Lift chair and a chair frame with a position holding mechanism for use therewith

In one aspect, the present invention relates a reclining lift chair frame used in a reclining lift chair. The reclining lift chair frame utilizes a position holding mechanism to eliminate the free (idle) fall of the footrest of the reclining lift chair.

FIELD OF THE INVENTION

The present invention generally relates to a lift chair, and more particular to a reclining lift chair frame used in a reclining lift chair. The reclining lift chair frame utilizes a position holding mechanism to eliminate the free (or idle) fall of the footrest of the reclining lift chair.

BACKGROUND OF THE INVENTION

Reclining lift chairs find widespread use. A reclining chair usually has a seat, backrest and footrest operable with three-way reclining mechanisms among three positions, a fully upright position, a TV position and a fully reclined position. In the TV position, the seat and backrest are partially reclined and the footrest extended, while in the fully reclined position, the seat and backrest are fully reclined and the footrest extended.

FIG. 10shows a reclining chair frame having the three-way reclining mechanisms. The three-way reclining mechanism assembly utilizes a conventional L-shaped position holding member1to hold a desired position among the fully upright position, the TV position and the fully reclined position. The conventional L-shaped position holding member1is pivotally connected to a seat link2, an end of a stop link3and an end of a brace link4, respectively. The stop link3and the brace link4, in turn, are pivotally connected to a base mounting plate5by the other ends. For such a design, however, it has been found that when the lift chair is in the full recline position, an unintended falling of the footrest7may occur when the footrest7is idle, i.e., no force applied thereto, or when a force, F, is applied thereto. The unintended falling is unsatisfactory in terms of the comfort it provide for the occupant.

SUMMARY OF THE INVENTION

The present invention, in one aspect, relates to a position holding mechanism used in a reclining lift chair having an upright position, a TV position and a fully reclined position.

In one embodiment, the position holding mechanism includes a position holding member having a triangle-shaped body and an arm extending from an apex of the triangle-shaped body, where the triangle-shaped body has a first side and a second side extending to the arm, a bottom extending to the first and second sides, a notched receptacle recessed from the first side proximal to the apex and an obround opening defined proximally along the second side; and where the arm has two openings defined in each end portion.

The position holding mechanism also includes a detent pin assembly having a stable spacer, a roller bushing received in the stable spacer, and a detent pin received in the roller bushing such that as assembled, the stable spacer is rotatable relative to the detent pin.

The position holding member is movably positioned in relation to the detent pin assembly such that when the reclining lift chair is in the upright position, the detent pin assembly is received in the notched receptacle of the position holding member, and when the reclining lift chair is in the fully reclined position, the detent pin assembly is against the first side of the position holding member.

In another aspect, the present invention relates to a reclining lift chair comprising the position holding mechanism as disclosed above.

In yet another aspect, the present invention relates to a reclining lift chair frame used in a reclining lift chair having an upright position, a TV position, and a fully reclined position. In one embodiment, the reclining lift chair frame includes a base mounting plate, a seat mounting link positioned movably relative to the base mounting plate, a footrest driving mechanism pivotally connected between the base mounting plate and the seat mounting link, a footrest linkage pivotally connected to the footrest driving mechanism and the seat mounting link, where the footrest linkage is operably driven by the footrest driving mechanism between a retracted position and an extended position, a backrest linkage pivotally connected to the seat mounting link and the base mounting plate, a rear drive linkage pivotally connected to the base mounting plate and the footrest driving mechanism, for driving the backrest linkage and the footrest driving mechanism to be in a desired position that is corresponding to one of the upright position, the TV position, and the fully reclined position of the reclining lift chair, and a position holding mechanism.

The position holding mechanism has a position holding member having a triangle-shaped body and an arm extending from an apex of the triangle-shaped body, where the triangle-shaped body has a first side and a second side extending to the arm, a bottom extending to the first and second sides, a notched receptacle recessed from the first side proximal to the apex and an obround opening defined proximally along the second side; where the arm has a first opening defined in free end portion and a second opening defined in the end portion proximal to the apex, and where the position holding member is pivotally connected to the seat mounting link through the first opening and to the rear drive linkage through the second opening, respectively, and a detent pin assembly mounted onto the base mounting plate, and having a stable spacer, a roller bushing received in the stable spacer, and a detent pin received in the roller bushing such that the stable spacer is rotatable relative to the detent pin, where the position holding member is movably positioned in relation to the detent pin assembly such that when the reclining lift chair is in the upright position, the detent pin assembly is received in the notched receptacle of the position holding member, and when the reclining lift chair is in the fully reclined position, the detent pin assembly is against the first side of the position holding member.

