Mechanical extension device for use in a movable seat unit and seat unit

Abstract

The present application relates to a mechanical extension device for use in a movable seat unit, the mechanical extension device comprising: a seat assembly including a base assembly, side panels and a central linkage member; a backrest assembly pivotally connected to the rear of the side panels; and a leg extension device pivotally connected to the front of the side panels and including a first footrest member, the mechanical extension device allowing the seat unit to be converted between a sitting position and a lying position, in the sitting position, both first footrest members are squeezed under the seat, and in the lying position, the highest point of the footrest is higher than the highest point of the backrest and the first footrest member extends forward and upward, and the present application further relates to a movable seat unit.

Description

[Technical Field]

[0001] The present application relates to a mechanical extension device for use in a movable seating unit and to a seating unit equipped with said mechanical extension device. [Background technology]

[0002] In the prior art, there are many known sofas or seats with multi-position conversion functions used in movable seating units. As people's living standards improve, the requirements for comfort in sofas and seats are also increasing. In existing designs, movable seating units are generally equipped with a mechanical extension device, which can be used to convert between a sitting position, a TV position (or resting position), and a reclining position. When the seating unit converts from the sitting position to the TV position, the footrest of the seating unit extends forward, and the angle between the backrest and the seat remains essentially unchanged. When the seating unit converts from the resting position to the reclining position, the footrest is raised further forward and upward than in the resting position, and the backrest is obviously reclined, so that the user of the seating unit experiences a so-called "zero gravity" feeling when reclining, with their feet higher than their head.

[0003] However, a flaw in existing designs is that as the seat unit converts to a reclining position, a gap forms between the backrest and the seat, which can pull the user's jacket upwards and poses the risk of items falling through the gap. Summary of the Invention [Problem to be solved by the invention]

[0004] The technical problem that the present application aims to solve is to provide a seat unit that is simple in structure and conforms to human dynamics. [Means for solving the problem]

[0005] In order to solve the above technical problem, the present application provides a mechanical extension device for use in a movable seat unit, the mechanical extension device comprising: a seat assembly including a base assembly, side panels attached to a seat of the seat unit, and a central linkage member connected between the base assembly and the side panels; a backrest assembly pivotally connected to the rear of said side panel, said backrest assembly including: a backrest connecting member for attachment to the backrest of a seat unit; and a backrest connecting rod assembly pivotally connected to the backrest connecting member, said backrest connecting rod assembly including a first backrest connecting rod hingedly connected to said central linkage member and a second backrest connecting rod hingedly connected to said side panel, said first backrest connecting rod hingedly connected to said second backrest connecting rod; a leg extension device pivotally connected to the front of the side panel, the leg extension device including a plurality of connecting rods pivotally connected to one another and a first foot rest member for mounting on a footrest; The mechanical extension device allows the seat unit to be converted between a sitting position, a TV position and / or a reclining position, in which in the sitting position the first foot rest member is squeezed under the seat, in the TV position the first foot rest member is extended forward, and in the reclining position the backrest is tilted backward, the highest point of the foot rest is higher than the highest point of the backrest and the first foot rest member extends forward and upward.

[0006] In some embodiments, the backrest is tilted back at least 35° in the lying position relative to the seated position, and in some embodiments at least 40° in the sitting position, thereby providing a more comfortable zero gravity experience for the user.

[0007] In alternative embodiments, in the recumbent position, the first footrest member has its front end raised so that the footrest surface of the first footrest member forms an acute angle between 10° and 23° with the horizontal plane, opening forward, and in some embodiments, the footrest surface of the first footrest member forms an acute angle between 16° and 19° with the horizontal plane, opening forward.

[0008] It should be noted that the "forward-opening" acute angle described herein means that the opening of the acute angle faces in the direction of the leg extension device.

[0009] In another alternative embodiment, the leg extension device further includes a second footrest member, wherein in the seated position, both the first and second footrest members are tilted downwardly of the seat, in the TV position, the first and second footrest members are extended forward, and in the reclining position, the backrest is tilted backward, the highest point of the footrest is higher than the highest point of the backrest, both the first and second footrest members extend forward and upward, and the second footrest member is located in front of the first footrest member.

[0010] In a first refinement of this alternative embodiment, in the recumbent position, the second footrest member has its front end raised so that the footrest surface of the second footrest member forms an acute angle between 10° and 23° with the horizontal plane, opening forward; in some embodiments, the footrest surface of the second footrest member forms an acute angle between 12° and 15° with the horizontal plane, opening forward.

[0011] In a second refinement of this alternative embodiment, in the recumbent position, the second footrest member has its front end hanging down so that the footrest surface of the second footrest member forms an acute angle between 8° and 30° with the horizontal plane, opening rearward; in some embodiments, the footrest surface of the second footrest member forms an angle between 12° and 20° with the horizontal plane.

[0012] It should be noted that the "rearward-opening" acute angle described herein means that the opening of the acute angle faces in the direction of the backrest assembly.

[0013] In some embodiments, the first foot rest member and the second foot rest member are connected by a foot rest extension assembly, the foot rest extension assembly including first and second extension members hinged to one another.

[0014] In this embodiment, one end of the first extension member is hingedly connected to the second footrest member at the distal end, the other end of the second extension member is hingedly connected to one end of the second extension member, and the other end of the second extension member is hingedly connected to a leg connecting rod that is connected to the first footrest member at the proximal end, and by adjusting the hinge connection position between the first extension member and the second footrest member, the front end of the second footrest member can be raised or lowered in the recumbent position, so that the corresponding footrest surface and the horizontal plane form an angle that is comfortable for the user.

[0015] In this embodiment, the backrest connecting member is connected to the seat assembly by a backrest connecting rod assembly, and the backrest connecting rod assembly has a scissors structure that compresses the backrest connecting member while compressing the backrest connecting rod assembly itself. This eliminates the gap that may occur between the backrest and the seat during the posture change process of the seat unit. This realizes a truly "wall-free" structure, saves installation space, eliminates the risk of items falling out due to gaps, and also prevents the user from having to pull out their jacket, providing a comfortable "no back rub" experience.

[0016] In some embodiments, the backrest connecting rod assembly further includes a third backrest connecting rod, a fourth backrest connecting rod, and a fifth backrest connecting rod, wherein a lower end of the third backrest connecting rod is hingedly connected to the second backrest connecting rod, an upper end of the third backrest connecting rod is hingedly connected to a rear end of the backrest connecting member, and a fifth backrest connecting rod is hingedly connected to the rear end of the backrest connecting member. The upper end of the fifth backrest connecting rod and the front end of the backrest connecting member are hingedly connected at a first pivot point, the front end of the fifth backrest connecting rod and the first backrest connecting rod are hingedly connected at a second pivot point, the rear end of the fifth backrest connecting rod is hingedly connected to the center of the third backrest connecting rod, and the lower end of the fourth backrest connecting rod is hingedly connected to the center of the fifth backrest connecting rod.

[0017] In some embodiments, as the seat unit transforms from a seated position to a lying position, compression of the seat back connecting rod assembly causes the seat back connecting member to tilt rearward.

[0018] In some embodiments, when the seat unit is transformed from a seated position to a reclining position, the relative movement of the side panel and the central linkage member increases the distance between the hinge connection point between the first backrest connecting rod and the central linkage member and the hinge connection point between the second backrest connecting rod and the side panel, thereby compressing the backrest connecting rod assembly.

