JP2721143B2 - Chair - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair provided with a rising mechanism used as a grandstand or the like.

[0002]

2. Description of the Related Art Conventionally, as this kind of chair, a plurality of supports are arranged at required intervals, and a seat is supported between the supports via a rising mechanism so that the seat can be raised and lowered. Are known. This rising mechanism is for automatically raising the seat to the standing position when a seated person stands, and the standing position is set in consideration of smoothness at the time of sitting next time, etc. It is set at a position standing up and down around 70 degrees close to. In addition, in consideration of the convenience of a person who moves back and forth in the passage in front of the chair, the seat stably held in the above-described standing position is pressed in the direction of the backrest as needed, thereby temporarily moving the seat further to the backrest side. Some have been developed so that they can be evacuated.

[0003]

By the way, such a two-stage operation type rising mechanism generally has a rotating part attached to a seat, a fixed part attached to a support, and a seating part between the seat and the support. It is common to have an intermediate portion that does not function while the seat performs the rising operation and that functions only when the seat performs the retreating operation. As a specific example,
As disclosed in Japanese Patent No. 3084, a rotating part is disposed integrally with the shaft center coincident with the center of rotation of the seat, and a fixed part is disposed on the support side around a bearing part that supports the center of rotation. In addition, an intermediate part (positioning fitting) which normally rotates integrally with the rotating part is arranged between the rotating part and the fixed part. In this device, a spring is interposed between a fixed portion and an intermediate portion, and this spring is configured to accumulate a repulsive force as the seat moves from a standing position to a falling position. When the user stands, the spring releases the repulsive force, and the seat pivotally returns from the lying position to the standing position via the rotating portion. A spring is also interposed between the intermediate part and the rotating part, and the intermediate body has its rotation area restricted only between the falling position and the standing position of the seat, and the seat is attached from the standing position to the retracted position. The spring is configured to accumulate repulsive force as it is urged, and when you release your seat after retreating the seat when passing in front of the chair, the spring releases the repulsive force, and the rotating part moves from the retracted position It is designed to return to the upright position.

[0004] As described above, in the conventional apparatus, the intermediate portion is used as a medium to clearly separate the normal rising operation and the subsequent retreating operation, thereby securing the function of stopping the seat at the upright position and providing such a function. The intermediate portion provides an operational bridge between the rising operation and the evacuation operation. For this reason, if an attempt is made to reduce the number of parts by omitting the intermediate portion, the seat loses its stopping function in the upright position, and the seat ends are not evenly arranged in the vacant state, resulting in a very unsightly appearance. Is inevitable.

[0005]

In order to solve the above problems, the present invention omits an intermediate portion and directly associates a rotating portion with a fixed portion. That is, a single spring can not only accumulate repulsive force when the seat moves from the upright position to the lying position, but also accumulate repulsive force when the seat moves from the upright position to the retracted position. And when the seat is in the upright position, the stop operation is performed by a moderation mechanism. For this reason, the seat can be returned to the vicinity of the upright position via the rotating portion by the spring force in a state where no external force is applied, and the detent mechanism can always draw and hold the seat at the fixed upright position.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is characterized in that when a seat is supported on a support via a rising mechanism, the seat is raised and lowered between a standing position, a standing position, and a retreating position by a rising mechanism. The mechanism includes a fixed part, a rotating part, a spring, and a moderation mechanism. That is, the rotating part is disposed integrally with the center of rotation of the seat so as to coincide with the axis thereof, the fixed part is provided around the center of rotation on the support side, and both ends of the spring can elastically contact the fixed part. Position, and when the seat is shifted from the upright position to the lying position side, one end is engaged with the rotating portion while the other end is in elastic contact with the fixed portion in a direction away from the elastic contact position. When the seat is shifted from the standing position to the retreat position side, one end is elastically contacted with the fixed portion, and the other end is engaged with the rotating portion when the seat is shifted from the standing position to the retreat position side. It is configured to accumulate repulsive force while being elastically deformed by being entrained in the direction away from the contact position, and the detent mechanism is configured so that the rotating part can be stopped at the fixed part when the seat is in the upright position Things.

