Mechanical Stretching Device for Movable Seat Unit and Seat Unit

The application is a continuation-in-part of U.S. application Ser. No. 18/592,504, filed on Feb. 29, 2024, which is based on and claims priority to the U.S. patent application Ser. No. 18/235,803 filed on Aug. 18, 2023, which claims priority to U.S. patent application Ser. No. 18/111,815 filed on Feb. 20, 2023, which claims priority to U.S. patent application Ser. No. 17/881,561 filed on Aug. 4, 2022, which claims priority to U.S. patent application Ser. No. 17/520,274 filed on Nov. 5, 2021, issued as U.S. Pat. No. 11,452,378 on Sep. 27, 2022, which claims priority to the Chinese Patent Application No. 202111258022.4, filed on Oct. 27, 2021. The application is also based upon and claims priority to International Application No. PCT/CN2025/093368, which is based on and claims priority to the Chinese Patent Application No. 202421577232.9, filed on May 7, 2024. The entire contents of the applications above are hereby incorporated by reference for all purposes.

The present disclosure relates to a mechanical stretching device for a movable seat unit and a seat unit including the same.

The movable seat unit is applied to a variety of scenarios, such as sofas or seats having a multi-position convertible function. With the improvement of people's living standards, increasingly higher requirements are imposed on the comfort of the sofas and seats. The movable seat unit is typically provided with a mechanical stretching device, through which the seat unit can be converted between a sitting state, a relaxing state (or a TV position), and a lying state. When the seat unit is converted from the sitting state to the relaxing state, the footrest of the seat unit is stretched forward and the angle between the backrest and the seating portion keeps substantially unchanged; and when the seat unit is converted from the relaxing state to the lying state, the footrest is further forward and upward than in the relaxing state, and the backrest bends backward obviously, such that the user on the seat unit in the lying state has the legs higher than the head and experiences the so-called “zero gravity.” However, during the transition to the lying position, a gap emerges between the backrest and the seating portion. This not only causes the user's upper garment to be pulled upward but also increases the risk of items falling into the gap.

The present disclosure provides a mechanical stretching device for a movable seat unit, and a movable seat unit thereof.

The first aspect of the present disclosure relates to a movable seat including a mechanical stretching device and a frame assembly connected to the mechanical stretching device. Furthermore, the frame assembly includes: a seat frame configured to support a seating portion of the movable seat; an armrest frame fixedly connected to the seat frame; and a backrest frame configured to support a backrest of the movable seat. Moreover, the backrest frame includes a lower frame section and an upper frame section, the upper frame section transitions to the lower section via a stepped portion, and a rear part of the armrest frame comprises a curved extending section, and a gap is formed between the armrest frame and the upper frame section.

The second aspect of the present disclosure relates to a mechanical stretching device in a movable seat. The mechanical stretching device includes a base assembly fixedly supported on a ground, a side plate movably supported above the base assembly, where the side plate is configured to connect to the seating portion of the movable seat, and a backrest assembly pivotally connected to a rear portion of the side plate. Furthermore, the backrest assembly includes a backrest mounting member and a backrest connecting rod assembly, the backrest connecting rod assembly includes a first backrest connecting rod and a second backrest connecting rod, an upper end of the first backrest connecting rod is hinged to a front end of the backrest mounting member at a first pivot point, a front end of the second backrest connecting rod is hinged to the side plate at a second pivot point, and the middle portion of the second backrest connecting rod is hinged to the first backrest connecting rod. Moreover, the backrest connecting rod assembly compresses to rotate the backrest mounting member rearward about the first pivot point and the backrest connecting rod assembly expands to rotate the backrest mounting member forward about the first pivot point.

The present disclosure is described with reference to examples and corresponding drawings. The described examples are only part but not all of the examples of the present disclosure. Based on the examples in the present disclosure, all other examples obtained by those ordinary skilled in the art without any inventive work belong to the protection scope of the present disclosure.