[0019] In some embodiments, when the seat unit is transformed from a seated position to a reclining position, both the first pivot point and the second pivot point move forward, reducing the distance between the first pivot point and the second pivot point.

[0020] In some embodiments, the seat assembly further includes a front swing lever, a rear swing lever, a seat linkage member, and a side plate linkage member, wherein the lower ends of the front swing lever and the rear swing lever are pivotally connected to the base assembly, and the upper ends of the front swing lever and the rear swing lever are connected to the side plate by a central linkage member, a seat linkage member, and a side plate linkage member.

[0021] In some embodiments, the swinging of the side panels relative to the base assembly facilitates movement of the backrest assembly and leg extension device relative to the seat assembly, thereby enabling the seat unit to be converted between a seated position and a reclining position.

[0022] In some embodiments, the mechanical stretching device further comprises an electrical drive coupled between the base assembly and the side plates.

[0023] In some embodiments, the seat further comprises an electric drive device, the electric drive device including a first electric actuator and a second electric actuator, the first electric actuator designed to facilitate extension and retraction of the leg extension device relative to the seat assembly, and the second electric actuator designed to facilitate movement of the back assembly relative to the seat assembly.

[0024] In this embodiment, the first electric actuator and the second electric actuator operate independently of each other, thereby allowing the backrest assembly and the leg extension device to be flexibly adjusted independently of each other.

[0025] According to this embodiment, the mechanical extension device can be converted among a plurality of positions, for example, among a sitting position, a TV position, and / or a reclining position. In the sitting position, the footrest is pushed down below the seat; in the TV position, the footrest is extended forward; and in the reclining position, the backrest is tilted backward and the highest point of the footrest is higher than the highest point of the backrest. It should be noted here that the mechanical extension device can not only represent the three positions of the sitting position, the TV position, and the reclining position, but also represent intermediate positions between the three positions by different positions of the backrest and the leg extension device, for example, the second electric actuator can only tilt the backrest backward relative to the seat assembly, while the first electric actuator is not active, so that the footrest is still pushed down below the seat.

[0026] In an alternative embodiment, the leg extension device further includes a second footrest member, the second footrest member being located forward of the first footrest member when the first electric actuator urges the leg extension device to extend forward of the seat assembly.

[0027] In this embodiment, the backrest connecting member is connected to the seat assembly by a backrest connecting rod assembly, and the scissor-type structure of the backrest connecting rod assembly allows the backrest connecting member to be compressed, while the backrest connecting rod assembly itself is compressed. This eliminates the gap that may occur between the backrest and the seat during the posture change process of the seat unit. This realizes a truly "wall-free" structure, which not only saves installation space and eliminates the risk of items falling out due to the gap, but also prevents the user from having to pull out their jacket, providing a comfortable "no back rub" experience.

[0028] In some embodiments, the first electric actuator acts between the seat assembly and the leg extension device, and the second electric actuator acts between the base assembly and the seat assembly.

[0029] In some embodiments, the base assembly includes a base rear cross member, the leg extension device includes a first motor cross bar, the seat assembly includes a second motor cross bar adjacent to the leg extension device and a third motor cross bar adjacent to the backrest assembly, the first electric actuator acting between the first motor cross bar and the second motor cross bar, and the second electric actuator acting between the third motor cross bar and the base rear cross member.

[0030] In some embodiments, the second motor crossbar is connected to the side plates and the third motor crossbar is connected to the central linkage member. In some embodiments, the second motor crossbar is fixedly connected to the side plates and the third motor crossbar is fixedly connected to the central linkage member.

[0031] However, in an alternative embodiment, the side panel of the seat assembly may be provided with only one side panel motor crossbar instead of the second and third motor crossbars, in which one end of a first electric actuator is coupled to the first motor crossbar and the other end is coupled to the side panel motor crossbar, and one end of a second electric actuator is coupled to the base rear cross member and the other end is also coupled to the side panel motor crossbar.

[0032] In some embodiments, the backrest connecting rod assembly further includes a third backrest connecting rod, a fourth backrest connecting rod, and a fifth backrest connecting rod, wherein a lower end of the third backrest connecting rod is hingedly connected to the second backrest connecting rod, an upper end of the third backrest connecting rod is hingedly connected to a rear end of the backrest connecting member, and a fifth backrest connecting rod is hingedly connected to the rear end of the backrest connecting member. The upper end of the fifth backrest connecting rod and the front end of the backrest connecting member are hingedly connected at a first pivot point, the front end of the fifth backrest connecting rod and the first backrest connecting rod are hingedly connected at a second pivot point, the rear end of the fifth backrest connecting rod is hingedly connected to the center of the third backrest connecting rod, and the lower end of the fourth backrest connecting rod is hingedly connected to the center of the fifth backrest connecting rod.

[0033] In some embodiments, when the second electric actuator moves the back assembly relative to the seat assembly, compression of the back connecting rod assembly causes the back connecting member to tilt rearward.

[0034] In some embodiments, when the backrest assembly is moved relative to the seat assembly by the second electric actuator, the relative movement of the side plate and the central linkage member increases the distance between the hinge connection point between the first backrest connecting rod and the central linkage member and the hinge connection point between the second backrest connecting rod and the side plate, thereby compressing the backrest connecting rod assembly.

[0035] In some embodiments, when the backrest assembly is moved relative to the seat assembly by the second electric actuator, both the first pivot point and the second pivot point move forward, decreasing the distance between the first pivot point and the second pivot point.

[0036] In some embodiments, the seat assembly further includes a front swing lever, a rear swing lever, a seat linkage member, a side plate linkage member, and a drive connecting rod, wherein the lower ends of the front swing lever and the rear swing lever are pivotally connected to the base assembly, respectively, and the upper ends of the front swing lever and the rear swing lever are connected to the side plates by a central linkage member, a seat linkage member, and a side plate linkage member, the upper end of the drive connecting rod is hingedly connected to the center of the seat linkage member, and the lower end of the drive connecting rod is hingedly connected to the base assembly.

[0037] In some embodiments, rocking of the side panels relative to the base assembly facilitates movement of the back assembly relative to the seat assembly.

[0038] In some embodiments, the first electric actuator and the second electric actuator are designed as linear electric actuators.

[0039] In order to solve the above technical problems, the present application further provides a seat unit, which comprises a seat, a backrest, a footrest and the mechanical extension device described above, wherein the side panels are attached to the seat, the backrest connection member is attached to the backrest, and the first footrest member is attached to the footrest. [Brief explanation of the drawings]

