Patent Description:
Functional sofas or chairs enable certain parts of the user's body to relax better by adjusting the structure. A main structural part of a functional sofa or chair is the lower-back supporting apparatus mounted on the backrest, which provides support to the user's back by adjusting the distance between the surface of the backrest and the user's back in order to ease the user's back fatigue.

The lower-back supporting apparatus in the prior art is, with complex structure, mostly a scissor lift structure cooperated with a driving screw. Inconvenient maintenance of the driving screw and the relatively restrictive mounting position may lead to a great limitation in the specific application (such as assembled on sofas or chairs) of the lower-back supporting apparatus, thereby leading to a limitation in the applicable circumstances and a poor versatility of the lower-back supporting apparatus.

<CIT> disclose a backrest adjustment mechanism, comprising a lower-back supporting apparatus. <CIT> discloses a lumbar support device, including an electromotive linear drive including a guide profile and two sliding blocks movable on the guide profile in synchronism towards one another and away from one another. <CIT> discloses an adjustable lumbar support for chairs and vehicle seats.

The invention is identified in the appended claims. In order to address the shortcomings of the prior art, the first purpose of the present invention is to provide a lower-back supporting apparatus whose structure is simple; the mounting of the extendable and retractable part may be adaptively adjusted based on the practical and applicable scene, which facilitates maintenance.

The second purpose of the present invention is to provide a backrest supporting frame, which may provide an adjustable support for the user's back and is suitable for a broad range of people.

The third purpose of the present invention is to provide a seating unit, which may ease the fatigue of the user's back and facilitate maintenance.

Embodiments of the present invention are implemented by the technical solution as follows:.

A lower-back supporting apparatus comprises a lower-back supporting plate; a lower mounting plate; two supporting structures, provided between the lower-back supporting plate and the lower mounting plate, hinged to the lower-back supporting plate and the lower mounting plate, respectively; and an extendable and retractable part, comprising an extendable and retractable end hinged to the lower-back supporting plate or the supporting structure, so as to drive the lower-back supporting plate away or close to the lower mounting plate; each of the supporting structures comprises a first link and a second link hinged to each other, wherein the first link is hinged to the lower-back supporting plate, and the second link is hinged to the lower mounting plate; or the second link is hinged to the lower-back supporting plate, and the first link is hinged to the lower mounting plate; and two restricting protrusions are provided on the first link, wherein the second link and a hinge point between the first link and the second link are located between the two restricting protrusions.

According to a preferred embodiment, each of the supporting structures comprises a first link and a second link hinged to each other, wherein the first link of one supporting structure is hinged to the lower-back supporting plate and the second link thereof is hinged to the lower mounting plate; the second link of another support structure is hinged to the lower-back supporting plate, and the first link thereof is hinged to the lower mounting plate; and two restricting protrusions are provided on the first link, wherein the second link and a hinge point between the first link and the second link are located between the two restricting protrusions.

According to a preferred embodiment, the extendable and retractable part is provided between any two of the lower-back supporting plate, the lower mounting plate, the first link, and the second link, so as to drive the lower-back supporting plate away or close to the lower mounting plate; or the extendable and retractable part is provided between two first links or two second links, so as to drive the lower-back supporting plate away or close to the lower mounting plate.

According to a preferred embodiment, the first link comprises a body part and a restricting part connected to each other; the hinge point between the first link and the second link is defined as the first hinge point, wherein the restricting protrusion and the first hinge point are both located on the restricting part; a convex arch is provided on an outer side of the first link, and a concave arch is provided on an opposite side of the convex arch, wherein the convex arch and the concave arch are both located on the restricting part; and at least one of the restricting protrusions is provided on the convex arch.

According to a preferred embodiment, ends of the two first links hinged to the lower-back supporting plate near the lower-back supporting plate are frictionally abutted, and ends of the two second links hinged to the lower mounting plate near the lower mounting plate are frictionally abutted; or ends of the two second links hinged to the lower-back supporting plate near the lower-back supporting plate are frictionally abutted, and ends of the two first links hinged to the lower mounting plate near the lower mounting plate are frictionally abutted.

