Reclining chair

Abstract

This chair features a slim design with a thin seat while incorporating a synchronized reclining function. [Solution] The base 6 is a shallow tray shape, and a compression coil spring 23 is arranged horizontally inside it. The back support frame 7 is connected to a downward-facing pivot 9 that protrudes downward from the lower surface of the base 6, and the downward-facing tip 8 of the back support frame 7 is connected to the downward-facing pivot 9. The rear part of the seat support member 16 is connected to an upward-facing projection 21 of the back support frame 7, and the movable spring support 25 at the front end of the compression coil spring 23 is supported at the front end of the seat support member 16. The seat support member 16 is almost entirely fitted into a recess 34 of the seat inner shell 14.

Description

Technical Field

[0001] The present invention relates to a reclining chair in which a backrest and a seat move in conjunction with each other.

Background Art

[0002] As one genre of chairs, there is a reclining chair in which a backrest reclines against the elastic resistance of an elastic body, and it is frequently used for office chairs and the like. As the elastic body, a torsion spring, a rubber material, etc. are also used, but a compression coil spring is frequently used.

[0003] The compression coil spring is supported at both ends by a fixed spring receiver and a movable spring receiver. When used for reclining a chair, generally, it is arranged in a reclined posture in a side view so that the rear end is lower, the front end is supported by the fixed spring receiver, the rear end is supported by the movable spring receiver, and the movable spring receiver is often pushed at the front end of the tilting member to which the backrest is attached.

[0004] The reason why the compression coil spring is often arranged in a reclined posture in the chair is that it directly pushes at the front end of a tilting member (back support frame) pivotally supported rotatably on the base. That is, in many cases, the portion near the front end of the tilting member is pivotally supported on the base. In this case, since the front end of the tilting member advances due to the rearward tilting of the tilting member, it becomes a method of pushing the compression coil spring forward with the movable spring receiver. However, since a certain span is required from the rotation fulcrum to the front end of the tilting member, the compression coil spring is arranged in a reclined posture.

[0005] On the other hand, although chairs are designed with various concepts, as one concept, there is a perspective of thinning and slimming. It is preferable to maintain the synchro reclining function while thinning the seat and the backrest. However, if the compression coil spring is arranged in a reclined posture, the seat receiving portion such as the base becomes large-sized (bulky) and it is difficult to respond to a slim design.

[0006] Compression coil springs are highly reliable and readily available, making them suitable for reclining mechanisms. However, to maintain a synchronous reclining function while using compression coil springs and thinning the seat, it is beneficial to position the compression coil springs horizontally. An example of such a structure is disclosed in Patent Document 1.

[0007] Patent Document 1 deals with a fixed chair for amusement facilities such as pachinko parlors, in which a support base is attached to a sliding mechanism fixed to the upper end of the leg support column, allowing it to slide back and forth, and the seat and backrest are attached to the support base. The support base is biased to the forward position by a spring.

[0008] Furthermore, the compression coil spring is supported at its rear end by a fixed spring support and at its front end by a movable spring support, while the tilting member (first back frame) is pivotally supported at its front end by a support base, and the portion of the tilting member behind the pivot point and the movable spring support are connected by a seat support plate. In other words, in Patent Document 1, the fixed spring support is compressed backward via the seat support plate, and the seat support plate and seat tilt backward while moving backward during reclining.

[0009] Furthermore, in Patent Document 1, the slide shaft connected to the movable spring receiver penetrates the side plate of the support base and is exposed to the outside, and the slide shaft is connected to the seat plate support plate. Therefore, the support base is covered from above by the seat plate support plate. Moreover, in Patent Document 1, the interlocking shaft for synchronization that connects the back support frame and the seat plate support plate is positioned at the same height as the spring (directly behind the spring). [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 4551918 [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] Now, Patent Document 1 deals with fixed chairs for amusement facilities and requires a specially shaped sliding support base as an essential component, making it difficult to directly apply to movable swivel chairs like those used in offices. Furthermore, in Patent Document 1, movable members such as the sliding shaft are exposed on the outside of the support base, which poses a finger-pinching problem. To avoid this, the gap between the members must be increased, which raises concerns about the chair becoming larger.

[0012] Furthermore, as mentioned above, arranging the compression coil spring in a horizontal position is beneficial as a means of making the seat thinner. However, in Patent Document 1, the pivot point of the tilting member is located on the base (support base), which limits how thin the base can be made, making it difficult to meet the design requirement of making the chair slimmer.

[0013] Furthermore, Patent Document 1's main purpose is to link the first and second back frames, and the concept (problem) of making the chair thinner and slimmer does not exist. Therefore, there is no consideration for any ingenuity to make the chair thinner and slimmer, and in fact, the presence of the first and second back frames can be seen as going against the goal of making the chair thinner and slimmer.

[0014] Furthermore, in Patent Document 1, the lower half of the first back frame is formed in a bifurcated shape with left and right forward-facing arms, and the left and right arm portions are positioned on the left and right outer sides of the base, with the tips of the arm portions connected to the base by pivot shafts. However, the fact that the left and right arm portions are easily visible is also considered to be a step away from making it thinner and slimmer.

[0015] This invention was conceived in response to the current situation, and aims to provide a chair that maintains a synchronized reclining function while allowing for a thinner and slimmer seat and superior design. While this application discloses many novel technologies, these can also constitute independent inventions. Similarly, the essence of the dependent claims can be made into independent claims. [Means for solving the problem]

[0016] The invention of the present application includes various configurations, and typical examples thereof are specified in each claim. Among these, the invention of claim 1 forms a superordinate concept, "a base supported by a leg device, a seat disposed above the base, and via the left and right longitudinal support axes a back support frame that is connected to the base so as to be tiltable backward, a backrest attached to the back support frame, and a reclining compression coil spring that imparts elastic resistance to the backward tilting of the back support frame, wherein the seat or Seat support member the rear portion of Longer left and right is connected to the back support frame via an interlocking shaft and Ori the backrest and the back support frame When it tilts backward, the interlocking shaft rotates with the support shaft as the pivot point. tilt backward while the seat retreats." This is the basic configuration.

[0017] And, in the above basic configuration, "the base is in the form of an upwardly open tray, and inside the base, the reclining compression coil spring is disposed in a substantially horizontal posture so as to be compressed backward in conjunction with the backward movement of the seat, The support shaft is positioned lower than the reclining compression coil spring without protruding to the left or right sides of the base, and the interlocking shaft is positioned higher than the reclining compression coil spring and behind the support shaft without protruding to the left or right sides of the base. " It has the feature of.