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Figure 1] FIG. 1 is a perspective view of a mechanical stretching device according to a first embodiment of the present invention, in which the mechanical stretching device is in a seated position. [Figure 2] FIG. 2 is a perspective view of the mechanical stretcher shown in FIG. 1, with the mechanical stretcher in the TV position. [Figure 3] FIG. 3 is a perspective view of the mechanical stretching device shown in FIG. 1, with the mechanical stretching device in a recumbent position. [Figure 4]FIG. 4 is a side view of the mechanical stretching device shown in FIG. [Figure 5] FIG. 5 is a side view of the mechanical extension device shown in FIG. 1 in the TV position. [Figure 6] FIG. 6 is a side view of the mechanical stretching device shown in FIG. 1 in a recumbent position. [Figure 7] FIG. 7 is a perspective view of a second alternative embodiment of a mechanical stretching device according to the present application, the mechanical stretching device being in a seated position. [Figure 8] FIG. 8 is a perspective view of the mechanical stretcher shown in FIG. 7, with the mechanical stretcher in the TV position. [Figure 9] FIG. 9 is a perspective view of the mechanical stretching device shown in FIG. 7, with the mechanical stretching device in a recumbent position. [Figure 10] FIG. 10 is a side view of the mechanical stretching device shown in FIG. [Figure 11] FIG. 11 is a side view of the mechanical stretching device shown in FIG. 10 at another angle. [Figure 12] FIG. 12 shows a mechanical extension device of a first modification of the alternative embodiment shown in FIG. 7, where the mechanical extension device is in the TV position. [Figure 13] FIG. 13 is a side view of the mechanical stretching device shown in FIG. 12 in a recumbent position. [Figure 14] FIG. 14 shows a mechanical stretcher of a second modification of the alternative embodiment shown in FIG. 7, with the mechanical stretcher in the TV position. [Figure 15] FIG. 15 is a side view of the mechanical stretcher shown in FIG. 14, with the mechanical stretcher in a recumbent position. [Figure 16] FIG. 16 is a perspective view of a third alternative embodiment of a mechanical stretching device according to the present application, the mechanical stretching device being in a seated position. [Figure 17] FIG. 17 is a perspective view of the mechanical stretcher shown in FIG. 16, with the mechanical stretcher in the TV position. [Figure 18] FIG. 18 is a perspective view of the mechanical stretching device shown in FIG. 16, with the mechanical stretching device in a recumbent position. [Figure 19] FIG. 19 is a side view of the mechanical stretching device shown in FIG. [Figure 20] FIG. 20 is a side view of the mechanical stretcher shown in FIG. 19, with the mechanical stretcher in the TV position. [Figure 21] FIG. 21 is a side view of the mechanical stretcher shown in FIG. 19, with the mechanical stretcher in a recumbent position. [Figure 22] FIG. 22 is a perspective view of a fourth alternative embodiment of a mechanical stretching device according to the present application, the mechanical stretching device being in a seated position. [Figure 23] FIG. 23 is a perspective view of the mechanical stretcher shown in FIG. 22, with the mechanical stretcher in the TV position. [Figure 24] FIG. 24 is a perspective view of the mechanical stretching device shown in FIG. 22, with the mechanical stretching device in a recumbent position. [Figure 25] FIG. 25 is a side view of the mechanical stretching device shown in FIG. [Figure 26] FIG. 26 is a side view of the mechanical stretching device shown in FIG. 25 at another angle. [Figure 27] FIG. 27 is a side view of the mechanical stretcher shown in FIG. 26, with the mechanical stretcher in the TV position. [Figure 28] FIG. 28 is a side view of the mechanical stretcher shown in FIG. 26, with the mechanical stretcher in a recumbent position. DETAILED DESCRIPTION OF THE INVENTION

[0041] First, a first embodiment of a mechanical extension device used in a movable seat unit is shown schematically in FIGS. 1 to 6. FIG.

[0042] The mechanical extension device comprises a seat assembly 1, a backrest assembly 2 and a leg extension device 3. The backrest assembly 2 is hingedly connected to the rear of the seat assembly 1, and the leg extension device 3 is hingedly connected to the front of the seat assembly 1. The seat assembly 1 is attached to the seat of a seat unit, the backrest assembly 2 is attached to the back of the seat unit, and the leg extension device 3 is attached to the footrest of the seat unit. Relative movement of the seat assembly 1, the backrest assembly 2 and the leg extension device 3 allows the seat unit or its mechanical extension device to be converted between a sitting position, a TV position and / or a reclining position. In the sitting position, the backrest is upright and the footrest is pulled down towards the bottom of the seat; in the TV position, the backrest does not tilt significantly back and the footrest moves upward and forward towards the front of the seat as the leg extension device extends; in the reclining position, the footrest remains extended towards the front of the seat but the backrest tilts significantly back.

[0043] The seat assembly 1 includes a base assembly 11, a front swing lever 12, a rear swing lever 13, and a side plate 140 attached to the seat of the seat unit.

[0044] 1, the mechanical extension device is used in a steel-frame-mounted seat unit, and the base assembly 11 directly supports the mechanical extension device on the bottom surface and includes two mirror-symmetrical base side members 111 installed on the left and right sides, and a base front cross member 112 and a base rear cross member 113 connecting the two base side members 111. However, in an embodiment not shown, the base assembly 11 may indirectly support the mechanical extension device above the bottom surface, for example, the base assembly 11 is rotatably attached to a rotating base, or the base assembly 11 is fixedly connected to the handrail of a handrail-mounted seat unit.

[0045] 1 , the front swing lever 12 has its lower end hingedly connected to the front end of the base side member 111, and the rear swing lever 13 has its lower end hingedly connected to the rear end of the base side member 111. The side plate 140 is movable relative to the base assembly 11, and for this purpose, in this embodiment, the seat assembly 1 further includes a central linkage member 15, a seat linkage member 16, and a side plate linkage member 17, and the central linkage member 15 has multiple pivot points, and is hingedly connected to the backrest assembly 2 and the side plate 140, and to the seat linkage member 16 and the rear swing lever 13, respectively, at the different pivot points. One end of the seat linkage member 16 is connected to the front swing lever 12 by the side plate linkage member 17, and the other end of the seat linkage member 16 is connected to the central linkage member 15. As a result, the swinging of the front swing lever 12 and the rear swing lever 13 drives the movement of the side plate 140 relative to the base assembly 11, and further drives the movement of the backrest assembly 2.

[0046] The backrest assembly 2 includes a backrest connecting member 20 attached to the backrest, and a backrest connecting rod assembly pivotally connected to the backrest connecting member 20. The backrest connecting rod assembly includes a first backrest connecting rod 21, a second backrest connecting rod 22, a third backrest connecting rod 23, a fourth backrest connecting rod 24, and a fifth backrest connecting rod 25. One end of the first backrest connecting rod 21 is hingedly connected to the central interlocking member 15, one end of the second backrest connecting rod 22 is hingedly connected to the rear end of the side plate 140, and the first backrest connecting rod 21 is hingedly connected to the second backrest connecting rod 22. The other end of the second backrest connecting rod 22 is hingedly connected to the lower end of the third backrest connecting rod 23, and the upper end of the third backrest connecting rod 23 is hingedly connected to the rear end of the backrest connecting member 20. The upper end of the fourth backrest connecting rod 24 is hingedly connected to the front end of the backrest connecting member 20 at a first pivot point P1, the front end of the fifth backrest connecting rod 25 is hingedly connected to the other end of the first backrest connecting rod 21 at a second pivot point P2, the rear end of the fifth backrest connecting rod 25 is hingedly connected to the center of the third backrest connecting rod 23, and the lower end of the fourth backrest connecting rod 24 is hingedly connected to the center of the fifth backrest connecting rod 25.

[0047] As shown in Figures 4 to 7, the leg extension device 3 is composed of a plurality of connecting rods that are pivotally connected to each other, with the rear end of the first leg connecting rod 31 connected to the side plate 140 by a hinge, the front end of the first leg connecting rod 31 connected to the rear end of the second leg connecting rod 32 by a hinge, the rear end of the third leg connecting rod 33 connected to the front end of the side plate 140 by a hinge, the front end of the third leg connecting rod 33 connected to the rear end of the fourth leg connecting rod 34 by a hinge, and the front ends of the second leg connecting rod 32 and the fourth leg connecting rod 34 are each connected to the first footrest member 35 by a hinge.