According to a preferred embodiment, respective ends of the first link and the second link hinged to the lower-back supporting plate near the lower-back supporting plate are frictionally abutted; and respective ends of the first link and the second link hinged to the lower mounting plate near the lower mounting plate are frictionally abutted.

According to a preferred embodiment, the extendable and retractable part is any one of a cylinder, a hydraulic cylinder, or an electric pusher.

According to a preferred embodiment, a distance between the lower-back supporting plate and the lower mounting plate is defined as H; the H is between <NUM> and <NUM> millimeters when the lower-back supporting plate is away or close to the lower mounting plate.

According to a preferred embodiment, an extending direction of the lower-back supporting plate is defined as a width direction; the lower-back supporting apparatus along the width direction is between <NUM> and <NUM> millimeters.

A backrest supporting frame comprises a fixing frame and the lower-back supporting apparatus mentioned above, wherein the fixing frame comprises two lateral plates connected by a crossbeam; the lower-back supporting apparatus is provided between two lateral plates and fixedly mounted on the crossbeam by the lower mounting plate.

According to a preferred embodiment, the backrest supporting frame further comprises a headrest structure provided between two lateral plates and located on an upper side of the lower-back supporting apparatus.

A seating unit comprises the backrest supporting frame mentioned above.

The technical solutions of embodiments of the present invention provide at least the advantages and beneficial effects as follows:.

The present invention has a simple structure. Lifting and lowering the lower-back supporting plate may be realized by cooperating the extendable and retractable part with the supporting structure; the mounting layout of the extendable and retractable part may be adaptively adjusted based on the appearance or contour of the product during practical assembly due to the flexibility of position and sufficiency of space while mounting the extendable and retractable part; the volume of lower-back supporting apparatus may be effectively reduced by adopting the extendable and retractable part; the whole of the extendable and retractable part is easy to maintain and replace.

In order to illustrate more clearly the technical solutions of the embodiments of the present invention, hereinafter provided is a brief description of the attached drawings required in the embodiments. It is to be understood that the following attached drawings only illustrate certain embodiments of the invention and thus should not be construed as a limitation of scope.

<NUM>: lower-back supporting plate; <NUM>: upper mounting plate; <NUM>: first link; <NUM>: body part; <NUM>: third hinged hole; <NUM>: first tooth; <NUM>: restricting part; <NUM>: restricting protrusion; <NUM>: concave arch; <NUM>: first hinged hole; <NUM>: convex arch; <NUM>: second hinged hole; <NUM>: first frictional plane; <NUM>: second link; <NUM>: first hinge point; <NUM>: fourth hinged hole; <NUM>: fifth hinged hole; <NUM>: second tooth; <NUM>: sixth hinged hole; <NUM>: second frictional plane; <NUM>: extendable and retractable part; <NUM>: lower mounting plate; <NUM>: first fixing part; <NUM>: second fixing part; <NUM>: fixing frame; <NUM>: lateral plate; <NUM>: second crossbeam; <NUM>: first crossbeam; <NUM>: third crossbeam; <NUM>: headrest structure; <NUM>: fixing part; <NUM>: transverse mounting link.

For better understanding and implementation, the technical solutions in embodiments of the present invention will be clearly and completely described below in conjunction with the attached drawings in embodiments of the present invention.

In the description of the present invention, it is to be noted that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and other orientation or lateral position relationships are based on the orientation or lateral position relationships shown in the attached drawings. It is only intended to facilitate description and simplify operation, but not to indicate or imply that the referred device or element has a specific orientation, or is constructed and operated in a specific orientation. Therefore, they should not be construed as a limitation of the present invention.

Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are used only to describe specific embodiments and are not intended as a limitation of the invention.

