Patent Description:
Chairs commonly used in offices or homes are designed with features to provide comfort to users. One such feature is an armrest to allow a user to comfortably rest his/her arm. A typical chair has armrests fixedly attached to the arm support portions and a user typically uses the same armrests throughout the lifetime of the chair. However, wear and tear of the armrests will inevitably occur. In certain circumstances, the armrests may wear out faster than the other portions of the chair and it is not economical to replace the entire chair.

Further, as the armrests are typically fixedly attached to the arm support portions of a chair, the chair can only be assembled with armrests of a particular design. In other words, there are no provisions for a user to select armrests of his/her choice. However, different users may have their own preferences with respect to the design, material, texture, etc. of the armrests.

Some current armrests may include a memory foam material which is typically a one-material injection molded polyurethane foam with a single integral skin. However, the armrests may have covers that may not be properly and securely integrated into the chair. In addition, user comfort may be compromised due to the integration of different armrest parts. For example, the material differences between the soft memory foam and the hard plastic housing may be obvious. Examples of previously known armrests for chairs are derivable from <CIT> and <CIT>.

A need therefore exists to provide an armrest for a chair that seeks to address at least some of the above problems.

The object above is resolved by means of an armrest for a chair according to claim <NUM>. Distinct embodiments are derivable from the dependent claims. According to a first aspect, there is provided an armrest for a chair, comprising: a first member having a body comprising one or more recesses, each of the one or more recesses configured to securely retain a corresponding magnet; and a second member releasably attached to the first member, the second member comprising: a bottom housing defining a cavity, the cavity configured to receive the first member; one or more magnetizable plate members disposed in the cavity, the one or more magnetizable plate members being adjacent the one or more magnets when the first member is received in the cavity; a rim member disposed on a periphery of the bottom housing; and a cushion member disposed on the rim member and configured to abut at least a surface of the bottom housing forming the cavity to snugly fit over the bottom housing.

The cushion member may be made of a memory foam material.

The second member may further comprise a base plate disposed at a lower surface of the cushion member and configured to abut the surface of the bottom housing forming the cavity. The base plate is removably attached to the cushion member.

The rim member and the bottom housing may be made from the same material.

The rim member and the bottom housing may have different surface finishes.

The rim member and the bottom housing may have different colours.

The bottom housing may comprise a plurality of protrusions disposed along the periphery. The rim member may comprise a corresponding plurality of grooves configured to receive the plurality of protrusions of the bottom housing to securely attach the rim member to the bottom housing.

The second member may further comprise an upholstery configured to cover the cushion member.

Embodiments and implementations are provided by way of example only, and will be better understood and readily apparent to one of ordinary skill in the art from the following written description, read in conjunction with the drawings, in which:.

Embodiments will be described, by way of example only, with reference to the drawings. Like reference numerals and characters in the drawings refer to like elements or equivalents.

Embodiments of the invention provide an armrest which may be installed at an arm support portion of a chair. The armrest may comprise a member that can be replaceable by the user. This allows the user to replace the armrest without having to replace the entire chair when wear and tear of the armrest occurs. Further, users may customize the armrests according to their preferences. For example, users may customize the design, material, texture, etc. of the armrests.

<FIG> is an exploded perspective view of an armrest <NUM> according to an example not according to the invention. <FIG> is a schematic representation of the assembly of magnets and <FIG> is a schematic representation of the assembly of steel plates in the armrest of <FIG>. The armrest <NUM> is suitable for a chair and comprises a first member <NUM>. The first member <NUM> comprises a body <NUM> extending in a longitudinal direction from a first end to a second end. The body <NUM> comprises one or more recesses <NUM>, and one or more magnets <NUM> are disposed in the one or more recesses <NUM>. The armrest <NUM> also comprises a second member <NUM> releasably attached to the first member <NUM>. The second member <NUM> comprises a cavity <NUM> configured to receive the first member <NUM> and one or more magnetizable plate members in the form of magnetizable metal sheets <NUM> disposed in the cavity <NUM>. The one or more magnetizable metal sheets <NUM> are adjacent the one or more magnets <NUM> when the first member <NUM> is received in the cavity <NUM>.

The cavity <NUM> of the second member <NUM> may be configured based on the structure of the first member <NUM> such that the first member <NUM> can fit snugly in the cavity <NUM>. In other words, the body <NUM> of the first member <NUM> comprises a geometry matching a geometry of the cavity <NUM> for retaining the first member <NUM> against lateral movement when the first member <NUM> is received in the cavity <NUM>. This reduces or minimizes possible movement of the second member <NUM> against the first member <NUM> when the armrest is in use, hence may improve user experience. Further, as mentioned above, the magnetizable metal sheet(s) <NUM> of the second member <NUM> are adjacent the magnet(s) <NUM> of the first member <NUM> when the first member <NUM> is assembled with the second member <NUM>. The magnetic attraction created between the magnetizable metal sheet(s) <NUM> and the magnet(s) <NUM> may allow the first member <NUM> and second member <NUM> to be kept in position, thereby further reducing or minimizing possible movement of the second member <NUM> against the first member <NUM> when the armrest is in use. As such, user experience may be further enhanced.