[0048] The mechanical extension device further comprises a first transmission member 18 and a second transmission member 19 pivotally connected to each other, one end of the first transmission member 18 is hinged to one end of the second transmission member 19, the other end of the first transmission member 18 is hinged to the side plate 140, and the other end of the second transmission member 19 is hinged to the leg extension device 3, in particular to the first leg connecting rod 31. Thus, when the side plate 140 of the seat assembly 1 moves relative to the base assembly 11, it drives the retraction and extension movements of the leg extension device 3.

[0049] An electric drive 4 is further provided to enable the seat unit to be converted between different positions. The side panel 140 includes a motor crossbar 40 fixedly connected to its inner side, and the electric drive 4 is coupled between the motor crossbar 40 and the base front cross member 112 of the base assembly 11. In some embodiments, the drive 4 is designed as a linear electric actuator, and the extension and contraction movement of the linear electric actuator can move the side panel 140 relative to the base assembly 11, and further drive the movement of the backrest assembly 2 and the leg extension device 3, thereby realizing the conversion of the seat unit between different positions, such as the sitting position, the TV position, and the reclining position.

[0050] In this embodiment, the electric drive device 4 is designed to facilitate the mechanical extension device of the seat unit to convert between the sitting position, the TV position, and the reclining position. The electric drive device 4 includes a motor head 41, a motor slide rail 42 fixedly connected to the motor head 41, a motor slider 43 slidable relative to the motor head 41 along the motor slide rail 42, and a motor connecting rod 44. The motor head 41 is fixedly attached to the base rear cross member 113, and the motor connecting rod 44 is hingedly connected at one end to the motor slider 43 and at the other end to the motor cross bar 40.

[0051] As shown in Figures 4 to 6, in the seated position shown in Figure 4, the first footrest member 35 is squeezed downward from the seat. When the seat unit is transformed from the seated position shown in Figure 4 to the TV position shown in Figure 5, the first leg connecting rod 31 and the third leg connecting rod 33 are rotated by the drive of the side plate 140. During this process, the second leg connecting rod 32 and the fourth leg connecting rod 34 drive the first footrest member 35 to rotate upward. When the seat unit is transformed from the TV position shown in Figure 5 to the reclining position shown in Figure 6, the first footrest plate 35 is lifted, and the footrest surface of the first footrest member 35 forms an acute angle α opening forward with respect to the horizontal plane. In this embodiment, the acute angle α is 16° to 19°, and in some embodiments, it is 17°.

[0052] The mechanical extension device further includes a first link 141, a second link 142, and a third link 143. The center of the second link 142 is rotatably connected to the side plate 140, one end of the second link 142 is connected to one end of the first link 141, the other end of the first link 141 is connected to the front swing lever 12, the other end of the second link 142 is connected to one end of a third link 143, and the other end of the third link 143 is pivotally connected to the first leg connecting rod 31 of the leg extension device 3.

[0053] When the mechanical extension device is in the seated position shown in FIG. 4, the backrest connecting member 20 of the backrest assembly 2 stands upright upward, and the backrest attached to the backrest connecting member 20 forms an included angle β with the horizontal plane.

[0054] 4 to the TV position shown in FIG. 5, the electric drive unit 4 operates to slide the motor slider 43 along the motor slide rail 42 toward the motor head 41, thereby reducing the distance between the motor head 41 and the motor slider 43. During this process, the motor slider 43 moves the side plate 140 forward, i.e., toward the leg extension device 3, via the motor connecting rod 44, and the front swing lever 12 and the rear swing lever 13 swing forward accordingly. As a result, the first link 141 moves forward together with the front swing lever 12, and pushes the first leg connecting rod 31 using the second link 142 and the third link 143, further extending the leg extension device 3. The side plate interlocking member 17 and the seat interlocking member 16 also move forward together with the front swing lever 12, driving the central interlocking member 15 to move forward. During this process, the central interlocking member 15 moves forward together with the side plate 140, and further uses the first backrest connecting rod 21 and the second backrest connecting rod 22 to drive the entire backrest assembly 2 to move forward and downward, but the backrest connecting member 20 does not tilt obviously, and both the first pivot point P1 and the second pivot point P2 move downward and forward.

[0055] 5 to the lying position shown in FIG. 6, the electric drive unit 4 continues to operate, thereby sliding the motor slider 43 further along the motor slide rail 42 toward the motor head 41, further reducing the distance between the motor head 41 and the motor slider 43. During this process, the motor slider 43 moves the side plate 140 forward, i.e., toward the leg extension device 3, via the motor connecting rod 44, and the front swing lever 12 and the rear swing lever 13 correspondingly swing forward by a larger amount. When the front swing lever 12 and the rear swing lever 13 swing to their maximum extent, the side plate 140 moves significantly forward relative to the central interlocking member 15, thereby increasing the distance between the hinge connection point between the central interlocking member 15 and the first backrest connecting rod 21 and the hinge connection point between the side plate 140 and the second backrest connecting rod 22. As the backrest connecting rod assembly moves forward, it is compressed, causing the backrest connecting member 20 to suddenly tilt backward. During this process, not only do the first pivot point P1 and the second pivot point P2 both move forward, but the distance between the first pivot point P1 and the second pivot point P2 is also significantly smaller than in the sitting position and the TV position. When the backrest connecting member 20 is attached to the backrest of the seat unit, the included angle β between the backrest and the horizontal plane increases by at least 40° during the process of the seat unit transforming from the sitting position to the lying position.

[0056] Figures 7 to 15 show a second alternative embodiment of the present invention, Figures 12 and 13 show side views of the first improved version in the TV position and recumbent position, and Figures 14 and 15 show side views of the second improved version in the TV position and recumbent position.

[0057] Unlike the embodiment shown in FIGS. 1 to 6, the leg extension device 3 of the second alternative embodiment further includes a second footrest member 37. The leg extension device 3 is composed of a plurality of connecting rods that are pivotally connected to each other, with the rear end of the first leg connecting rod 31 hinged to the side plate 140, the front end of the first leg connecting rod 31 hinged to the rear end of the second leg connecting rod 32, the rear end of the third leg connecting rod 33 hinged to the front end of the side plate 140, the front end of the third leg connecting rod 33 hinged to the rear end of the fourth leg connecting rod 34, the front ends of the second leg connecting rod 32 and the fourth leg connecting rod 34 hinged to the first footrest member 35, and the front end of the fourth leg connecting rod 34 hinged to the second footrest member 37. The first footrest member 35 is hinged to one end of an interlocking lever 36, and the other end of the interlocking lever 36 is hinged to the center of the fourth leg connecting rod 34.

[0058] The leg extension device 3 further includes a footrest extension assembly 38, which includes a first extension member 381 and a second extension member 382, ​​one end of the first extension member 381 is hingedly connected to the center of the second footrest member 37, the other end of the first extension member 381 is hingedly connected to one end of the second extension member 382, ​​the other end of the second extension member 382 is hingedly connected to the center of the second leg connecting rod 32, and the center of the second extension member 382 is hingedly connected to the center of the fourth leg connecting rod 34.

