WO2013104150A1 - Furniture underframe of sitting-lying type furniture - Google Patents

Description

 Furniture chassis for horizontal furniture

Technical field

 The invention belongs to the technical field of furniture, and particularly relates to a furniture chassis for sitting/horizontal furniture. Background technique

 The furniture/seat furniture chassis is used for sitting horizontal furniture, such as a reclining chair, a sofa chair in front of the TV, etc. The chair can be adjusted from the sitting position to the lying position or from the lying position to the sitting position. In such a seat/horizontal furniture chassis, the corresponding sitting/horizontal furniture can be installed in different designs, because the chassis has a support frame on which the furniture legs, the footrest, Seat frame, backrest and armrests. When using seated furniture, these furniture components, such as the footrest, are first adjusted by means of an adjustment gear, such as an outward swing, which is related to the adjustment movement of the seated furniture by the electric drive built into the seated furniture. , or by moving the weight of the person sitting on the sitting furniture. Such a footrest is fully deflected to a so-called retracted position or at an angled position under the seat/horizontal furniture. In the outwardly swung position, the footrest is substantially linear or curved with respect to the extension of the support surface before the seat/horizon furniture chassis. In addition, the footrest can be equipped with a so-called footrest extension which can be pulled into the footrest in the retracted position or can be withdrawn from the footrest for extension in the withdrawal position.

The furniture chassis for seated/horizontal furniture is known from the German utility model 29600282 UI. For the seated furniture described in this patent, the seat frame is part of a parallel steering system that enables the seat of the seated furniture to be displaced from sitting to lying position. At this time, the upper longitudinal steering rod of the parallel steering system constitutes or carries the seat frame, and the lower longitudinal steering rod is fixed on the lower structure side. The footrest includes two rails by means of which the footrest is reversibly attached to the seat frame. In this seated/horizontal furniture, the rails of the footrest constitute the lateral steering rods in front of the seat frame, so that the guide rails are also hinged to the lower longitudinal steering rods fixed to the bracket side. Movement of the seat frame from the sitting position to the lying position causes the inwardly swinging footrest in the rest position below the seat frame to swing outward. On one side of the footrest, a footrest member that moves in the direction of the longitudinal axis of the rail is supported to form a closure of the footrest. In view of the guide rails, the movable and retractable arrangement, the footrests associated with the stretch distance of the footrest elements have different lengths. The footrest member is pulled in a position where the footrest swings inward so that it can swing in the downward direction of the seat frame. If the seated furniture is in a lying position where the footrest has been swung outward, the footrest element is pulled out to increase the length of the footrest. Another type of sitting/horizontal furniture chassis of this type is known from the patent EP 2 369 922 A1, in which the swivel movement of the footrest is linked to the movement of the seat frame by a buffer unit and is placed in the retracted position. The stand is held in position by a support stop spring. In view of the design of the longitudinal steering rod and the vertical lever and the lack of a stable end position between the longitudinal steering rod, the vertical lever and the seat frame, the addition is made in terms of forming a kinematic configuration for the sitting or lying position. The buffer unit and the support stop spring are essential for constructing a parallel steering system for a seat/horizon furniture chassis. Changing the dead weight of the seat frame and the footrest by sitting or lying on the seat/horizontal furniture may have the consequence that loading within the range of the footrest may cause unintentional movement of the seat frame or vice versa.

Summary of the invention

 According to the above prior art, the present invention continues to design a furniture/seat furniture chassis that aims to: cause a seat frame and a footrest for a person sitting or lying on a seat/horizontal piece of furniture The static weight changes, and the invention can prevent the movement characteristics of the seat/horizon furniture chassis. In order to achieve the above object, the technical solution adopted by the present invention is as follows:

 a furniture chassis for horizontal furniture, the furniture chassis comprising a support frame and a seat frame with a backrest, the seat frame being movably mounted on the support frame by a quasi-parallel steering system; the quasi-parallel steering system supported by The frame, the seat frame, the first rocker and the second rocker are configured to move the seat frame between the end positions of the seat and the lying position, wherein the first rocker and the support frame are hingedly formed a side fulcrum, the second rocker is hinged with the support frame to form a front side fulcrum; the rear fulcrum and the front fulcrum are positioned such that the seat frame: when in the lying position, the person's own gravity is along the backrest direction Applied to the rear of the rear side fulcrum and the front side fulcrum, acting on the seat frame, when in the seated state, the person's own gravity is applied to the front side of the rear side fulcrum to act on the seat frame.