The terms “one embodiment” or “an embodiment” as used herein refer to a particular feature, structure, or characteristic that may be included in at least one implementation of the present disclosure. It should be understood that the directional or positional terms such as “upper,” “lower,” “left,” “right,” “top,” and “bottom” are based on the orientation shown in the accompanying drawings. These terms are used for ease of description and simplification, and are not intended to indicate or imply that the referenced device or component must have a specific orientation or be constructed and operated in a particular direction. Therefore, such terms should not be interpreted as limitations of the present disclosure.

It shall be understood that, the terms “first” and “second” are used solely for descriptive purposes and should not be construed as indicating relative importance or implying a specific number of the mentioned technical features. Features labeled as “first” or “second” may explicitly or implicitly include one or more of such features. Furthermore, these terms are intended to distinguish between similar elements and do not necessarily define a sequential order. It should be understood that such elements may be interchanged where appropriate, allowing the embodiments of the present disclosure to be implemented in sequences other than those illustrated or described herein.

Unless otherwise specified, the terms “front” or “front of the seat unit” or “front of the mechanical stretching device” refer to the direction toward the leg stretching device relative to the seat unit; correspondingly, the terms “rear” or “rear of the seat unit” or “rear of the mechanical stretching device” refer to the direction toward the backrest assembly relative to the seat unit.

The description of numerals used in this disclosure may include:

toschematically illustrate an example of a mechanical stretching

device for a movable seat unit. The mechanical stretching device includes: a linkage support, a back mechanism, and a leg stretching structure.

Specifically, the linkage supportincludes a support structureand a linkage structure.

The support structureincludes a base, a first support element, a second support element, and a base coupling component. The baseincludes two lateral railsin a mirror symmetry on a left side and a right side, and optionally further includes a front transverse railand a rear transverse railfor connecting the two lateral rails. A lower end of the first support elementis hinged to a front end of the lateral rail, a lower end of the second support elementis hinged to a rear end of the lateral rail, and the base coupling componentis provided between the first support elementand the second support element.

The linkage structureincludes a lateral plate, a first coupling element, a second coupling element, and a third coupling element, a middle of the second coupling elementis rotatably connected to the lateral plate, one end of the second coupling elementis connected to one end of the first coupling element, the other end of the first coupling elementis connected to the first support element, the other end of the second coupling elementis connected to one end of the third coupling element, and the other end of the third coupling elementis pivotally connected to the leg stretching structure.

Specifically, the back mechanismincludes a backrest connection elementattached to a backrest and a back connecting rodpivotally connected to the backrest connection element. The backrest connection elementis hinged to a rear end of the lateral plateof the linkage structure.

Specifically, the leg stretching structureis composed of multiple connecting rods that are pivotally connected to one another, where a rear end of a first connecting rodis hinged to the lateral plateof the linkage structure, a front end of the first connecting rodis hinged to a rear end of a second connecting rod, a rear end of a third connecting rodis hinged to a front end of the lateral plate, a front end of the third connecting rodis hinged to a rear end of a fourth connecting rod, a front end of each of the second connecting rodand the fourth connecting rodis hinged to a first footrest element, an end of the second connecting rodclose to the first connecting rodis provided with a first connecting point, and the second connecting rodis hinged to a middle of the third connecting rodat the first connecting point.

Specifically, the base coupling componentincludes: a back coupling element, a seat coupling element, and a lateral plate coupling element, where the back coupling elementis provided with multiple pivotal points; and the back coupling element is respectively hinged to the back connecting rodof the back mechanism, the lateral plateof the linkage structure, the seat coupling elementand the second support elementby means of different pivotal points. One end of the seat coupling elementis connected to the first support elementby means of the lateral plate coupling element, and the other end of the seat coupling elementis connected to the back coupling element.

Specifically, the linkage supportfurther includes a transmission structure, the transmission structureincludes a first transmissive elementand a second transmissive elementthat are connected to one another, the first transmissive element is connected to a driving device, the second transmissive element is connected to the first connecting rodof the leg stretching structure, and the driving device drives a movement of the linkage support by means of the transmission structure. In some examples, the driving device may be a manual driving device; and in other examples, the driving device may be a motor driving device, and the motor driving device may be a push rod motor or slider motor driving device.