[0059] In the second alternative embodiment, the first footrest member 35 is hingedly connected to the fourth leg connecting rod 34 by the interlocking lever 36, and the fourth leg connecting rod is connected to the second footrest member, so that the first footrest member 35 and the fourth leg connecting rod are not connected to each other, improving the movement flexibility of the first and second footrest members during contraction or extension. The first footrest member 35, interlocking lever 36, fourth leg connecting rod 34, second extension member 382, ​​and second leg connecting rod 32 form a five-section connecting rod mechanism, which allows the first footrest member to approach or separate from the second footrest member more flexibly, increasing the distance between them after separation and increasing the extension length of the second footrest member.

[0060] According to a first refinement of the second alternative embodiment, in the seated position shown in Fig. 11, the foot rest surfaces of the first and second foot rest members 35, 37 are flush with each other, and the first and second foot rest members 35, 37 are squeezed downwards on the seat, with the first foot rest member 35 positioned above the second foot rest member 37. When the seat unit is transformed from the seated position shown in Fig. 11 to the reclining position shown in Fig. 13, the front end of the second foot rest member 37 is raised, and the foot rest surface of the second foot rest member 37 forms an acute angle α opening forward with respect to the horizontal plane, and in this first refinement, the acute angle α is 12° to 15° in some embodiments, and 13° in some embodiments.

[0061] According to a second improvement of the second alternative embodiment, when the seat unit is transformed from the seated position shown in FIG. 11 to the TV position shown in FIG. 14, the first leg connecting rod 31 and the third leg connecting rod 33 are rotated by the driving of the side plate 140 to move the footrest extension assembly 38 from the contracted position shown in FIG. 11 to the extreme position shown in FIG. 14, and in this process, the second leg connecting rod 32 drives the first footrest member 35 to rotate upward, and the interlocking lever 36 rotates together with the first footrest member 35 to support the first footrest member 35 while allowing it to rotate more flexibly, and the fourth leg connecting rod 34 drives the second footrest member 37 and the footrest extension assembly 38 to extend forward and rotate upward until the second footrest member 37 is extended to the extreme position. When the leg extension assembly 38 is extended to its extreme position shown in Figure 14, the leg surface of the first leg rest member 35 is essentially horizontal, while the leg surface of the second leg rest member 37 is inclined downward at its front end. In the lying position shown in Figure 15, in some embodiments, the second leg rest member 37 has its front end drooping, and its leg surface forms an acute angle α with the horizontal plane, opening rearward. In this second refinement, the acute angle α is 12° to 20°, and in some embodiments, 15°. This allows the user to hang their legs slightly when the seat unit is in the TV position, preventing them from uncomfortably raising their legs too high.

[0062] 16 to 21 show a schematic representation of a third alternative embodiment of a mechanical extension device for use in a movable seating unit.

[0063] 16 to 18, the mechanical extension device comprises a base assembly 11, a seat assembly 1, a backrest assembly 2 and a leg extension device 3. The backrest assembly 2 is hingedly connected to the rear of the seat assembly 1, and the leg extension device 3 is hingedly connected to the front of the seat assembly 1. The seat assembly 1 is attached to the seat of a seat unit, the backrest assembly 2 is attached to the backrest of the seat unit, and the leg extension device 3 is attached to a footrest of the seat unit. By relative movement of the seat assembly 1, the backrest assembly 2 and the leg extension device 3, the seat unit or its mechanical extension device can be converted among a sitting position, a TV position and / or a reclining position. In the sitting position, the backrest is upright and the footrest is pulled down towards the bottom of the seat; in the TV position, the backrest does not tilt significantly back and the footrest moves upward and forward towards the front of the seat as the leg extension device extends; in the reclining position, the footrest remains extended towards the front of the seat but the backrest tilts significantly back.

[0064] In a third alternative embodiment, the mechanical extension device is used in a steel-frame-mounted seat unit, and the base assembly 11 directly supports the mechanical extension device on the bottom surface and includes two mirror-symmetrical base side members 111 installed on the left and right sides, and a base front cross member 112 and a base rear cross member 113 connecting the two base side members 111. However, in an embodiment not shown, the base assembly 11 may indirectly support the mechanical extension device above the bottom surface, for example, the base assembly 11 is rotatably attached to a rotating base, or the base assembly 11 is fixedly connected to the handrail portion of a handrail-mounted seat unit.

[0065] The seat assembly 1 includes a front swing lever 12, a rear swing lever 13, and a side plate 140 attached to the seat of the seat unit. In the embodiment shown in Fig. 16, the front swing lever 12 has its lower end hinged to the front end of a base side member 111, and the rear swing lever 13 has its lower end hinged to the rear end of the base side member 111.

[0066] The side plate 140 is movable relative to the base assembly 11, and for this purpose, in the illustrated embodiment, the seat assembly 1 further includes a central linkage member 15, a seat linkage member 16, and a side plate linkage member 17. The central linkage member 15 has a plurality of pivot points, and is hingedly connected to the backrest assembly 2 and the side plate 140 at the different pivot points, and is hingedly connected to the seat linkage member 16 and the rear swing lever 13. One end of the seat linkage member 16 is connected to the front swing lever 12 by the side plate linkage member 17, and the other end of the seat linkage member 16 is connected to the central linkage member 15. As a result, the swing of the front swing lever 12 and the rear swing lever 13 can drive the movement of the side plate 140 relative to the base assembly 11, and further drive the movement of the backrest assembly 2.

[0067] The backrest assembly 2 includes a backrest connecting member 20 attached to the backrest, and a backrest connecting rod assembly pivotally connected to the backrest connecting member 20. The backrest connecting rod assembly includes a first backrest connecting rod 21, a second backrest connecting rod 22, a third backrest connecting rod 23, a fourth backrest connecting rod 24, and a fifth backrest connecting rod 25. One end of the first backrest connecting rod 21 is hingedly connected to the central interlocking member 15, one end of the second backrest connecting rod 22 is hingedly connected to the rear end of the side plate 140, and the first backrest connecting rod 21 is hingedly connected to the second backrest connecting rod 22. The other end of the second backrest connecting rod 22 is hingedly connected to the lower end of the third backrest connecting rod 23, and the upper end of the third backrest connecting rod 23 is hingedly connected to the rear end of the backrest connecting member 20. The upper end of the fourth backrest connecting rod 24 is hingedly connected to the front end of the backrest connecting member 20 at a first pivot point P1, the front end of the fifth backrest connecting rod 25 is hingedly connected to the other end of the first backrest connecting rod 21 at a second pivot point P2, the rear end of the fifth backrest connecting rod 25 is hingedly connected to the center of the third backrest connecting rod 23, and the lower end of the fourth backrest connecting rod 24 is hingedly connected to the center of the fifth backrest connecting rod 25.

[0068] In a third alternative embodiment shown in Figures 16 to 21, the leg extension device 3 is composed of a plurality of connecting rods that are pivotally connected to one another, with the rear end of the first leg connecting rod 31 hinged to the side plate 140, the front end of the first leg connecting rod 31 hinged to the rear end of the second leg connecting rod 32, the rear end of the third leg connecting rod 33 hinged to the front end of the side plate 140, the front end of the third leg connecting rod 33 hinged to the rear end of the fourth leg connecting rod 34, and the front ends of the second leg connecting rod 32 and the fourth leg connecting rod 34 are each hinged to the first footrest member 35.

[0069] The mechanical extension device further comprises a first transmission member 18 and a second transmission member 19 pivotally connected to each other, one end of the first transmission member 18 is hinged to one end of the second transmission member 19, the other end of the first transmission member 18 is hinged to the side plate 140, and the other end of the second transmission member 19 is hinged to the leg extension device 3, in particular to the first leg connecting rod 31.

