GB2610854A

GB2610854A - Weight plate

Info

Publication number: GB2610854A
Application number: GB2113338.4A
Authority: GB
Inventors: John Witzmann Frederick; Elsayed Eltilib Maimana
Original assignee: Hone Innovations Ltd
Current assignee: Hone Innovations Ltd
Priority date: 2021-09-17
Filing date: 2021-09-17
Publication date: 2023-03-22

Abstract

A weight plate 100 for an exercise system comprises first and second coupling members 105, (107, figure 1B) on opposite sides of a weight plate 100. The first coupling member 105 is configured to interlock with the second coupling member (107) of a like-weight plate by rotation of the weight plate relative to the like-weight plate. The weight plate also comprises first and second retaining elements 106, (108, figure 1B) on opposite sides of the weight plate. The first retaining element 106 is engageable with the second retaining element (108) of a like-weight plate to retain the first coupling member in an interlocked position with the second coupling member of the like-weight plate. The first and second retaining elements are configured to permit release of the first coupling member from the interlocked position upon rotation of the weight plate relative to the like-weight plate by a user. The first retaining element may take the form of spring biased detent, such as a sprung ball plunger. The second retaining element may take the form of a concave recess to receive the sprung ball plunger therein when engaged.

Description

WEIGHT PLATE

Technical Field

The present disclosure relates to a weight plate for a modular free weight system. 5 Background Free weights such as kettlebells, barbells, dumbbells, and triceps bars are commonly used for weight training, either in gyms or at a user's home. In some cases (typically in gyms), to allow a user to train with a particular weight, a set of free weights (e.g. dumbbells or barbells) of different weights is provided. This can, however, require a significant amount of space, especially where a large range of weights is required.

As an alternative, it is known to provide a bar (or a set of bars) and a separate set of weight plates (i.e. of varying weight) that can be mounted to the bar. Typically the bar will include a grip that is held by a user, and two ends that are each configured for receipt of one or more weight plates thereon. In particular, each weight plate includes a central hole that allows the weight plate to be threaded onto the bar (by insertion of the end of the bar through the hole).

Sometimes, to ensure that the weight plates are retained on the bar, collars are provided that can be mounted between the weight plates and each respective end of the bar.

The provision of a separate bar and weight plates reduces the space requirements of the free weight system, while maintaining the benefit of being able to adjust the weight of the free weight to suit a particular exercise. However, such systems can be somewhat less convenient than those in which several individual dumbbells or barbells are provided. It can take significant time (e.g. between exercises) to replace the weight plates on the bar with other weight plates of a different weight. For example, where a user wishes to replace the weight plate closest to the centre of the bar (i.e. the innermost weight plate), they must first remove all of the weights outside of that weight plate to allow the innermost weight plate to be slid from the end of the bar.

Furthermore, it can be difficult to mount weight plates to the bar, especially in the case of particularly cumbersome weight plates. It is typical to provide a small tolerance between the diameter of the central hole of a weight plate and the outer diameter of the end of the bar. This minimises movement of the weight plate on the bar in use, but at the same time can make it difficult to align the end of the bar with the central hole and slide the weight plate onto the bar.

Other systems are known that attempt to rectify these issues. Such systems typically involve a plurality of weight plates that include slots for slotting onto a central bar. The weight plates can be selectively interlocked with the central bar by rotating one or more dials at opposing ends of the bar. Thus, for example, a user selects a desired weight by rotating the dials to a particular position, and this causes the interlocking of a selection of the weights slotted onto the bar. The remaining (i.e. non-interlocked) weights are left behind (e.g. on a mount) when the user then lifts the bar. These systems rely on a complex arrangement of moving components to provide the selective interlocking mechanism. This increases manufacturing cost and reduces the durability (i.e. by increasing the possibility that a component may fail) The present disclosure has been devised in light of the above considerations. Summary In a first aspect, there is provided a weight plate for a modular free weight system, the weight plate comprising: first and second coupling members on opposite sides of the weight plate, the first coupling member configured to interlock with the second coupling member of a like-weight plate by rotation of the weight plate relative to the like-weight plate; and first and second retaining elements on opposite sides of the weight plate, the first retaining element engageable with the second retaining element of the like-weight plate to retain the first coupling member in an interlocked position with the second coupling member of the like-weight plate, the first and second retaining elements configured to permit release of first coupling member from the interlocked position upon rotation of the weight plate relative to the like-weight plate by a user.

The provision of a weight plate that can interlock with a like-weight plate means that the weight plates can be interlocked with one another directly rather than via a handle (e.g. a bar). This can speed up the process of replacing one or more weights on a bar by allowing multiple interlocked weights to be removed as a single assembly. Likewise, it may mean that a shorter bar can be provided (as the bar only needs to extend between the innermost weights rather than for the entire length of the assembly), which can reduce the amount of space required to store and transport the free weight system.

The provision of the retaining element means that the first and second coupling members can be provided with a greater tolerance and so can be engaged with greater ease (e.g. than a weight plate having a central hole). That is, the retaining element is able to perform the function of retaining the weight plate against movement in use rather than relying on a close tolerance between the coupling members to perform this function.