In one embodiment, the footrest linkage has a scissor-type linkage.

In one embodiment, the footrest linkage has a first front link, a second front link, a first rear link, a second rear link and a footrest mounting bracket, each link having a first end portion and a second end, where the first end portions of the first and second front links are pivotally connected to the footrest mounting bracket, and the second end portions of the first and second front links are pivotally connected to the first end portions of the first and second rear links, respectively, where the second front link is pivotally connected to the first rear link, and where the second end portion of the first rear link is pivotally connected to a front end portion of the seat mounting link.

The footrest driving mechanism comprises a front link, a rear link and a drive link, each link having a first end portion and a second end, where the first end portion of the front link is pivotally connected to the first rear link of the footrest linkage, the first end portion of the drive link is pivotally connected to the seat mounting link, the second end portion of the rear link is pivotally connected to the base mounting plate, and where the second end portions of the front and drive links, the first end portion of the rear link and the second end portion of the second rear link of the footrest linkage are pivotally connected together.

The rear drive linkage comprises a stop link, a brace link and a connection link, each link having a first end portion and a second end, where the first end portion of the stop link is pivotally connected to the position holding member of the position holding mechanism through the second opening, and the second end portion of the stop link is pivotally connected to the base mounting plate, where the first end portion of the connection link is pivotally connected to the second end portion of the rear link of the footrest driving mechanism, and the second end portion of the connection link is pivotally connected to the second end portion of the stop link, and where the first end portion of the brace link is pivotally connected to the position holding member of the position holding mechanism through the obround opening, and the second end portion of the brace link is pivotally connected to the base mounting plate. The brace link is operably movable back and forth along the obround opening of the position holding member of the position holding mechanism.

The backrest linkage comprises a backrest link having a first end portion and a second end portion pivotally connected to the base mounting plate, and a backrest mounting bracket pivotally connected to the second end portion of the backrest link and a rear end portion of the seat mounting link.

In one embodiment, when the base mounting plate moves, relative to the seat mounting link, to a most rearward position, the footrest linkage is in the retracted position, the detent pin assembly is received in the notched receptacle of the position holding member of the position holding mechanism, and the backrest mounting bracket and the seat mounting link define a first angle therebetween, which corresponds to a position in which the reclining chair is in the upright position.

When the base mounting plate moves, relative to the seat mounting link, to a most forward position, the footrest linkage is in the extended position, the detent pin assembly is positioned against the first side of the position holding member of the position holding mechanism, and the backrest mounting bracket and the seat mounting link define a second angle therebetween, where the second angle is greater then the first angle, which corresponds to a position in which the reclining chair is in the fully reclined position.

When the base mounting plate moves to a desired position between the most rearward and forward positions, the footrest linkage is in the extended position, and the seat mounting link define a third angle therebetween, where the third angle is greater then the first angle but less than the second angle, which corresponds to a position in which the reclining chair is in the fully reclined position.

In a further aspect, the present invention relates to a reclining lift chair comprising the reclining lift chair frame as disclosed above.

DETAILED DESCRIPTION OF THE INVENTION

The terms used in this specification generally have their ordinary meanings in the art, within the context of the invention, and in the specific context where each term is used. Certain terms that are used to describe the invention are discussed below, or elsewhere in the specification, to provide additional guidance to the practitioner regarding the description of the invention. The use of examples anywhere in this specification, including examples of any terms discussed herein, is illustrative only, and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to various embodiments given in this specification.

The description will be made as to the embodiments of the present invention in conjunction with the accompanying drawings inFIGS. 1-9. In accordance with the purposes of this invention, as embodied and broadly described herein, this invention, in one aspect, relates to a position holding mechanism and a reclining lift chair frame that are used in a reclining lift chair having an upright position, a TV position and a fully reclined position.

