Footrest Assembly for Attachment to a Chair

The present disclosure relates broadly, but not exclusively, to a footrest assembly for attachment to a chair.

The following discussion of the background is intended to facilitate an understanding of the present disclosure only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or is part of the common general knowledge of the person skilled in the art in any jurisdiction as of the priority date of the disclosure.

Conventional footrest assembly attached to a chair is configured to take strain off a user's thighs and provides comfort to the user during prolonged period of sitting. The conventional footrest assembly may elevate the user's legs, allowing the user to achieve comfortable alignment of the user's hip and knees to avoid blood pooling, reduce pressure on the spine and decrease fatigue.

However, the conventional footrest assembly to a chair may have some problems. For example, the conventional footrest assembly may be built-in and may not be attached to or detached from a chair as desired. Another problem of the conventional footrest assembly may relate to the range of adjustability of the footrest assembly which are typically limited to only 2 possible positions: fully extended and fully retracted. Furthermore, the mechanism of such footrest assembly may be bulky.

In addition, components of the conventional footrest assembly, such as a footrest cushion, may not be detachable from the footrest assembly. Extensive use of the footrest assembly may lead to wear and tear and therefore it would be desirable to replace such components without disposing the entire footrest assembly or chair.

Accordingly, there exists a need for an improved footrest assembly for attachment to a chair, that seeks to address at least one of the aforementioned issues.

According to a first aspect of the disclosure, there is provided a footrest assembly for attachment to a chair, the footrest assembly comprising a mounting frame configured to be attached to a seat portion of the chair, the mounting frame comprising a pair of brackets; a recliner frame comprising a first portion configured to be slidably received by the pair of brackets, and a second portion configured to support (for example, attached to) a footrest, the first portion pivotably connected to the second portion to define a recliner angle therebetween; and an actuator assembly configured to allow adjustment of the recliner angle between the first portion and the second portion, the actuator assembly comprises a gas spring configured to urge the second portion to an extended position, the extended position corresponding to a maximum allowable recliner angle.

In some embodiments, the pair of brackets, the first portion and the second portion form a six-bar mechanical linkage, the six-bar mechanical linkage arranged to move from a retracted state to the extended position upon actuation of the gas spring.

In some embodiments, the second portion comprises a linkage system, the linkage system having a main linkage, the main linkage configured to provide structural support to the linkage system. In some embodiments, the main linkage may comprise two limb portions joined by a cross member to form a H-shaped structure. The two limb portions may be casings for housing one or more other linkages of the linkage system.

In some embodiments, the second portion comprises a fastener for attaching the footrest to the main linkage when the six-bar mechanical linkage is in the retracted state. The fastener may comprise at least one magnet.

In some embodiments, the second portion comprises a support plate shaped and dimensioned to receive the footrest.

In some embodiments, the second portion comprises an end portion shaped and dimensioned to receive the footrest.

In some embodiments, the footrest comprises a base formed from or of a medium-density fiberboard (MDF), a cushion comprising memory foam, and a clip for attachment to an end portion.

In some embodiments, the clip is formed from or of a thermoplastic compound and glass fiber.

In some embodiments, the clip comprises polyamide and at least 10% of the glass fiber.

In some embodiments, each of the pair of brackets comprises a base portion and a pair of ribs extending from longitudinal opposing sides of the base portion, wherein the free end of at least one of the pair of ribs is inclined towards the free end of the other rib.

In some embodiments, each of the pair of ribs comprises at least one slot shaped and dimensioned to receive at least one fastener.

In some embodiments, the actuator assembly comprises a compression spring coupled to a piston of the gas spring. The compression spring may be sleeved on a piston rod of the gas spring, and one end of the compression spring may be directly or indirectly positioned in contact with the piston of the gas spring. When the gas spring is being compressed, the piston of the gas spring may compress the compression spring, thereby storing energy in the compression spring. Upon the actuation of the gas spring, the compression spring may extend, thus providing a reaction force on the piston which reinforces the force produced by the gas spring to overcome static friction and allow the gas spring to smoothly extend even after a period of inactivity.

According to a second aspect of the disclosure, there is provided a chair comprising a seat portion and a footrest assembly installed to the seat portion, the footrest assembly comprising a mounting frame configured to be attached to the seat portion of the chair, the mounting frame comprising a pair of brackets; a recliner frame comprising a first portion configured to be slidably received by the pair of brackets, and a second portion configured to support a footrest, the first portion pivotably connected to the second portion to define a recliner angle; and an actuator assembly configured to allow adjustment of the recliner angle between the first portion and the second portion, the actuator assembly comprises a gas spring configured to urge the second portion to an extended position, the extended position corresponding to a maximum allowable recliner angle.