The configuration of the retaining element so that it releases the weight plate upon rotation means that the act of rotating the weight plate relative to the like-weight plate both releases the engagement of the retaining element and the interlocking of the first and second coupling members. This means that the weight plate can be disengaged/released from the like-weight plate in a single movement. Likewise, it does not require access to the retaining element itself, which could otherwise prevent the ability of a user to release a weight that is interposed between at least two other weights.

Optional features of the first aspect will now be set out. These are applicable singly or in any combination with any aspect.

The first retaining element and/or the second retaining element may form part of the first or second coupling member. Alternatively, the first retaining element and/or second retaining element may be separate from (e.g. external to) the first and second coupling members (i.e. the retaining element may not form part of the first or second coupling member). The first retaining element may be spaced from the first and second coupling members. For example, the first retaining element and/or second retaining element may be provided on a surface of a side of the weight plate that faces (and is in contact with or proximate to) a like-weight plate when interlocked with the weight plate (i.e.a surface that does not form part of either coupling member).

The first retaining element may comprise a resilient portion. The resilient portion may be configured to (e.g. may have a resilience such that it is able to) permit release of first coupling member from the interlocked position upon rotation of the weight plate (e.g. about a central rotational axis) relative to the like-weight plate by a user (i.e. while otherwise retaining the first coupling member in the interlocked position in normal use). The resilient portion may likewise be configured to (e.g. may have a resilience such that) the weight plate is not dislodged from the interlocked position during normal use, such as during weight training or handling of the weight plate).

The provision of a resilient portion may allow the retaining element to move in response to force in a particular direction. This allows the retaining element to be configured to allow disengagement by application of a rotational force by user (i.e. a rotational force above a particular threshold level), but to otherwise prevent such disengagement when other forces (experienced in normal use) are applied.

The resilient portion may be in the form of a biasing device such as a spring (e.g. a compression spring). The resilient portion may otherwise be in the form of a resilient body (e.g. an elastomeric body).

The first retaining element may comprise a detent portion for engaging the second retaining element of the like-weight plate when interlocked with the weight plate (to retain the weight plates in the interlocked position). The resilient portion may be configured to urge the detent portion into engagement with the second retaining element. The first retaining element (e.g. detent portion) may comprise a ramp surface (i.e. a sloped surface). The ramp surface may be configured to allow a portion of a like-weight plate (e.g. the second retaining element) to ride over the detent when the weight is being disengaged by a user (i.e. by rotation). The ramp surface may be oriented in a circumferential direction of the weight plate. Thus, the ramp surface may be oriented in a direction of travel of the detent during rotation of the weight plate (i.e. oriented in a circumferential direction). The ramp surface may be planar or may be a curved surface.

The resilient portion may be configured to urge the first retaining element (e.g. the detent portion) against the like-weight plate when the weight plate is interlocked with the like-weight plate. The resilient portion may be configured to urge the detent portion in a direction away from the weight plate (e.g. away from a side of the weight plate on which the retaining element is provided). The resilient portion may be configured to urge the first retaining element (e.g. the detent portion) against a like-weight plate, when the weight plate is interlocked with the weight-plate, to urge the like-weight plate in a direction away from the weight plate.

By urging the detent portion against a like-weight plate in this way, in addition to providing the above described feature of managing disengagement, the first retaining element may help to reduce axial movement (i.e. perpendicular the first and second sides) of the weight plate and the like-weight plate relative to one another (e.g. by urging the like-weight plate away from the weight plate). This may reduce rattling of the interlocked weight plates in use (i.e. caused by contact of two interlocked weight plates).

In some embodiments, the first retaining element may be located closer to a periphery of the weight plate than the centre of the weight plate. This may facilitate reduction of axial movement (and rattling). In other embodiments, the first retaining element may be located closer to a centre of the weight plate than a periphery of the weight plate.

The detent portion may be in the form of e.g. a ball or a pin. The detent portion may, for example, have a spherical shape, a hemispherical shape, or a cuboid shape (e.g. with a rounded end). In this respect, the first retaining element may be in the form of a sprung plunger (e.g. a sprung ball plunger).

As may be appreciated, the weight-plate may include a plurality of first retaining elements (e.g. each in the form of a sprung plunger).

The total preload (i.e. the force required to begin compression of the spring) of the one or more sprung plungers may be between 10 N and 70 N, or e.g. between 15 N and 40 N, or e.g. about 17N.

The total (i.e. combined) maximum load (i.e. the force required to fully compress the spring) of the one or more spring plungers may be between 20 N and 100 N, or e.g. between 30 N and 60 N, or e.g. about 37 N. For example, when the weight-plate includes two first retaining elements in the form of sprung plungers, the preload of each sprung plunger may be between 5 N and 25 N, or e.g. between 7 N and 20 N, or e.g. about 8.5 N. The maximum load may be between 10 N and 40 N, or e.g. between 15 N and 30 N, or e.g. about 18.5 N. As should be appreciated, the optimal maximum load and preload will be somewhat dependent on the weight of the weight plate.

The second retaining element may be in the form of a recess for receipt of a portion (e.g. the detent portion) of the first retaining element of a like-weight plate (i.e. when the weight plate is interlocked with the like-weight plate).