[0070] The mechanical extension device further includes a drive connecting rod 16a, the upper end of which is hingedly connected to the seat linkage member 16 and the lower end of which is hingedly connected to the base side member 111. In the seated posture position and the TV posture position of the mechanical extension device, the upper end of the drive connecting rod 16a is behind the lower end, i.e., the upper end of the drive connecting rod 16a is tilted backward, whereas in the reclining posture position, the upper end of the drive connecting rod 16a is ahead of the lower end, i.e., the upper end of the drive connecting rod 16a is tilted forward.

[0071] An electric drive unit 4 is further installed to enable the seat unit to be converted between different positions. A first motor crossbar 401 is fixedly connected to the first leg connecting rod 31 of the leg extension unit 3, and a second motor crossbar 402 and a third motor crossbar 403 are installed on the seat assembly. Specifically, the second motor crossbar 402 is fixedly connected to the side panel 140, and the third motor crossbar 403 is fixedly connected to the central linkage member 15. The electric drive unit 4 includes a first electric actuator 404 connected between the first motor crossbar 401 and the second motor crossbar 402, and a second electric actuator 405 connected between the third motor crossbar 403 and the base rear cross member 113 of the base assembly 11. In some embodiments, the first electric actuator 404 and the second electric actuator 405 are designed as linear electric actuators, and each includes a motor head, a motor slide rail fixedly connected to the motor head, and a motor slider slidable relative to the motor head along the motor slide rail. The motor slider slides along the motor slide rail to change the distance between the motor head and the motor slider, and such extension and contraction movement of the linear electric actuator can move the member connected to the motor head relative to the member connected to the motor slider.

[0072] In this embodiment, the first electric actuator 404 and the second electric actuator 405 operate independently of each other, the first electric actuator 404 is designed to extend and retract what is attached to the leg extension device 3 and also to extend and retract the footrest, and the second electric actuator 405 is designed to extend and retract the backrest assembly 2 and also to tilt the backrest. By operating the first electric actuator 404 and the second electric actuator 405 independently or in conjunction with each other, the seat unit can be placed in different positions, such as the sitting position shown in FIG. 19, the TV position shown in FIG. 20, and the reclining position shown in FIG. 21.

[0073] In the seated position shown in Fig. 19, the backrest connecting member 20 of the backrest assembly 2 stands upright together with the backrest attached thereto, and the first footrest member 35 of the leg extension device 3 causes the footrest to be squeezed downwards on the seat. In the TV position shown in Fig. 20, the leg extension device 3 is unfolded, and the first footrest member 35 extends the footrest forward of the seat. In the reclining position shown in Fig. 21, the backrest connecting member 20 is tilted sharply backwards.

[0074] For this reason, when the seat unit is to be converted from the sitting position to the TV position, only the first electric actuator 404 is operated, and the distance between the motor head and the motor slider of the first electric actuator 404 increases, thereby increasing the distance between the first motor crossbar 401 and the second motor crossbar 402, and driving the leg extension device 3 by the first leg connecting rod 31 to extend it relative to the side panel 140. This converts the mechanical extension device from the sitting position shown in FIG. 19 to the TV position shown in FIG. 20.

[0075] At this time, if the second electric actuator 405 operates, the distance between the motor head and motor slider of the second electric actuator 405 increases, and the distance between the third motor crossbar 403 and the base rear cross member 113 increases, causing the central linkage member 15 to drive the side plate 140 to move forward relative to the base assembly 11, i.e., toward the leg extension device 3, and causing the front swing lever 12 and the rear swing lever 13 to swing forward correspondingly. The side plate linkage member 17 and the seat linkage member 16 also move forward together with the front swing lever 12. Since the upper end of the drive connecting rod 16a is originally tilted backward in the TV position, when the front swing lever 12 and the rear swing lever 13 swing forward, the upper end of the drive connecting rod 16a pivots forward, supporting the seat interlocking member 16 to move forward and upward. This further drives the central interlocking member 15 to move forward and rotate, increasing the distance between the pivot point between the central interlocking member 15 and the first backrest connecting rod 21 and the pivot point between the side plate 140 and the second backrest connecting rod 22. As the backrest connecting rod assembly moves forward, the backrest connecting rod assembly itself is compressed, causing the backrest connecting member 20 to suddenly tilt backward. During this process, not only do the first pivot point P1 and the second pivot point P2 both move forward, but the distance between the first pivot point P1 and the second pivot point P2 also becomes significantly smaller than in the sitting position and the TV position, thereby achieving the reclining position shown in FIG.

[0076] Of course, the seat unit may be in other positions not specifically shown in the drawings. For example, if only the second electric actuator 405 is activated, the backrest connecting member 20 tilts the backrest backward, but the first electric actuator 404 is not activated, so that the leg extension device is still squeezed under the seat.

[0077] 22 to 28 show a fourth alternative embodiment of the present invention. Unlike the third alternative embodiment, in the fourth alternative embodiment, the leg extension device 3 further includes a second footrest member 37. The leg extension device 3 is composed of a plurality of connecting rods that are pivotally connected to each other, with the rear end of the first leg connecting rod 31 hinged to the side plate 140, the front end of the first leg connecting rod 31 hinged to the rear end of the second leg connecting rod 32, the rear end of the third leg connecting rod 33 hinged to the front end of the side plate 140, the front end of the third leg connecting rod 33 hinged to the rear end of the fourth leg connecting rod 34, the front end of the second leg connecting rod 32 hinged to the first footrest member 35, and the front end of the fourth leg connecting rod 34 hinged to the second footrest member 37. The first footrest member 35 is hinged to one end of an interlocking lever 36, and the other end of the interlocking lever 36 is hinged to the center of the fourth leg connecting rod 34.

[0078] The leg extension device 3 further includes a footrest extension assembly 38, which includes a first extension member 381 and a second extension member 382, ​​one end of the first extension member 381 is hingedly connected to the center of the second footrest member 37, the other end of the first extension member 381 is hingedly connected to one end of the second extension member 382, ​​the other end of the second extension member 382 is hingedly connected to the center of the second leg connecting rod 32, and the center of the second extension member 382 is hingedly connected to the center of the fourth leg connecting rod 34.

[0079] In the fourth alternative embodiment, the first footrest member 35 is hingedly connected to the fourth leg connecting rod 34 by the interlocking lever 36, and the fourth leg connecting rod is connected to the second footrest member, so that the first footrest member 35 and the fourth leg connecting rod are not connected to each other, improving the movement flexibility of the first and second footrest members during contraction or extension. The first footrest member 35, interlocking lever 36, fourth leg connecting rod 34, second extension member 382, ​​and second leg connecting rod 32 form a five-section connecting rod mechanism, which allows the first footrest member to approach or separate from the second footrest member more flexibly, increasing the distance between them after separation and increasing the extension length of the second footrest member.

[0080] 26 to 28 show exemplary posture positions of the mechanical stretching device of the fourth alternative embodiment.

[0081] In the seated position shown in Fig. 26, the foot rest surfaces of the first and second foot rest members 35, 37 are flush with each other, and the first and second foot rest members 35, 37 are squeezed downwards on the seat, with the first foot rest member 35 positioned above the second foot rest member 37. In the TV position shown in Fig. 27, the first and second foot rest members 35, 37 are both extended forwards on the seat. In the reclining position shown in Fig. 28, the first and second foot rest members 35, 37 are still held forwards on the seat, but the backrest connecting member 20 is tilted sharply backwards.

