JPH10262769A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To incline a seat back backward without using a torsion bar in the seat back, when a sitting person takes an easy posture, move a seat backward, and lower the rear end of the seat. SOLUTION: This chair has a torsion bar 4 in the lower part of a seat 5 and a seat back 6 having an L-shape in a side view in the rear of the seat 5. The rear part 17a of the middle part 17 of the torsion bar is mounted on a base frame 3 fixed to the upper end of a leg column 2, a lateral pair of horizontal pieces formed by laterally bending both sides of the intermediate part are rotatably mounted on the front part of the base frame 3, the seat back 6 whose lower front end is fixed to the rear part of the base frame 3 is connected to a lateral pair of longitudinal pieces 4c in such a manner as to be longitudinally slidable and tiltable, and the lower part of the longitudinal middle part of the seat is mounted on the longitudinal pieces 4c of the torsion bar in such a manner as to be longitudinally slidable to connect the seat back 6 to the rear part of the seat, whereby the seat can be longitudinally slid and tilted in interlocking with the tilting of the seat back.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair using a bent torsion bar, in which a seat moves rearward as a backrest leans and a comfortable posture is easily taken.

[0002]

2. Description of the Related Art Chairs using a bent torsion bar are disclosed in JP-B-47-43226 and JP-B-48-33.
No. 223 or Japanese Utility Model Laid-Open No. 52-39314.

In the chair described in the first publication, the ends of the side pieces bent in a U-shape are bent outward, respectively.
It has a front torsion bar having a horizontal portion formed by folding back along the lower edge of the front half of the seat, and a horizontal portion bent along the lower edge of the rear half of the seat on both sides. At the center of the rim, a rear torsion bar that is bent upright is fixed to the bottom of the seat, and the right and left ends of both torsion bars are connected at substantially the center of the left and right side edges of the bottom of the seat, and the center of the front torsion bar is The rear end of the rear torsion bar is attached to the upper end of the rear torsion bar while the back end is attached to the leg side.

In the chair described in the second publication, a pair of torsion bars bent in a U-shape are provided in parallel, the ends of the inner arms are fixed to the legs, and the U-shaped bottom and Place the outer arm in the same horizontal plane, attach the lower edge of the front half of the seat along this, and place a backrest in the center of the rear of the seat,
It is configured to be adjustable back and forth.

The chair described in the third publication has a configuration in which a seat to which a backrest is fixed is provided on a footrest via a bent torsion bar.

[0006]

The chairs described in the first and second publications require a rear torsion bar for a backrest separately from a front torsion bar for tilting a seat, and the design is difficult. However, there are problems such as the fact that the structure is complicated, the balance between the elasticity of both torsion bars is difficult to adjust, and the like.

In the chair described in the third publication, the backrest does not elastically lean backward with respect to the seat.
There is a problem that it is difficult to take a comfortable posture.

The present invention has been made in view of the above-mentioned problems of the conventional chair, and allows the backrest to be tilted backward by the torsion bar provided at the lower portion of the seat without using the torsion bar for the backrest. It is another object of the present invention to provide a chair in which the seat and the backrest are interlocked to easily balance the urging force between the rearward movement of the seat and the tilting of the backrest.

[0009]

According to the present invention, the above-mentioned problem is solved as follows. (1) A pair of left and right horizontal pieces on the same horizontal line formed by bending the tips of the side pieces bent in a U-shape outward, respectively, and bending both outer ends of each horizontal piece backward. A chair provided with a torsion bar having a pair of left and right front and rear pieces formed at the lower part of the seat, and having an L-shaped backrest in a side view having a backrest at the upper part of the seat, The rear part of the intermediate part is mounted on a base frame fixed to the upper end of a pillar, the left and right horizontal pieces are rotatably mounted on the front part of the base frame, and the lower front end is pivotally mounted on the rear part of the base frame. The worn backrest can be slid back and forth on the pair of left and right front and rear pieces,
And tiltably connected, and furthermore, the lower part of the middle part in the front-rear direction of the seat is attached to the front and rear pieces of the torsion bar so as to be slidable back and forth, and the backrest and the rear part of the seat are connected to each other. The seat is slid forward and backward and tilted in conjunction with the tilting of the backrest.

(2) In the above item (1), the torsion bar is formed by a pair of left and right torsion bar pieces which are bent and formed in a U-shape and are arranged side by side. An intermediate portion is formed by a bent portion in which the ends of the arm portions are bent so as to abut each other.

(3) In the above item (1) or (2), the rear portion of the intermediate portion of the torsion bar is located below the front and rear pieces.

(4) In any one of the above items (1) to (3), the long holes provided at the front portion of the seat may be fitted to a pair of left and right engagement pieces provided at the left and right of the front portion of the base frame. An intermediate portion of the seat in the front-rear direction is connected to a movable piece provided on a pair of left and right front and rear pieces of the torsion bar so as to be movable back and forth.