[0018] The invention of claim 2 is a development example of claim 1, " The aforementioned support shaft is connected to a support shaft portion that protrudes downward from the rear of the base, the support shaft portion has a width smaller than the width of the base, and the portion of the lower surface of the base excluding the support shaft portion is formed in a flat shape. It has the feature of.

[0022] Claim 3 The invention of is a development example of claim 1 or 2 , "the seat has a seat inner made of synthetic resin shell and , superimposed on the upper surface of the seat inner shell a seat cushion material disposed thereon, wherein a recess into which the seat receiving member enters from below is formed in the seat inner shell and downward opening " The interlocking shaft is positioned in a recess in the inner shell of the seat. " It possesses the following characteristics.

[0023] Claim As an example of the development of 3, "The back support frame has an upward-facing projection that fits into the rear of the recess in the seat inner member, and the upward-facing projection is connected to the seat receiving member so as to be rotatable relative to it within the recess." Features It can be added.

[0024] As an example of the development of claim 1, "The upper end of the gas cylinder constituting the leg device is fitted to the left-right intermediate position of the base, The aforementioned reclining springs are arranged in pairs, one on each side, in front of the gas cylinder. This characteristic It can be added.

[0026] As an example of the development of claim 1, "The seat support member has left and right side members that are long in the front-rear direction, left and right longitudinal front members connected to the front of the left and right side members, and left and right longitudinal interlocking shafts that connect the rear of the left and right side members to the back support frame so as to be rotatable relative to each other." This characteristic It can be added. [Effects of the Invention]

[0029] In the present invention, since a compression coil spring is placed inside a tray-shaped base fixed to the upper end of the leg support, it can be applied without problems to office chairs such as swivel chairs, and the overall structure can also be simplified.

[0030] Now, in a chair where the seat moves backward in conjunction with the backward tilt of the backrest, the seat moves backward relative to the base. If the base is recessed into the seat, this can cause the problem of fingers getting pinched when a person inserts their fingers into the gap between the base and the seat. However, by setting the upper edge of the base and the lower edge of the seat to roughly the same height, as in claim 2, it is possible to prevent a gap from opening even when the seat moves backward, thus preventing the problem of fingers getting pinched.

[0031] However, if the upper edge of the base and the lower edge of the seat are set to roughly the same height, the lower edge of the base will become lower, which could be counterproductive to making it compact. In this application, The pivot point of the back support frame is coil spring Because it is located below, the base can be kept to the minimum thickness necessary to accommodate compression coil springs, etc. And the connecting part (axis support part) of the back support frame is Claim 2 As shown, it can be projected downward from the underside of the base, but the connecting part can be formed so that it is hidden and not visible from the base, allowing the seat portion having the seat and base to be formed in a thin state.

[0032] Therefore, by making the seat thinner to achieve a slim design, while also having a highly safe synchronized reclining function, it is possible to maintain a clean design while preserving high levels of safety and comfort, thereby improving the product's value.

[0033] Looking at the relationship between the width of the back support frame and the width of the base, if the width of the back support frame is made larger than the width of the support base, as in Patent Document 1, and the tip of the back support frame is connected to the base, there is a concern that the back support frame will be more visible to people, reducing the slim appearance, and that the design freedom of the base will be reduced. In addition, if the movable member is exposed to the outside of the base, there is a concern about the aforementioned problem of finger pinching.

[0034] In response to this In the present invention, Insert the back support frame into the base. hand, By making the back support frame less conspicuous, the slimmer appearance can be improved, and the external shape of the base can be freed up, ensuring design freedom. Furthermore, In the embodiment, Since the front end of the back support frame is recessed into the pocket-shaped downward pivot support of the base, there are no problems with the connection function of the back support frame, ensuring that both a slim design and a synchronized reclining function are achieved.

[0035] When the seat retracts in conjunction with the backward tilt of the back support frame, the distance from the pivot point of the back support frame to the linkage axis is much smaller than the distance from the pivot point of the back support frame to the backrest. Therefore, a large moment acts on the linkage axis during reclining. In this case, in order to reduce the load acting on the linkage axis, it is preferable to make the distance from the pivot point of the back support frame to the linkage axis as large as possible. In this regard, The present invention If adopted, the span from the pivot point of the back support frame to the interlocking axis can be made as short as possible. Large This has the advantage of reducing the load acting on the interlocking shaft and its connection point, thereby improving the durability of the components.

[0036] As a means of linking the backrest and seat, it is also possible to connect the seat inner shell that makes up the seat with the back support frame, seat Using support members (intermediate fittings, intermediate members) makes it easier to ensure strength by using metal for the seat support members, and also improves the design flexibility and ease of manufacturing (molding) of the seat inner shell.

[0037] When using a seating member, 3 Inserting the seat support member into the space of the seat inner shell, as shown, further contributes to making the seat thinner. In this case, if the seat cushion material is integrally molded into the seat inner shell by an insert molding method or a two-color molding method, as in the embodiment, the seat cushion material can be molded without gaps even if the seat inner shell has a complex shape, thus eliminating any partial floating of the seat cushion material and resulting in a comfortable seat, which is preferable.

[0038] Claim 3 By adopting this configuration, the back support frame can be brought closer to the seat inner shell, which further contributes to making the seat thinner. part It fits into a recess in the inner shell of the seat. ThereforeSince the recess in the inner shell of the seat can be formed in a closed manner with an inner circumferential surface having a closed loop shape, a reduction in the strength of the inner shell of the seat can be prevented. Therefore, a seat with high strength can be constructed without using an outer shell of the seat.

[0039] The arrangement of the compression coil springs can be specified in various ways, Embodiment By placing a compression coil spring in front of the gas cylinder, which acts as a leg support, the front-to-back length of the seat support member increases, thereby improving the seat's support stability. Conversely, this allows for a balanced placement of the compression coil spring while increasing the length of the seat support member to enhance the seat's support stability.

[0040] Furthermore, in the present invention, it is also possible to use a single compression coil spring, Embodiment Using two compression coil springs, one on each side, as shown, allows for smaller diameters, further contributing to a thinner base. It also has the advantage of allowing the seat support member to move smoothly back and forth without twisting.