When the furniture chassis moves between the sitting position and the lying position, the rear side fulcrum of the near backrest and the front side fulcrum of the near backrest of the quasi-parallel steering system for the seat frame are designed and arranged on the support frame, so that the lying position The synthetic gravity of the person lying on the seat/horizon furniture is applied to the backrest on the seat frame behind the fulcrum, whereas in the seat, the synthetic gravity of the person sitting on the seat/horizon furniture is applied to the seat. The front of the rear fulcrum on the frame. In the lying position, the rockers of the quasi-parallel steering system are always turned back and forth along the backrest, so that the hinges of the seat frames on the rockers are located behind the rear side pivot of the seat frame and thus occupy a stable end position. The limit can be a corresponding block structure fixed on the support frame to make. When adjusting to the seat position, the seat frame must be adjusted to a position above the top dead center of the quasi-parallel steering system where the synthetic gravity of the sitting/horizontal furniture is placed on the rear side of the seat frame. The front of the point falls between the rear side fulcrum and the front side fulcrum of the seat frame. Therefore, it is again necessary here to achieve a definition of the sitting position and a final position of the mechanical stability by means of, for example, a corresponding stop. This ensures that no additional fixing or force acts such as spring pretensioning or the like are required at the two final positions to reliably maintain the posture of the seat frame in these two positions. Thus, the slight, or rather unintentional, weight transfer of a person lying or sitting on a seat/horizontal furniture does not cause the seat frame to be adjusted to a position that is inconsistent with the person lying/sitting. In particular, even when the person's foot has additional support, since the footrest can be folded, the footrest is coupled with the adjustment movement of the seat frame in a manner known per se, with only a slight loading through the footrest. On the seat frame, this may result in an undesired movement of the seat frame. The design of the present invention ensures that this is prevented from occurring without interfering with the adjustment of the seat frame desired by the user.

 A particular advantage of the present invention is that the seat frame of the seat/horizontal furniture chassis maintains an unstable balance when adjusted between the sitting position and the lying position, at which point a lying or sitting seat/sleeping The resultant gravity of the person on the furniture passes just past the rear fulcrum of the seat frame, which is the top dead center of the quasi-parallel steering system about the rear fulcrum of the seat frame, so that the seat frame usually does not stay at that A stable equilibrium state, either for the lying position or for the moving end of the sitting position, and then achieving mechanical stability. Another advantage is that if the sitting position and the lying position respectively constitute a stable end position of the seat frame adjustment movement, wherein the position of the quasi-parallel steering system for the seat frame is respectively limited by the fixed connection with the support frame, correspondingly The components that are fixed to the support frame, for example on a longitudinal steering rod or the like, are fastened, for example by means of a rocker interaction, such that only certain maximum pivot angles of the specified rocker are achieved.

According to a further improvement of the present invention, the front transverse support tube and the rear transverse support tube of the seat frame are respectively hingedly fixed to the support of the longitudinal steering rod constituting the quasi-parallel steering system by a rocker. In this case, the seat frame is supported as a part of the quasi-parallel steering system over the entire length of the seat frame, so that a particularly advantageous force introduction/supporting action of the seat frame is obtained at its end position. The member mounted on the support frame and the formed rear side fulcrum are located in the lower region of the lateral support tube on the back side of the seat frame. Thereby, since the longitudinal steering rod has a large length and a corresponding weight distribution of gravity acting on the seat frame and the backrest, the gravity comes from the weight of the seat/horizon furniture, and due to the seat/horizontal furniture user Heavy Quantity, to achieve the most advantageous lever transmission ratio. In this way, the lever ratio between the front fulcrum and the rear fulcrum of the seat frame is improved, so that it is not necessary to use other auxiliary devices, such as springs or the like, to keep the seat frame in the seat and the lying position correspondingly. Mechanical safety and stability in the terminal position. The seat/horizontal furniture chassis of the present invention can be switched from a sitting position to a lying position or vice versa simply by weight transfer of a person sitting or lying on a seat/horizontal furniture, or by an additional drive mechanism, preferably It is an electric or hydraulic drive mechanism that switches the seat frame from the sitting position to the lying position or vice versa. In addition, manual adjustment by electric adjustment or by elastic support of the gas spring can also be used.