In some implementations, there may be two magnetizable metal sheets <NUM>. Each of the magnetizable metal sheet <NUM> may be disposed at each longitudinal end of the second member <NUM>. For example, the magnetizable metal sheets <NUM> may be ferritic steel plates. Further, there may be four recesses <NUM> and four magnets <NUM>, each magnet <NUM> disposed in one recess <NUM>. The recesses <NUM> and magnets <NUM> may be positioned based on the positions of the magnetizable metal sheets <NUM>. For example, in the scenario that a magnetizable metal sheet <NUM> is disposed at each longitudinal end of the second member <NUM>, two recesses <NUM> and two magnets <NUM> may be positioned at each longitudinal end of the first member <NUM> accordingly. The number of magnetizable metal sheets and magnets can vary.

Each of the recesses <NUM> may be configured based on the shape of the magnets <NUM> such that each magnet <NUM> can fit snugly in the recess <NUM>. In other words, the magnets <NUM> are securely retained in the respective recesses <NUM>.

The second member <NUM> includes a shell <NUM> and a cover <NUM> disposed on the shell <NUM>, the shell <NUM> defining the cavity <NUM>. The one or more magnetizable plate members in the form of magnetizable metal sheets <NUM> may be fixedly attached to the shell <NUM>, and the one or more magnets <NUM> may be securely retained in the one or more recesses <NUM>. The magnetizable metal sheets <NUM> can be fixedly attached to the shell <NUM> by means of over molding, welding, gluing, etc. In some implementations, the shell <NUM> may comprise one or more recesses structured based on the shape and thickness of the one or more magnetizable metal sheets <NUM> such that the magnetizable metal sheets <NUM> can fit snugly in the respective recesses. Further, by fabricating the depth of the recesses to match the thickness of the magnetizable metal sheets <NUM>, the assembled armrest can be more compact.

According to one example not according to the invention, the cover <NUM> may be releasably attached to the shell <NUM>. This allows a user to replace the cover <NUM> when wear and tear occurs or when the user wishes to install a customized cover <NUM> with a design, material, texture, etc. of his/her preference. To replace the cover <NUM>, the user can manually pull the cover <NUM> away from the shell <NUM> to dislodge the cover <NUM> from the shell <NUM>. The new cover <NUM> can then be installed by positioning it over the shell <NUM> and exerting a force in a downwards direction such that it snaps into place with the shell <NUM>.

According to another example not according to the invention, the cover <NUM> may be fixedly attached to the shell <NUM>. When wear and tear occurs or when a user wishes to customize the armrest, the user can replace the entire second member <NUM> comprising both the cover <NUM> and the shell <NUM>. To replace the second member <NUM>, the user can manually overcome the magnetic attraction created between the magnetizable metal sheet(s) <NUM> and the magnet(s) <NUM> by pulling the second member <NUM> away from the first member <NUM> to dislodge the second member <NUM> from the first member <NUM>. The new second member <NUM> can then be installed by positioning it over the first member <NUM>. The magnetic attraction created between the magnetizable metal sheet(s) <NUM> of the new second member <NUM> and the magnet(s) <NUM> of the first member <NUM> can keep the new second member <NUM> and the first member <NUM> in position.

The shell <NUM> may comprise a composite material such as nylon-glass fiber composite. For example, the nylon-glass fiber composite can be Polyamide <NUM> (Nylon <NUM>) combined with <NUM> percent glass fiber. The cover <NUM> disposed on the shell <NUM> may comprise polyurethane foam. According to another example not according to the invention, the cover <NUM> may comprise thermoplastic polyurethane.

<FIG> is a side view <NUM> of the armrest <NUM> of <FIG> and <FIG> is a cross-sectional view <NUM> of the armrest <NUM> of <FIG>. In one implementation, the body <NUM> of the first member <NUM> includes a small gradient and the cavity <NUM> includes a corresponding gradient (the opening of the cavity <NUM> is slightly wider than the bottom of the cavity <NUM>), such that assembly of the body <NUM> into the cavity can be made easier while a snug fit can be achieved when assembly is completed. As shown in the figures, when fully assembled, the first member <NUM> and second member <NUM> can be snugly fitted. Further, the fully assembled armrest can be compact.