[0041] Embodiment If the front part of the back support frame is positioned inside the base as shown, the gap between the back support frame and the base narrows when the back support frame tilts backward. This poses a risk of fingers getting caught if a person inserts their fingers into the space between the base and the back support frame. One possible solution is to ensure that there is sufficient space between the back support frame and the base even when the back support frame is fully tilted backward. However, in this case, the gap between the base and the seat widens, making it difficult to achieve a slimmer and thinner design.

[0042] In this regard, Embodiment By providing downward-facing ribs on the back support frame, as shown above, finger pinching can be prevented even if the back support frame tilts backward so that it contacts or comes close to the base. This allows for minimizing the gap between the back support frame and the base, promoting a slimmer and thinner design while also ensuring safety.

[0043] The seat support member can be made, for example, by sheet metal processing from a single metal plate, EmbodimentBy adopting a grid structure consisting of multiple members, as shown above, a large space is created with openings at the top and bottom, allowing for weight reduction. In addition, although the seat support member retracts and tilts backward, interference with other members such as the gas cylinder lock release member can be easily avoided. Interference with the seat inner shell is also easily eliminated, which can be said to improve the design flexibility of the seat inner shell.

[0044] Embodiment Therefore, since the side members that make up the seat support member are L-shaped, which has high resistance to bending, high strength can be ensured while keeping the weight down. Also, when using the seat support member, a movable spring support will be connected to its front end, Embodiment In this configuration, the movable spring support can be connected using the downward-facing piece of the side member, allowing the compression coil spring to be positioned as low as possible on the base, thus promoting a thinner base.

[0045] Embodiment Therefore, since the seat support member and the back support frame are connected at points separated on the left and right sides, the stability of the back support frame and seat support member is high, enabling a smooth reclining position. [Brief explanation of the drawing]

[0046] [Figure 1] The diagram shows the external appearance of the chair according to the embodiment, where (A) is a perspective view showing a 3-stage mid-back type, (B) is a perspective view showing a 4-stage high-back type, (C) is a perspective view showing a 2-stage low-back type, and (D) is a perspective view showing a 2-stage mid-back type. [Figure 2] (A) is a partial side view, (B) and (C) are separate side views, (D) is a perspective view from the rear and lower, and (E) is a perspective view from the front and lower. [Figure 3] (A) is a separated perspective view, and (B) is a perspective view with the seat removed. [Figure 4] (A) is a partial, isolated perspective view of the reclining mechanism, and (B) is an overall, partially isolated perspective view showing the reclining mechanism. [Figure 5]This is a perspective view of the seat area excluding the cushion. [Figure 6] (A) is a separated perspective view of the seat, and (B) is a rearward perspective view with the back support frame separated. [Figure 7] This is a plan view with the seat support member omitted. [Figure 8] (A) is a perspective view showing the seat inner shell separated, and (B) is a downward perspective view showing the functional state of the seat catch. [Figure 9] This is a longitudinal cross-sectional side view of the seat. [Figure 10] This diagram shows the lifting and lowering mechanism and the tilting control mechanism. (A) is a separated perspective view from the front, and (B) is a perspective view from the rear. [Figure 11] This diagram shows the lifting and lowering mechanism and the tilting control mechanism. (A) is a perspective view from the front and above, (B) is a perspective view from the rear and side, and (C) is a perspective view from below and side. [Figure 12] (A) and (B) are separate perspective views of the control unit, and (C) is a separate perspective view of the tilt control mechanism. [Figure 13] The diagram shows the tilt control mechanism. (A) is a separated perspective view seen from the upper front, (B) is a perspective view seen from the upper front, (C) is a separated perspective view seen from the rear lower, (D) is a separated perspective view seen from the front right lower, (E) is a separated perspective view seen from the front lower, and (F) is a perspective view of the guide member of the tilt control mechanism seen from the side. [Modes for carrying out the invention]

[0047] Next, embodiments of the present invention will be described based on the drawings. In the following, the terms front, back, left, and right will be used to specify directions, but these terms are defined as directions as seen from the perspective of a person sitting normally in a chair. The up and down direction is the vertical direction, and the front view is the direction opposite to the user.

[0048] (1) Overview of the chair First, the chair's overview will be explained primarily based on Figures 1-4. The embodiment is applied to a swivel chair commonly used in offices and other similar settings. The basic structure of the chair is the same as conventional chairs, and it includes, as essential elements, a leg assembly 1, a seat 2, and a backrest 3. The leg assembly 1 has a leg support 4 made of a gas cylinder and leg wings 5 ​​extending radially, with casters provided at the ends of the leg wings 5.

[0049] As shown in Figures 3 and 4, a tray-shaped base 6 is attached to the upper end of the leg support column 4, and an L-shaped back support frame 7 is connected to the base 6 so as to be able to tilt backward, and a backrest 3 is attached to the back support frame 7. The back support frame 7 has a horizontal part 7a and an upright part (support column part) 7b, and the upright part 7b is inserted into the interior of the backrest 3 from below.

[0050] As will be described in more detail later, as shown in Figure 2(D), downward-facing portions 8 are formed on the front end of the back support frame 7, extending downward through the base 6. These downward-facing portions 8 are connected to downward-facing pivot supports 9 projecting downward from the base 6 by longitudinal support shafts 10. Therefore, the back support frame 7 and the backrest 3 tilt backward using the support shafts 10, which are located lower than the lower surface of the base 6, as the pivot point. The downward-facing portions 8 and the downward-facing pivot supports 9 are covered by a cover 11.

[0051] As can be seen from Figure 1, the backrest 3 of this embodiment is configured to be made up of multiple backrest units 12 stacked on top of each other to create different heights. Figure 1(A) shows a middle-back specification consisting of three units 12, (B) shows a high-back specification consisting of four backrest units 12, (C) shows a low-back specification consisting of two backrest units 12, and (D) shows a middle-back specification consisting of two units 12. A low-back specification using only the lower unit 12 in (D) is also possible.

[0052] As shown in Figures 3 and 4, the seat 2 has a synthetic resin inner shell 14 and a seat cushion material 15, and the seat cushion material 15 is covered with upholstery (surface material) not shown. The seat cushion material 15 is made of a foamed resin such as urethane resin and is integrally molded to the seat inner shell 14 by insert molding or two-color molding. Alternatively, a separate product such as a seat cushion can be used as the seat cushion material 15 and placed on top of the seat inner shell 14.