The second retaining element may comprise a ramp surface (i.e. a sloped surface). The ramp surface may be configured to allow a portion of a like-weight (e.g. the first retaining element) to ride over ramp surface when the weight is being disengaged by a user (i.e. by rotation). The ramp surface may be oriented in a circumferential direction of the weight plate. Thus the ramp surface may be oriented in a direction of travel of the second retaining element during rotation of the weight plate (i.e. oriented in a circumferential direction). The ramp surface may be planar or may be a curved surface.

The recess may have a concave shape. This may be particularly suited to, for example, an arrangement in which the first retaining element is a sprung ball plunger. In such arrangements the ball of the sprung ball plunger may be received in the concave recess of the second retaining element of a like-weight plate to retain the weight plates in an interlocked position. As may be appreciated, rotation of the weight-plate by a user may then dislodge the ball from the recess so as to allow the weight-plate to be rotated further resulting in disengagement from the like-weight plate.

The first and second retaining elements may be arranged such that, when the weight plate is interlocked with a like-weight plate, the first retaining element is aligned with (e.g. directly opposite) the second retaining element of the like-weight plate.

The first and second retaining elements may represent a first retaining element pair. The weight plate may comprise a second retaining element pair, which may be as described above with respect to the first retaining element pair. The provision of two retaining element pairs may increase the ability of the weight plate to be retained in the interlocked position with a like-weight plate. The weight plate may comprise additional retaining element pairs (e.g. may comprise a total of three or four retaining element pairs).

The first retaining elements of the pairs of retaining elements may be provided on the same side of the weight plate. The first retaining elements (of the two pairs) may diametrically oppose one another (and may e.g. be spaced either side of a centre of the weight plate). The second retaining elements of the two pairs of retaining elements may be provided on the same side of the weight plate. The second retaining element may diametrically oppose one another (and may e.g. be spaced either side of a centre of the weight plate). Such an arrangement may mean that the retaining elements are symmetrically arranged.

One of the first and second coupling members may be in the form of a male coupling member and the other may be in the form of a female coupling member.

The male coupling member may protrude from a side of the weight plate (i.e. the side on which it is located). The male coupling member may be disposed at or proximate to the centre of the side of the weight plate on which it is provided (i.e. may protrude from the centre of the side). The male coupling member may protrude in a direction that is generally perpendicular to the side of the weight plate (i.e. an axial direction).

The male coupling member may comprise a projection extending laterally outwardly for engaging the second coupling member. The term "laterally" is used here to describe a direction that is generally perpendicular to the direction in which the male coupling member protrudes. This direction may be in a radially outward direction of the weight plate. For the avoidance of doubt, the term "radially" is not intended to require the weight plate to have a circular shape (it merely describes a direction that extends outwardly from a centre of the weight plate).

A space (referred to herein as a tooth-receiving space) may be defined by the laterally extending projection (e.g. at an underside of the projection). The space may be in the form of e.g. a passage, cut-out, recess, groove, etc. The laterally extending projection may be spaced from the side of the weight plate, so as to define the tooth-receiving space between the projection and the side. The tooth-receiving space may be in the form of a groove. A rotation-limiting wall may be provided at an end of the groove (e.g. extending between the projection and the side) to limit movement of a tooth along the groove (as will be discussed further below).

The male coupling member may comprise a plurality of projections, each being as described above. The plurality of projections may be spaced evenly about the male coupling member (e.g. about a body of the male coupling member).

For example, the projection may be a first projection and the male coupling member may comprise a second projection. The second projection may be the same as the first projection described above. The first and second projections may extend in opposite directions (e.g. from opposite sides of the body of the male coupling member). As may be appreciated, the male coupling member may comprise more than two projections. Alternatively, the male coupling member may comprise only two projections (i.e. the first and second projections as discussed above).

The female coupling member may be directly opposite the male coupling member (i.e. on the opposite side of the weight plate). The female coupling member may comprise a recess formed in the side of the weight plate on which it is provided. In this respect, the female coupling member may be in the form of a socket. The female coupling member may be disposed at a centre of the side of the weight plate on which it is provided.

The female coupling member may comprise a space (referred to herein as a projection-receiving space) configured for receipt of (and engagement with) the projection of the male coupling member (the space may be in the form of e.g. a passage, cut-out, recess, groove, etc.). The projection-receiving space may extend in a circumferential direction (partly about the female coupling member).

The female coupling member may comprise a tooth for engaging the male coupling member. The tooth may extend laterally inwardly (e.g. radially inwardly). The tooth may extend partway across an opening of the recess. The tooth may define the projection-receiving space (e.g. at an underside of the tooth). That is, the tooth may be spaced from a base of the recess (i.e. the innermost surface of the recess) so as to define the projection-receiving space (i.e. between the tooth and the base of the recess).

One end of the tooth-receiving space or projection-receiving space may define an entrance into which a tooth/projection is received in use (i.e. the end at which the corresponding tooth/projection is received in use). The entrance to the tooth-receiving space may taper inwardly (i.e. in a direction into the tooth-receiving space). This may guide a portion of the female coupling member (e.g. a tooth as discussed further below) into the tooth-receiving space.

The female coupling member may comprise a plurality of teeth, each being as described above.

The plurality of teeth may be spaced evenly about a periphery of the recess.

For example, the tooth described above may be a first tooth and the female coupling member may comprise a second tooth. The second tooth may be the same as the first tooth described above. The first and second teeth may oppose one another across the recess (e.g. may extend towards one another from opposite sides of the recess). As may be appreciated, the female coupling member may comprise more than two teeth. Alternatively, the female coupling member may comprise only two teeth (i.e. the first and second teeth as discussed above).