According to the example, the movement of the linkage supportdrives the back mechanismand the leg stretching devicefor stretching or retracting, such that the mechanical stretching device can implement a sequential conversion or a reverse sequential conversion of the seat unit from a sitting state shown into a relaxing state shown inand then to a lying state shown in. In the sitting state, the first footrest elementis folded below a seating portion; in the relaxing state, the first footrest elementis stretched to be in front of the seating portion; and in the lying state, an angle between the backrest and the seating portion is increased relative to the relaxing state, and the first footrest elementextends further forward and upward than in the relaxing state, as shown in, such that a height of a highest point of the leg stretching structurerelative to a horizontal plane is greater than that of a highest point of the back mechanismrelative to the horizontal plane, with a height difference being in a range between 200 mm and 400 mm, and is preferably 265 mm.

An included angle α is formed between an end surface of the footrest element and the horizontal direction, and an included angle β is formed between the seating portion or a contact surface on which the lateral plateis coupled to the seating portion and the horizontal direction.

As shown into, the included angle α between the footrest element in the relaxing state and the horizontal direction is less than the included angle α between the footrest element in the lying state and the horizontal direction. Specifically, in the relaxing state, the angle α formed between the footrest element and the horizontal direction is in a range between 8° and 20°, preferably between 12° and 19°, and more preferably between 14° and 15°; and in the lying state, the angle α formed between the footrest element and the horizontal direction is in a range between 9° and 23°, preferably 14° and 21°, and more preferably 18° and 19°.

In the lying state, the angle β formed between the seating portion and the horizontal direction is in a range between 8° and 17°, and preferably between 13° and 16°.

toillustrate a second alternative example of the present disclosure.

An example further provides a mechanical stretching device for a movable seat unit. The difference between the second example and the first example mainly lies in the design of the leg stretching structure. According to the second example, the leg stretching mechanismis constructed as a footrest extension mechanism as shown in, including: a first connecting rod, a second connecting rod, a third connecting rod, a fourth connecting rod, a first footrest element, a coupling rod, a second footrest elementand a footrest connection element.

One end of the second connecting rodis hinged to the first footrest element, the other end of the second connecting rodis hinged to the first connecting rod, the first connecting rodis hinged to the linkage supportof the seat unit, one end of the fourth connecting rodis hinged to the second footrest element, the other end of the fourth connecting rodis hinged to the third connecting rod, the first footrest elementis hinged to one end of the coupling rod, and the other end of the coupling rodis hinged to a middle of the fourth connecting rod.

The footrest connection elementincludes a first connection elementand a second connection element, one end of the first connection elementis hinged to a middle of the second footrest element, the other end of the first connection elementis hinged to one end of the second connection element, the other end of the second connection elementis hinged to a middle of the second connecting rod, and a middle of the second connection elementis hinged to the middle of the fourth connecting rod.

In the example, the first footrest elementis hinged to the fourth connecting rodby means of the coupling rod, the fourth connecting rod is connected to the second footrest element, and the first footrest elementis not connected to the fourth connecting rod, such that the first footrest element and the second footrest element are retracted or stretched more flexibly. The first footrest element, the coupling rod, the fourth connecting rod, the second connection element, and the second connecting rodare formed into a five-rod structure, which implements the effect that the first footrest element can be drawn close to or spaced apart from the second footrest element more flexibly, increases a distance between the first footrest element and the second footrest element that are spaced apart, and increases an extended length of the second footrest element.

Specifically, the middle of the second footrest elementis provided with a first limit element, and when the first limit elementabuts against the second connection element, the second footrest elementis retracted to a limit position. In the example, the first limit elementlimits a maximum retracted position of the second footrest element, to avoid a phenomenon that the second footrest element is not retracted to a predetermined position and is loose. Meanwhile, a footrest surface of the second footrest element and a footrest surface of the first footrest element are in the same vertical plane, thereby improving the aesthetics of the seat in the retracted state.