[0053] As shown in Figures 3 and 4, a lattice-structured seat support member 16 is positioned between the seat 2 and the base 6. The seat support member 16 has long left and right side members 17 in the front-rear direction, long left and right front members 18 connected to the front of the left and right side members 17, and a stay (upper stopper) 19 connecting the left and right side members 17 near the rear end. The rear ends of the side members 17 and the horizontal portion 7a of the back support frame 7 are connected by an interlocking shaft 20.

[0054] The horizontal portion 7a of the back support frame 7 has a pair of upward-facing projections (upward ribs) 21, which are V-shaped in side view and located on the inner surfaces of the left and right side members 17, and the interlocking shaft 20 is inserted through the upward-facing projections 21.

[0055] As shown in Figures 3(B) and 4, two compression coil springs 23 that expand and contract in the front-to-back direction are arranged in parallel in a horizontal position inside the front part of the base 6. The rear end of each compression coil spring 23 is supported by a weir 24 formed in the base 6, and the front end is supported by a movable spring support 25. Left and right longitudinal slide supports 26 are fitted into the movable spring support 25, and both left and right ends of the slide supports 26 are connected to downward-facing pieces 17a of side members 17 that constitute the seating member 16.

[0056] Therefore, as shown in Figure 2(C), the seat support member 16 compresses the compression coil spring 23, causing the back support frame 7 and backrest 3 to tilt backward around the pivot shaft 10. However, since the rear end of the seat support member 16 and the back support frame 7 are connected by the interlocking shaft 20, the seat support member 16 and the seat 2 move backward and downward in conjunction with the backward tilting of the backrest 3. In this case, the distance between the pivot shaft 10 and the interlocking shaft 20 is much smaller than the distance from the pivot shaft 10 to the backrest 3, so the amount of downward movement of the rear end of the seat 2 is also much smaller than the amount of downward movement of the backrest 3. The backrest 3 is a cushion type with back cushioning material stretched over the front of the back inner shell, but it is made as thin as possible.

[0057] For example, as shown in Figures 2(D) and 2(E), the left and right long operating cylinders 27 are provided protruding from the right side of the base 6, in front of the leg support 4. A lever 28 is provided at the tip of the operating cylinder 27, protruding diagonally downward and forward, which a seated person can place their finger (thumb) on. By pushing the lever 28 downward with the fingertip and rotating the operating cylinder 27, the lock on the leg support 4 is released, and the seat 2 can be adjusted to any desired height.

[0058] The operating cylinder 27 has a push button 29 that protrudes to the right outside of the lever 28. The push button 29 is part of a tilt control mechanism that switches the backrest 3 between a reclined and non-reclined state. When the push button 29 is pressed, as indicated by the arrows in Figures 2(D) and 2(E), the lower stopper 30 shown in Figure 3(B) alternately changes position between the reclined and forward positions in conjunction with repeated push operations.

[0059] When the lower stopper 30 is in the forward position, the stay 19 of the seat support member 16 becomes free to descend, and the backrest 3 can recline freely. On the other hand, when the lower stopper 30 is retracted, the lower stopper 30 is positioned directly below the stay 19 of the seat support member 16, preventing the seat support member 16 from descending, and as a result, the backrest 3 is locked in a position where it cannot be tilted backward. It is also possible to change the backward tilt angle of the backrest 3 by forming the lower stopper 30 in a stepped shape when viewed from the side.

[0060] The chair is equipped with an optional armrest 13. The armrest 13 has an arm support 13b with an inward-facing portion 13a at its lower end. As shown in the figures of Figure 2, outward-facing openings 13c are formed on the left and right inner surfaces of the base 6, into which the inward-facing portion 13a of the arm support 13b is inserted and fixed.

[0061] (2) Structure of the seat Next, we will explain the structure of the components and the details of the reclining mechanism. First, let's describe the seat inner shell 14. As shown in Figure 3(A), the upper surface of the seat inner shell 14 is roughly curved upwards in a front view, and the rear part is also curved slightly downwards in a side cross view. The upper surface of the seat cushion material 15 has a similar shape to the seat inner shell 14. In other words, it has a three-dimensionally concave structure to fit the person sitting on it.

[0062] The seat 2 has a roughly rectangular shape with rounded corners, and as shown in Figure 8(A), it has the same shape as the seat inner shell 14. As shown in Figure 8(A), a pair of positioning bosses 32 are provided projecting downward from the rear of the lower surface of the seat inner shell 14, and the positioning bosses 32 are set to be in close contact with or close to the inner surfaces of the left and right side members 17 of the seat receiving member 16. Therefore, the seat inner shell 14 and the seat receiving member 16 are held in a position where they cannot be shifted from side to side.

[0063] The seat inner shell 14 is an injection-molded product made of synthetic resin such as polypropylene, and as shown in Figure 8(A), it has a recess 34 surrounded by an inner wall 33 that surrounds the seat support member 16. As can be seen from the comparison in Figures 2(B) and 2(C), the entire seat support member 16 is set to fit into the recess of the seat inner shell 14.

[0064] Numerous triangular reinforcing ribs 35 are connected to the inner wall 33 and base plate that constitute the seat inner shell 14. As a result, although the outer surface of the seat 2 is a sloping surface that tapers downwards, the outer surface is not visible when viewed from an oblique angle while a person is standing, thus giving it a slim appearance. As shown in Figure 8(A), numerous communication holes 36 are formed in the base plate of the seat inner shell 14. The seat cushion material 15 penetrates through the communication hole 36 and extends downward, filling the space between the reinforcing ribs 35.

[0065] Although not explicitly shown in the diagram, the upholstery also covers the inclined surface of the seat cushion material 15. As a means of securing the upholstery, tape material is sewn to the inner edge, and the tape material consists of multiple strips, which snap into place on bosses 33a provided on the inner surface of the inner wall 33 (it is fitted in using elastic deformation). The upholstery can also be secured by tightening it with a string or by stapling.

[0066] The seat inner shell 14 is connected to the seat receiving member 16 using left and right catches 37. Specifically, as shown in Figure 8(A), left and right hook-shaped claws 39 are integrally formed on the front of the recess in the seat inner shell 14, and the hook-shaped claws 39 are held by the front member 18 of the seat receiving member 16 from the front, while the left and right catches 37 are inserted from the rear into the rectangular tunnel portion 40 provided at the rear of the seat inner shell 14, and the claws 38 at the tips of the catches 37 are fitted from the front into the lateral engaging pieces 41 formed on the side member 17 of the seat receiving member 16.