[0007] A simple and effective configuration of the moderating mechanism includes an engaging element provided on one of the rotating section and the fixed section so as to be able to protrude and retract in the radial direction, and an urging element for urging the engaging element in the protruding direction. An engaging recess provided on the other of the rotating portion or the fixed portion and opening at a position where the engaging element can be inserted when the seat is in the upright position. In this case, in order to effectively enhance the moderation stop function, a guide surface that smoothly continues to the engaging concave portion is provided at a position where the engaging member abuts when the seat is near the standing position, and the engaging member protrudes. At this time, it is preferable that the engaging element is drawn into the engaging recess by a reaction force received from the guide surface.

In order to prohibit the seat from turning beyond the lying position, a first turning direction end surface is set on the rotating portion side as the first turning restricting means, and the rotation direction is set on the fixed portion side. It is preferable to set a first stationary end face that makes the end face abut at the seated down position.

In order to prohibit the seat from rotating beyond the retracted position, a second rotation direction end face is set on the rotating section side as the second rotation restricting means, and the rotation direction is fixed on the fixed section side. It is preferable to set a second stationary end face that makes the end face abut at the retracted position of the seat.

In order to avoid the inconvenience of clothes or the like being sandwiched between the end face in the rotation direction and the stationary end face constituting these rotation restricting means, and at the same time to improve the appearance of the mechanism, the rotation restricting means is provided. , It is desirable to include it between the rotating part and the fixed part.

In such a configuration, when the seat is in the vicinity of the upright position by the action of the spring, the detent mechanism moves the engaging element provided on one of the rotating part or the fixed part into the engaging concave part provided on the other. Since the positioning operation is performed by entering the seat, the seat is stably stopped at the standing position by the positioning operation. In other words, the seat is in the upright position, and
If there is no processing error in each part, both ends of the spring resiliently contact the both ends of the fixed part and also engage with the rotating part, so the seat is positioned at its upright position by the repulsive force accumulated in the spring. Is held. On the other hand, when there is a processing error, and when both ends of the spring engage with the rotating part preferentially over the fixed part, the spring can perform the action of the repulsive force by being completely supported by the rotating part. In this state, the rotating portion is rotatable together with the spring independently of the spring force, and the other end of the spring is rotated by its own weight to a position where the other end of the spring hits the corresponding engagement position of the fixed portion. Also, when both ends of the spring are in elastic contact with the fixed part preferentially over the rotating part, the spring is completely supported by the fixed part and cannot act on the repulsive force. The edge is cut off and becomes rotatable independently of the spring force, and rotates by its own weight to a position where it hits one end of the spring. However, since the present invention is provided with a moderation mechanism for moderating the rotating portion to the fixed portion at the standing position, there is no processing error or the like and the spring force is effectively applied. Even if there is rattling, it is possible to reliably guide and hold the seat to the standing position by setting the moderation mechanism to operate within the range of the rattling.

Next, it is assumed that a person who is going to sit on the seat from the standing position urges the seat toward the lying position. With this, the spring is elastically deformed by being entrained at one end by the rotating part while the other end is kept in elastic contact with the fixed part, and stores the repulsive force. The power is at its maximum. When the occupant leaves the seat, the spring urges the seat toward the upright position via the rotating part while releasing the repulsive force. When the seat reaches the standing position and tries to pass through it, the spring has one end elastically contacted with the fixed portion and the other end is entrained by the rotating portion and accumulates a repulsive force in the opposite direction. For this reason, even if the seat can pass through the standing position transiently, the seat is returned to the vicinity of the standing position again.

Conversely, suppose that a person trying to pass forward from the standing position urges the seat toward the evacuation position. With this, the spring is elastically deformed by being entrained at the other end by the rotating part while one end is kept in elastic contact with the fixed part, and when the seat reaches the retracted position, the spring repels it. The power is at its maximum. When the passerby leaves, the spring urges the seat toward the upright position via the rotating part, releasing repulsive force. When the seat reaches the standing position and tries to pass through it, the spring has its other end elastically contacted with the fixed portion and one end is entrained to the rotating portion to accumulate the repulsive force in the opposite direction. For this reason, even if the seat can pass through the standing position transiently, the seat is returned to the vicinity of the standing position again.

When the seat stops near the upright position by the action of the spring, the detent mechanism effectively performs the positioning operation as described above, and the seat returns to the predetermined upright position properly. You can do it.

As described above, according to the present invention, although the rotating portion and the fixed portion are directly associated with each other through a spring or the like, a force for returning the seat to the upright position can always be applied. The seat can be stably stopped at the upright position without using an intermediate portion which leads to such a complicated mechanism.