According to a third aspect of the disclosure, there is provided a method of manufacturing a footrest assembly for attachment to a chair, the method comprising a step of providing a mounting frame, the mounting frame configured to be attached to a seat portion of the chair, the mounting frame comprising a pair of brackets; a step of providing a recliner frame, the recliner frame comprising a first portion configured to be slidably received by the pair of brackets, and a second portion configured to support a footrest, the first portion pivotably connected to the second portion to define a recliner angle therebetween; and a step of providing an actuator assembly, the actuator assembly configured to allow adjustment of the recliner angle between the first portion and the second portion, the actuator assembly comprises a gas spring configured to urge the second portion to an extended position, the extended position corresponding to a maximum allowable recliner angle.

The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure. Other embodiments may be utilized and structural, and logical changes may be made without departing from the scope of the disclosure. The various embodiments are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments.

The disclosure illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising”, “including,” containing”, etc. shall be read expansively and without limitation. The word “comprise” or variations such as “comprises” or “comprising” will accordingly be understood to imply the inclusion of a stated integer or groups of integers but not the exclusion of any other integer or group of integers. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the disclosure. Thus, it should be understood that although the present disclosure has been specifically described in exemplary embodiments and optional features, modification and variation of the disclosure embodied herein may be resorted to by those skilled in the art.

Features that are described in the context of an embodiment may correspondingly be applicable to the same or similar features in the other embodiments. Features that are described in the context of an embodiment may correspondingly be applicable to the other embodiments, even if not explicitly described in these other embodiments. Furthermore, additions and/or combinations and/or alternatives as described for a feature in the context of an embodiment may correspondingly be applicable to the same or similar feature in the other embodiments.

In the context of various embodiments, the articles “a”, “an” and “the” as used with regard to a feature or element include a reference to one or more of the features or elements. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

While terms such as “first”, “second” etc., may be used to describe various elements, such elements are not limited to the above terms. The above terms are used only to distinguish one element from another, and do not define an order and/or significance of the elements unless explicitly stated. Without departing a scope of rights of the specification, a first element may be referred to as a second element, and similarly, the second element may be referred to as the first element.

It should be understood that the terms “on”, “over”, “top”, “bottom”, “down”, “side”, “back”, “left”, “right”, “front”, “lateral”, “side”, “up”, “down” etc., when used in the following description are used for convenience and to aid understanding of relative positions or directions, and not intended to limit the orientation of any device, structure or any part of any device or structure.

The term “coupled” (or “connected”) herein may be understood as mechanically coupled, for example attached or fixed, or just in contact without any fixation, and it will be understood that both direct coupling or indirect coupling (in other words: coupling without direct contact) may be provided.

In order that the disclosure may be readily understood and put into practical effect, various embodiments will now be described by way of examples and not limitations, and with reference to the figures.

Throughout the description, the term “footrest assembly” refers broadly to a plurality of components of a footrest unit. In some embodiments, the footrest assembly may be assembled by a user.

shows a schematic drawing, in perspective view, of a footrest assembly, according to an embodiment. The footrest assemblyincludes a mounting frameconfigured to be removably attached to a furniture. In some embodiments, the furniture may be a chair, and the footrest assemblymay be attachable to a seat portion of a chair. The mounting framecomprises a pair of brackets.shows a perspective view of the mounting frame, according to an embodiment. Each of the pair of bracketscomprises a base portionand a pair of ribsextending from longitudinal opposing sides of the base portion. A free end of at least one of the pair of ribsis inclined towards a free end of the other (opposing side) rib. Additionally, at least one of the pair of ribscomprises at least one slotshaped and dimensioned to receive at least a fastener. As an example, the fastener may include a screw, a piece of wire and/or a bolt. In some embodiments, the fastener may include magnetic fasteners.

The pair of bracketscan be fastened to a surface, such as a bottom surface of a seat portionof a chairby, for example, a plurality of screwsas shown in.depicts a bottom view of the chairwith the pair of bracketsmounted and fastened to the seat portionof the chairby the plurality of screws. The pair of bracketsmay be mounted on top of an existing chair mechanism, such as a tilt mechanism. There may be variations in the size of the slotto account for variances in mounting points across different chairs or chair product lines.