In use, the male coupling member may be interlocked with the female coupling member of a like-weight plate by way of receipt of the projection(s) in the projection-receiving space(s) and receipt of the tooth (or teeth) in the tooth-receiving space(s). This positioning may be achieved by inserting the male coupling member into the recess of the female coupling member of the like-weight plate and then rotating the male coupling member relative to the female coupling member. The end wall(s) of the male coupling member may restrict this rotational movement (i.e. may restrict further rotational movement once the coupling members are interlocked).

As should be appreciated, the female coupling member is able to engage with the male coupling member of a like-weight plate in the same manner.

In this way, the male coupling member and the female coupling member may form bayonet connections (with corresponding male and female coupling members of like-weight plates). In a bayonet connection, the two coupling members are brought together (e.g. male coupling member fully inserted into female coupling member) and then rotated to provide the engagement. A bayonet connection does not require careful axial alignment of the male/female coupling members. Instead, the male coupling member can be approximately aligned with the female coupling member, and insertion of the male coupling member fully into the female coupling member then fully aligns the coupling members for subsequent rotation (upon which engagement is provided).

In other embodiments, the male coupling member and female coupling member may form screw connections, such as a quarter turn screw connection. Thus, the male coupling member may comprise one or more thread portions that extends about only a portion of the circumference of a protrusion of the male coupling member. The female coupling member may comprise an internal thread in a recess thereof and a groove that extends axially along the length of the recess so as to define one or more gaps/breaks in the thread. Thus, in use., the one or more thread portions may be aligned with the groove for insertion of the male coupling member into the female coupling member, and the male coupling member can then be rotated relative to the female coupling member to engage the one or more thread portions with the internal thread.

The first and second sides of the weight plate may represent major (e.g. substantially planar) faces of the weight plate, which may be joined by a peripheral edge. The first and second sides may be substantially parallel to one another. This may permit close stacking of the weight plate with one or more like-weight plates.

The weight plate may comprise a body. The body may form the bulk (i.e. the majority) of the weight of the weight plate (i.e. may be the major component of the weight plate). The female coupling member and/or the male coupling member may be integrally formed with the body. An outer cover (e.g. formed of a resilient material such as rubber) may extend about a periphery of the body of the weight plate.

The body of the weight plate may be formed by way of e.g. metal injection moulding and/or CNC milling (which may be suitable for small scale manufacturing) or e.g. investment casting, die casting, etc. (which may be suitable for mass manufacture).

The male coupling member may be mounted to the body of the weight plate (i.e. the male coupling member may be a separate component to the body). The male coupling member may be mounted by way of a fastener (e.g. by way of a threaded connection). For example, the male coupling member may comprise a threaded bore for engagement with a corresponding threaded fastener, such as a bolt or screw (e.g. a countersunk screw). A bore may extend (e.g. centrally) through the body of the weight plate (i.e. from one side of the weight plate to the other). The threaded fastener may extend through the bore of the body to the threaded bore of the male coupling member.

One of the male coupling member and the body of the weight plate may comprise a raised portion (e.g. a boss) and the other of the male coupling member and the body may comprise a complementary On shape) recessed portion for receipt of the raised portion. Each of these portions may have a square shaped cross section (taken parallel to the sides of the weight plate). These portions may be other shapes, such as elliptical, rectangular, hexagonal, octagonal, etc. These portions help to align the male coupling member and the body. Their presence also means that shear forces applied to the male coupling member are transferred directly to the body rather than via the threaded fastener. This can avoid failure (e.g. via fatigue) of the fastener and so improves the durability of the weight plate. Further, the provision of the raised/recessed portions mean that when screwing the threaded fastener into the male coupling member, the male coupling member is prevented from rotating with the threaded fastener.

The weight plate may be substantially circular (i.e. the peripheral edge may have a circular shape). Alternatively, the peripheral edge may comprise a planar portion. The peripheral edge may comprise a plurality of planar portions. Thus the weight plate may have a polygonal shape.

For example, the weight plate may have e.g. a pentagonal, hexagonal, heptagonal, octagonal, nonagonal or decagonal shape. The provision of one or more planar portions may allow the weight plate to be supported on the peripheral edge.

The weight plate may have a weight of between 0.5 kg and 25 kg, e.g. between 1 kg and 10 kg.

In a second aspect there is provided a modular free weight system, the system comprising: a weight plate according to the first aspect; and a handle comprising a grip portion and a mounting portion, the mounting portion having: a coupling member configured to interlock with the first or second coupling member of the weight plate; and a retaining element configured to engage the first or second retaining element of the weight plate when interlocked with the mounting portion.

Optional features of the second aspect will now be set out. These are applicable singly or in any combination with any aspect.

The coupling member of the handle may be the same as the male coupling member described above with respect to the first aspect. Alternatively, the coupling member of the handle may be the same as the female coupling member described above with respect to the first aspect.

It can be desirable for the handle to have a female coupling member as this means the male coupling member of the weight plate will face the handle in use (i.e. for interlocking with the female coupling member) and the female coupling member of the weight plate will face away from the handle. Unlike the male coupling member (which may protrude), the female coupling member does not impede the ability to rest the weight plate on a surface (i.e. because it may be recessed), such as a user's leg.