(5) In the above item (4), the engaging piece is provided with a slip-off preventing flange for preventing the elongated hole from being pulled upward from the engaging piece, and the elongated hole has a width smaller than the width of the elongated hole. The permissible through holes having a large diameter are continuously formed.

[0014]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. The chair (1) is shown in Figs.
As shown in the figure, a base frame (3) provided with legs (2) and armrests (7) on both left and right sides, and a torsion bar (4) provided on the base frame (3)
And a seat (5) provided on the base frame (3) directly or via the torsion bar (4), and a seat (5) provided on the base frame (3) so as to be tiltable back and forth. And a backrest (6) connected to the backrest.

As shown in FIG. 4, a pair of left and right legs (2)
(One leg is omitted), the base frame by bolts (8)
It is attached to (3). The left and right armrests (7) are supported by an armrest support shaft (9), and a backrest (6) having a backrest (15)
The backrest support shaft (14) is provided on the base frame (3) so as to be tiltable in the front-rear direction. The backrest support shaft (14) is shown in FIG.
Bearing part on base frame (3) via bush (31) shown in FIG.
(32) The bearing is mounted on (32).

The bearing portion (32) is provided with a receiving piece (30) so that the support shaft (14) does not come off. A retaining flange (14a) is provided at one end of the support shaft (14), and a retaining protrusion (33) is provided on the base frame (3) so as to face the flange (14a). In order to prevent the support shaft (14) from coming off, the flange (14a) may be omitted, and a protruding piece may be protruded from the base frame (3) opposite to both ends of the support shaft (14).

The upper end of the armrest (7) shown in FIG.
And is tilted in the front-rear direction integrally with the backrest (6). For this reason, the tilting centers of the armrest (7) and the backrest (6) must coincide with each other, and the armrest support shaft (9) and the backrest support shaft (14) have four (2 in FIG. (Not shown) are aligned in the left-right direction on the base frame (3) with their axes aligned.

The backrest (6) is shown in FIGS. 1, 3, 9, and 10.
As shown in FIG. 6, a pair of left and right connecting pieces (16) (one of which is not shown) provided near both sides in the left-right direction of the backrest (6) are connected to a rear portion of an inner shell (11) described later. I have. A hole (34) that engages with the connecting piece (16) is formed in the rear portion. The seat (5) includes an outer shell (10) shown in FIGS. 1 and 2 and an inner shell (11). Both shells (10) and (11) have their ends connected by a connection shaft (12), and their middle portions in the front-rear direction are appropriately connected.

The torsion bar (4) shown in FIG. 3 is formed by bending a single round steel bar. The torsion bar (4) is a side piece at the middle portion (17) bent in a U-shape.
The tip of (4a) is formed by bending a pair of left and right horizontal pieces (4b) on the same horizontal line formed by bending outwards, and bending both outer ends of the pair of horizontal pieces backward. And a pair of left and right front and rear pieces (4c).

As shown in FIGS. 1 and 2, the torsion bar (4) is also bent vertically so that the rear portion (17a) of the intermediate portion (17) is located below the front and rear pieces. The intermediate portion (17) of the torsion bar comes into contact with the recess (18a) of the receiving piece (18) provided on the base frame (3) from above and is received by the receiving piece (18). By changing the depth of the recess (18a),
You can change the elasticity of the torsion bar.

A pair of left and right horizontal pieces (4b) of the torsion bar
Is a pair of left and right torsion bars that fit into a pair of left and right recesses (19) formed on the left and right of the front part of the base frame (3) shown in FIGS. The support piece (20) is rotatably provided. The torsion bar support piece (20) has a horizontal piece
(4b) and the horizontal piece (4b) with the fitting part (20a)
An opening (20b) for receiving is formed in a). The opening (20b) is formed at the front of the torsion bar (4), but may be formed at the rear. The torsion bar support piece (20) is a retaining piece provided in the recess (19).
(21) is locked.

At the upper end of each of the pair of left and right torsion bar support pieces (20), an engagement piece () that engages with a long hole (22) formed in the front part of the outer shell (10) in the front-rear direction. 23) is formed.

On the head of the engaging piece (23), a seat (5) is provided with an engaging piece (2).
A detachment prevention collar (24) is provided to prevent the detachment from going upward from 3). In the long hole (22), a through-permissible hole (22a) is formed continuously so as to penetrate the escape prevention flange (24) having a diameter larger than the width of the long hole (22).