Referring back to, the footrest assemblyincludes a recliner frame, the recliner framecomprising a first portionand a second portion. The first portionmay be configured to be slidably received by the pair of brackets. The first portioncomprises a framethat may be configured to interface with pair of bracketsto attach the recliner framein position, allowing proper usage together with the chair. In the embodiment shown in, the framemay comprise a mounting portion, the mounting portionbe configured for an actuator (such as a gas spring) to be mounted thereon. The framealso has at least one mounting pointfor a linkage of the second portionto be mounted thereto. The second portionmay be attached to the mounting pointby one or more fastener(s), such as the fastener(s) as described in other embodiments.

The first portionmay be pivotably connected to the second portionto define a recliner angle therebetween. In some embodiments, the second portioncomprises a mechanical linkage systemwhich allows for attachment to the first portion. The linkage systemincludes a main linkage. Referring to, the main linkagehas a cross memberthat provides structural support to the overall system. In some embodiments, the main linkage may comprise two limb portionsand a cross memberarranged in a H-shaped structure. Each of the two limb portionsmay be configured to house one or more other linkages of the linkage system. The limb portionsmay be attached to a portion of the footrest. In some embodiments, each limb portionhouses a set of linkages, the set of linkages configured to move the footrestbetween the retracted position and the extended position. Each set of linkages housed within each limb portionmay be akin to an arm, and in some embodiments, the two limb portionsmay be attached to opposing ends of the footrestfor proper support of the footrestwhen a force is applied on the footrest. The cross-memberjoining the two limb portionsmay be used to ensure that the linkages are synchronized in movement between the retracted position and the extended position, so as to avoid uneven extension of the two limb portions.

In operation, when the one or more other linkages of linkage systemis urged to move from a first position (which may correspond to the retracted position) to a second position (which may correspond to the extended position), the movement causes the main linkage as well as any other linkages of the linkage systemencased within the main linkageto move in tandem by virtue of the at least one cross member. The at least one cross membermay further introduce additional points of contact between various linkages of the linkage systemso as to distribute load and pressure from the footrest and/or a user's legs to the linkage system. The linkage systemalso includes at least a first linkage (long linkage), a second linkage (medium linkage)or a third linkage (short linkage), embodiments of which are shown in.

The linkage systemmay further comprise a linkage coveras shown in. The linkage coverfits over an exposed moving part of the linkage systemto cover at least one pinch point around the system, such as a gap that could potentially trap or pinch a human body part.illustrates the exposure of linkages and pinch points when the linkage coveris removed from the linkage system, andshows that the linkages and pinch points are covered when the linkage coveris attached to the same system. Aside from minimizing or eliminating pinch points, the linkage coverminimizes or prevents dust and/or debris from entering the linkage systemwhich helps to improve the lifespan and performance of the system. The linkage covermay be shaped and dimensioned for easy installation and removal, e.g. via a snap-fit configuration, and may be made of or from polypropylene (PP) to resist or withstand the wear and tear of regular use.

The second portionmay be configured to support a footrest. The second portionmay comprise a support plate shaped and dimensioned to receive the footrest.illustrates an embodiment of the support plate. In another embodiment as shown in, the second portionmay comprise an end portionshaped and dimensioned to receive the footrest.

shows a perspective view of an embodiment of the footrest. The footrestincludes a baseformed from or of a medium-density fiberboard (MDF), a cushioncomprising memory foam, and a clip. The clipprovides a hook-on and clipping function for attachment to the end portion. The clipmay be formed from or of a thermoplastic compound and glass fiber. The thermoplastic compound may include a polyamide, such as polyamide 6. When the thermoplastic compound is reinforced with glass fibers, the resulting compound is stiffer and stronger compared to the thermoplastic compound. Glass fiber reinforcement also reduces the coefficient of thermal expansion, which makes the resulting compound more dimensionally stable over a wide range of temperatures. In particular, a compound comprising a polyamide and at least 10% of glass fiber has higher strength and stiffness over the polyamide, making the compound more durable and resistant to wear and tear. When in use, the clip will be subjected to both stress and strain. The stable dimensions of the polyamide and glass fiber compound allows the clip to hooked on to the end portion precisely and minimizes wobble when weight is applied to the cushion. With better durability and resistance to wear and tear, the hook can be subjected to load and still be able to withstand the load without breaking.

