JP7385405B2 - Chair - Google Patents

Description

The present invention relates to a chair having a rocking function, and is directed to a chair in which a backrest and a seat are separated.

Chairs have a wide variety of structures and can be classified according to various criteria, but one criterion is whether or not the backrest has a rocking function. In the case of a simple structure called a pipe chair, it often does not have a locking function. Even in rotating chairs whose legs are made of gas cylinders, the backrest often does not have a locking function.

Therefore, it has been proposed to provide the backrest with a locking function using a structure as simple as possible. As an example, Patent Document 1 describes a type of chair in which a backrest and a seat are integrally continuous, and there are side supports on both the left and right sides of the seat that are T-shaped in side view and whose upper ends are the upper horizontal portions of the front and rear longitudinal sides. The seat is suspended from the front part of the upper horizontal part so as to be movable back and forth, and the backrest is connected to the rear part of the upper horizontal part via an upper support frame so as to be tiltable backward.

In Patent Document 1, the upper support frame has left and right side parts and a rear part connected to the rear end, and surrounds the backrest from behind. A receiving bracket connected to the shaped part is fixed, and the spring is sandwiched between the receiving bracket of the upper support frame and the upper horizontal part of the side part.

Further, Patent Document 2 discloses that backward-facing arms made of pipe material are arranged on both the left and right sides of the seat and at a higher position than the seat, and a backrest is attached to the arms so as to be tiltable backwards. In Patent Document 2, a boss body is provided to protrude sideways from the left and right sides of the backrest, and the boss body is inserted into the rear end of the arm, thereby making it possible to tilt the backrest backwards, and to make the backrest move forward and backward inside the arm. A long leaf spring is arranged, and the front end of the leaf spring is fixed to the arm, and the rear end is fixed to the boss body, thereby providing elastic resistance to the backward tilting of the backrest. .

Japanese Patent Application Publication No. 2007-167577 Microfilm of Utility Model No. 61-129557

Patent Document 1 targets a type of chair in which a backrest and a seat are integrally connected, and cannot be applied to a chair with a separated back and seat type as targeted by the present invention. Also, since the back and seat are integrated, the rocking angle cannot be made too large.

On the other hand, Patent Document 2 targets a chair with a seat and back separation system similar to the present invention, but in Patent Document 2, the left and right arm portions are separated, and the rear ends (free ends) of the separated arm portions are separated from each other. Since the backrest is connected to the backrest, the load acting on the backrest acts to spread the left and right arm portions. Therefore, in order to ensure the necessary strength and smooth rotation, it is necessary to configure the arm portion with a thick member to ensure rigidity, which may cause problems in terms of weight and design.

In addition, the backrest is connected to the bearing hole of the arm part by a pin (support shaft) that protrudes to the left and right outside, but since the support shaft is in a cantilevered state, the load acting on the backrest causes There is a risk that twisting may easily occur between the pin and the bearing hole, and therefore, in order to ensure smooth rotation, it is necessary to increase the size of the member to ensure rigidity.

The present invention includes various configurations, typical examples of which are specified in each claim. Among these, the invention of claim 1 is:
"It has a seat and a backrest that are separated from each other, and an upper support frame to which the backrest is attached at a position higher than the seat,
The upper support frame has side parts located on the left and right sides of the backrest and the seated person, and a rear part in which the left and right side parts are connected in series , and the rear part of the upper support frame has : The backrest is attached so that it can tilt backward through a left and right longitudinal support shaft that connects a forward-facing receiving bracket provided on the rear portion and a push bracket provided on the backrest,
An elastic body that provides resistance to backward tilting of the backrest is disposed between the receiving bracket and the pushing bracket .
In the basic configuration,
``The backrest includes a back inner shell made of synthetic resin in which a large number of reinforcing ribs extending vertically and horizontally are formed on the back surface, and by partially cutting out the reinforcing ribs on the back inner shell, the reinforcing ribs are partially cut out. A recess is formed in which the movable bracket is fixed, and the support shaft and the elastic body are arranged in the recess .
This configuration has been added. The side portions may also be referred to as forward-facing arms.

The invention of claim 2 is, in claim 1,
"The backrest includes a back cushioning material disposed on at least the front surface of the back inner shell, and a bag-shaped skin material that entirely covers the back inner shell and the back cushioning material."
The structure is as follows.

The invention of claim 3 is:
"It has a seat and a backrest that are separated from each other, and an upper support frame to which the backrest is attached at a position higher than the seat,
The upper support frame has side parts located on the left and right sides of the backrest and the seated person, and a rear part in which the left and right side parts are connected in series, and the backrest is attached to the rear part of the upper support frame. Mounted so that it can tilt backwards
In the basic configuration,
"The backrest includes a back inner shell made of synthetic resin, a back cushioning material disposed at least in front of the back inner shell, and a bag-shaped skin material that entirely covers the back inner shell and the back cushioning material. We are equipped with
A rearward-opening recess is formed in the back inner shell into which a receiving bracket provided on the rear portion via a forward-facing boss body is inserted, and the pushing bracket fixed to the recess and the receiving bracket are connected to each other. An elastic body is disposed between the pushing bracket and the receiving bracket, which are connected by left and right longitudinal support shafts,
Further, a cover is provided that enters the recess from behind and covers the receiving bracket and the pushing bracket from behind, the support shaft is held by the cover so as not to be able to move from side to side, and the cover is fixed to the pushing bracket. It is fixed to the back inner shell of the backrest with a screw together with a moving bracket.
The structure is as follows.