[0067] The catch 37 is biased backward by a spring 46, and by pushing the catch 37 forward and fitting the seat inner shell 14 onto the seat support member 16 from the front, the seat 2 can be attached to the seat support member 16 with a single touch. Conversely, by pushing the catch 37 from behind and releasing the engagement of the seat support member 16 with the catch 37, the seat 2 can be easily removed. For example, as can be seen from Figures 2(A) and 2(D), there is a through hole 42 in the rear part of the seat cushion material 15 for inserting the catch 37.

[0068] Although not shown in the diagram, the catch 37 is covered with upholstery. Therefore, when the seat 2 is attached to the seat support member 16, the catch 37 is not visible to the eye, resulting in a clean and aesthetically pleasing appearance. However, since the catch 37 can be pushed from behind through the upholstery, there is no hindrance to attaching or detaching the seat 2.

[0069] As shown in Figure 8, forward-facing slits 43 are formed in the left and right intermediate portions of the front member 18 that constitutes the seat support member 16, while positioning ribs 44 that fit into the slits 43 are formed on the seat inner shell 14. Therefore, the seat inner shell 14 is held in place at the front by the ribs 44 to prevent lateral displacement, and at the rear by the left and right catches 37 to prevent lateral displacement. The seat inner shell 14 has a group of foot portions 45 that contact the seat support member 16 from above.

[0070] (3) Seat support member, base, and back support frame The base 6 is made of metal, such as die-cast aluminum (it can also be made of resin), and is roughly shaped like a rectangular tray that is long in the front-to-back direction. For example, as shown in Figure 2, the outer surface is sloped to taper downwards, but it is slightly offset inward from the lower end of the seat inner shell 14. Therefore, the base 6 is not visible to a person in a normal viewing position.

[0071] As the seat 2 moves relative to the base 6, as can be seen from Figure 2(E), there is a small gap between the outer circumference of the base 6 and the recess 34 of the seat inner shell 14. As shown in Figure 8(A), upward-facing ribs 47 are provided on both the left and right sides of the base 6, while notches 48 are formed in the inner wall 33 of the seat inner shell 14 to accommodate the ribs 47. The notches 48 are closed by the seat cushion material 15, and the ribs 47 are positioned inside the seat cushion material 15.

[0072] The ribs 47 and notches 48 are positioned in areas corresponding to the inward-facing portion 13a of the armrest 13 and the base end of the operating cylinder 27, and are intended to prevent finger pinching when the armrest 13 is attached and when the operating cylinder 27 is provided. Specifically, when the armrest 13 is attached, if a finger is inserted into the gap between its inward-facing portion 13a and the inner shell 14, the inner shell 14 may descend, potentially pinching the finger between the inner wall 33 of the inner shoulder and the inward-facing portion 13 of the armrest 13. Therefore, notches 48 are formed in the inner wall 33 to prevent finger pinching. Furthermore, to prevent fingers inserted inward through the notches 48 from being pinched between the inner wall 33 and the base 6, ribs 47 are provided to prevent fingers from being inserted inside the lower inner part 33. The operating cylinder 27 is treated similarly.

[0073] The notch 48 is covered with cushioning material 15, and the notch 48 cannot be seen from the outside (when attempting to insert a finger, the cushioning material 15 deforms to prevent finger pinching). ). On the right side of the seated person, an inward-facing portion 13a and an operating cylinder 27 are provided side by side, front to back. Therefore, the ribs 47 and notches 48 provided on the left and right sides are formed to be longer front to back on the right side than on the left side of the seated person. In any case, the notches 48 are covered with the seat cushion material 15, so finger pinching can be prevented without compromising aesthetics.

[0074] The seat support member 16 has the form already described, but as shown in Figure 4 for example, the side member 17 has an L-shape with a downward-facing piece 17a on its longitudinal inner edge, and the stay 19 is welded to the left and right downward-facing pieces 17a. The interlocking shaft 20 is inserted through the upward-facing projection 21 of the back support frame 7 via a bush 49. The interlocking shaft 20 is secured in place by a snap ring or the like.

[0075] For example, as shown in Figure 5, the front member 18 is fixed to the side member 17 with screws 50. Therefore, even if some distortion occurs when the stay 19 is welded to the left and right side members 17, the front member 18 can be fixed to the side members 17 in the correct position. In other words, even if distortion occurs during the welding of the stay 19, the distortion can be absorbed and the seating member 16 can be finished with high precision. At the rear end of the front member 18, a downward-facing piece 18a is bent to contact the inner surface of the side member 17. Therefore, dimensional accuracy can be further improved and strength can be increased.

[0076] For example, as shown in Figures 3(B) and 4(B), the horizontal portion 7a of the back support frame 7 and the rear ends of the left and right upward protrusions 21 are integrally connected by the left and right longitudinal rib plates 51. As a result, the back support frame 7 maintains high strength while being as thin as possible.

[0077] As shown in Figure 5, a thick, elongated weir section 24 is formed in the interior of the base 6, slightly towards the rear, and the leg supports 4 are fitted from below into the middle of the weir section 24. Therefore, the weir section 24 has a downward-expanding tapered hole 52 (see Figure 6) into which the leg supports 4 are fitted. Also, as shown in Figures 4(B) and 5, the base 6 has a rearward-facing land section 53 that is integrally continuous with the weir section 24, and there are relief holes 54 (see also Figure 6(A)) on both the left and right sides of the rearward-facing land section 53 through which the downward-facing portion 8 of the back support frame 7 passes.

[0078] As shown in Figure 6(A) (see also Figure 2(D)), a downward-facing pivot support 9 is integrally formed below the rearward-facing land portion 53, and the downward-facing portion 8 of the back support frame 7 is connected to the downward-facing pivot support 9 by a support shaft 10. The support shaft 10 is fixed to the downward-facing pivot support 9 by screws 55 shown in Figures 6(A) and 9 (it can also be locked in place by the cover 11). The cover 11 is positioned on the base 6 by an upward-facing boss portion 56, and screws 57 that penetrate the base 6 from above are screwed into the boss portion 56. The cover 11 has a flange 11a, and the base 6 has a stepped portion 58 into which the flange 11a fits.

[0079] The structure has a base 6 and a shallow tray-like shape with an upward opening, but as shown in Figure 4(B), for example, the base 6 is open towards the rear. That is, an opening 6a is formed at the rear end of the base 6, and the front end of the back support frame 7 fits into the opening 6a. Furthermore, as shown in Figure 6(A), for example, a downward-facing rib 59 is provided at the front end of the horizontal portion 7a of the back support frame 7.