Referring first toFIG. 1, a reclining lift chair or sofa is schematically shown according to one embodiment of the present invention. The reclining lift chair includes a chair base151placed on a floor, a reclining lift chair frame100mounted on a chair base151, a backrest156, a seat158and a footrest150supported by the reclining lift chair frame100. The reclining lift chair also has an armrest mounted onto the chair base151. The reclining lift chair frame100has a scissor-type footrest linkage152that is operably in a retracted position or an extended position. The reclining lift chair frame100is configured such that the seat, backrest and footrest are movable among an upright, a semi-reclined or TV position and a fully reclined position. In the TV position, the scissor-type footrest linkage152is in the extended position and the backrest and the seat define an angle, α, as shown inFIG. 1(a). In the fully reclined position, the scissor-type footrest linkage152is in the extended position and the backrest and the seat define an angle, β, where β>α, as shown inFIG. 1(b).

One of the objectives of the present invention is to provide the reclining lift chair frame100that eliminates the free (or idle) fall of the footrest10when the reclining lift chair is in the fully reclined position. To accomplish this, a position holding mechanism is utilized in the reclining lift chair frame100. Actually, the reclining lift chair shown inFIG. 1includes two chair frames100located on opposite sides of the reclining lift chair and interconnected by appropriate cross pieces, as necessary. Since the two chair frames100on either side of the reclining lift chair are substantially identical and mirror images of one another, as shown inFIG. 2for the left-hand side chair frame andFIG. 3for the right-hand side chair frame, only one reclining lift chair frame100is described herein for the purposes of simplicity.

Referring toFIGS. 2-9, and particularly toFIG. 6, the position holding mechanism is shown according to one embodiment of the present invention. The position holding mechanism includes a position holding member124and detent pin assembly141mounted onto a base mounting plate120.

The position holding member124has a triangle-shaped body124aand an arm124eextending from an apex124jof the triangle-shaped body124a. The triangle-shaped body124ahas a first side124cand a second side124dextending to the arm124e, a bottom124bextending to the first and second sides124cand124d, a notched receptacle124irecessed from the first side124cproximal to the apex124jand an obround opening124hdefined proximally along the second side124d. The arm124ehas two openings124fand124gdefined in each end portion. Additionally, the arm124ealso has a rib124kformed on a surface and a notch124lformed on one side.

The detent pin assembly141has a stable spacer140, a roller bushing138received in the stable spacer140, and a detent pin136received in the roller bushing138such that as assembled, the stable spacer140is rotatable relative to the detent pin136.

The position holding member124is movably positioned in relation to the detent pin assembly141such that when the reclining lift chair is in the upright position, the detent pin assembly141is received in the notched receptacle124iof the position holding member124, as shown inFIG. 7, and when the reclining lift chair is in the fully reclined position, the detent pin assembly141is against the first side124cof the position holding member124, as shown inFIG. 9.

Referring toFIGS. 2-9, the reclining lift chair frame100is shown according to one embodiment of the present invention. The reclining lift chair frame120includes a base mounting plate120for mounting the chair frame100onto a chair base (not shown), and a seat mounting link116positioned movably relative to the base mounting plate120,

The reclining lift chair frame100also includes a footrest driving mechanism pivotally connected between the base mounting plate120and the seat mounting link116, a footrest linkage pivotally connected to the footrest driving mechanism and the seat mounting link116. The footrest linkage is operably driven by the footrest driving mechanism between a retracted position and an extended position.

The reclining lift chair frame100further includes a backrest linkage pivotally connected to the seat mounting link116and the base mounting plate120, a rear drive linkage pivotally connected to the base mounting plate120and the footrest driving mechanism, for driving the backrest linkage and the footrest driving mechanism to be in a desired position that is corresponding to one of the upright position, the TV position, and the fully reclined position of the reclining lift chair, and a position holding mechanism.

The footrest linkage has a scissor-type linkage. The footrest linkage has a first front link104, a second front link106, a first rear link108, a second rear link110and a footrest mounting bracket102, with each link having a first end portion and a second end portion. The first end portions of the first and second front links104and106are spatially and pivotally connected to the footrest mounting bracket102, and the second end portions of the first and second front links104and106are pivotally connected to the first end portions of the first and second rear links108and110, respectively. The second front link106is pivotally connected to the first rear link108in an intermediate position. The second end portion of the first rear link108is pivotally connected to a front end portion of the seat mounting link116.