 In terms of the comfort of the sitting/lying person, the front side fulcrum of the seat frame is arranged vertically above the rear side fulcrum of the seat frame. When sitting, the surface of the seat frame used for seating is tilted slightly rearward in the direction of the backrest. At the same time, depending on the length of the rocker and the geometry of the quasi-parallel steering system, the reverse slope of the lying position can be increased. Make the lying position more comfortable.

 According to a further development of the invention, a footrest with a footrest frame is arranged on the seat frame in a known manner, the frame being rotatable about a steering axis substantially parallel to the front transverse support tube of the seat frame, And the ejector can be adjusted relative to the seat frame. The ram and quasi-parallel steering system enters the closed position with the footrest, and the seat frame becomes seated. When it enters the open position, the seat frame is placed. In a flat state, the footrest frame is coupled to the quasi-parallel steering system by a jack for deflecting the footrest from a retracted position when the seat frame is in a sitting position to an outwardly swinging position when the seat frame is in a lying position. . A retractable extension member is disposed in the footrest frame, and the extension member extends in parallel with the extension member extending parallel to the frame. Only when the footrest frame swings from the inside to the outside, when the distance from the end of the frame to the ground exceeds the minimum value, the ejector will drive the extension member to perform the extension action. If the lower end of the footrest frame has not reached the lowest point, the extension of the extension member will hinder the outward swing of the footrest frame, thereby also reducing the structural height of the support frame.

To this end, in a further solution, the overhanging transmission of the footrest frame extension is a curved rod transmission, and when the footrest is opened outward for a small swing angle, the curved rod transmission correspondingly extends the extension Doing a small linear extension action, when the footrest frame makes a relatively large swing outward, the crank lever transmission device drives the entire footrest to perform a relatively large extension action on the extension member. When the low point of the footrest frame step by step exceeds the lowest point of the rotary motion, the corresponding design of the crank gear transmission starts to move the footrest extension in a targeted manner. Subsequently, such a crank lever transmission can ensure a sufficient adjustment length of the footrest extension when the lever length and the turning point are correspondingly designed, whereby the footrest extends far beyond the front side of the seat frame, almost at It provides comfortable support for the user's legs/foot throughout its length. In addition, the outward movement of the footrest extension can also be guided by linear guides, in particular roller guides. By coordinating the forces acting on the seat/horizontal furniture undercarriage, it is possible to avoid the use of common and expensive ball-extended guide rails, which can be replaced by low-cost roller guides. The furniture chassis of the present invention is capable of moving the footrest without a cushioning unit or supporting a stop spring.

DRAWINGS

 BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an enlarged view of the components of the furniture chassis of the horizontal furniture of the present invention, wherein the chassis is in a lying position, showing a seat frame with a heavily tilted backrest and a fully flipped and overhanging footrest.

 2 to 6 are diagrams showing the orientation of the seated furniture chassis of the present invention and the different directions in the form of a stage plan view from the adjustment of the lying position according to Fig. 1 to the sitting position.

 Figure 7 is an enlarged view of the swing position of the footrest frame at a certain time in Figure 5, at which time the footrest frame swings past the lowest point.

 In the figure, 1-seat/horizontal furniture underframe; 2-support frame; 3-seat frame; 4-footrest; 5-footrest frame; 6-footrest frame extension; 7-fixed on support frame Upper longitudinal steering rod; 8-brace; 9-back side fulcrum on seat back side; 10-flange; 11-mounting plate; 12-riser; 13-support bracket fork; 14-rocker 15 rocker; 16-stop; 17-seat support spring; 18-for motor adjustment flange; 19-seat frame hinge joint flange; 20-footrest frame hinged steering shaft; 21- Footrest adjustment lever; 22- footrest frame extension adjustment lever; 23-footrest frame extension support; 24-wheel; 25-guide profile; 26-seat frame front cross support tube; 27-seat frame rear cross Support tube; 28-curvature transmission lever; 29- crank lever transmission lever; 30-curv transmission lever; 31-stop; 32-intermediate connecting rod; 33- front frame side of seat frame footrest side Point; 34-spring; 35-steering shaft; 36-footrest purely swivel motion track; 37-footrest overlapping track.