The retaining element may be the same as the first or second retaining element described above with respect to the first aspect.

The mounting portion may comprise two opposing major faces and an outer peripheral (e.g. edge) surface connecting the major faces. The outer peripheral surface may comprise a planar portion. This may allow the handle to rest in a stable manner on a flat surface.

The grip portion may be elongate and may be e.g. cylindrical or tubular. The grip portion may follow a linear path or a curved path. The mounting portion may be a first mounting portion and the handle may comprise a second mounting portion. The second mounting portion may be the same as the first mounting portion. The first and second mounting portions may be disposed at opposing ends of the grip portion. Each mounting portion may comprise a mounting face on which the coupling member and retaining element is provided. Each mounting face may be directed away from the grip portion.

In other embodiments, the handle may comprise only one mounting portion. Such embodiments may, for example, be suited to use of the modular free weight system as a kettle bell. In such embodiments, the grip portion may form a loop (e.g. a half loop).

The or each mounting portion may be mounted to the grip portion by way of a fastener (e.g. a screw, such as a countersunk screw). The grip portion may comprise one or more threaded bores for threaded engagement with the fastener. One of the grip portion and the mounting portion may comprise a raised portion (e.g. a boss) and the other of the grip portion and the mounting portion may comprise a complementary (in shape) recessed portion for receipt of the raised portion. Each of these portions may have a square shaped cross section. These provide the same function as those described above with respect to the weight plate.

The handle may be in the form of a kettlebell handle, barbell handle, dumbbell handle or z-bar.

In a third aspect, there is provided a weight plate for a modular free weight system, the weight plate comprising: first and second coupling members on opposite sides of the weight plate, the first coupling member configured to interlock with the second coupling member of a like-weight plate by rotation of the weight plate relative to the like-weight plate; and a body providing the majority of the weight of the weight plate, wherein at least one of the coupling members is integrally formed with the body.

Such an arrangement may simplify construction of the weight plate. This may reduce manufacturing costs and reduce the complexity of the weight plate so as to increase durability (e.g. may reduce the possibility of a connection between components failing by reducing the number of connections).

Optional features of the third aspect will now be set out. These are applicable singly or in any combination with any aspect.

In some embodiments the first coupling member may be mounted to the body (i.e. may be a separate component mounted to the body) and the second coupling member maybe integrally formed with the body.

One of the first and second coupling members may be in the form of a male coupling member and the other may be in the form of a female coupling member. The male coupling member may be mounted to the body (i.e. may be a separate component mounted to the body) and the female coupling member may be integrally formed with the body.

The male coupling member may be mounted by way of a fastener (e.g. by way of a threaded connection). For example, the male coupling member may comprise a threaded bore for engagement with a corresponding threaded fastener, such as a bolt or screw (e.g. a countersunk screw). A bore may extend (e.g. centrally) through the body of the weight plate (i.e. from one side of the weight plate to the other). The threaded fastener may extend through the bore of the body to the threaded bore of the male coupling member.

The weight plate of the third aspect may be as otherwise defined with respect to the first aspect.

For example, the weight plate of the third aspect may comprise the retaining elements as described in the first aspect.

Brief Summary of the Figures

Embodiments will now be discussed with reference to the accompanying figures in which: Figure 1A is a perspective view of a first side of a weight plate Figure 1B is a perspective view of a second side of the weight plate of Figure 1A; Figure 1C is a section view of the weight plate of Figure 1A; Figure 2A is a perspective view of a handle for use with the weight plate of Figure 1A; and Figure 2B is a detailed section view of an end of the handle of Figure 2A.

Detailed Description

Aspects and embodiments will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art.

Figures 1A, 1B and 1C illustrate a weight plate 100 for use as part of a modular dumbbell system. The weight plate 100 includes first 101 and second 102 opposite sides that define major faces of the weight plate 100 and that are substantially parallel to one another. The sides 101, 102 are joined by a peripheral edge 103 that, in the present embodiment, is formed of a plurality of connected planar surfaces 104. In particular, the peripheral edge 103 includes ten of such planar surfaces 104, which gives the weight plate 100 (and each side 101, 102) a substantially decagonal shape. The provision of these planar surfaces 104, means that the weight plate 100 can rest on a horizontal surface in a plurality of orientations.

The first side 101 of the weight plate 100 (as shown in Figure 1A) includes a first coupling member in the form of a male coupling member 105 and two first retaining elements, each in the form of a sprung ball plunger 106. The second side 102 (as shown in Figure 1B) includes a second coupling member in the form of a female coupling member (i.e. socket) 107 and two second retaining elements, each in the form of a concave recess 108.

The provision of the male 105 and female 107 coupling members on opposite sides 101, 102 of the weight plate 100 allows the weight plate 100 to form part of a modular free weight system.

In particular, the weight plate 100 is able to interlock with other components that include corresponding male 105 and female 107 coupling members. For example, the weight plate 100 is able to interlock with another identical weight plate 100, or another similar weight plate 100 (e.g. that includes the same features but is a different size). This means several like-weight plates 100 may be interlocked together to provide an assembly of weight plates. Various combinations of like-weight plates 100 may be interlocked to provide assemblies of weight plates of varying weight.