[0080] As can be clearly seen from Figure 9, the downward-facing rib 59 is in close proximity to the rear end of the base 6 with only a small gap between them, and closes the gap between the back support frame 7 and the base 6 from the state before the back support frame 7 is tilted backward to the state when it is fully tilted backward. Therefore, it is possible to keep the horizontal portion 7a of the back support frame 7 as close as possible to the bottom surface of the base 6, while preventing a person's fingers from being inserted between the back support frame 7 and the base 6. Thus, the downward-facing rib 59 functions as a safety device, but also has a reinforcing effect on the back support frame 7. The front surface of the downward-facing rib 59 is formed in an arc centered on the support axis 10.

[0081] Referring to Figure 2, we mentioned the outward-facing opening 13c for attaching the armrest 13, which is formed at the location of the weir 24. As a result, the support strength of the armrest 13 is excellent.

[0082] (4) Reclining mechanism The support mechanism for the compression coil spring 23 has been outlined with reference to Figure 4, but will be described in more detail below. The rear end of the compression coil spring 23 is supported by the weir section 24 via a fixed spring support 61. Although not explicitly shown, the fixed spring support 61 has a boss that holds the side member 17 in a way that prevents lateral movement. Also, as shown in Figures 4 and 5, in the area of ​​the base 6 in front of the weir section 24, a long central projection 62 in the front-to-back direction and left and right side projections 63 located on either side of it are formed in a manner that is continuous with the weir section 24, and the fixed spring support 61 is held in a way that prevents lateral movement by the left and right side projections 63.

[0083] The front half of the side projection 63 is a stepped section 63a, and the slide support 26 is held in place by upper and lower guide rails 64 and 65 positioned at the stepped section 63a, allowing it to slide freely but preventing it from moving up and down. The upper guide rail 64 has a trough-like shape that opens upward, and the lower guide rail 65 has a trough-like shape that opens downward. The front and rear ends of the upper guide rail 64 are fixed to the stepped section of the side projection 63 with screws 66, and only the front end of the lower guide rail 65 is fixed to the front end of the side projection 63 with screws 67.

[0084] As shown in Figure 4, the movable spring receiver 25 is made of die-cast aluminum or synthetic resin and has a forward-facing U-shape when viewed from the side, and the slide support 26 is fixed to the movable spring receiver 25 with screws 68.

[0085] The slide support 26 has an oval shape with flat upper and lower surfaces, and both left and right ends are connected to the side members 17 of the seating member 16 via bushings 69. Specifically, a downward-facing pivot portion 17b is formed at the front end of the downward-facing piece 17a of the side member 17, and the slide support 26 is connected to the pivot portion 17b via the bushings 69. The bushings 69 have oval-shaped holes. A burring portion 17c is formed on the downward-facing pivot portion 17b of the side member 17 to stably hold the bushings 69. The slide support 26 is made of metal. The upper and lower guide rails 64 and 65 are made of metal or synthetic resin, and grease is applied to their sliding surfaces.

[0086] (5) Overview of the operating mechanism and lifting mechanism Next, the operating mechanism will be explained with reference to the drawings from Figure 10 onwards. First, the overall outline and the lifting mechanism will be explained in Figures 10 and 11.

[0087] The operating mechanism consists of an operating unit 71 located on the base 6, an operating unit 72 located on the weir section 24 and the rearward land section 53 of the base 6, and a first wire 73 and a second wire 74 connecting the two.

[0088] The operating unit 71 has a block 76 fixed to a boss 75a on the right inner surface of the base 6 with a screw 75b (see Figure 10(A)). The block 76 also overlaps the weir section 24. Therefore, it is stably held in place by a single screw 75.

[0089] The operating cylinder 27 described above is rotatably held in block 76. As clearly shown in Figure 12(A), a two-part holding ring 77 is fixed to the base end of the operating cylinder 27 with screws, and is positioned between the holding ring 77 and the notched groove 78 formed in block 76. Therefore, the holding link 77 is fixed after the operating cylinder 27 is inserted into block 76.

[0090] A ball 73a, provided at one end of the first wire 73, is locked to the holding ring 77. Therefore, as shown in Figure 12(A), the holding ring 77 has a ball locking portion 77a. On the other hand, the ball 73a provided at one end of the first wire 73 is locked to the upper end of a valve retaining member 79 provided on the operating unit 72. The valve retaining member 79 is a bell crank type having a pushing portion located on the axis of the leg support 4, and its upper and lower intermediate portions are rotatably mounted on the base material 80 of the operating unit 72.

[0091] Between the operating unit 71 and the operating unit 72, a trough-shaped guide body 81 is positioned to hold the first wire 73 in a bent state. As shown in Figure 7, the guide body 81 is fixed to the weir section 24 with screws 82. When a seated person pushes down the lever 28 and rotates the operating cylinder 27, the first wire 73 is pulled through the guide body 81, causing the valve retaining member 79 to rotate. This pushes down the valve (see, for example, Figure 10) 4a protruding from the upper end of the leg support 4, releasing the lock on the leg support 4.

[0092] The operating wire is often inserted through a flexible tube, in which case the wire is pulled by fixing both ends of the tube. However, the tube needs a certain radius of curvature or greater in order for the wire to slide smoothly. If the wire is short and the force is applied in different directions from left to right, the degree of bending is increased by lengthening the wire and tube, but this has the problem of making the wire and tube unnecessarily long.

[0093] In contrast, by using a curved guide body 81 as in this embodiment, the first wire 73 can be held in a curved state without using a tube, so that the lock of the leg support 4 can be accurately released while keeping the first wire 73 to the minimum necessary length.

[0094] (6) Tilt control mechanism For example, as shown in Figure 11(A), the block 76 of the operating unit 71 has an extension portion 76a that extends forward and to the left inward of the operating cylinder 27. The first link 83, which constitutes the tilt control mechanism, is attached to the extension portion 76a via a screw 84 (and boss) so as to be horizontally rotatable. The first link 83 has a first portion 83a that faces the axis side of the operating cylinder 27 with the screw 84 in between, and a second portion 83b into which the ball 74a at one end of the second wire 74 engages. Since the second portion 83b is much larger than the first portion 83a, the movement of the tip of the first portion 83a is amplified and transmitted to the second portion 83b.