detailed description

 The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

The seat/horizontal furniture chassis of the present invention presented in the drawings is a structure without a cushion and a cover, which helps us to better understand its components and functions, and the basic design and function can be obtained from the current Known in the state of the art, it is therefore not only a component of the use or a combination of its geometry and function, but only a description of the specific properties and the structures necessary for this and the necessary functions for their function. For other aspects, reference is made to a seat/horizon furniture chassis 1 known from the state of the art. The seat/horizontal furniture chassis 1 of the present invention is a type of chassis that is adapted to support the support frame 2, for example, by the mounting plate 11 and the riser 12, and also has a seat. A chair frame 3 which can grip and/or maneuver the backrest and footrest 4 attachable to the flange 10, not shown continuously. The same or similar components with the same and similar functions are already provided with the same reference symbol. The term "front" refers to the front side of the seat/horizontal furniture chassis 1 within the scope of the footrest 4, in which case the concept "back" refers to a seated/horizontal furniture bottom in a backrest area not shown. On the back side of the frame 1, the backrest can be arranged to be movable or fixed on the respective flange 10 for the seat frame 3.

 The seat/horizontal furniture chassis 1 is supported on the legs by the mounting plate 11 and the riser 12 on the base, and has a fork-shaped support bracket fork 13 on the upper portion thereof, on which two of the support brackets 13 are supported The two tubular longitudinal steering rods 7 on the forks extend forward in the direction of the footrest 4. Above the longitudinal steering rods 7 arranged on both sides and fixed to the support frame 2, the seat frame 3 can be seen to be substantially rectangular from a complete pipe structure, in which case the two longitudinal supports of the seat frame 3 The tube is substantially parallel to the longitudinal steering rod 7 and is interconnected at its two ends with the transverse support tubes 26, 27, respectively. The seat frame 3, with the seat cushion support spring 17, constitutes a support for forming a seat cushion, not shown, of the seat/horizon furniture together with the seat/horizon furniture chassis 1. Below the layer of the seat frame 3, from the intermediate portion of the rear transverse support tube 27 to the central region of the front transverse support tube 26, a tubular and multi-folded diagonal brace 8 can be identified which urges the seat The frame frame 3 is reinforced and, in the case of reinforcement, two flanges 18 can be arranged, which can be used for electric adjustment of the seat frame 3, for example not shown. The seat frame 3 and the two longitudinal steering rods 7 together with the rockers 14, 15 and the intermediate connecting rod 32 form a quasi-parallel steering system by which the seat frame 3 can be seen from the enlarged view of Fig. 1. The bit is adjusted to the seat shown in Figure 6. At this time, the seat frame 3 in the sitting position and the backrest not shown can be easily tilted back by ergonomically by arranging the longitudinal steering rod 7 inclined forward and upward and according to the length of the rockers 14, 15. The arrangement, at the same time, magnifies the inclination of the lying seat frame 3 as seen in Figure 1 with respect to the sitting position.

 The concept of a quasi-parallel steering system shows that it is a steering system that has been modified compared to a purely parallel steering system in which not only the length of the rockers 14, 15 can be varied, but also their geometry and bending. Modifications, but the basic geometry of the quasi-parallel steering system remains unchanged in principle.

Here, with respect to the two longitudinal steering rods 7, the seat frame 3 passes through the hinged rear side fulcrum 9 on the backrest side And an articulated front side fulcrum 33 on the side of the footrest in an adjustable arrangement, in which the rocker 14 , 15 is rotatably mounted in the hinges 9, 33 and hingedly connected to the seat frame 3 either directly or via the intermediate connecting rod 32 Together. The seat frame 3 can perform a swiveling motion extending around the two hinge fulcrums 9, 33, and the tilt of the seat frame 3 changes from a seat position to a lying position due to the lever length of the rocker 14, 15 and the lever ratio during movement, as above The increase is increased. The adjustment movement of the seat frame 3 to the lying position is limited by a front stop 16 for which blocking is performed when the rocker 15 shown in Fig. 1 is moved to the right. On the contrary, the adjustment movement of the seat frame 3 to the seat position is restricted by the stopper 31 on the backrest side, for which the blocking is performed when the rocker 14 shown in Fig. 1 is moved to the left. Thus, the two stops 16, 3 1 define the range of rotation allowed when the seat frame 3 is moved between the sitting and lying positions.