Likewise, the weight plate 100 is able to interlock with various types of handles (one of which is shown in Figure 2A) for use in weight training by a user. In this way, the weight plate 100 may form part of e.g. a barbell, dumbbell, triceps bar, kettle bell, etc. For the purposes of explaining the operation of the weight plate 100, a like-weight plate is referred to below. This is a reference to a second weight plate that is the same as the illustrated weight plate 100. For that reason, the same reference numerals are used to refer to the features of the weight plate 100 and the like-weight plate.

The male 105 and female 107 coupling members of the illustrated embodiment provide a bayonet connection. The male coupling member 105 (as shown in Figure 1A) comprises a body 109 that protrudes from the first side 101 of the weight plate 100. Two projections 110 extend laterally and radially outwardly from opposite sides of the body 109 of the male coupling member 105 (and thus extend in opposite directions to one another) towards the outer peripheral edge 103 of the weight plate 100. Each of these projections 110 is spaced from the first side 101 of the weight plate 100 such that a tooth-receiving space 111 (in the form of a groove) is defined therebetween. A rotation-limiting wall 112 is provided at an end of each of these tooth-receiving spaces 111 and extends between the respective projection 110 and the first side 101 to cap the end of the tooth-receiving space 111.

The female coupling member 107 (as shown in Figure 1B) comprises a recess 113 formed in the second side 102 of the weight plate 100. The female coupling member 107 also comprises two teeth 114 that extend laterally inwardly and partway across an opening of the recess 113. The teeth 114 diametrically oppose one another, so as to extend towards each other. Each tooth 114 is spaced from a base 116 of the recess 113, such that a projection-receiving space 115 is defined between each tooth 114 and the base 116 of the recess 113.

As should be apparent from figures 1A and 1B, the shape of the distal end of the male coupling member 105 (i.e. the end that is distal from the first side 101) is complementary to the shape of the opening defined by the recess 113 and the teeth 114 of the female coupling member 107. This allows the male coupling member 105 to be inserted into the female coupling member 107 of a like-weight plate. To further facilitate this, the distal end of the male coupling member 105 includes a radiused edge 117, which helps to guide the male coupling member 105 into the recess 113. Likewise, the female coupling member 107 includes a radiused edge 118 defining the opening to the recess 113, which similarly aids in guiding the male coupling member 105 into the recess 113.

Once the male coupling member 105 is inserted into the recess 113 (e.g. of a like-weight plate), the weight plate 100 can be rotated through 90 degrees to interlock the male coupling member 105 with the female coupling member 107 of the like-weight plate (and thus to interlock the weight plate 100 with the like-weight plate). In particular, the projections 110 of the male coupling member 105 are received in the projection-receiving spaces 115 of the female coupling member 107 (of the like-weight plate). Likewise, the teeth 114 of the female coupling member 107 (of the like-weight plate) are received in the tooth-receiving spaces 111 of the male coupling member 105. When received in this way, the rotation-limiting walls 112 of the male coupling member 105 prevent further movement of the teeth 114 of the female coupling member 107 so as to prevent further rotation of the weight plate 100 relative to the like-weight plate.

The above description is provided from the perspective of the male coupling member 105 being inserted into the recess 113 of a like-weight plate. Of course, it should be appreciated that the recess 113 of the weight-plate can receive the male coupling member 105 of a like-weight plate in the same manner as described above.

The sprung ball plungers 106 and concave recesses 108 (i.e. the retaining elements) ensure that, once the weight plate 100 is interlocked with a like-weight plate, the weight plates 100 remain interlocked. To achieve this, the sprung ball plungers 106 are arranged such that when the weight plate 100 is in an interlocked position with a like-weight plate (as described above), each sprung ball plunger 106 aligns directly opposite a corresponding concave recess 108 of the like-weight.

As is best seen from Figure 1C, each sprung ball plunger 106 includes a detent in the form of a ball 119 and a resilient portion (i.e. biasing device) in the form of a compression spring 120 that urges the ball 119 in a direction away from the first side 101 of the weight plate 100. As the male coupling member 105 is rotated relative to the female coupling member 107 of a like-weight plate, the balls 119 of the sprung ball plungers 106 are urged against (and slide along) the second side 102 of the like-weight plate. However, once the rotation is such that the sprung ball plungers 106 align with the concave recesses 108, the balls 119 are urged into the concave recesses 108 by the respective compression springs 120. Receipt of the balls 119 in the concave recesses 108 prevents dislodgement of the weight plate 100 from the interlocked position in normal use of the weight plate 100 (e.g. during use of the weight plate as part of a free weight system).

In order to disengage the weight plate 100 (i.e. to move the weight plate 100 out of the interlocked position), a user must rotate the weight plate 100 relative to the like-weight plate (in the opposite direction to the interlocking rotation) with sufficient force to overcome the bias of the springs 120 urging the balls 119 into the concave recesses 108. The sprung ball plungers 106 are configured (e.g. the resiliency of the springs is selected) such that this force is not so much that it prevents a user from disengaging the weight plate 100, but is enough that the weight plate 100 does not become disengaged during normal use.