Please refer to <FIG>; a lower-back supporting apparatus, applicable to a backrest of a seating unit, provides support for the user's lower back. In the present embodiment, the lower-back supporting apparatus comprises a lower-back supporting plate <NUM>; a lower mounting plate <NUM>; two supporting structures, provided between the lower-back supporting plate <NUM> and the lower mounting plate <NUM>, hinged to the lower-back supporting plate <NUM> and the lower mounting plate <NUM>, respectively; and an extendable and retractable part <NUM>, comprising an extendable and retractable end hinged to the lower-back supporting plate <NUM> or the supporting structure, so as to drive the lower-back supporting plate <NUM> away or close to the lower mounting plate <NUM>. In addition, the lower-back supporting apparatus further comprises an upper mounting plate <NUM> fixedly connected to the lower-back supporting plate <NUM>, wherein the supporting structure is hinged to the lower-back supporting plate <NUM> through the upper mounting plate <NUM>. In use, by controlling the extension and the retraction of the extendable and retractable part, the extendable and retractable end on the extendable and retractable part <NUM> drives the lower-back supporting plate <NUM> or the supporting structure to move, so as to drive the lower-back supporting plate <NUM> away or close to the lower mounting plate <NUM>, thereby realizing the adjustment of the distance between the lower-back supporting plate <NUM> and the lower mounting plate <NUM>. In such a setup, the mounting layout of the extendable and retractable part <NUM> may be adaptively adjusted based on the appearance or contour of the product during practical assembly due to the flexibility of position and sufficiency of space during mounting the extendable and retractable part <NUM>; the volume of lower-back supporting apparatus may be effectively reduced by adopting the extendable and retractable part <NUM>; the whole of the extendable and retractable part <NUM> is easy to maintain and replace.

Specifically, each of the supporting structures comprises a first link <NUM> and a second link <NUM> hinged to each other, wherein the first link <NUM> of one of the supporting structures is hinged to the lower-back supporting plate <NUM> and the second link <NUM> thereof is hinged to the lower mounting plate <NUM>; the second link <NUM> of another one of the support structures is hinged to the lower-back supporting plate <NUM>, and the first link <NUM> thereof is hinged to the lower mounting plate <NUM>; and two restricting protrusions <NUM> are provided on the first link <NUM>, wherein the second link <NUM> and a hinge point between the first link <NUM> and the second link <NUM> are located between the two restricting protrusions <NUM>. The structural design by cooperating the first link <NUM> with the second link <NUM> enables a wide range of a lifting height for the lower-back supporting apparatus, which may meet the demand of a broad range of the user.

As shown in <FIG> and <FIG>, the first link <NUM> comprises a body part <NUM> and a restricting part <NUM> connected to each other; the hinge point between the first link <NUM> and the second link <NUM> is defined as the first hinge point <NUM>, wherein the restricting protrusion <NUM> and the first hinge point <NUM> are both located on the restricting part <NUM>; a convex arch <NUM> is provided on an outer side of the first link <NUM>, and a concave arch <NUM> is provided on an opposite side of the convex arch <NUM>, wherein the convex arch <NUM> and the concave arch <NUM> are both located on the restricting part <NUM>; and at least one of the restricting protrusions <NUM> is provided on the convex arch <NUM>. In the present embodiment, the body part <NUM> and the restricting part <NUM> are formed integrally; a more rational layout of the two restricting protrusions <NUM> provided on the restricting part <NUM> may be realized by providing the convex arch <NUM>, that is, the lower-back supporting apparatus may realize the ultimate positions as shown in <FIG> and <FIG>, which brings the lower-back supporting plate <NUM> as close as possible to the lower mounting plate <NUM> when the lower-back supporting apparatus is in the stored state, thereby leading to a more compact lower-back supporting apparatus in the stored state. In contrast, in the extended state, the lower-back supporting plate <NUM> is as far as possible from the lower mounting plate <NUM>. In other words, the layout of the restricting protrusion <NUM> may increase the movement path of the lower-back supporting plate <NUM> relative to the lower mounting plate <NUM> by providing the convex arch <NUM>.