A particularly advantageous design of the seat/horizon furniture undercarriage 1 according to the invention is only described, due to the geometry of the quasi-parallel steering system components, and the absence of other means of controlling the position of the fulcrums 9, 33, the seat frame 3 Keep the lying position or sitting position unchanged, adjust to a stable lying position or sitting position. Therefore, in the lying position, the resultant gravity of the person lying on the seat/horizon furniture is applied to the fulcrums 9 and 33 on the seat frame 3 in the backrest direction, and conversely, when sitting, sitting/sitting/ The resultant gravitational force of the person on the horizontal furniture is applied to the front of the fulcrum 9 on the backrest side of the seat frame 3. As shown, in the lying position, the rockers 14, 15 of the quasi-parallel steering system are always turned back on the backrest side, so that the hinge of the seat frame 3 on the rockers 14, 15 is located at the fulcrum of the backrest side of the seat frame 3. After 9 , thus occupying a stable end position, the limit can be formed by a corresponding stop 16 . When adjusting to the sitting position, the seat frame 3 must be adjusted to a position beyond the top dead center of the quasi-parallel system, in which the resultant gravity of the person sitting on the seat/horizon furniture falls on the seat frame 3 The front side of the backrest side fulcrum 9 acts to act between the backrest side fulcrum 9 and the front side fulcrum 33 of the seat frame 3. As a result, the definition of the seat and the mechanically stable end position by a corresponding stop 31 are again achieved. Therefore, it is necessary to ensure that no additional fixing or force is required at these two end positions to maintain the posture of the seat frame 3 in these two positions, such as spring preload or the like. Thus, the slight, or rather unintentional, weight transfer of a person lying or sitting on a seat/horizontal furniture does not result in the inadvertent movement of the seat frame 3 to the intent of the person lying/sitting. The position, in particular on the foldable footrest 4, even in the case of a person's foot, which is associated with the adjustment movement of the seat frame 3 in a well-known manner, with only a slight loading Acting on the seat frame 3 by the footrest 4, which may result in an undesired seat frame The movement of the shelf 3. The design of the present invention ensures that this is prevented from occurring without hindering the adjustment of the seat frame 3 desired by the user.

 The seat frame 3 is moved from the lying position shown in Fig. 1 in accordance with the illustration in the middle of Fig. 2 to the sitting position seen in Fig. 6, this process can be clearly identified and understood from Fig. 2 to Fig. 6, so here We will not continue to study the individual drawings in detail.

 On the seat/horizontal furniture chassis 1, an adjustment arrangement with levers 21, 22 is used to forcibly shift the movement of the seat frame 3 to the footrest 4. The levers 21, 22 each have a horizontal or approximately horizontal steering shaft 20, 35, and each has one end connected to the movement of the quasi-parallel steering system, either directly or indirectly via one or more actuators. At this time, the lever 21 is responsible for the deflection of the footrest frame 5 about the steering shaft 20, and the steering shaft 20 is fixed to the seat frame 3 by the flange 19. As seen in Figures 2 to 5, the footrest frame 5 is rotated from the sitting position (Fig. 6) to the lying position (Fig. 2), which emerges below the seat frame 3 to its extended position, which is substantially horizontal with the base. . In the sitting position, on the contrary, the footrest frame 5 is completely turned inwardly arranged under the seat frame 3. In overlapping with the swivel motion of the footrest frame 5, an elongate member 6 disposed in the stud frame 5 can be pulled linearly relative to the footrest frame 5, thereby extending the footrest 4 as compared to the length of the inward flip. For this purpose, a plurality of rollers 24 are arranged on the outside of the footrest frame 5, on which the guide profiles 25 of the C-shape can be guided. The linear adjustment movement of the footrest frame extension 6 is caused by a crank-type drive consisting of a number of individual levers 28, 29, 30. When the seat frame 3 is moved by the lever 22, it is driven in a substantially well known manner. In this regard, the lever 22 and the crank-actuated lever 29 are coupled and mated together by means of an articulated steering shaft 35 in a manner not shown. If the seat frame 3 is adjusted from the sitting position (Fig. 6) to the lying position (Fig. 2) as described above, the footrest frame 5 can be swung outwardly only by adjusting the seat frame 3, or from the footrest frame. In 5, the extension member 6 of the footrest frame is linearly removed.