<FIG> is an exploded perspective view of a second member <NUM> of the armrest <NUM> of <FIG> according to a first embodiment while <FIG> is a perspective view of the assembled second member <NUM> of <FIG>. In this embodiment, the second member <NUM> includes a bottom housing <NUM> defining a cavity <NUM> (see <FIG>) configured to receive the first member <NUM> (see <FIG>). The bottom housing <NUM> also includes one or more magnetizable plate members <NUM> disposed in the cavity <NUM>. The one or more magnetizable plate members <NUM> are similar to the magnetizable plate members <NUM> as shown in <FIG> and they are adjacent to the one or more magnets <NUM> (see <FIG>) when the first member <NUM> is received in the cavity <NUM>. The second member <NUM> further includes a rim member <NUM> disposed on the bottom housing <NUM>. The rim member <NUM> may have an opening <NUM> shaped such that the rim member <NUM> is disposed around a periphery of the bottom housing <NUM> when assembled.

For example, the opening <NUM> of the rim member <NUM> comprises a geometry matching a geometry of a wall on the bottom housing <NUM> that forms the cavity <NUM> for retaining the bottom housing <NUM> against relative lateral movement when the rim member <NUM> is assembled on the periphery of the bottom housing <NUM>. The bottom housing <NUM> may include a plurality of protrusions <NUM> disposed along the periphery. The rim member <NUM> may include a plurality of grooves <NUM> configured to receive the corresponding plurality of protrusions <NUM> of the bottom housing <NUM> to securely attach the rim member <NUM> to the bottom housing <NUM>. In an alternate embodiment, the rim member <NUM> may include a plurality of protrusions (not shown) while the bottom housing <NUM> may include a plurality of grooves (not shown) to securely attach the rim member <NUM> to the bottom housing <NUM>. Other engagement mechanisms are possible. The rim member <NUM> and the bottom housing <NUM> may be made from the same material, such as plastic, while having different surface finishes and/or colours. Having the same material may provide the user with a better hand feel on the second member <NUM> as one seamless surface. Having a different surface finish and/or colour may allow customization, for example, a glossy rim that contrasts with a matt bottom housing, or a colour that matches with a theme or decoration of the chair or adjacent furniture. It can be appreciated that the rim member <NUM> and the bottom housing <NUM> may be made from different materials. For example, the rim member <NUM> may be made from plastic while the bottom housing <NUM> may be made from metal, or vice versa.

The second member <NUM> further includes a cushion member <NUM> disposed on the rim member <NUM> and configured to abut at least a surface of the cavity <NUM> to snugly fit over the bottom housing <NUM>. The cushion member <NUM> may be covered in upholstery <NUM> and may include a base plate <NUM> disposed at a lower surface to abut a surface of the bottom housing <NUM> that forms the cavity <NUM>. In one implementation, the base plate <NUM> may be removably attached to the cushion member <NUM>. In an alternate implementation, the base plate <NUM> may be fixedly attached to the cushion member <NUM> to form a single component. In an example embodiment, the cushion member <NUM> may be made of a memory foam material, which can retain a certain profile matching the arm position of a frequent user. As a nonlimiting example, the memory foam cushion may have a height that is approximately <NUM> thicker than one made of polyurethane foam so that it can accommodate the compression which can be <NUM> when a user exerts a point force of approximately 100N. The memory foam may be designed to have a safety factor of <NUM> to ensure that the user would not feel the supporting bottom housing <NUM> under normal usage. Compared to the embodiment shown in <FIG>, the cushion member <NUM> in the embodiment shown in <FIG> is significantly thicker, and may therefore provide a more luxurious hand feel to the user. It can be appreciated that the memory foam may have a different height and be deformed by more or less than <NUM> depending on the force exerted by the user. The deformation may also depend on the memory foam, for example, its density. Accordingly, it can be envisioned that the second member <NUM> for a "Medium"-sized chair may have the cushion member <NUM> of different thickness and/or density compared to one for a "Large"-size chair.

Claim 1:
An armrest (<NUM>) for a chair, comprising:
a first member (<NUM>) having a body (<NUM>) comprising one or more recesses (<NUM>), each of the one or more recesses (<NUM>) configured to securely retain a corresponding magnet (<NUM>); and
a second member (<NUM>) releasably attached to the first member (<NUM>), the second member (<NUM>) comprising:
a bottom housing (<NUM>) defining a cavity (<NUM>), the cavity (<NUM>) configured to receive the first member (<NUM>);
one or more magnetizable plate members (<NUM>) disposed in the cavity (<NUM>), the one or more magnetizable plate members (<NUM>) being adjacent the one or more magnets (<NUM>) when the first member (<NUM>) is received in the cavity (<NUM>);
characterized in that the second member (<NUM>) further comprises:
a rim member (<NUM>) disposed on a periphery of the bottom housing (<NUM>); and
a cushion member (<NUM>) disposed on the rim member (<NUM>) and configured to abut at least a surface of the bottom housing (<NUM>) forming the cavity (<NUM>) to snugly fit over the bottom housing (<NUM>).