In the present embodiment, a first hinged hole <NUM> is provided on the restricting part <NUM>, and a fifth hinged hole <NUM> is provided on the second link <NUM>; when the first link <NUM> is hinged to the second link <NUM>, the first hinged hole <NUM> and the fifth hinged hole <NUM> share the same axis; the first hinged hole <NUM> and the fifth hinged hole <NUM> are fixed by a pin passing through both of them, with a first hinge point <NUM> locating on the central axis of the pin. Further, respective ends of the first link <NUM> and the second link <NUM> hinged to the lower-back supporting plate <NUM> near the lower-back supporting plate <NUM> are frictionally abutted. Specifically, a first tooth <NUM> and a second tooth <NUM> are correspondingly provided on the first link <NUM> and the second link <NUM>; the first link <NUM> and the second link <NUM>, hinged to the upper mounting plate <NUM>, are engaged by the first tooth <NUM> and the second tooth <NUM>; correspondingly, the first link <NUM> and the second link <NUM>, hinged to the lower mounting plate <NUM>, are also engaged by the first tooth <NUM> and the second tooth <NUM>.

As shown in <FIG>, in other embodiments, a first frictional plane <NUM> and a second frictional plane <NUM> are correspondingly provided on the first link <NUM> and the second link <NUM>; the first frictional plane <NUM> and the second frictional plane <NUM> are two rounded arc surfaces that abut each other. In use, the first frictional plane <NUM> and the second frictional plane <NUM> are always in linear contact when the first link <NUM> and the second link <NUM> rotate around the upper mounting plate <NUM> and the lower mounting plate <NUM>. In order to further increase the friction between the first frictional plane <NUM> and the second frictional plane <NUM>, elastic rubber gaskets may be provided on both working surfaces respectively, so that the two parts press and deform each other after assembly and they always maintain surface contact, so as to effectively prevent a relative sliding between the first frictional plane <NUM> and the second frictional plane <NUM> from leading to distortion of the lower-back supporting plate, thereby increasing the structural stability of the lower-back supporting plate when it is switched between the stored state and the extended state.

In the present embodiment, the extendable and retractable part <NUM> is provided between any two of the lower-back supporting plate <NUM>, the lower mounting plate <NUM>, the first link <NUM>, and the second link <NUM>, so as to drive the lower-back supporting plate <NUM> away or close to the lower mounting plate <NUM>; or the extendable and retractable part <NUM> is provided between two first links <NUM> or two second links <NUM>, so as to drive the lower-back supporting plate <NUM> away or close to the lower mounting plate <NUM>. As shown in <FIG>, preferably, a fixed end of the extendable and retractable part <NUM> is hinged to the first link <NUM> on the left side by a pin; an extendable and retractable end of the extendable and retractable part <NUM> is hinged to the second link <NUM> on the right side by a pin. Specifically, a second hinged hole <NUM> is provided on the restricting part <NUM> of the first link <NUM>; a sixth hinged hole <NUM> is provided on the second link <NUM>; the fixed end of the extendable and retractable part <NUM> is hinged to the second hinged hole <NUM> by a pin; the extendable and retractable end of the extendable and retractable part <NUM> is hinged to the sixth hinged hole <NUM> by a pin. In the other embodiment, the fixed end of the extendable and retractable part <NUM> may be provided on one of the first links <NUM>, and the extendable and retractable end of the extendable and retractable part <NUM> may be provided on the other one of the first links <NUM>; or the fixed end of the extendable and retractable part <NUM> may be provided on the one of the second link <NUM>, the extendable and retractable end of the extendable and retractable part <NUM> may be provided on the other one of the second link <NUM>.

In the present embodiment, a third hinged hole <NUM> is provided on the body part <NUM> of the first link <NUM>; the first link <NUM> is respectively hinged to the upper mounting plate <NUM> and the lower mounting plate <NUM> through the third hinged hole <NUM> by pins. Correspondingly, a fourth hinged hole <NUM> is provided on the second link <NUM>; the second link <NUM> is hinged to the upper mounting plate <NUM> and the lower mounting plate <NUM> through the fourth hinged hole <NUM> by pins. As shown in <FIG>, the sixth hinged hole is located between the fourth hinged hole <NUM> and the fifth hinged hole <NUM>; the sixth hinged hole <NUM> is provided near the fifth hinged hole <NUM> (the first hinge point <NUM>), so as to facilitate the extendable and retractable part <NUM> to impose forces on the supporting structure (more effort saving when the extendable and retractable part <NUM> drives the supporting structure to move).