The recliner framemay be configured to slidably receive the pair of brackets. Similarly, the pair of bracketsmay be configured to slidably receive the recliner frame.shows a perspective view of one of the pair of bracketswhich has a C-shaped bendto receive the recliner frame. In some embodiments, each of the pair of bracketscomprises a C-shaped bend.

shows a perspective view of the recliner framethat is being attached to the mounting frameby fastening one or more slotson the side of each of the pair of brackets. The slotmay be elongated to account for variances in mounting points across the different chairs, therefore providing a wider range of compatibility. The slotoffers adjustability by allowing the recliner frameto shift in and out depending on the user's needs and preferences. Having elongated sloton the pair of bracketsalso allow for easy installation and removal of components. This could save time and effort during installation or maintenance tasks, reducing downtime and increasing productivity. Furthermore, the elongated shape of the slotdistributes the load over a wider area, reducing stress concentrations and preventing the pair of bracketsfrom becoming damaged and/or deformed. The improvements to durability and strength could extend the lifespan of the pair of bracketsand reduce the need for repairs or replacements.shows a perspective view of a part of the recliner framefastened to one of the pair of brackets.

In some embodiments, at least one of the pair of bracketsmay include a hook assembly to secure the mounting frameto the seat portion.shows an exploded view of a hook assemblyfor securing the mounting frameto the seat portion. The hook assemblymay include a frame bracket, a stopperand a back plate. In some embodiments, the frame bracketmay comprise the at least one of the pair of bracketsor a portion thereof. A portion of the frame bracketmay be shaped and dimensioned as hookswhich allows the hook assemblyto be attached to at least one part of the seat portion. In some embodiments, the frame bracket, the stopperand/or the back platemay be attached together by one or more fastener(s), such as the fastener(s) described in other embodiments.

In some embodiments, the stoppermay include a tabconfigured to fit into a slotof the frame bracket. The tabmay be integrally formed with the stopper, as can be seen in. The profile of the slotmay correspond to a shape of the tabto allow the tabto fit into the slot. When the tabis fitted into the slot, the slotmay function as a frame that prevents the tabfrom moving in one or more directions. In some embodiments, the frame bracketmay include one or more rods configured to support the stopper. In some embodiments, one or more fasteners attaching the frame bracketto the stopperand/or the back platemay also be used to support the stopper. The stoppermay include a catch, the catchin the form of a protrusion angled from one end of the stoppertowards the tab, so as to operably engage the one or more rods and/or the one or more fasteners. In some embodiments, the stoppermay rotatable about an axis of a first rod of the one or more rods and/or a first fastener of the one or more fasteners so as to bring the catchtowards a second rod of the one or more rods and/or a second fastener of the one or more fasteners. The user may then press the catchagainst the second rod and/or the second fastener for the catchto engage the second rod and/or the second fastener.

shows an embodiment of the hook assemblyin a locked state where the catchis engaged to a fastener(which may be in the form of a screw). An engagement of the catchto the fastenerallows the user to secure the stopperto the fastener. In this configuration, the tabmay be fitted into the slot. Therefore, the engagement of the catchto the fastenermay lock the frame bracketin position with the stopper. When the mounting frameis attached to the seat portion, the engagement of the catchto the fastenerhelps to secure the mounting frameto the seat portionand prevent the mounting framefrom unintentional/inadvertent dislodgement from the seat portion. That is, the user would have to apply an additional force to intentionally disengage the stopperfrom the fastenerin order to remove the mounting framefrom the seat portion.

shows a side view of an embodiment of the hook assemblyin an unlocked state where the catchis disengaged from the one or more rods and/or the one or more fasteners.shows a side view of an embodiment of the hook assemblyin the locked state where the catchis engaged to the one or more rods and/or the one or more fasteners. In this embodiment, the tabis fitted into the slot.

The footrest assemblyfurther includes an actuator assembly. The actuator assemblymay be configured to allow adjustment of the recliner angle between the first portionand the second portion. In some embodiments, the actuator assemblyis mounted on the frameof the first portion. According to, the actuator assemblymay include a gas spring, a lever shaft, a cable, a locking mechanismand a lever.

The gas springmay be configured or biased to urge the second portionto an extended position, the extended position corresponding to a maximum allowable recliner angle. The gas springmay be triggered by the user through the application of a force on a lever, which may be transmitted through the lever shaftand the cableto the gas spring. In some embodiments, the cablemay include a ball-shaped attachment on each end. The stroke of the gas springallows the range of motion of the footrestto be adjusted to any position between fully extended and fully retracted. Advantageously, the gas springmay provide a smooth extending and retracting movement. The motion of the footrestcan be stopped at precise positions, thereby allowing the user to control the recliner angle between the first portionand the second portion. The user may then activate the locking mechanismto lock the piston position of the gas springin place.

