, and a second passage extending through the second head and having a second inner end opening on the second inner side and a second outer end opening on the second outer side, wherein the second head has a second inner bevel on the second inner side extending around the second inner end opening of the second passage and a second outer bevel on the second outer side extending around the second outer end opening of the second passage,

wherein the first end portion of the handle member is received in the first passage of the first head and extends through the first passage from the first inner side to the first outer side, and the first end portion of the handle member is connected to the first head by welding comprising a first inner weld bead extending at least partially around the first inner end opening between the first inner bevel of the first head and the first end portion of the handle member and a first outer weld bead extending at least partially around the first outer end opening between the first outer bevel of the first head and the first end portion of the handle member,

wherein the second end portion of the handle member is received in the second passage of the second head and extends through the second passage from the second inner side to the second outer side, and the second end portion of the handle member is connected to the second head by welding comprising a second inner weld bead extending at least partially around the second inner end opening between the second inner bevel of the second head and the second end portion of the handle member and a second outer weld bead extending at least partially around the second outer end opening between the second outer bevel of the second head and the second end portion of the handle member, and

wherein the first head and the second head are configured to provide weight to the dumbbell for use in a weightlifting exercise.

2. The dumbbell of claim 1, wherein the first inner weld bead extends completely around the first inner end opening, the first outer weld bead extends completely around the first outer end opening, the second inner weld bead extends completely around the second inner end opening, the second outer weld bead extends completely around the second outer end opening.

3. The dumbbell of claim 2, wherein the first inner weld bead completely fills the first inner bevel, the first outer weld bead completely fills the first outer bevel, the second inner weld bead completely fills the second inner bevel, and the second outer weld bead completely fills the second outer bevel.

4. The dumbbell of claim 1, wherein the first end portion and the second end portion of the handle member have cylindrical shapes.

5. The dumbbell of claim 4, wherein the center portion, the first end portion, and the second end portion of the handle member have equal diameters.

6. The dumbbell of claim 4, wherein the center portion of the handle member has a larger diameter than the first end portion and the second end portion, and wherein the handle member has step changes in diameter between the center portion and the first end portion and between the center portion and the second end portion.

7. The dumbbell of claim 1, wherein the first inner side and the first outer side of the first head have curved surfaces, and the first head further has a first cylindrical peripheral surface extending between the first inner side and the first outer side, and wherein the second inner side and the second outer side of the second head have curved surfaces, and the second head further has a second cylindrical peripheral surface extending between the second inner side and the second outer side.

8. The dumbbell of claim 7, wherein the handle member has a first distal end and a second distal end, and wherein the first distal end is substantially flush with the first outer side and is curved to match a curvature of the first outer side, and the second distal end is substantially flush with the second outer side and is curved to match a curvature of the second outer side.

9. The dumbbell of claim 7, wherein the first head and the second head are formed by casting a metallic material to near net shape.

10. The dumbbell of claim 9, wherein the first inner weld bead extends completely around the first inner end opening, the first outer weld bead extends completely around the first outer end opening, the second inner weld bead extends completely around the second inner end opening, the second outer weld bead extends completely around the second outer end opening.

11. The dumbbell of claim 10, wherein the first end portion and the second end portion of the handle member have cylindrical shapes.

12. The dumbbell of claim 11, wherein the center portion of the handle member is knurled over at least a portion of a length thereof.

13. A method of manufacturing a dumbbell, the method comprising:

providing a handle member having a center portion having a cylindrical shape and configured for gripping by a user, a first end portion extending from the center portion to a first distal end of the handle member, and a second end portion extending from the center portion to a second distal end of the handle member, such that the center portion is located between the first and second end portions;

casting a first head to near net shape from a metallic material, the first head having a first inner side facing toward the center portion of the handle member, a first outer side facing away from the center portion of the handle member, and a first passage extending through the first head and having a first inner end opening on the first inner side and a first outer end opening on the first outer side, wherein the first head has a first inner bevel on the first inner side extending around the first inner end opening of the first passage and a first outer bevel on the first outer side extending around the first outer end opening of the first passage;

casting a second head to near net shape from the metallic material, the second head having a second inner side facing toward the center portion of the handle member, a second outer side facing away from the center portion of the handle member, and a second passage extending through the second head and having a second inner end opening on the second inner side and a second outer end opening on the second outer side, wherein the second head has a second inner bevel on the second inner side extending around the second inner end opening of the second passage and a second outer bevel on the second outer side extending around the second outer end opening of the second passage;

inserting the first end portion of the handle member into and through the first passage of the first head, such that the first end portion extends through the first passage from the first inner side to the first outer side;

connecting the first end portion of the handle member to the first head by welding comprising forming a first inner weld bead extending at least partially around the first inner end opening between the first inner bevel of the first head and the first end portion of the handle member and a first outer weld bead extending at least partially around the first outer end opening between the first outer bevel of the first head and the first end portion of the handle member;

inserting the second end portion of the handle member into and through the second passage of the second head, such that the second end portion extends through the second passage from the second inner side to the second outer side;

connecting the second end portion of the handle member to the second head by welding comprising forming a second inner weld bead extending at least partially around the second inner end opening between the second inner bevel of the second head and the second end portion of the handle member and a second outer weld bead extending at least partially around the second outer end opening between the second outer bevel of the second head and the second end portion of the handle member; and

smoothing at least one of the first inner weld bead, the first outer weld bead, the second inner weld bead, and the second outer weld bead, using a material removal technique,

wherein the handle member, the first head, and the second head form the dumbbell, and the first head and the second head are configured to provide weight to the dumbbell for use in a weightlifting exercise.

14. The method of claim 13, wherein the first inner weld bead extends completely around the first inner end opening, the first outer weld bead extends completely around the first outer end opening, the second inner weld bead extends completely around the second inner end opening, the second outer weld bead extends completely around the second outer end opening.

15. The method of claim 14, wherein the first inner weld bead completely fills the first inner bevel, the first outer weld bead completely fills the first outer bevel, the second inner weld bead completely fills the second inner bevel, and the second outer weld bead completely fills the second outer bevel.

16. The method of claim 13, wherein the first inner side and the first outer side of the first head have curved surfaces, and the first head further has a first cylindrical peripheral surface extending between the first inner side and the first outer side, and wherein the second inner side and the second outer side of the second head have curved surfaces, and the second head further has a second cylindrical peripheral surface extending between the second inner side and the second outer side.

17. The method of claim 16, wherein the handle member has a first distal end and a second distal end, and wherein the first distal end is substantially flush with the first outer side and is curved to match a curvature of the first outer side, and the second distal end is substantially flush with the second outer side and is curved to match a curvature of the second outer side.

18. The method of claim 17, wherein the smoothing step further comprises smoothing at least one of the first distal end of the handle member, the second distal end of the handle member, the first outer side of the first head, and the second outer side of the second head using the material removal technique, such that the first distal end, the first outer weld bead, and the first outer side form a first smooth surface, and such that the second distal end, the second outer weld bead, and the second outer side form a second smooth surface.

19. The method of claim 18, wherein the first inner weld bead extends completely around the first inner end opening, the first outer weld bead extends completely around the first outer end opening, the second inner weld bead extends completely around the second inner end opening, the second outer weld bead extends completely around the second outer end opening.

20. The method of claim 19, further comprising machining a metallic component to manufacture the handle member.