[0095] On the other hand, as shown in Figures 12(A) and 12(B), the operating cylinder 27 contains a rod 85 that abuts against the first portion 83a of the first link 83, an intermediate member 86 fitted onto the push button 29, a first spring 87 that pushes the intermediate member 86 outward, and a second spring 88 that biases the rod 85 in the forward direction. The rod 85 has a flat plate portion 85a that fits into the intermediate member 86. The tip of the flat plate portion 85a is a bifurcated portion 85b, and a claw 85c formed on the bifurcated portion 85b engages with an elongated hole 89 provided in the intermediate member 86.

[0096] The second spring 88 is fitted onto the flat plate portion 85a of the rod 85 and abuts against the intermediate flange 85d provided on the rod 85. Therefore, the rod 85 is biased inward by the second spring and is held in place by the claw 85c so as not to come off the intermediate member 86. The intermediate member 86 is held in place so as not to come off by a cap 90 that is forcibly fitted onto the operating cylinder 27 from the outside. An end flange 85e is provided near the tip of the rod 85 to prevent vibration.

[0097] When the push button 29 is pressed, the rod 85 moves forward via the intermediate member 86 and the second spring 88, causing the first link 83 to rotate. However, even if the first link 83 does not rotate, pressing the push button 29 is permitted. That is, as the intermediate member 86 moves forward, the rod 85 tends to move backward relative to the second spring 88, allowing the push button 29 to be pressed while the first link 83 does not rotate. In other words, even if, for example, a person is leaning against the backrest 3 and the lower stopper 30 is immobile, pressing the push button 29 is permitted to prevent damage to the components.

[0098] As previously described, the operating unit 72 is equipped with a plate-shaped base material 80. The base material 80 overlaps the weir portion 24 and the rearward-facing land portion 53 of the base 6 and is fixed to the weir portion 24 with screws 92, for example, as shown in Figure 11(A). As shown in Figure 12(C), the lower stopper 30 overlaps the base material 80 in the form of a left-right elongated block, but is held in place by left and right inverted L-shaped rails 93 provided on the base material 80, allowing it to slide back and forth freely and preventing it from being pulled out from above.

[0099] In other words, the lower stopper 30 has a front plate portion 30a, with notches cut out to correspond to the left and right inverted L-shaped rails 93, and the middle portion of the front plate portion 30a is fitted into a dovetail groove made by the left and right inverted L-shaped rails 93, thereby allowing it to slide freely back and forth but preventing it from moving upward.

[0100] As shown in Figure 13(B), the lower stopper 30 has left and right longitudinal second links 94 positioned on the front plate portion 30a. As shown in Figure 12(C), the left end of the second link 94 is horizontally rotatable connected to the left end of the base material 80 via a boss 95 and a screw 96, and the right end of the second link 94 is fitted onto a boss 97 that protrudes upward from the lower stopper 30.

[0101] Therefore, when the second link 94 rotates with its left end as the pivot point, the lower stopper 30 changes position from a free position located in front of the stay 19 of the seating member 16 to a locked position located directly below the stay 19, as previously described. Note that in Figure 10, the lower stopper 30 is shown in both the free position and the locked position.

[0102] The rotation of the second link 94 is performed, for example, by a slider 98 shown in Figure 13(D). As shown in Figure 13(C), the slider 98 is slidably fitted into a cylindrical portion 99 formed on the lower surface of the base material 80. The slider 98 has an upward-facing boss 98a, which is inserted from below into the portion of the second link 94 closer to the rotation center. Therefore, the forward and backward movement distance of the right end of the second link 94 is greater than the movement distance of the slider 98.

[0103] For example, as shown in Figure 12(C), notches 100 and 101 are formed in the base material 80 and the lower stopper 30 to prevent interference with the upward boss 98a of the slider 98. (See also Figures 13(A) and 13(D)).

[0104] The slider 98 is driven by the second wire 74 described above. That is, when the push button 29 on the operating cylinder 27 is pressed, its movement is converted into the rotation of the second link 94, and the rotation of the second link 94 is converted into the movement of the slider 98 via the second wire 74, causing the lower stopper 30 to move back and forth. The amount of movement of the push button 29 is first amplified by the first link 83 and then secondarily amplified by the second wire 74. Therefore, even if the push dimension of the push button 29 is small (a few mm), the lower stopper 30 can be moved back and forth significantly, changing it between the free position and the locked position.

[0105] In this case, repeatedly pressing the push button 29 causes the lower stopper 30 to alternately switch between the free position and the locked position. As shown in Figures 13(A) and 13(C), the mechanism consists of a fixed cam 102 and a rotary cam 103 arranged concentrically behind the slider 98 and housed together with the slider 98 in the cylindrical portion 99 of the base material 80. A ball 74b provided at the other end of the second wire 74 is inserted into and locked to the rotary cam 103. The rotary cam 103 is guided by the fixed cam 102 and can rotate intermittently. With each intermittent rotation, its front-to-back position changes between being engaged with the fixed cam 102 and resting on the rear surface of the fixed cam 102.

[0106] Furthermore, the slider 98 and cams 102 and 103 are biased rearward by a spring 104. The spring 104 is supported from the front by a guide member 105 that is attached to the base material 80 from the front. Due to the action of the spring 104, the front-rear position of the slider 98 changes in accordance with the change in the front-rear position of the rotary cam 103, and the second link 94 rotates accordingly.

[0107] The guide member 105 has a support function for the spring 104 and a guide function for the second wire 74. As shown in Figure 13(E), the second wire 74 is pulled out forward and upward through the inside of the guide member 105. Therefore, it has a guide surface 105a that holds the second wire 74 in an upward position. The second wire 74 is fitted into the guide member 105 from the right side. Consequently, the guide member 105 has an opening on the right side.

[0108] Although not shown in the diagram, the second wire 74 is inserted through a flexible tube, and locking devices are provided at one end and the other end of the tube to fix its position. The locking device at the other end of the tube is attached to the upper part of the guide member 105. Therefore, the guide member 105 is provided with a pair of locking ribs 106 into which the annular grooves of the locking device fit.

[0109] As shown in Figure 13(F), the base material 80 has a space 107 into which the guide member 105 enters from the front. When the guide member 105 is attached to the base material 80, the space created by the pair of locking ribs 106 of the guide member 105 is closed by the right inner surface of the space 107 in the base material 80. Therefore, the locking device at the other end of the tube is held in place by the base material 80 in a way that prevents it from coming loose.

[0110] To secure a locking device attached to one end of the tube of the second wire 74, for example, as shown in Figure 10, an upward-facing receiving portion 108 is provided on the inner surface of the right front corner of the base 6. The locking device is held in place from above by a retaining member, which is fixed with screws to a boss 109 attached to the receiving portion 108.