The invention of claim 4 is, in claim 3 ,
" The receiving bracket and the boss body are fitted from the front and back directions, and are irremovably fixed with screws. "
The structure is as follows.

The invention of claim 5 is:
"It has a seat and a backrest that are separated from each other, and an upper support frame to which the backrest is attached at a position higher than the seat,
The upper support frame has side parts located on the left and right sides of the backrest and the seated person, and a rear part in which the left and right side parts are connected in series. The backrest is attached so that it can tilt backward through a left and right longitudinal support shaft that connects a forward-facing receiving bracket provided on the rear portion and a push bracket provided on the backrest,
An elastic body that provides resistance to backward tilting of the backrest is disposed between the receiving bracket and the pushing bracket.
In the basic configuration,
"A recess with a rearward opening to which the push bracket is fixed is formed in a lower part of the backrest, a rear part of the upper support frame is located behind the recess, and the support The shaft is placed in the recess ."
The structure is as follows.

The invention of claim 6 is:
" It has a seat and a backrest that are separated from each other, and an upper support frame to which the backrest is attached at a position higher than the seat,
The upper support frame is made of pipe or bar material, and has side parts located on the left and right sides of the backrest and the seated person, and a rear part in a horizontal position in which the left and right side parts are connected in series. The rear portion of the upper support frame and the rear surface of the backrest are curved so as to be concave forward in a plan view, and there is a gap between the rear portion and the backrest that prevents backward tilting of the backrest. There is a gap along the entire left and right length of the backrest to allow for
The backrest is connected to a forward-facing support bracket fixed to the rear portion so as to be tiltable backward, and an elastic body that provides resistance to backward tilting of the backrest is supported by the support bracket.
The structure is as follows.

In the present invention, the upper support frame can be fixedly arranged so that its posture does not change, or the upper support frame can be tilted backward as in the embodiment. If the upper support frame is also configured to be able to tilt backward, a double locking effect can provide greater comfort to the seated person.

◎Effect of each claim In each invention of the present application, since the left and right side parts and the rear part of the upper support frame are integrally connected, the left and right side parts are subjected to the action of separating from each other due to the load acting on the backrest. Never. Therefore, the upper support frame can ensure necessary rigidity without making it excessively thick.

In addition, since the connecting portion of the backrest is located between the left and right ends of the backrest, the support shaft that connects the backrest can support both ends. Therefore, the connecting portion does not become strained, and smooth rotation (back and forth tilting) of the backrest can be ensured.

In this way, the claimed inventions can stably support the backrest in a state where it can tilt smoothly without making the upper support frame excessively thick, thereby ensuring weight reduction and high design quality. At the same time, smooth rotation and high strength can be maintained.

When rotating the backrest , it is also possible to configure the backrest to rotate around the axis of the rear part of the upper support frame, but in this case, the distance between the front of the backrest and the axis of rotation is As the distance between the two increases, the backrest tends to rise while tilting backwards, which may impede the smooth backward tilting movement of the backrest. Further, as the backrest rises, a phenomenon occurs in which the backrest rises relative to the back of the seated person, which may lead to the so-called shirt-turning phenomenon.

On the other hand, if the backrest is connected to the receiving bracket that projects forward from the rear part so as to be tiltable backwards , the tilting fulcrum of the backrest can be positioned in front of the rear part of the upper support frame. Therefore, it is possible to prevent or significantly suppress the backrest from rising while tilting backward. As a result, the backrest can be tilted back smoothly, and the so-called shirt-up phenomenon can also be prevented.

Further, in order to fit the back of the seated person, the backrest is often recessed forward (inflated backward) in plan view, but in the present invention , as specified in claim 6 , By leaving a gap between the backrest and the rear part, the backrest can be tilted backward without interfering with the rear part even if the rear surface of the backrest bulges backward in plan view .

◎Effect of Claim 6 As described above, the backrest is curved in plan view as claimed in Claim 6 , so that the fit for the seated person can be improved . The backrest is curved in the same way as the rear surface of the backrest, so the design of the backrest and rear portion is unified, resulting in an excellent aesthetic appearance.

◎Effects of Claims 1 to 5 In the configurations of Claims 1 to 5 , since the connecting portion is built into the backrest, the appearance can be made neat and can greatly contribute to improving the aesthetic appearance. Further, as described above, if the pivot point of the backrest is brought as far forward as possible, the backward tilting movement of the backrest can be made smooth and the shirt roll-up can be prevented . Therefore, it is possible to ensure that the rotation fulcrum is moved toward the front. Therefore, it is highly realistic.

◎Effect of Claim 4 Now, when the backrest is rocking, an elastic body that provides resistance to backward tilting is essential, and a receiving portion supported by the elastic body and a receiving portion of the backrest that receives the elastic body by backward tilting are required. It is necessary to have a pushing part that presses towards the part. In this case, it is possible to provide the receiving part integrally with the boss body, but if the receiving part is integrated with the boss body, there is a possibility that assembling the backrest to the upper support frame becomes troublesome. In particular, in the case of a knockdown method in which separately manufactured members are assembled in an assembly factory, the advantages of the knockdown method may be lost due to the time required for assembly.