[0082] When the seat unit is transformed from the seated position shown in FIG. 26 to the TV position shown in FIG. 27, only the first electric actuator 404 begins to extend, and the first motor crossbar 401 drives the first leg connecting rod 31 and the third leg connecting rod 33 to rotate forward, thereby moving the footrest extension assembly 38 from the contracted position shown in FIG. 26 to the extreme position shown in FIG. 27. In this process, the second leg connecting rod 32 drives the first footrest member 35 to rotate upward, and the interlocking lever 36 rotates together with the first footrest member 35, supporting the first footrest member 35 while allowing it to rotate more flexibly, and the fourth leg connecting rod 34 drives the second footrest member 37 and the footrest extension assembly 38 to extend forward and rotate upward until the second footrest member 37 is extended to the extreme position. When the footrest extension assembly 38 is extended to the extreme position shown in Fig. 27, the front end of the footrest surface of the second footrest member 37 is inclined upward, thereby realizing the TV posture position shown in Fig. 27.

[0083] 28, the second electric actuator 405 is operated, and the distance of the third motor crossbar 403 to the base rear cross member 113 increases, causing the central linkage member 15 to drive the side plate 140 to move forward relative to the base assembly 11, i.e., toward the leg extension device 3, and the front swing lever 12 and the rear swing lever 13 also swing forward correspondingly. The side plate linkage member 17 and the seat linkage member 16 also move forward together with the front swing lever 12. Since the upper end of the drive connecting rod 16a is originally tilted backward in the TV position, when the front swing lever 12 and the rear swing lever 13 swing forward, the upper end of the drive connecting rod 16a pivots forward, supporting the seat interlocking member 16 to move forward and upward. This further drives the central interlocking member 15 to move forward and rotate, increasing the distance between the pivot point between the central interlocking member 15 and the first backrest connecting rod 21 and the pivot point between the side plate 140 and the second backrest connecting rod 22. As the backrest connecting rod assembly moves forward, the backrest connecting rod assembly itself is compressed, causing the backrest connecting member 20 to suddenly tilt backward. During this process, not only do the first pivot point P1 and the second pivot point P2 both move forward, but the distance between the first pivot point P1 and the second pivot point P2 is also significantly smaller than in the sitting position and the TV position, thereby achieving the reclining position shown in FIG. [Explanation of symbols]

[0084] 1 Seat Assembly 11 Base Assembly 111 Base side member 112 base front cross member 113 base rear cross member 12 Front swing lever 13 Rear swing lever 140 Side Panel 141 First Link 142 Second Link 143 Third Link 15 Central interlocking member 16 Seat interlocking member 16a Drive connecting rod 17 Side plate interlocking member 18 First transmission member 19 Second transmission member 2 Backrest Assembly 20 Backrest connecting member 21 First seat back connecting rod 22 Second seat back connecting rod 23 Third seat back connecting rod 24 Fourth seat back connecting rod 25 5th seat back connecting rod 3 Leg extension device 31 First leg connecting rod 32 Second leg connecting rod 33 Third leg connecting rod 34 Fourth leg connecting rod 35 First foot rest member 36 Interlocking lever 37 Second foot rest member 38 Footrest Extension Assembly 381 1st extension member 382 Second extension member 4 Electric drive unit 40 Motor crossbar 41 Motörhead 42 Motor slide rail 43 Motor slider 44 Motor connecting rod 401 First motor crossbar 402 Second motor crossbar 403 3rd motor crossbar 404 First Electric Actuator 405 Second Electric Actuator

Claims

1. 1. A mechanical extension device for use in a movable seating unit, comprising: a seat assembly (1) including a base assembly (11), side panels (140) attached to a seat of a seat unit, and a central linkage member (15) connected between the base assembly (11) and the side panels (140); a backrest assembly (2) pivotally connected to the rear of said side panel (140), said backrest assembly (2) including a backrest connecting member (20) for mounting to the backrest of a seat unit, and a backrest connecting rod assembly pivotally connected to said backrest connecting member (20), said backrest connecting rod assembly including a first backrest connecting rod (21) hingedly connected to said central linkage member (15) and a second backrest connecting rod (22) hingedly connected to said side panel (140), said first backrest connecting rod (21) hingedly connected to said second backrest connecting rod (22); a leg extension device (3) pivotally connected to the front of the side panel (140), the leg extension device (3) including a plurality of connecting rods pivotally connected to one another and a first foot rest member (35) for mounting on a footrest; The mechanical extension device enables the seat unit to be converted between a sitting position, a TV position and / or a reclining position, and in the sitting position, the first footrest member (35) is squeezed under the seat, and in the TV position, the first footrest member (35) is extended forward, and in the reclining position, the backrest is tilted backward, the highest point of the footrest is higher than the highest point of the backrest, and the first footrest member (35) extends forward and upward.

2. 10. The mechanical stretching device of claim 1, wherein the backrest is tilted at least 35 degrees further back in the lying position than in the sitting position.

3. 3. The mechanical stretching device of claim 2, wherein the backrest is tilted at least 40 degrees further back in the lying position than in the sitting position.

4. 2. The mechanical stretching device according to claim 1, wherein in the recumbent position, the front end of the first footrest member (35) is raised so that the footrest surface of the first footrest member (35) forms an acute angle of 10° to 23° with the horizontal plane, opening forward.

5. 5. The mechanical stretching device according to claim 4, wherein in the recumbent position, the front end of the first footrest member (35) is raised so that the footrest surface of the first footrest member (35) forms an acute angle of 16° to 19° with the horizontal plane, opening forward.

6. 2. The mechanical leg extension device of claim 1, wherein the leg extension device (3) further includes a second footrest member (37), and in the sitting position, both the first footrest member (35) and the second footrest member (37) are tilted downward from the seat, and in the TV position, the first footrest member (35) and the second footrest member (37) are extended forward, and in the reclining position, the backrest is tilted backward, the highest point of the footrest is higher than the highest point of the backrest, and both the first footrest member (35) and the second footrest member (37) extend forward and upward, and the second footrest member (37) is located in front of the first footrest member (35).

7. 7. The mechanical stretching device according to claim 6, wherein in the recumbent position, the front end of the second footrest member (37) is raised so that the footrest surface of the second footrest member (37) forms an acute angle of 10° to 23° with the horizontal plane, opening forward.

8. 8. The mechanical stretching device according to claim 7, wherein in the recumbent position, the front end of the second footrest member (37) is raised so that the footrest surface of the second footrest member (37) forms an acute angle of 12° to 15° with the horizontal plane, opening forward.

9. 7. The mechanical stretching device according to claim 6, wherein in the recumbent position, the front end of the second footrest member (37) hangs down so that the footrest surface of the second footrest member (37) forms an acute angle of between 8° and 30° with the horizontal plane, opening rearward.

10. 10. The mechanical stretching device according to claim 9, wherein in the lying position, the foot rest surface of the second foot rest member (37) forms an angle between 12° and 20° with the horizontal plane.

11. 7. The mechanical stretching device of claim 6, wherein the first footrest member (35) and the second footrest member (37) are connected by a footrest extension assembly (38), the footrest extension assembly (38) including a first extension member (381) and a second extension member (382) hinged to each other.