In the present embodiment, a concave arch <NUM> is provided on an opposite side of the convex arch <NUM>, wherein the concave arch <NUM> is located on the restricting part <NUM>. In the present embodiment, the concave arch <NUM> is used to accommodate the pin for mounting the extendable and retractable end of the extendable and retractable part <NUM> when the supporting structure is moving. In such a setup, specifically shown in <FIG>, a more compact lower-back supporting apparatus in the stored state may be achieved. The structural design of the convex arch <NUM> and the concave arch <NUM> provided oppositely optimizes the structure of the first link <NUM> by realizing the respective structural purpose of the convex arch <NUM> and the concave arch <NUM> and ensuring the strength of the first link <NUM>.

In the present embodiment, the extendable and retractable part <NUM> is any one of a cylinder, a hydraulic cylinder, or an electric pusher. Preferably, the extendable and retractable part <NUM> is an electric pusher.

As shown in <FIG>, <FIG>, a distance between the lower-back supporting plate <NUM> and the lower mounting plate <NUM> is defined as H; the H is between <NUM> and <NUM> millimeters when the lower-back supporting plate <NUM> is away or close to the lower mounting plate <NUM>. In the present embodiment, the lower mounting plate <NUM> is L-shaped, and comprises a first fixing part <NUM> and a second fixing part <NUM> connected to each other, wherein the first link <NUM> and the second link <NUM> are connected to the second fixing part <NUM> when assembled on the lower mounting plate <NUM>; the distance H between the lower-back supporting plate <NUM> and the lower mounting plate <NUM> is the distance between the upper surface of the lower-back supporting plate <NUM> and the lower surface of the lower mounting plate <NUM>.

Specifically, as shown in <FIG>, when the lower-back supporting apparatus is in a stored state, that is, when the lifting height of the lower-back supporting plate is in the lowest ultimate position, the distance H between the lower-back supporting plate <NUM> and the lower mounting plate <NUM> equals to H1, wherein H1 is between <NUM> and <NUM> millimeters. Preferably, H1 is <NUM> millimeters. H1 may be <NUM>, <NUM>, or <NUM> millimeters in the other embodiments.

As shown in <FIG>, when the lower-back supporting apparatus is in the extended state, that is, when the lifting height of the lower-back supporting plate is in the highest ultimate position, the distance H between the lower-back supporting plate <NUM> and the lower mounting plate <NUM> equals to H2, wherein H2 is between <NUM> and <NUM> millimeters. Preferably, H2 is <NUM> millimeters. H2 may be <NUM>, <NUM>, or <NUM> millimeters in the other embodiments.

In the present embodiment, an extending direction of the lower-back supporting plate <NUM> is defined as a width direction; the lower-back supporting apparatus along the width direction is D, wherein D is between <NUM> and <NUM> millimeters. Preferably, D is <NUM> millimeters. D may be <NUM>, <NUM>, or <NUM> millimeters in the other embodiments. In the present embodiment, the overall width of the lower-back supporting apparatus is relatively narrow, while the adjustable lifting height of the lower-back supporting plate <NUM> is relatively sufficient when lifting, which may realize a wide range adjustment of the lower-back supporting plate <NUM> without occupying too much mounting space.