On the other hand, if the configuration of claim 4 is adopted, the backrest can be fixed by a simple operation of incorporating the receiving bracket into the recess in the backrest in advance, fitting the receiving bracket and the boss body, and fixing them with screws. can be assembled. Therefore, the chair assembly work can be carried out efficiently. Particularly, when applied to a knockdown method, it is suitable because assembly can be performed quickly without requiring operator skill.

◎Effects of Claims 3 and 5 When the configuration of claim 3 is adopted, the support shaft is held by the cover so that it cannot be removed, so the structure can be simplified and costs can be reduced. In addition, since the cover is screwed together with the push bracket to the back inner shell, it has a simple structure, but the cover is held in place, ensuring safety and preventing the support shaft from coming off. This can be achieved with
In claim 5, when the backrest is tilted backward with respect to the rear portion of the upper support frame, a large moment is applied to the backrest, making it easier to tilt the backrest backward. Further, it is possible to prevent the lower end of the backrest from hitting the seated person's body strongly.

Figures illustrating the appearance of the chair according to the first embodiment, in which (A) is a perspective view seen from the upper front, (B) is a partial front view, (C) is a perspective view seen from the upper back, and (D) is a perspective view seen from the upper front. It is a perspective view seen from the rear lower part. (A) is a plan view with the leg device omitted, (B) is a side view, and (C) is a rear view. (A) is a partial side view in a state before locking, and (B) is a side view in a locking state. (A) is a perspective view with the back cushion separated, and (B) is a separated perspective view showing the connection structure of the backrest. Both (A) and (B) are separated perspective views showing the connection structure of the backrest. (A) is a VIA-VIA sectional view of FIG. 2(C), and (B) is a perspective view showing a nut holding portion of the back inner shell. 6(A) is an exploded perspective view seen from the rear, (B) is a sectional view of the same location as FIG. 6(B), and (C) is an exploded perspective view seen from the front. FIG. It is a figure which shows the connection structure of an upper support frame, (A) is a perspective view with the cover separated, (B) is a perspective view with the upper support frame separated. It is a figure which shows the connection structure of an upper support frame, (A) is an exploded perspective view seen from the front upper part, and (B) is an exploded perspective view seen from the rear upper part. FIG. 3 is a sectional view taken along line XX in FIG. 2(A). FIGS. 3A and 3B are diagrams showing a modified example of the connection structure of the upper support frame, in which (A) is an exploded perspective view, (B) is an exploded perspective view of some members, (C) is a perspective view of the front cap, and (D) is the upper support frame. A perspective view of the frame, (E) is a sectional view of the same location as FIG. 10.

Next, embodiments of the present invention will be described based on the drawings. In the following, we will use forward/backward/left/right questions to identify directions, but these directions are based on the state seen from a person sitting normally on a chair. The front view direction is a direction facing the seated person.

(1).Outline of the chair First, the outline of the chair will be explained with reference to Figures 1 to 3. As shown in FIG. 1, the chair includes a leg device 1, a seat 2, and a backrest 3 as basic elements. The leg device 1 has a structure in which a leg column 5 made of a gas cylinder is erected at the center of a grounding body 4 having a plurality of (five) branch arms, and a caster is provided at the tip of each arm. Therefore, this embodiment is applied to a rotating chair.

As shown in FIG. 1(D), a base 6 having a substantially rectangular shape when viewed from the bottom (and when viewed from above) is fixed to the upper end of the pedestal 5. As shown in FIG. A seat support member 7 is attached to the base 6 so as to be slidable back and forth, and the seat 2 is attached to the upper surface of the seat support member 7. The base 6 is, for example, an aluminum die-cast product, and the seat support member 7 is, for example, a synthetic resin molded product.

The seat support member 7 is biased to the retracted position by a spring, and when the seated person's body becomes flexible during rocking, the seat 2 and the seat support member 7 can be pushed forward by the buttocks. In FIG. 3(B), a state in which the seat 2 is moved forward is displayed. As can be understood from the comparison between FIGS. 3A and 3B, in this embodiment, the seat support member 7 and the seat 2 move forward while rising slightly.

The chair includes an upper support frame 8 arranged at a position higher than the seat 2 so as to surround the seated person from behind. Therefore, the upper support frame 8 includes left and right side parts 9 located on the left and right sides of the backrest 3 and the seated person when viewed from the front, and left and right side parts 9 located behind the backrest 3 and the seated person when viewed from the front. It has a rear part 10 that is connected in series, and a backrest 3 is connected to the rear part 10 so as to be tiltable rearward.

Naturally, the backrest 3 is arranged in front of the rear section 10. The upper support frame 8 is manufactured from a metal pipe such as a steel pipe, but it can also be manufactured from a square steel pipe or a metal round bar or square bar.

The backrest 3 of the embodiment is curved so as to bulge backward (concave forward) in a plan view so as to support the body of the seated person from behind, and the rear part 10 of the upper support frame 8 It is curved to follow the curve of the rear surface of 3. Therefore, the rear surface of the backrest 3 and the rear portion 10 of the upper support frame 8 have similar shapes in plan view.