[0111] (7) Summary In this embodiment, when viewed from a diagonal side while standing, only the top surface (seat surface) and the end edge of the seat 2 are visible, and the base 6 is not visible. Combined with the fact that the backrest 3 is flat, it presents a simple appearance. However, because it has a synchronized reclining function, it is perceived as a highly functional chair that exceeds expectations based on its appearance, and can be said to receive high praise from users. Therefore, the product value can be improved. In addition, since all movable parts are hidden inside the base 6, it is compact and does not detract from the aesthetics, and there is no problem of fingers getting pinched on the left and right sides.

[0112] As can be seen from Figure 9, the backward load acting on the backrest 3 (backrest load) acts as a moment on the interlocking shaft 20. Therefore, a certain distance (span) is required between the support shaft 10 and the interlocking shaft 20 for the safety of the members. However, as in the embodiment, if most of the seat support member 16 is fitted into the recess 34 of the seat inner shell 14 and positioned higher than the compression coil spring 23, or if the downward shaft support 9 is provided projecting downward from below the base 6, it is preferable to make the seat thinner while securing the necessary distance between the two support shafts 10 and 20.

[0113] In this embodiment, the downward-facing pivot support 9 to which the back support frame 7 is connected is located below the rearward-facing land portion 53, and therefore the downward-facing pivot support 9 is formed with high strength to firmly support the support shaft 10.

[0114] As already mentioned, in chairs with movable elements, such as reclining chairs, there is a problem of fingers getting pinched due to the gap between the movable and fixed elements becoming blocked. As means of preventing fingers from getting pinched, there are two methods: one that prevents fingers from getting pinched by increasing the gap, and another that prevents fingers from getting pinched by blocking the gap. An example of the latter is disclosed in Japanese Patent Publication No. 10-127403.

[0115] In Japanese Patent Publication No. 10-127403, the seat is fixed to the base, and to prevent fingers from getting caught in the gap between the rear of the seat 2 and the back support frame, a downward-facing wall is provided on the underside of the seat and an upward-facing wall is provided on the back support frame. This is difficult to apply to a structure in which the back support frame 7 is inserted inside the base 6, as in this embodiment. Furthermore, in Japanese Patent Publication No. 10-127403, fingers get caught when the back support frame returns to its original position, but in this embodiment, fingers get caught when the back support frame 7 tilts backward, and in this respect as well, the configuration of Japanese Patent Publication No. 10-127403 is difficult to apply.

[0116] In this embodiment, finger pinching is prevented by providing a downward-facing rib 59 at the front end of the back support frame 7. No special processing is required for the base 6, and there is also the advantage of being able to reinforce the back support frame 7.

[0117] As in the embodiment, by welding the stay 19 to the seat support member 16, the seat support member 16 becomes lighter while maintaining a robust structure. Therefore, even if the interlocking shaft 20 is not welded to the side member 17, the back support frame 7 and the seat support member 16 can be securely connected.

[0118] As in the embodiment, sandwiching the slide support 26 between the upper and lower guide rails 64 and 65 provides excellent ease of assembly. Furthermore, since the upper and lower surfaces of the slide support 26 are flat (they are in surface contact), the load per unit area of ​​the slide support 26 and the guide rails 64 and 65 is small, resulting in high durability. In addition, the movable spring receiver 25 is held in place by a pair of guide rails 64 and 65 on the left and right sides, preventing lateral movement, thus providing high stability to the movable spring receiver 25. Moreover, since the slide support 26 is fixed to the movable spring receiver 25 with screws 68, there is no need for a means to prevent the slide support 26 from coming off the side member 17, thus simplifying the structure.

[0119] The embodiments of the present invention have been described above, but the present invention can be implemented in various other ways. For example, it is possible to connect the seat inner directly to the base without using a seat support member. The seat support member may be made of synthetic resin. The seat 2 can also be constructed by stretching mesh material over a frame (or shell with an upper recess) that has openings at the top and bottom. In other words, the present invention can also be applied to chairs with a mesh design. A four-legged leg system can also be adopted for the leg device. [Industrial applicability]

[0120] The present invention can be applied to reclining chairs. Therefore, it is industrially applicable. [Explanation of symbols]

[0121] 1 leg device 2nd seat 3 Backrest 4-legged support (gas cylinder) 6 Base 7. Back support frame 8. Downward part of the back support frame 9. Downward pivot support 10 spindle 14-seat inner shell 15. Seat cushion material 16. Seat support member 17 Side Members 17a Downward-facing piece 18 Front Members 19. Stay (upper stopper) 20 Interlocking shaft 21 Upward projection 23 Compression coil spring 24 Weir 25. Movable spring receiver 26 Slide Support 27. Operating cylinder (lever shaft) 28 Lever (finger rest) 29 Push button 30 Lower stopper 34. Recess 59 Downward Ribs 61 Fixed spring receiver 64, 65 Guide rails

Claims

1. It comprises a base supported by a leg mechanism, a seat positioned above the base, a back support frame connected to the base via left and right longitudinal support shafts so as to be able to tilt backward, a backrest attached to the back support frame, and a reclining compression coil spring that provides elastic resistance to the backward tilting of the back support frame. In a chair in which the rear of the seat or seat support member and the back support frame are connected via left and right longitudinal interlocking shafts, when the backrest and back support frame tilt backward, the interlocking shafts rotate around the pivot shaft as a fulcrum, causing the seat to move backward while tilting backward, The base has an upward-opening tray shape, and the reclining compression coil spring is positioned inside the base in a substantially horizontal position so as to be compressed rearward in conjunction with the backward movement of the seat. The support shaft is positioned lower than the reclining compression coil spring without protruding to the left and right sides of the base, and the interlocking shaft is positioned higher than the reclining compression coil spring and behind the support shaft without protruding to the left and right sides of the base. Reclining chair.

2. The support shaft is connected to a support shaft portion projecting downward from the rear of the base, the support shaft portion has a width smaller than the width of the base, and the portion of the lower surface of the base excluding the support shaft portion is formed in a flat shape. A reclining chair as described in claim 1.

3. The seat comprises a seat inner shell made of synthetic resin and a seat cushion material placed on top of the upper surface of the seat inner shell, The seat inner shell has a downward-facing recess formed therein into which the seat receiving member enters from below, and the interlocking shaft is positioned in the recess of the seat inner shell. A reclining chair as described in claim 1 or 2.

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