As shown in <FIG> and <FIG>, further provided in the present embodiment is a backrest supporting frame comprising a fixing frame <NUM> and the lower-back supporting apparatus mentioned above, wherein the fixing frame <NUM> comprises two lateral plates <NUM> provided parallel; the lower-back supporting apparatus is fixedly mounted between two lateral plates <NUM>. Further, a first crossbeam <NUM>, a second crossbeam <NUM>, and a third crossbeam <NUM> are respectively provided between two lateral plates <NUM>, wherein the first crossbeam <NUM> is arranged close to an upper side of the lateral plate <NUM>, the third crossbeam <NUM> is arranged close to a lower side of the lateral plate <NUM>, and the second crossbeam <NUM> is arranged between the first crossbeam <NUM> and the third crossbeam <NUM>. In the present embodiment, the lower-back supporting apparatus is fixedly mounted on the third crossbeam <NUM>. The first crossbeam <NUM>, the second crossbeam <NUM>, and the third crossbeam <NUM> increase the structural stability of the fixing frame <NUM>. After mounting, a lower surface of the first fixing part <NUM> abuts the third crossbeam <NUM>, and they are fixedly connected by bolts or screws.

In addition, the backrest supporting frame further comprises a headrest structure <NUM>, provided between two lateral plates <NUM> and located on an upper side of the lower-back supporting apparatus. The headrest structure <NUM> is referenced from the headrest assembly, fixing part <NUM>, and transverse mounting link <NUM> disclosed in Chinese patent No. <CIT>, i.e., the headrest structure <NUM> in the present embodiment, is a combination of the headrest assembly, fixing part <NUM>, and transverse mounting link <NUM> in Chinese patent No. <CIT>, which is prior art and will not be repeated hereby. It is to be noted that the fixing part <NUM> is fixedly mounted on the lateral plate <NUM> by screws or bolts. As shown in <FIG>, the lower-back supporting apparatus in the other embodiment may connect to the headrest structure <NUM> integrally. Specifically, the first fixing part <NUM> is mounted on the transverse mounting link <NUM> by screws or bolts.

Provided in the present embodiment is a seating unit comprising the backrest supporting frame mentioned above, which may ease the fatigue of the user's back and facilitate maintenance.

The present embodiment is an improvement of the first embodiment, in which the same content will not be repeated herein.

In the present embodiment, the supporting structure comprises a first link <NUM> and a second link <NUM> hinged to each other, wherein the first link <NUM> is hinged to the lower-back supporting plate <NUM> and the second link <NUM> is hinged to the lower mounting plate <NUM>; or, the second link <NUM> is hinged to the lower-back supporting plate <NUM> and the first link <NUM> is hinged to the lower mounting plate <NUM>; and two restricting protrusions <NUM> are provided on the first link <NUM>, wherein the second link <NUM> and a hinge point between the first link <NUM> and the second link <NUM> are located between the two restricting protrusions <NUM>. In the present embodiment, the first link <NUM> and the second link <NUM> are identical in shape. The first link <NUM> and the second link <NUM> may, as well, not be limited in shape in any way, as it is sufficient that they may enable the lower-back supporting plate <NUM> to move up and down after they cooperate with each other.

Claim 1:
A lower-back supporting apparatus, comprising:
a lower-back supporting plate (<NUM>);
a lower mounting plate (<NUM>);
two supporting structures, provided between the lower-back supporting plate (<NUM>) and the lower mounting plate (<NUM>), hinged to the lower-back supporting plate (<NUM>) and the lower mounting plate (<NUM>) respectively; and
an extendable and retractable part (<NUM>), comprising an extendable and retractable end hinged to the lower-back supporting plate (<NUM>) or the supporting structures, so as to drive the lower-back supporting plate (<NUM>) away or close to the lower mounting plate (<NUM>);
wherein each of the supporting structures comprises a first link (<NUM>) and a second link (<NUM>) hinged to each other; wherein
the first link (<NUM>) is hinged to the lower-back supporting plate (<NUM>), and the second link (<NUM>) is hinged to the lower mounting plate (<NUM>); or, the second link (<NUM>) is hinged to the lower-back supporting plate (<NUM>), and the first link (<NUM>) is hinged to the lower mounting plate (<NUM>);
characterized in that
two restricting protrusions (<NUM>) are provided on the first link (<NUM>), wherein the second link (<NUM>) and a hinge point between the first link (<NUM>) and the second link (<NUM>) are located between the two restricting protrusions (<NUM>).