Furthermore, the side portions 9 and the rear portion 10 are smoothly continuous. Therefore, the left and right side portions 9 are also gently curved in plan view. Therefore, the upper support frame 8 as a whole is curved in a shape close to a circular arc, and as clearly shown in FIG. 2, there is a gap of a certain distance E between the upper support frame 8 and the backrest 3. There is. Moreover, the upper support frame 8 is in a horizontal position as a whole.

The left and right side parts 9 of the upper support frame 8 are connected to side supports 13 arranged on the left and right sides of the seat 2 so as to be tiltable backward. The side support body 13 is, for example, an aluminum die-cast product, and has a vertical and longitudinal plate-shaped support portion 14 and a front and rear longitudinal upper horizontal portion 15 integrally formed at the upper end thereof. A side portion 9 of the upper support frame 8 is connected to the rear portion of the upper horizontal portion 15 so as to tilt backward against elasticity. The upper horizontal portion 15 is covered with a protective cover 16 made of an elastomer-based elastic material.

A base portion 17 that wraps around below the seat 2 is integrally formed in the column portion 14 of the side support body 13, and the tip of the base portion 17 is connected to an engagement hole 18 (FIG. 1) formed in the base 6. D) and FIG. 2(B)), and the tip is fixed to the base 6 with a bolt.

As mentioned above, the pedestal 5 is made of a gas cylinder, and when the gas cylinder is unlocked, the heights of the seat 2 and the backrest 3 can be adjusted freely. For example, as clearly shown in FIGS. 1(A) and 1(C), a knob 19 for unlocking the gas cylinder is provided on the upper horizontal portion 15 of the right side support 13. It is mounted so that it can be rotated around the axis of 15. The knob 19 can be rotated in either the left or right direction, and the gas cylinder is unlocked when rotated in either direction.

Rotation of the knob 19 is transmitted to the unlock lever via a wire inserted through the tube. The wires are arranged in grooves formed in the column portions 14 of the side supports 13. It is also possible to attach the elbow rest 20 to the upper horizontal portion 15 of the side support 13, as shown by the dashed line in FIGS. 2(A) and 2(B).

(2) Rocking Movement As shown in FIG. 3, in this embodiment, when a seated person leans back against the backrest 3, the upper support frame 8 first tilts backward with respect to the side supports 13. This performs the first stage of locking. Next, when the seated person arches his or her upper body backward, the backrest 3 tilts backward with respect to the upper support frame 8, and a second stage of locking is performed. Therefore, even if the rotation angle of the upper support frame 8 and the rotation angle of the backrest 3 are not very large, the overall backward tilt angle can be increased. Therefore, although the structure is simple, it is possible to provide high comfort to the seated person.

Furthermore, since the rotational fulcrum of the upper support frame 8 is located at a higher position than the seat 2 and has a horizontal posture when viewed from the side, the backrest 3 does not move rearward due to the rearward tilting of the upper support frame 8. Therefore, rocking does not cause problems such as the body moving significantly backwards and causing inconvenience to the person behind.

Furthermore, when the upper body tilts backward, the body tends to stretch; however, in this embodiment, the seat moves forward, allowing the body to stretch. Therefore, the seated person can enjoy high comfort without having to lock the seat in a cramped state. In other words, by combining the two-stage locking and the forward motion of the seat, a high locking function and high comfort can be ensured without moving the backrest 3 backward.

In addition, for example, when working in an office, you may look at a monitor on a desk in a rocking position. In this case, you will lean against the backrest 3 without arching your upper body and direct your eyes toward the monitor with your chin pulled back. In the embodiment, the upper support frame 8 is tilted backward by leaning against the backrest 3 without arching the upper body, so the monitor can be viewed while maintaining a stable rocking posture.

On the other hand, when the upper body is arched, the backrest 3 tilts backward relative to the upper support frame 8. Therefore, the user can enjoy a comfortable rocking state due to the stretching effect. Therefore, the backward tilting state of the backrest 3 can be selected according to the wishes of the seated person. This point is also one of the major advantages of this embodiment.

As shown in FIGS. 2(B) and 2(C), the attachment position of the backrest 3 to the upper support frame 8 is located below the vertical intermediate height position of the backrest 3. Therefore, when the backrest 3 is tilted backward with respect to the upper support frame 8, a large moment is applied to the backrest 3, making it easy to tilt the backrest 3 backward. Further, it is possible to prevent the lower end of the backrest 3 from strongly hitting the body of the seated person.

Now, as shown in FIG. 3(A), if the backrest 3 rotates around the axis O1 of the rear end of the rear part 10 in the upper support frame 8, an arbitrary point P0 at the lower end of the backrest 3 is However, since P1 is considerably higher than P0, the backrest 3 tends to rotate while pushing up the seated person, which becomes a factor that suppresses the easy backward tilting movement of the backrest 3, and It can be said that the phenomenon of shirt turning up is more likely to occur due to the rise of the shirt relative to the back of the seated person.

On the other hand, in this embodiment, as shown in FIGS. 2(A) and 3(A), the rotation axis O2 of the backrest 3 is shifted toward the front of the back surface of the backrest 3. Even if P0 moves to P2 by tilting backward, the height positions of P0 and P2 hardly change. Therefore, the backrest 3 can be easily rotated without resistance, and the phenomenon of shirt turning up can also be prevented.