Another feature is shown in Figure 7 again, that is, due to the use of the crank drive and its geometry and the position of the crank to drive the pivot point, only when the footrest frame 5 is deflected from the sitting position to the lying position or When the deepest point of the track involving the chassis is involved, it is basically possible to exit from the footrest frame 5 and start to adjust the linear movement of the footrest frame extension 6. If the linear adjustment movement of the footrest frame extension 6 has been started beforehand, the ground clearance of the seat/horizon furniture chassis 1 must be increased as much as possible, so that the outward movement and extension of the footrest frame extension 6 When the end does not collide with the base. By This may result in an uncomfortable seating condition or the footrest frame extension 6 must be limited, for which the footrest 4 is generally shortened compared to the achievable length, so that the bearing surface for the legs is also required to be shortened. The crank lever drive in this case allows a simple adjustment of the performance of the footrest frame extension 6, since the motion characteristics of the crankshaft drive can be designed accordingly, when the range in which the crankshaft drives a small amount of linear movement is exceeded, Allows sufficient linear travel for the footrest frame extension 6 linear adjustment.

Claims

Claim 1. A furniture chassis for horizontal furniture, the furniture chassis (1) comprising a support frame (2) and a seat frame (3) with a backrest, characterized in that the seat frame (3) is guided by a quasi-parallel The system is movably mounted on the support frame (2); the quasi-parallel steering system is composed of a support frame (2), a seat frame (3), a first rocker (14) and a second rocker (15). The seat frame (3) is moved between end positions in the two positions of sitting and lying, wherein the first rocker (14) is hinged with the support frame (2) to form a rear side fulcrum (9), The second rocker (15) is hinged with the support frame (2) to form a front side fulcrum (33); the rear side fulcrum (9) and the front side fulcrum (33) are positioned such that the seat frame (3): When in the lying position, the person's own gravity is applied to the rear side fulcrum (9) and the rear side fulcrum (33) in the backrest direction to act on the seat frame (3), when in the sitting position, the person The self-gravity is applied to the front side fulcrum (9) to act on the seat frame (3).  2. The furniture chassis of a horizontal furniture according to claim 1, wherein two support blocks (16, 31) are fixed on the support frame (2) for limiting the quasi-parallel steering The extent of movement of the system between two end positions.  3. The furniture chassis of a horizontal furniture according to claim 2, wherein the support frame (2) comprises two longitudinal steering rods (7) fixed to the support frame (2), The stopper (16, 31) is fixed on the longitudinal steering rod (7); one end of the longitudinal steering rod (7) is hinged with the second rocker (15) to form a front side fulcrum (33), and the second rocker ( 15) hinged to the front transverse support tube (26) of the seat frame (3), the other end of the longitudinal steering rod (7) is hinged with the first rocker (14) to form a rear side fulcrum (9), A rocker (14) is hinged to the rear cross support tube (27) of the seat frame (3) either directly or through the intermediate connecting rod (32).  4. The furniture chassis of a horizontal furniture according to claim 1, wherein the transition of the seat frame (3) between the sitting and lying positions is by a person's own weight transfer, Either by means of an electric or hydraulic drive or by manual adjustment.  The furniture chassis of the horizontal furniture according to claim 1, characterized in that the front side fulcrum (33) of the seat frame (3) is perpendicular to the ground from the rear side fulcrum (9) The location is high.  The furniture chassis of the horizontal furniture according to any one of claims 1 to 5, characterized in that: the seat frame (3) is provided with a footrest (4) with a footrest frame (5) ) , footrest frame (5) oscillating around the seat frame (3) by means of a steering shaft (20), which is fixed in parallel to the front transverse support tube (26) of the seat frame (3) by a flange (19) The footrest The frame (5) is coupled to the quasi-parallel steering system by a jack (21) for deflecting the footrest (4) from the inward swing position when the seat frame (3) is in the seated position to the seat frame (3) An outward swing position when in the lying position; a telescopic extension (6) is provided in the footrest frame (5) only when the footrest frame (5) is swinging from the inside to the outside, When the distance from the end of the frame to the ground exceeds the minimum value, the ejector pin (21) will drive the extension member (6) to perform the extension action. 7. A furniture chassis for a horizontal furniture according to claim 6, wherein the ram is provided with two, which are hinged together with the quasi-parallel steering system either directly or through an actuator. A furniture chassis for sitting horizontal furniture according to claim 6, wherein the extension and contraction of the extension member (6) is driven by a curved rod composed of three linkage rods (28, 29, 30) and utilized The roller guide guides the overhanging movement of the extension member (6).