In addition to preventing rotational movement during normal use, because the balls 119 of the sprung ball plungers 106 are urged against the second side 102 of the like-weight plate, axial movement of the weight plates 100 (i.e. towards and away from one another) is reduced. This reduces rattling that could otherwise occur between the weight plate 100 and the like-weight plate in use.

To guide each ball 119 to a respective concave recess 108 during rotation of the weight plate 100, arcuate guiding grooves 121 are formed in the second side 102 of the weight plate 100. These grooves 121 may guide each ball 119 and prevent scratching that could otherwise occur without the presence of the grooves 121. Each guiding groove 121 extends from a respective concave recess 108 to a distal end that is an angular distance of approximately 90 degrees from the concave recess 108 (taking the central axis of the weight plate 100 as the origin). In this way, when the male coupling member 105 is inserted into the recess 113 of a like-weight plate, each ball 119 locates at the distal end of a respective guiding groove 121 of the like-weight plate. As the weight plate 100 is then rotated about 90 degrees (to perform the interlocking), the balls 119 travel along the guiding grooves 121 to the concave recesses 108.

Figure 1C depicts the construction of the weight plate 100. As is evident from this figure the weight plate 100 includes a body 122 and an outer cover 123 that extends about (and covers) a periphery of the body 122. The body 122 is formed of stainless steel and provides most of the weight of the weight plate 100. The outer cover 123 is formed of rubber and acts as a protective layer (both for the body 122, and in case of impact of the weight plate 100 on other surfaces).

The female coupling member 107 is integrally formed with the body 122. On the other hand, the male coupling member 105 is a separate component that is mounted to the body 122. To enable this mounting the male coupling member 105 includes an internal threaded bore 124 that extends centrally into the male coupling member 105. The body 122 also includes a bore 125 that extends centrally therethrough (from the first side 101 to the recess 113 formed in the second side 102 of the weight plate 100), and that aligns with the bore 124 of the male coupling member 105. A fastener, in the form of a countersunk screw 126 extends through the bore 125 in the body 122 and threadedly engages with the threaded bore 124 of the male coupling member 105. An enlarged head of the screw 126 seats within a tapered portion of the bore 125 of the body 122 (adjacent the recess 113) so as to retain the male coupling member 105 on the first side 101 of the weight plate 100.

To strengthen the connection between the male coupling member 105 and the first side 101 of the body 122, the male coupling member 105 comprises a raised portion 138 (e.g. a boss) and the first side 101 comprises a complementary recessed portion 139 (in other embodiments, these may be reversed such that the recessed portion is provided on the male coupling member 105). Although not apparent from the figures, each of the recessed 139 and raised 138 portions has a square shape (i.e. in a section taken parallel to the first side 101). These portions 138, 139 help to align the male coupling member 105 and the first side 101. Their presence also means that shear forces applied to the male coupling member 105 are transferred directly to the body 122 (via the raised portion 139) rather than via the countersunk screw 126. This can avoid failure (e.g. via fatigue) of the countersunk screw 126 and so improves the durability of the weight plate 100.

Figures 2A and 2B illustrate an exemplary handle 230 that may be used with the weight plate 100 described above with respect to figures 1A, 1B and 1C. The handle 230 includes many of the same features as the weight plate 100. Those features have been given the same reference numerals and will not be discussed again in detail.

The illustrated handle 230 is a dumbbell handle and includes an elongate and cylindrical central grip portion 231 for gripping by a user. Each end of the grip portion 231 is provided with a disc-shaped mounting portion 232 and each mounting portion 232 includes a mounting face 233 directed outwardly (i.e. away from the central grip portion 231). Each mounting portion 232 has an outer periphery that is substantially obround (i.e. circular, except with upper and lower linear portions). Thus, the periphery of each mounting portion 232 includes upper and lower (as illustrated) planar surfaces 234. These allow the handle 230 to rest in a stable manner on a horizontal surface (i.e. in one of two orientations).

Each mounting face 233 has the same configuration as the second side 102 of the weight plate 100 described above. Thus, each mounting face 233 includes a female coupling member 107 (that is the same as that provided on the weight plate 100 described above), two retaining elements in the form of concave recesses 108, and corresponding guiding grooves 121. In this way, each mounting face 233 is configured for interlocking with the first side 101 of a weight plate 100 as described above (i.e. by interlocking of each female coupling member 107 with male coupling members of two weight plates 100).

As should be appreciated, when two weight plates 100 are mounted to the handle 230 in this manner, the second sides 102 of those weight plates 100 will remain exposed. In this way, further weight plates 100 may be mounted to those weight plates 100. Accordingly, a user can mount a selection of weight plates 100 to the handle 230 to achieve a desired total weight (i.e. for the purpose for the purpose of weight training).

The construction of the handle is apparent from Figure 2B. Only one of the mounting portions 232 is illustrated, but it should be appreciated that the illustrated construction applies to both mounting portions 232. As is apparent from this figure, each mounting portion 232 is mounted to the grip portion 231 by way of a fastener in the form of a countersunk screw 235. Each end of the grip portion 231 includes a centrally extending threaded bore 236 that threadedly engages with a threaded portion of the countersunk screw 235. Each mounting portion 232 includes a tapered (conical) bore 237 into which an enlarged head of the screw 235 is received to secure the mounting portion 232 to the grip portion 231.