Specifically, an end of the second connecting rodclose to the first connecting rodis provided with a first connecting point, the second connecting rodis hinged to a middle of the third connecting rodat the first connecting point, and the third connecting rodis connected to the linkage support. The second connecting rodis intersected with the third connecting rod.

Specifically, an end of the second connecting rodclose to the first footrest elementis provided with a second connecting point, and the second connecting rodis connected to the second connection elementat the second connecting point. In the example, the first connection elementand the second connection elementare used to connect and support the second footrest element, and the second footrest element, the first connection element, the second connection element, and the fourth connecting rodare formed into a foldable and stretchable four-rod structure to support and drive the second footrest elementfor stretching.

Specifically, an end of the fourth connecting rodclose to the second footrest elementis sequentially provided with a footrest connecting point, a coupling rod connecting point, and a connection element connecting point; and the fourth connecting rodis connected to the second footrest elementat the footrest connecting point, the fourth connecting rodis connected to the coupling rodat the coupling rod connecting point, the fourth connecting rodis connected to the second connection elementat the connection element connecting point, and the coupling rod connecting pointis provided between the footrest connecting pointand the connection element connecting point.

Specifically, a second connecting rod connecting pointand a linkage pointare arranged on the first footrest element, and a distance from the linkage pointto the coupling rod connecting pointis greater than that from the linkage pointto the second connecting rod connecting point. Specifically, the distance from the linkage pointto the second connecting rod connecting pointis less than that from the linkage pointto the coupling rod connecting point, such that the second connecting roddrives the second connecting rod connecting pointto move downward relative to the linkage pointwhen the first footrest elementis stretched, the footrest surface of the first footrest elementsmoothly rotates to a horizontal position where the footrest surface is upward, and thus the first footrest element is stretched more flexibly and quickly.

Specifically, in the example, the first connecting rod, the second connecting rod, the third connecting rod, the fourth connecting rod, the first footrest element, the coupling rod, the second footrest elementand the footrest connection elementare all pivotally connected or hinged; and all parts may be connected by means of a rotary shaft, a shaft pin, a rivet, a bolt, a nut and a combination thereof or other fasteners capable of implementing the pivotal connection.

Optionally, in the example, when the footrest extension mechanism is retracted to the limit position, the first footrest elementis located above the second footrest element, and the footrest surface of the first footrest elementand the footrest surface of the second footrest elementmay be in the same vertical plane. When the footrest extension mechanism is stretched to a limit position from a retracted position, the footrest surface of each of the first footrest elementand the second footrest elementrotates upward, and the first footrest elementand the second footrest elementare spaced apart from one another.

Specifically, as shown in, the footrest extension mechanism further includes a footrest plate component, where the footrest plate componentincludes a first footrest plateand a second footrest plate, the first footrest plateis connected to the first footrest element, and the second footrest plateis connected to the second footrest element. Specifically, a footrest surface bending inward is respectively provided on the first footrest element and the second footrest element, and the footrest surface is fixedly connected to the footrest plate, namely the first footrest plate and the second footrest plate are respectively fixed on the corresponding footrest surface.

In the example, as shown inand, the linkage supportof the seat drives the first connecting rodand the third connecting rodto rotate, such that the footrest extension mechanism moves from the retracted position shown into the stretched position shown in, and at the stretched position, the footrest surface of each of the first footrest elementand the second footrest elementis horizontal. When the footrest extension mechanism is stretched from the retracted position to the limit position, the second connecting roddrives the first footrest elementto rotate upward and the coupling rodrotates with the first footrest element, such that while the first footrest elementrotates more flexibly, the first footrest elementis supported; and the fourth connecting roddrives the second footrest elementand the footrest connection elementto extend forward and rotate upward, until the second footrest elementis stretched to the limit position. When the footrest extension mechanism is retracted from the stretched position to the limit position, movement directions of components in the footrest extension mechanism are reversed to those in the stretching process.