(3).Backrest and its attachment structure Next, the structure of the backrest 3 and the connection structure of the backrest 3 to the upper support frame 8 will be explained. First, the structures shown in FIGS. 4 to 6 will be explained.

As shown in FIG. 4 (see also FIG. 1(B)), the backrest 3 includes a back inner shell (backboard) 22 and a back cushioning material 23 stretched on the front surface thereof. It is covered with a skin material 24. As can be understood from FIGS. 1(C), 1(D) and 6, the skin material 24 is bag-shaped and also covers the rear surface of the back inner shell 22. Therefore, the outer appearance of the backrest 3 is mostly composed of the skin material 24. Note that the back cushion material 23 can also be attached to the back inner shell 22 by insert molding. Further, the back cushion material 23 may be wrapped around the rear surface of the back inner shell 22, either by insert molding or by retrofitting.

The back inner shell 22 is a synthetic resin molded product, and as described above, has a concave shape facing forward in plan view. Therefore, it has a shape that envelops the seated person. As shown in FIG. 4, a large number of reinforcing ribs 25 extending vertically and horizontally are formed on the rear surface of the back inner shell 22. As shown in FIG. 6, the backrest 3 is gently curved so as to swell toward the front in a vertical side view. Therefore, the seat fits the S-curve of the back and allows the seated person to easily arch his/her upper body back. Furthermore, the protrusion phenomenon caused by the lower end is less likely to occur during locking.

For example, as shown in FIG. 4(B), two left and right boss bodies 26 are protruded forward from the rear part 10 constituting the upper support frame 8, and as shown in FIGS. A receiving bracket 27 is fixed to 26. The receiving bracket 27 includes a pipe (backward protrusion) 28 that fits into the boss body 26 from the outside, and left and right forward side plates 27a, and the pipe 28 is fixed to the boss body 26 with screws 30. The boss body 26 has a solid structure (a pipe can also be used) and is welded to the rear part 10 of the upper support frame 8.

As shown in FIG. 5, in front of the receiving bracket 27, a vertically longitudinal push bracket 31 having left and right backward facing side plates 31a is arranged, and the receiving bracket 27 is arranged between the left and right side plates 31a of the pushing bracket 31. Both side plates 27a, 31a are connected by left and right longitudinal support shafts 33. Further, a block-shaped elastic body 34 made of resin rubber such as foamed urethane elastomer is disposed between the push bracket 31 and the receiving bracket 29 and above the support shaft 33.

The receiving bracket 27 and the pushing bracket 31 are covered from behind by a vertically longitudinal synthetic resin cover 35, and the receiving bracket 27, the pushing bracket 31, and the cover 35 constitute a connection unit. As shown in FIG. 4, a vertically longitudinal rectangular recess 36 is formed in the lower portion of the rear surface of the back inner shell 22 by partially eliminating the reinforcing rib 25. A connecting unit consisting of a receiving bracket 27, a push bracket 31, and a cover 35 is fitted into the position 36 from behind.

The pipe 28 of the receiving bracket 27 is covered with a cylindrical protective cap 37 made of a rubber material such as elastomer. As clearly shown in FIGS. 5 and 6, a relief hole 38 is formed in the lower part of the protective cap 37 so that the screw 30 can be inserted therethrough.

As shown in FIG. 6, a nut holding hole 40 into which a nut 39 can be fitted from the front is formed at a portion of the front surface of the back inner shell 22 corresponding to the upper and lower portions of the left and right square recesses 36. The nut 39 is formed into a rectangular shape, and an engagement protrusion 41 is formed in the nut holding hole 40 to hold the nut 39 so that it does not fall out. The nut 39 is forcibly fitted into the nut holding hole 40 with the engaging protrusion 41 deformed.

As shown in FIGS. 5 and 6, the cover 35 is formed with a pair of upper and lower overlapping parts 35a that overlap the upper and lower parts of the push bracket 31. The inserted screw 42 is screwed into the nut 39. Therefore, the cover 35 and the push bracket 31 are fastened together to the back inner shell 22.

As shown in FIG. 5(B), the push bracket 31 and the elastic body 34 are formed with concentric positioning holes 43 that communicate with each other, while as shown in FIG. A positioning protrusion 44 that fits into the positioning hole 43 is formed. As a result, the position of the push bracket 31 is accurately defined, and the elastic body 34 is held so that it cannot fall.

Although the cover 35 is exposed in FIGS. 1C and 2D and 2B and 2C, the cover 35 is actually covered with the skin material 24 and cannot be visually recognized. Only the protective cap 37 is exposed from the skin material 24.

FIG. 7 shows a modified example. In this modification, first, the boss body 26 and the pipe 28 are non-circular with flat surfaces on the top and bottom. By forming flat surfaces on the top and bottom in this way, drilling can be performed accurately. Further, in the modification shown in FIG. 7, the push bracket 31 is fixed to the back inner shell 22 only at its lower portion with screws 42. As a means for attaching the cover 35, a snap engagement using engagement claws 35b provided on the upper and lower sides is employed. Therefore, an engagement hole 22a is formed in the back inner shell 22, with which the engagement claw 35b engages after being elastically deformed. The nut 39 is T-shaped.