The grip portion 231 comprises a raised portion 240 (e.g. a boss) and the mounting portion 232 comprises a complementary (in shape) recessed portion 241 for receipt of the raised portion 240. Each of these portions 240, 241 has a square shaped cross section. These portions provide the same function as those of the weight plate described above.

The exemplary embodiments set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

Thus, for example, in the illustrated embodiment the retaining members are in the form of sprung ball plungers and recesses that engage with one another. In other embodiments, the weight plate may, for example, include protrusions extending into each of the tooth-and projection-receiving spaces, that may interact to provide engagement (to retain the weight plates in an interlocked position). One or both of the protrusions may include a sloped (ramp) surface and may include a resilient portion. In this way, on interlocking of the weight plates the protrusions may pass one another and, after doing so, may engage to prevent disengagement of the weight plates from one another during normal use. However, the weight plates may then be disengaged by as user rotating them relative to one another to overcome the resiliency of the protrusion(s) and to move the protrusions back past one another.

For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations.

Throughout this specification, including the claims which follow, unless the context requires otherwise, the word "comprise" and "include", and variations such as "comprises", "comprising", and "including" will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

It must be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent "about," it will be understood that the particular value forms another embodiment. The term "about" in relation to a numerical value is optional and means for example +/-10%.

Claims

Claims: 1. A weight plate for a modular free weight system, the weight plate comprising: first and second coupling members on opposite sides of the weight plate, the first coupling member configured to interlock with the second coupling member of a like-weight plate by rotation of the weight plate relative to the like-weight plate; and first and second retaining elements on opposite sides of the weight plate, the first retaining element engageable with the second retaining element of the like-weight plate to retain the first coupling member in an interlocked position with the second coupling member of the like-weight plate, the first and second retaining elements configured to permit release of first coupling member from the interlocked position upon rotation of the weight plate relative to the like-weight plate by a user.
2. A weight plate according to claim 1 wherein the first and/or second retaining elements are separate from the first and second coupling members.
3. A weight plate according to claim 1 or 2 wherein the first retaining element comprises a resilient portion.
4. A weight plate according to claim 3 wherein the first retaining element comprises a detent portion for engaging the second retaining element of a like-weight plate, the resilient portion configured to urge the detent portion into engagement with the second retaining element.
5. A weight plate according to claim 4 wherein resilient portion is configured to urge the detent portion against a like-weight plate, when the weight plate is interlocked with the weight-plate, to urge the like-weight plate in a direction away from the weight plate.
6. A weight plate according to any one of the preceding claims wherein the first retaining element is located closer to a periphery of the weight plate than the centre of the weight plate.
7. A weight plate according to any one of the preceding claims wherein the first retaining element and/or second retaining element comprises a ramp surface.
8. A weight plate according to any one of the preceding claims comprising one or more first retaining elements, each in the form of a sprung plunger.
9. A weight plate according to claim 8 wherein the total preload of the one or more sprung plungers is between 10 N and 70 N.
10. A weight plate according to claim 8 or 9 wherein the total maximum load of the one or more sprung plungers is between 20 N and 100 N.
11. A weight plate according to any one of the preceding claims wherein one of the first and second coupling members is in the form of a male coupling member that protrudes from a side of the weight plate and the other is in the form of a female coupling member comprising a recess formed in a side of the weight plate opposite the male coupling member.
12. A weight plate according to claim 11 wherein: the male coupling member comprises a projection extending laterally outwardly for engaging the female coupling member of a like-weight plate; and the female coupling member comprises a projection-receiving space configured for engaging the projection of the male coupling member of a like weight-plate.
13. A weight plate according to claim 12 wherein the female coupling member comprises a tooth extending laterally inwardly that defines the projection-receiving space.
14. A weight plate according to claim 13 wherein the projection defines a tooth-receiving space for receipt of the tooth of a like-weight plate.
15. A weight plate according to claim 14 wherein the tooth-receiving space and/or projection-receiving space comprises an entrance into which a tooth/projection is received in use, the entrance tapering inwardly in a direction into the tooth-/projection-receiving space.
16. A weight plate according to any one of claims 12 to 15 comprising a body providing the majority of the weight of the weight plate, the female coupling member integrally formed with the body.
17. A weight plate according to claim 16 wherein the male coupling member is mounted to the body on an opposing side of the body to the female coupling member.
18. A modular free weight system, the system comprising: a weight plate according to any one of the preceding claims; and a handle comprising a grip portion and a mounting portion, the mounting portion having: a coupling member configured to interlock with the first or second coupling member of the weight plate; and a retaining element configured to engage the first or second retaining element of the weight plate when interlocked with the mounting portion.
19. A system according to claim 18 wherein the mounting portion comprises two opposing major faces and an outer peripheral surface connecting the major faces, the outer peripheral surface comprising a planar portion.
20. A weight plate for a modular free weight system, the weight plate comprising: first and second coupling members on opposite sides of the weight plate, the first coupling member configured to interlock with the second coupling member of a like-weight plate by rotation of the weight plate relative to the like-weight plate; and a body providing the majority of the weight of the weight plate, wherein at least one of the coupling members is integrally formed with the body 21 A system according to claim 20 wherein one of the first and second coupling members is in the form of a male coupling member and the other is in the form of a female coupling member, and wherein the male coupling member is mounted to the body and the female coupling member is integrally formed with the body.