Therefore, after the engagement piece (23) and the elongated hole (22) are made to pass through the penetration prevention hole (22a) through the slip-off preventing flange (24), the engagement piece (2
When 3) is moved along the long hole (22) in a direction away from the through-permissible hole (22a), they are engaged so as not to come off from each other. The lower surface (24a) of the stopper flange (24) and the upper surface (21a) of the retaining piece (21) are formed with protruding arc surfaces that allow the seat (5) to tilt backward and move backward.

As shown in FIGS. 1 and 4, the outer shell
At the lower end of (10), a movable piece (25) that can move back and forth on a pair of left and right front and rear pieces (4c) of the torsion bar (4) is connected by bolts (13). The moving piece (25) has a recess (25a) for receiving a torsion bar.

On the left and right sides of the backrest (6), a pair of left and right parts which contact the rear ends of the front and rear pieces (4c) of the torsion bar (4) shown in FIGS. 1, 3, 7, and 8 from above. A pressing piece (26) is provided. The pressing piece (26) has a recess (26a) for receiving the torsion bar.

A rotation restricting projection (27) shown in FIG. 11 is provided at the front of the lower end of the backrest. A pad (28) is provided on the base frame facing the rotation restricting projection (27).

At the front of the lower end of the backrest, an excessive tilting restricting piece (29) is provided.
Are integrally formed. Excess tilt control piece (29)
A receiving piece (30) for receiving the light is provided. The receiving piece (30) is formed in a substantially V-shaped cross-sectional side view,
The front half portion is a rearward tilt restriction surface (30a), and the rear half portion is a front tilt restriction surface (30b).

Next, the operation will be described. When a person sits on the chair (1) and takes a comfortable posture, a force of backward tilt is applied to the backrest (6), and the backrest (6) is tilted backward about the backrest support shaft (14). .

As the backrest (6) is tilted backward, the connecting piece (16) on the backrest (6) moves backward and downward integrally with the backrest (6) while moving the inner shell (6). Pull down the rear end of the inner shell (11) while pulling back on (11). When the inner shell (11) is pulled backward, the outer shell (10) also moves backward. That is, the rear part of the seat (5) descends while the seat (5) moves rearward.

As the backrest (6) is tilted backward, the pressing pieces (26) on the backrest (6) also push the rear ends of the front and rear pieces (4c) of the torsion bar (4) against the elasticity of the torsion bar. And push down. When the leaning force of the seated person against the backrest (6) and the elasticity of the torsion bar are balanced, the backward leaning of the backrest stops.

Thus, the seated person can take a comfortable posture by lowering the rear end while moving backward from the seat (5) and tilting the backrest (6) backward. These effects are
Since the elastic deformation and elasticity of one torsion bar are used, the structure of the chair is simplified.

In the case where the backrest is largely tilted backward, the tilt-restricting projection (29) hits the pad (28) to reduce the impact caused by preventing the backrest from tilting backward. )
Abuts on the rearward tilt regulating surface (30a) of the receiving piece (30) to restrict the rearward tilt of the backrest, thereby preventing the seated person from rolling backward.

When the seated person leaves the chair, the backrest (6) is tilted forward by the torsion bar, and the overtilt movement restricting piece (27) is placed on the forward tilt restricting surface (30b) of the receiving piece (30). Abuts, the forward lean is regulated, and returns to a predetermined standing state.

As a modification of the torsion bar, there is a torsion bar (40) shown in FIG. This torsion bar
(40) is formed by a pair of right and left torsion bar pieces (41) and (41) which are bent and arranged in a U-shape, and the inner arm (42) of the torsion bar piece and the tip of the arm are formed. With the bent portion (42a) bent in a direction to abut each other, the torsion bar
A portion corresponding to the intermediate portion (17) of (4) is formed.

[0036]

According to the first aspect of the present invention, the seat and the backrest are interlocked and tilted by one bent torsion bar provided below the seat without forming the backrest with a torsion bar. Therefore, the structure can be simplified, and the balance between the tilting of the seat and the backward tilt of the backrest, and the elasticity of the torsion bar can be easily achieved. In addition, the degree of freedom in design can be increased.

When the torsion bar is formed of a pair of left and right torsion bar pieces as in the second aspect of the present invention, the bending of the torsion bar is facilitated.

When the intermediate portion of the torsion bar is positioned below the front and rear pieces as in the invention of claim 3, the torsion bar can have a desired elasticity.

According to a fourth aspect of the present invention, the long hole formed in the front portion of the seat is connected to a pair of left and right engagement pieces provided on the left and right of the front portion of the base frame so as to be movable back and forth, When the middle portion of the seat in the front-rear direction is connected to a movable piece provided to be movable back and forth on a pair of left and right front and rear pieces of the torsion bar, the seat can be reliably supported by the base frame and the torsion bar.