(4).Summary regarding the backrest As shown in FIGS. 5 and 6, the side plate 27a of the receiving bracket 27 is formed with an inclined portion 45 that shifts backward as it goes upward. Therefore, there is a gap between the side plate 27a of the receiving bracket 27 and the push bracket 31 that widens upward at a predetermined angle θ1. Therefore, when the seated person leans back against the backrest 3 and recoils the upper body, the backrest 3 resists the elasticity of the elastic body ( chelast ) 34 and pivots around the axis of the support shaft 33 (rotation axis O2). can be tilted backward (rotated) by θ1.

The elastic body 34 is pre-compressed so that an elastic restoring force is generated when no load is applied by the seated person. Therefore, when the seated person leans back, the backrest 3 does not suddenly tilt backwards without resistance, and appropriate resistance is provided to the backward tilting movement. Note that forward rotation of the backrest 3 is restricted by a portion of the side plate 27a of the receiving bracket 27 below the inclined portion 45 coming into contact with the push bracket 31.

As mentioned above, the backrest 3 of this embodiment has a concave shape facing forward in plan view and has an excellent fit to the user, but the upper support frame 8 has a similar shape to the rear surface of the backrest 3. Because of this, the design is cohesive and has an excellent aesthetic appearance. Further, the upper support frame 8 has excellent rigidity because the side portions 9 and the rear portion 10 are integrally continuous. Therefore, the upper support frame 8 can ensure the necessary strength without being made excessively thick.

Although a spring such as a coil spring can be used as the elastic body that provides resistance to the backward tilting of the backrest 3, if the elastic body 34 made of resin rubber is used as in this embodiment, it can easily fit into a narrow space. It has the advantage of being easy to place.

Further, in this embodiment, since the receiving bracket 27, the push bracket 31, the cover 35, and the protective cap 37 are integrated into a unit, the unit is attached to the backrest 3 in advance and then covered with the skin material 24. The chair can be easily assembled by fitting the pipe 28 of the receiving bracket 27 into the boss body 26 and fixing it with screws 30. Therefore, it is suitable for a chair that can be assembled using a knockdown method.

(5). Upper support frame attachment structure Next, the connection structure of the upper support frame 8 to the side supports 13 will be explained. First, the structures shown in FIGS. 8 to 10 will be explained. As described above, an operating member for unlocking the pedestal 5 (gas cylinder) is arranged on the right side support 13. Therefore, although the structures of the left and right side supports 13 are slightly different, the connection structure of the upper support frame 8 is common between the left and right sides. Here, the left part not provided with the knob 19 will be explained.

As clearly shown in FIG. 9, a push bracket 48 having left and right upward side plates 48a is fixed to the side portion 9 of the upper support frame 8. The push bracket 48 includes a channel-shaped portion having an upward side plate 48a and a cylindrical boss portion 49 located behind the channel-shaped portion.The boss portion 49 is welded to the side portion 9 of the upper support frame 8. Fixed. The push bracket 48 is made of cast steel .
A flange 50 that corresponds to the front end surface of the upper support frame 8 is integrally formed at the base of the boss portion 49 . The push bracket 48 is made of medium-grade steel. The boss portion 49 may have a pipe shape. Furthermore, when the upper support frame 8 is square, the boss portion 49 may also be formed square.

As shown in FIG. 9, a flat part 51 is formed in the upper horizontal part 15 of the side support 13, and a square block 52 and a tapped hole 53 located behind it are formed in the flat part 51. There is. A channel-shaped lower receiving bracket 54 having an upward side plate 54a is stacked on the flat part 51, and the lower receiving bracket 54 is fixed to the flat part 51 by a screw 55 screwed into a tapped hole 53. ing. A notch is formed in the front part of the lower receiving bracket 54 to avoid interference with the square block 52, and side plates 54a of the lower receiving bracket 54 are located on the left and right sides of the square block 52.

An upper receiving bracket 57 having a downward side plate 57a is fitted inside the lower receiving bracket 54. The upper receiving bracket 57 holds the square block 52 from above, and the front parts of the side plates 57a, 54a of the upper and lower receiving brackets 57, 54 and the square block 52 are connected by a left and right longitudinal front support shaft 58. . A downward hook portion 59 is bent and formed at the front end of the upper receiving bracket 57.

Further, the pushing bracket 48 is inserted into the upper receiving bracket 57, and the rear parts of the side plates 57a and 54a of the upper and lower receiving brackets 57 and 54 and the rear part of the side plate 48a of the pushing bracket 48 are connected to the left and right longitudinal rear support shafts. 60. A block-shaped elastic body 61 made of resin rubber such as foamed urethane elastomer is sandwiched between the push bracket 48 and the upper receiving bracket 57.

The upper and lower receiving brackets 57 and 54 are fixed unrotatably, while the push bracket 48 is connected by one rear support shaft 60, and is attached to the left and right side plates 48a of the push bracket 48 at the front. An inclined portion 62 is formed which becomes lower toward the surface. Therefore, the upper support frame 8 can tilt backward about the axis of the rear support shaft 60 by the spread angle θ2 between the inclined portion 62 and the upper receiving bracket 57 against the elasticity of the elastic body 61. The elastic body 61 is also pre-compressed.