Although the components of the gas springmay be lubricated, “stiction” or “breakaway friction”, which is static friction that needs to be overcome to enable relative motion of stationary objects in contact, may become prominent after a period of inactivity. In some embodiments, the lubrication may be by way of one or more lubricating films attached or applied between two or more surfaces of the gas springin a manner such as to reduce friction between the two or more surfaces. Stiction, for example, may occur due to pressure within the gas springwhich could cause lubrication to migrate away from a seal of the gas springand into the minute cracks and crevices within a rod of the gas spring. This leads to additional force being required to free the seal from the cracks and crevices which may be present as a momentary force “spike” when the gas springis compressed after a period of inactivity. As such, the gas springmay require additional force to activate, i.e. to extend or to retract the gas spring, when operated for the first time after a period of inactivity which could cause inconvenience to the user. In some embodiments, stiction may be minimized by using lubricants, low friction seals, highly finished rods and/or adding a spring to a piston of the gas spring.

In the embodiment shown in, the actuator assemblymay comprise a compression springcoupled to a pistonof the gas spring. The compression springmay be sleeved on a piston rodof the gas spring, and one end of the compression springmay be directly or indirectly placed in contact with the pistonof the gas spring. The compression springmay be configured or biased to urge the gas springto an extended position. As the footrestis being adjusted from an extended position to a retracted position, the gas springis being compressed and causes the pistonto compress the compression springagainst one end of the gas spring, thereby storing energy in the compression spring. When the gas spring is left unused for a period of inactivity, the problem of stiction as described in the preceding paragraph may become prominent. The user, when operating the gas spring for the first time after the period of inactivity, may actuate the gas springto extend the gas spring. This provides the compression springroom to extend, thus providing a reaction force on the pistonwhich reinforces the force produced by the gas springthat urges the footrestto the extended position so as to overcome stiction and allow the gas springto smoothly extend even after a period of inactivity.

The pair of brackets, the first portionand the second portiontogether may form a six-bar mechanical linkage. The six-bar mechanical linkage may comprise six rigid bars connected by six hinge joints. The six-bar mechanical linkage may be located at the base of the chairand connected the to the frame of the chair.shows an embodiment of a six-bar mechanical linkage which comprises two first linkages (long linkages), two second linkages (medium linkages)and two third linkages (short linkages). One of the two third linkagesmay be fastened to the support plateand the two second linkages. The two second linkagesmay each be fastened to separate pieces of the two first linkages. The two first linkagesmay each be fastened to the other third linkagewhich in turn could be fastened to the framevia the mounting point. A fastener to fastened these linkages may, for example, be the fastener as described in other embodiments.

The six-bar mechanical linkage may be arranged to move from a retracted position or state to an extended position or state upon actuation of the gas spring. The second portionmay rotate around a fixed point, causing the footrestto extend and adjusting the recliner angle between the first portionand the second portion. The six-bar mechanical linkage may be specifically designed to avoid collision between the footrestand a fixed area of the chairor a component of the chair, such as a chair tilt mechanism, a wheelbase, and/or a chair hydraulic mechanism. This ensures that the footrestcan move freely without interfering with the other functions of the chair. By optimizing the placement of the linkages and pivots, the six-bar mechanical linkage maximizes the available space and yet retain the maximum possible extension for the footrest.

In some embodiments, the second portionmay comprise means for attaching the footrestdirectly or indirectly to a linkage, such as the main linkage, of the linkage systemof the second portionwhen the six-bar mechanical linkage is in the retracted state. In some embodiments, the means for attaching may comprise at least one magnet. The magnet may comprise a permanent magnet such as a neodymium magnet. The strength of the magnet may correspond to the weight of the footrest. In some embodiments, the strength of the magnet may be of various neodymium magnet grades, such as N42, N45, N48, N52 and N55. In other embodiments, the means for attaching may comprise a plurality of magnets, and the total strength of the magnets may correspond to the weight of the footrest. In some embodiments, the movement of the footrestbetween the retracted state and the extended state may comprise an arc formed by the configuration of the footrestbeing pivotable about the frameat the mounting point. At the retracted state of the footrest, the magnetic force produced by the magnet further urges the footrestto an enhanced retracted position. In other words, the minimum retracted position of the retractable recliner may be enhanced by the magnet such that the footrestmay be held in place and minimize any adverse effects on the ergonomics of the user when the recliner is tugged away under the chair.