In some examples, when the footrest extension mechanism is stretched to the limit position, a distance between the first footrest element and the second footrest element is greater than 140 mm, and may be preferably 145 mm, 147 mm, 150 mm, or 155 mm, namely the spacing distance after the first footrest element and the second footrest element are stretched is increased.

In the footrest extension mechanism of the present disclosure, the first footrest element is hinged to the fourth connecting rod by means of the coupling rod, such that the first footrest element and the second footrest element can be drawn close and separated apart more flexibly; when the footrest extension mechanism is retracted, the two footrest elements are retracted and drawn close, with a small space occupation; and when the footrest extension mechanism is stretched, the stretched length of the footrest extension mechanism is increased to better support legs and feet, improve the comfort of the seat and meet use requirements of users at different heights.

An example further provides a seat stretching device as shown in, including: a leg stretching deviceconstructed as a footrest extension mechanism, a linkage support, and a back mechanism, where one end of the linkage supportis connected to the back mechanism, the other end of the linkage supportis connected to the footrest extension mechanism, and the footrest extension mechanism is connected to a footrest plate component.

Specifically, the linkage supportincludes a support structureand a linkage structure, the support structureincluding a base, a first support element, a second support element, and a base coupling component, where one end of the baseis connected to the first support element, the other end of the baseis connected to the second support element, and the base coupling componentis provided between the first support elementand the second support element. Specifically, the base coupling componentincludes: a seat coupling elementand a back coupling element, one end of the seat coupling elementis connected to the first support element, and the other end of the seat coupling elementis connected to the back coupling element.

Specifically, the linkage structureincludes: a lateral plate, a first coupling element, a second coupling elementand a third coupling element, a middle of the second coupling elementis rotatably connected to the lateral plate, one end of the second coupling elementis connected to one end of the first coupling element, the other end of the first coupling elementis connected to the first support element, the other end of the second coupling elementis connected to one end of the third coupling element, and the other end of the third coupling elementis pivotally connected to the footrest extension mechanism.

Specifically, the linkage supportfurther includes a transmission structure, the transmission structureincludes a first transmissive elementand a second transmissive elementthat are connected to one another, the first transmissive element is connected to a driving device, the second transmissive element is connected to the footrest extension mechanism, and the driving device drives a movement of the linkage support by means of the transmission structure. In some examples, the driving device may be a manual driving device; and in other examples, the driving device may be a motor driving device, and the motor driving device may be a push rod motor or slider motor driving device.

Specifically, in the example, the back mechanismis connected to the lateral plateof the linkage structure; and the movement of the linkage supportdrives the back mechanismand the footrest extension mechanism for stretching or retracting.

In the example, the footrest extension mechanism and the back mechanism can also be continuously adjusted; when only the footrest extension mechanism is stretched, the corresponding seat is in the relaxing state; when both the footrest extension mechanism and the back mechanism are stretched to the limit position, the corresponding seat is in the lying state; and when both the footrest extension mechanism and the back mechanism are retracted to the limit position, the corresponding seat is in the sitting state.

The footrest extension mechanism and the seat stretching device are provided in the example. The footrest extension mechanism is stretched and retracted more flexibly and has a greater stretched length by adjusting the structure of the footrest extension mechanism, thereby better supporting legs and feet, improving the comfort of the seat, and meeting use requirements of users at different heights.

There are two mechanical stretching devices in the above examples of the present disclosure; and the two mechanical stretching devices are spaced apart and arranged symmetrically based on a central surface of the base. With a seat frame respectively provided on the mechanical stretching devices, the mechanical stretching devices are packaged into the finished sofa.

The present disclosure is to provide a seat unit with a simpler structure and a better ergonomic adaptation.

The present disclosure provides a mechanical stretching device for a movable seat unit. The mechanical stretching device includes left and right parts in a mirror symmetry; and hereinafter, descriptions are made to one part.