The footrest driving mechanism has a front link112, a rear link118and a drive link114, with each link having a first end portion and a second end. The first end portion of the front link112is pivotally connected to the first rear link108of the footrest linkage. The first end portion of the drive link114is pivotally connected to the seat mounting link116. The second end portion of the rear link118is pivotally connected to the base mounting plate120. The second end portions of the front and drive links112and118, the first end portion of the rear link118and the second end portion of the second rear link110of the footrest linkage are pivotally connected together.

The rear drive linkage comprises a stop link128, a brace link122and a connection link126, with each link having a first end portion and a second end. The first end portion of the stop link128is pivotally connected to the position holding member124of the position holding mechanism through the second opening124g, and the second end portion of the stop link128is pivotally connected to the base mounting plate120. The first end portion of the connection link126is pivotally connected to the second end portion of the rear link118of the footrest driving mechanism, and the second end portion of the connection link126is pivotally connected to the second end portion of the stop link128. The first end portion of the brace link122is pivotally connected to the position holding member124of the position holding mechanism through the obround opening124h, and the second end portion of the brace link122is pivotally connected to the base mounting plate120. For such an arrangement, the brace link122is operably movable back and forth along the obround opening124hof the position holding member124of the position holding mechanism.

The backrest linkage has a backrest link130having a first end portion134pivotally connected to the base mounting plate120and a second end portion136, and a backrest mounting bracket132pivotally connected to the second end portion136of the backrest link130and a rear end portion of the seat mounting link116.

The position holding mechanism includes a position holding member124and detent pin assembly141mounted onto a base mounting plate120.

The position holding member124has a triangle-shaped body124aand an arm124eextending from an apex124jof the triangle-shaped body124a. The triangle-shaped body124ahas a first side124cand a second side124dextending to the arm124e, a bottom124bextending to the first and second sides124cand124d, a notched receptacle124irecessed from the first side124cproximal to the apex124jand an obround opening124hdefined proximally along the second side124d. The arm124ehas two openings124fand124gdefined in each end portion. Additionally, the arm124ealso has a rib124kformed on a surface and a notch124lformed on one side. The position holding member124is pivotally connected to the seat mounting link116through the first opening124fand to the first end portion of the stop link128of the rear drive linkage through the second opening124g, respectively.

The detent pin assembly141has a stable spacer140, a roller bushing138received in the stable spacer140, and a detent pin136received in the roller bushing138such that as assembled, the stable spacer140is rotatable relative to the detent pin136.

For such an arrangement, the base mounting plate120, the seat mounting link120, footrest driving mechanism, the footrest linkage, the rear drive linkage and the backrest linkage are operably moveable relative to one another. The movements are achieved usually by an actuator, such as motors or other actuating mechanisms (not shown).

When the base mounting plate120moves, relative to the seat mounting link116, to a most rearward position, the footrest linkage is in the retracted position, the detent pin assembly141is received in the notched receptacle124iof the position holding member124of the position holding mechanism, and the backrest mounting bracket132and the seat mounting link116define a first angle therebetween, as shown inFIG. 7. This corresponds to a position in which the reclining chair is in the upright position. According to the present invention, no free fall of the footrest occurs in this position.

When the base mounting plate120moves, relative to the seat mounting link116, to a most forward position, the footrest linkage is in the extended position, the detent pin assembly141is positioned against the first side124cof the position holding member124of the position holding mechanism, and a small pin142mounted on the seat mounting link116is positioned against the notch124iof the position holding member124of the position holding mechanism, and the backrest mounting bracket132and the seat mounting link116define a second angle therebetween, where the second angle is greater then the first angle, as shown inFIG. 9. This corresponds to a position in which the reclining chair is in the fully reclined position. In this position, when forces F1and F2are respectively applied to the backrest and footrest simultaneously or individually, no free fall of the footrest will occur, since the detent pin assembly141is positioned against the first side124cof the position holding member124of the position holding mechanism, which holds the extended position of the footrest linkage solidly.

When the base mounting plate120moves to a desired position between the most rearward and forward positions, the footrest linkage is in the extended position, and the backrest mounting bracket132and the seat mounting link116define a third angle therebetween, where the third angle is greater then the first angle but less than the second angle, as shown inFIG. 8. This corresponds to a position in which the reclining chair is in the fully reclined position. No free fall of the footrest occurs in this position.

Preferably, the chair frame100is made from durable materials such as steel, alloy, plastic, wood, or any combination of them, as known to people skilled in the art.