According to the fifth aspect of the present invention, the engaging piece is provided with a retaining flange for preventing the elongated hole from coming off from the engaging piece, and the elongated hole has a diameter larger than the width of the elongated hole. If a large penetration allowable hole is formed continuously, after the penetration prevention flange is penetrated through the penetration allowable hole, by moving the seat to a normal front and rear position, so that the seat does not come off from the base frame, The seat can be easily incorporated into the base frame.

[Brief description of the drawings]

FIG. 1 is a sectional side view of a lower portion of a seat, a base frame, and a backrest of a chair according to an embodiment of the present invention.

FIG. 2 shows a state in which the backrest is tilted backward from the state of FIG.
It is a sectional side view of the lower part of a seat, a base frame, and a backrest.

FIG. 3 is a plan view in which a right half of a base frame having a torsion bar is omitted.

FIG. 4 is a sectional view taken along the line IV-IV in FIG.

FIG. 5 is a cross-sectional side view of a mounting portion of a horizontal portion of the torsion bar to a base frame.

6 is a sectional view taken along the line VI-VI in FIG.

FIG. 7 is a sectional side view of a mounting portion of a rear end of the torsion bar to a base frame.

8 is a sectional view taken along the line VIII-VIII in FIG.

FIG. 9 is a cross-sectional side view of a connection portion between the inner shell of the seat and the backrest.

FIG. 10 is a sectional view taken along the line XX in FIG. 9;

FIG. 11 is a side view of a connecting portion between the base frame and the backrest;
Partly shown in cross section.

12 is a sectional view taken along the line XII-XII in FIG.

FIG. 13 is a plan view of a torsion bar according to another embodiment.

[Explanation of symbols]

 (1) Chair (2) Leg (3) Base frame (4) Torsion bar (4a) Side piece (4b) Horizontal piece (4c) Front and rear piece (5) Seat (6) Backrest (7) Armrest (8) Leg Mounting bolt (9) Armrest support shaft (10) Outer shell (11) Inner shell (12) Connecting shaft (13) Bolt (14) Backrest support shaft (15) Backrest (16) Between backrest and innershell Connection piece (17) Intermediate part (17a) Rear part of intermediate part of torsion bar (18) Receptacle (18a) Recess recess (19) Recess (20) Torsion bar support piece (20a) Fitting part (20b) Opening (21) Retaining piece (21a) Upper surface of retaining piece (22) Elongated hole (22a) Permissible hole (23) Engagement piece (24) Prevention flange (25) Moving piece (25a) Recess (26 ) Pressing piece (26a) Recess (27) Tilt restricting projection (28) Pad (29) Excessive tilt restricting piece (30) Receiving piece (30a) Rear tilt restricting surface (30b) Forward tilt restricting surface (31) Bush (32 ) Bearing part (33) Retaining protrusion (34) Hole (40) Torsion bar (41) Torsion bar element (42) Inner arm (42a) Bend

Claims (5)

[Claims] 1. A pair of left and right horizontal pieces on the same horizontal line formed by bending the ends of side pieces bent in a U-shape outward, respectively, and the outer ends of each horizontal piece to the rear. A chair provided with a torsion bar having a pair of left and right front and rear pieces formed to be bent at a lower portion of a seat, and having an L-shaped backrest having a backrest at an upper portion at a rear side of the seat, wherein the torsion is provided. The rear part of the middle part of the bar is mounted on a base frame fixed to the upper end of a pillar, the pair of left and right horizontal pieces are rotatably mounted on the front part of the base frame, and the lower front end is mounted on the rear part of the base frame. Is connected to the pair of left and right front and rear pieces so as to be slidable back and forth and tiltable, and further, a lower part of a middle portion of the seat in the front and rear direction is connected to the front and rear pieces of the torsion bar. By slidably attached to the back and forth, and connecting the backrest and the rear of the seat, In conjunction with the tilting of the dress against a chair, characterized in that the said seat so as to slide and tilt back and forth. 2. The torsion bar is formed by a pair of left and right torsion bar pieces which are bent and arranged substantially in a U-shape, and each inner arm portion of the torsion bar base piece and a tip of the arm portion are formed. 2. The chair according to claim 1, wherein an intermediate portion is formed by the bent portions bent in a direction in which they abut each other. 3. The chair according to claim 1, wherein a rear portion of the intermediate portion of the torsion bar is located below the front and rear pieces. 4. An elongated hole formed in the front portion of the seat is connected to a pair of left and right engagement pieces provided on the left and right of the front portion of the base frame so as to be movable back and forth. , Left and right of torsion bar 1
The chair according to any one of claims 1 to 3, wherein the chair is connected to a movable piece provided to be movable back and forth on a pair of front and rear pieces. 5. An engaging piece is provided with a stopper for preventing a long hole from coming out of the engaging piece upward, and a permissible through-hole having a diameter larger than the width of the long hole is continuously formed in the long hole. 5. The chair according to claim 4, wherein the chair is formed as follows.