12. The backrest connecting rod assembly further includes a third backrest connecting rod (23), a fourth backrest connecting rod (24) and a fifth backrest connecting rod (25), wherein the lower end of the third backrest connecting rod (23) is hingedly connected to the second backrest connecting rod (22), the upper end of the third backrest connecting rod (23) is hingedly connected to the rear end of the backrest connecting member (20), and the upper end of the fourth backrest connecting rod (24) is hingedly connected to the backrest connecting portion (20).

2. The mechanical stretching device according to claim 1, wherein the front end of the fifth backrest connecting rod (25) and the first backrest connecting rod (21) are hinged at a first pivot point (P1), the front end of the fifth backrest connecting rod (25) and the first backrest connecting rod (21) are hinged at a second pivot point (P2), the rear end of the fifth backrest connecting rod (25) is hinged to the center of the third backrest connecting rod (23), and the lower end of the fourth backrest connecting rod (24) is hinged to the center of the fifth backrest connecting rod (25).

13. 13. The mechanical extension device of claim 12, wherein the backrest connecting member (20) is tilted backward by compression of the backrest connecting rod assembly during the process of the seat unit converting from the seated position to the lying position.

14. 14. The mechanical extension device of claim 13, wherein, during the process of the seat unit converting from the seated position to the lying position, the relative movement of the side plate (140) and the central linkage member (15) increases the distance between the hinge connection point of the first backrest connecting rod (21) and the central linkage member (15) and the hinge connection point of the second backrest connecting rod (22) and the side plate (140), thereby compressing the backrest connecting rod assembly.

15. 13. The mechanical stretching device of claim 12, wherein, during the process of the seat unit transforming from a seated position to a lying position, both the first pivot point (P1) and the second pivot point (P2) move forward, and the distance between the first pivot point (P1) and the second pivot point (P2) decreases.

16. 2. The mechanical stretching device of claim 1, wherein the seat assembly (1) further includes a front swing lever (12), a rear swing lever (13), a seat linkage member (16), and a side plate linkage member (17), the lower ends of the front swing lever (12) and the rear swing lever (13) are pivotally connected to the base assembly (11), respectively, and the upper ends of the front swing lever (12) and the rear swing lever (13) are connected to the side plate (140) by the central linkage member (15), the seat linkage member (16), and the side plate linkage member (17).

17. 17. The mechanical extension device of claim 16, wherein the swinging of the side panels (140) relative to the base assembly (11) facilitates movement of the backrest assembly (2) and the leg extension device (3) relative to the seat assembly (1), thereby enabling the seat unit to be transformed between a seated position and a reclining position.

18. 2. The mechanical stretching device of claim 1, further comprising an electric drive (4) coupled between the base assembly (11) and the side plate (140).

19. 2. The mechanical extension device of claim 1, further comprising an electric drive unit (4), the electric drive unit (4) including a first electric actuator (404) and a second electric actuator (405), the first electric actuator (404) designed to facilitate extension and retraction of the leg extension device (3) relative to the seat assembly (1), and the second electric actuator (405) designed to facilitate movement of the backrest assembly (2) relative to the seat assembly (1).

20. 20. The mechanical extension device of claim 19, wherein the leg extension device (3) further comprises a second footrest member (37), the second footrest member (37) being located in front of the first footrest member (35) when the first electric actuator (404) urges the leg extension device (3) to extend forward of the seat assembly.

21. 20. The mechanical extension device of claim 19, wherein the first electric actuator (404) acts between the seat assembly (1) and the leg extension device (3), and the second electric actuator (405) acts between the base assembly (11) and the seat assembly (1).

22. 22. The mechanical extension device of claim 21, wherein the base assembly (11) includes a base rear cross member (113), the leg extension device (3) includes a first motor cross bar (401), the seat assembly (1) includes a second motor cross bar (402) adjacent to the leg extension device (3) and a third motor cross bar (403) adjacent to the backrest assembly (2), the first electric actuator (404) acts between the first motor cross bar (401) and the second motor cross bar (402), and the second electric actuator (405) acts between the third motor cross bar (403) and the base rear cross member (113).

23. 23. The mechanical stretching device of claim 22, wherein the second motor crossbar (402) is connected to the side plate (140) and the third motor crossbar (403) is connected to the central linkage member (15).

24. The backrest connecting rod assembly further includes a third backrest connecting rod (23), a fourth backrest connecting rod (24) and a fifth backrest connecting rod (25), wherein the lower end of the third backrest connecting rod (23) is hingedly connected to the second backrest connecting rod (22), the upper end of the third backrest connecting rod (23) is hingedly connected to the rear end of the backrest connecting member (20), and the upper end of the fourth backrest connecting rod (24) is hingedly connected to the backrest connecting member (20). 20) is hinged to the center of the third backrest connecting rod (23), and the front end of the fifth backrest connecting rod (20) is hinged to the center of the third backrest connecting rod (23), and the front end of the fifth backrest connecting rod (25) is hinged to the center of the first backrest connecting rod (21) at a first pivot point (P1), the front end of the fifth backrest connecting rod (25) is hinged to the center of the first backrest connecting rod (21) at a second pivot point (P2), the rear end of the fifth backrest connecting rod (25) is hinged to the center of the third backrest connecting rod (23), and the lower end of the fourth backrest connecting rod (24) is hinged to the center of the fifth backrest connecting rod (25).

25. 25. The mechanical extension device of claim 24, wherein when the backrest assembly (2) is moved relative to the seat assembly (1) by the second electric actuator (405), the backrest connecting member (20) is tilted backward by compression of the backrest connecting rod assembly.

26. 26. The mechanical extension device of claim 25, wherein when the backrest assembly (2) is moved relative to the seat assembly (1) by the second electric actuator (405), the relative movement of the side plate (140) and the central linkage member (15) increases the distance between the hinge connection point between the first backrest connecting rod (21) and the central linkage member (15) and the hinge connection point between the second backrest connecting rod (22) and the side plate (140), thereby achieving compression of the backrest connecting rod assembly.

27. 25. The mechanical extension device of claim 24, wherein when the backrest assembly (2) is moved relative to the seat assembly (1) by the second electric actuator (405), both the first pivot point (P1) and the second pivot point (P2) move forward, and the distance between the first pivot point (P1) and the second pivot point (P2) decreases.

28. 20. The mechanical stretching device of claim 19, wherein the seat assembly (1) further includes a front swing lever (12), a rear swing lever (13), a seat linkage member (16), a side plate linkage member (17), and a drive connecting rod (16a), wherein lower ends of the front swing lever (12) and the rear swing lever (13) are pivotally connected to a base assembly (11), respectively, and upper ends of the front swing lever (12) and the rear swing lever (13) are connected to a side plate (140) by a central linkage member (15), a seat linkage member (16), and a side plate linkage member (17), wherein an upper end of the drive connecting rod (16a) is hingedly connected to the center of the seat linkage member (16), and a lower end of the drive connecting rod (16a) is hingedly connected to the base assembly (11).

29. 29. A mechanical stretching device according to claim 28, wherein the swinging of the side plates (140) relative to the base assembly (11) facilitates movement of the back assembly (2) relative to the seat assembly (1).

30. 20. The mechanical stretching device according to claim 19, wherein the first electric actuator (404) and the second electric actuator (405) are designed as linear electric actuators.

31. 1. A seating unit comprising: A seat unit comprising a seat, a backrest, a footrest and the mechanical extension device according to any one of claims 1 to 30, wherein the side panels (140) are attached to the seat, the backrest connection member (20) is attached to the backrest, and the first footrest member (35) is attached to the footrest.

Images