As shown in FIG. 10, the upper support bracket 57, the square block 52, and the front support shaft 58 are fixed by a front screw 55 screwed into the front support shaft 58 from above, and the push bracket 48 and the rear support shaft 60 are fixed together. is fixed by a rear screw 64 screwed into the rear support shaft 60 from above.

As clearly shown in FIG. 10, the lower receiving bracket 54 has a downwardly protruding portion 54b into which the head of the front screw 55 is inserted, and a flat portion of the upper horizontal portion 15 corresponds to the downwardly protruding portion 54b. 51 is formed with a recess 51a into which the downward protrusion 54b enters.

The upper horizontal portion 15 of the side support 13 is covered with the previously described protective cover 16. As clearly shown in FIG. 9(B), the rear part of the protective cover 16 is a complete cylindrical part 16a, and a downward opening 65 is formed at the rear thereof. Further, inside the protective cover 16, a large number of longitudinal ribs 66 (see FIG. 9(B)) are formed.

(6). Modification of upper support frame attachment structure FIG. 11 shows a modification of the form of the upper horizontal portion 15 and the connection structure of the upper support frame 8. In this modification, first, the upper horizontal portion 15 is square, and the square block 52 is U-shaped in plan view. Further, although this embodiment also has upper and lower receiving brackets 57, 54, it does not include the front support shaft 58 shown in FIG. The upper receiving bracket 57 is formed with an upwardly bulging portion 57b that holds the second cell last 61 so as not to be displaced.

Further, in this modification, the protective cover 16 is opened forward, and a portion in front of the opening 65 is divided by a front slit 16c that opens downward. The front surface of the protective cover 16 is covered with a front cap 67 made of resin. The front cap 67 is integrally formed with a lower rib 67a that protrudes backward and an upper rib 67b that has a larger horizontal width than the lower rib 67a.

On the other hand, a wall 16e overlapping the front surface of the upper horizontal portion 15 is formed at the front portion of the protective cover 16, and a front cap 67 is formed between the wall 16e of the protective cover 16 and the upper horizontal portion 15 of the side support 13. recesses 16f and 15b are formed into which the upper rib 67b is fitted. An engaging pawl 67c is formed at the rear end of the upper rib 67b of the front cap 67, and the engaging pawl 67c engages with an engaging portion 15c formed inside the upper horizontal portion 15. Thereby, the front cap 67 is held so that it cannot be removed.

The upper half of the lower rib 67a of the front cap 67 fits into the front slit 16c of the protective cover 16. The lower half of the lower rib 67a of the front cap 67 is an umbrella portion that spreads from side to side, and the portions of the protective cover 16 on both sides of the front slit 16c are covered from below by the umbrella portion of the lower rib 67a. ing. Therefore, even if a person's fingertip hits the front part of the protective cover 16 from below, the protective cover 16 will not be turned over.

The protective cover 16 is manufactured by injection molding, and since it has a forward-facing opening and a front slit 16c, it can be manufactured in a state where it can be easily cut out. Since it is covered with the lower rib 67a, it is possible to prevent it from turning over due to contact with a person's fingertips. Note that the protective cover 16 is molded using a mold and then elastically deformed and cut out, and the presence of the front slit 16c allows it to be deformed into a state where it can be easily cut out.

The upper support frame 8 is connected, for example, by the following procedure. That is, first, as a pre-process, the push bracket 48 is fixed in advance to the forward arm portion 9 of the upper support frame 8, while the side support body 13 is fixed to the base 6. Further, the protective cover 16 is fitted into the forward arm portion 9 of the upper support frame 8 in advance.

(7). Procedure for attaching the upper support frame The upper support frame 8 is connected, for example, in the following procedure. That is, first, as a pre-process, the push bracket 48 is fixed in advance to the side portion 9 of the upper support frame 8, while the side support body 13 is fixed to the base 6. Further, the protective cover 16 is fitted into the side portion 9 of the upper support frame 8 in advance.

Then, the rear support shaft 60 is inserted through the upper and lower receiving brackets 57 and 54 and the pushing bracket 48, and the elastic body 61 is fitted between the pushing bracket 48 and the upper receiving bracket 57. Then, the lower receiving bracket 54 is fixed to the upper horizontal portion 15 with screws 55, and then, in the example of FIG. 11, the upper receiving bracket 57 is fixed to the square block 52 with front screws 63. When the front screw 63 is screwed into the rectangular block 52, it is gradually pressurized with the elastic body 61 and pre-compressed.

In the example shown in FIGS. 8 to 10, the elastic body 61 is sandwiched between the lower receiving bracket 54 and the pushing bracket 48, and then the elastic body 61 is pre-compressed by pushing the upper receiving bracket 57 downward manually or with a jig. Then, in this state, the front support shaft 58 is inserted to connect the upper and lower receiving brackets 57, 54 and the square block 52. In any case, after the upper support frame 8 has been connected to the upper horizontal portion 15, the protective cover 16 is moved forward and fitted into a predetermined position.

The upper horizontal portion 15 of the side support body 13 can function as an elbow rest, and the user can sit on or stand up from a chair by grasping the upper horizontal portion 15. It can also be used as an attachment member for a knob 19 that unlocks the pillar 5.

(8) Others Although the embodiments of the present invention have been described above, the present invention can be embodied in various other ways. For example, it is also possible to form the pushing part integrally with the back inner shell.

Further, in the embodiment, the boss body and the receiving bracket face in the front-rear direction, but the rear part of the upper support frame may be placed below the backrest so that the boss body and the receiving bracket face upward. It is possible. In this case, the pivot point of the backrest will be located near the lower end of the backrest. The elastic body is not limited to resin rubber, and various other materials such as metal spring bodies and torsion bars can be used.

The backrest (and seat) is not limited to a cushion type in which a back inner shell is covered with a back cushioning material. For example, a structure in which mesh material is stretched over a back frame material with openings at the front and rear, or a type in which the back plate is exposed can also be used. Furthermore, the present invention can be applied to various types of chairs, such as a four-legged non-swivel chair and a fixed chair.

The present invention can be embodied in a chair. Therefore, it can be used industrially.

2 Seat 3 Backrest 8 Upper support frame 9 Side part of upper support frame (forward-facing arm part)
10 Rear part of upper support frame 13 Side support body 14 Pillar part 15 Upper horizontal part 22 Back inner shell (back plate)
23 Back cushion material 26 Boss body 27 Receiving bracket 28 Pipe (female boss part)
30 Screw 31 Push bracket 33 Support shaft 34 Elastic body made of urethane foam elastomer 35 Cover 36 Square recess 37 Protective cap 39 Nut

Claims (6)

It has a seat and a backrest that are separated from each other, and an upper support frame to which the backrest is attached at a position higher than the seat,
The upper support frame has side parts located on the left and right sides of the backrest and the seated person, and a rear part in which the left and right side parts are connected in series , and the rear part of the upper support frame has : The backrest is attached so that it can tilt backward through a left and right longitudinal support shaft that connects a forward-facing receiving bracket provided on the rear portion and a push bracket provided on the backrest,
A chair in which an elastic body is disposed between the receiving bracket and the pushing bracket to provide resistance to backward tilting of the backrest,
The backrest is equipped with a back inner shell made of synthetic resin in which a large number of reinforcing ribs extending vertically and horizontally are formed on the back surface, and by partially cutting out the reinforcing ribs in the back inner shell, the pushing force is reduced. A recess is formed in which the bracket is fixed, and the support shaft and the elastic body are arranged in the recess.
Chair. The backrest includes a back cushioning material disposed at least on the front surface of the back inner shell, and a bag-shaped skin material that entirely covers the back inner shell and the back cushioning material.
A chair according to claim 1. It has a seat and a backrest that are separated from each other, and an upper support frame to which the backrest is attached at a position higher than the seat,
The upper support frame has side parts located on the left and right sides of the backrest and the seated person, and a rear part in which the left and right side parts are connected in series, and the backrest is attached to the rear part of the upper support frame. A chair mounted so as to be tiltable backward,
The backrest includes a back inner shell made of synthetic resin, a back cushion material disposed at least in front of the back inner shell, and a bag-shaped skin material that entirely covers the back inner shell and the back cushion material. and
A rearward-opening recess is formed in the back inner shell into which a receiving bracket provided on the rear portion via a forward-facing boss body is inserted, and the pushing bracket fixed to the recess and the receiving bracket are connected to each other. An elastic body is disposed between the pushing bracket and the receiving bracket, which are connected by left and right longitudinal support shafts,
Further, a cover is provided that enters the recess from behind and covers the receiving bracket and the pushing bracket from behind, the support shaft is held by the cover so as not to be able to move from side to side, and the cover is fixed to the pushing bracket. fixed to the back inner shell of the backrest by screws together with a moving bracket;
Chair . The receiving bracket and the boss body are fitted from the front and back directions, and are fixed irreleasably with screws.
A chair according to claim 3 . It has a seat and a backrest that are separated from each other, and an upper support frame to which the backrest is attached at a position higher than the seat,
The upper support frame has side parts located on the left and right sides of the backrest and the seated person, and a rear part in which the left and right side parts are connected in series. The backrest is attached so that it can tilt backward through a left and right longitudinal support shaft that connects a forward-facing receiving bracket provided on the rear portion and a push bracket provided on the backrest,
A chair in which an elastic body is disposed between the receiving bracket and the pushing bracket to provide resistance to backward tilting of the backrest,
A recess with a rearward opening to which the push bracket is fixed is formed in a lower portion of the backrest, a rear portion of the upper support frame is located behind the recess, and the support shaft is placed in the recess,
Chair . It has a seat and a backrest that are separated from each other, and an upper support frame to which the backrest is attached at a position higher than the seat,
The upper support frame is made of pipe or bar material, and has side parts located on the left and right sides of the backrest and the seated person, and a rear part in a horizontal position in which the left and right side parts are connected in series. The rear portion of the upper support frame and the rear surface of the backrest are curved so as to be concave forward in a plan view, and there is a gap between the rear portion and the backrest that prevents backward tilting of the backrest. There is a gap along the entire left and right length of the backrest to allow for
The backrest is connected to a forward-facing support bracket fixed to the rear portion so as to be tiltable backward, and an elastic body that provides resistance to backward tilting of the backrest is supported by the support bracket.
Chair.

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