[0016]

An embodiment of the present invention will be described below with reference to the drawings.

In the chair of this embodiment, as shown in FIGS. 1 to 3, a plurality of supports 1 are arranged at required intervals, and a seat 2 is provided between the supports 1 via a rising mechanism 3. It is made to support.

The support 1 has a lower end portion on an upright surface 1 of a corrugated floor 11.
2 is attached using a bolt 13, and its upper end is formed as an armrest 14. A backrest 15 is attached via a bracket 16 between the rear edges of each support 1.

The seat 2 is made of, for example, a synthetic resin seat body 21 formed by blow molding or the like, and a metal having an L-shaped cross section attached to both sides of the base end of the seat body 21 using screws 22. And the reinforcing plate 23.

As shown in FIGS. 4 to 7, the rising mechanism 3 includes a rotating part 4, a fixed part 5, a spring 6, a detent mechanism 8, a first rotation restricting means 7, and a second rotation restricting means 7. The seat 2 is supported by the rotation restricting means 9 so that the seat 2 can be raised and lowered between a retracted position A and a retracted position C from a lowered position A shown in FIG.

More specifically, the rotating portion 4 is a cylindrical member having a bottom, and a hole 41a provided at the center of the bottom wall 41 is disposed so as to coincide with the center of rotation m of the seat 2, and the bottom wall is provided. 41 is integrally fixed to the vertical wall 23a of the reinforcing plate 23. The rotating part 4 is provided with an inner wall 43 that forms a partial arc around a concentric circle with a smaller diameter than the peripheral wall 42. On both sides of the inner wall 43, a groove forming surface 44 extending in the radial direction and reaching the peripheral wall 42, 45 are formed. These groove engaging surfaces 44, 4
5, a spring receiving groove 44 a extending from the outer end to the vicinity of the inner end is formed in one groove forming surface 44, and a spring receiving groove 45 a is formed in the outer end 45 in the other groove forming surface 45. Has been established. Further, the inner wall 4 is sandwiched between the rotation center m.
At a position facing the inner wall 3, there is provided an inner wall 46 that forms a partial arc around a concentric circle smaller in diameter than the peripheral wall 42.
6, first and second end faces 47, 48 in the rotation direction extending in the radial direction and reaching the peripheral wall 42 are formed.

The fixing portion 5 is disposed at a position where the rotation center m is supported on the support 1 side. More specifically, the fixing portion 5 is fitted to the inner periphery of the peripheral wall 42 of the rotating portion 4 by projecting from the bottom wall 51 and the bottom wall 51 integrally formed or rigidly fixed to the support 1. A pair of partial cylindrical protruding portions 52a, 52 arranged at a position
b, an arc-shaped protruding portion 53 protruding from the bottom wall 51 toward the lower semicircular portion where the partial cylindrical protruding portions 52a and 52b are not provided, and along the rotation center m from the center of the bottom wall 51. And a support shaft 54 projecting therefrom.
Is inserted into the hole 41a of the bottom wall 41 of the rotating unit 4 described above,
The arc-shaped projecting portion 53 is located on the inner peripheral side of the inner wall 43 of the rotating section 4. That is, the rotating portion 4 has its peripheral wall 42 supported by the partially cylindrical projecting portions 52a, 52b of the fixed portion 5 or the hole 41a supported by the support shaft 54, and is rotatably supported by the fixed portion 5. Is done. A pair of spring engaging recesses 53b and 53c are displaced by a predetermined angle in the forward and reverse rotation directions from the circumferential center of the arc-shaped projecting portion 53.
Is formed. The first and second stationary end surfaces 55 and 56 according to the present invention are set on the mutually facing surfaces of the pair of partial cylindrical projecting portions 52a and 52b.

The spring 6 is of a torsion coil type, and is disposed in a wound state around the support shaft 54. One end 61 of the spring 6 is provided at one of the spring engaging recesses of the fixed portion 5 as shown in FIG. The other end 62 is disposed at a position where it can be elastically contacted with the other spring engagement recess 53c while being disposed at a position where it can be elastically contacted with 53b. That is, the seat 2 is in the standing position B
8, the other end 62 is resiliently contacted with the spring engaging recess 53c of the fixed portion 5 as shown in FIG. The groove bottom is scooped up from the spring engaging recess 53b. Thereafter, as the seat 2 rotates in the same direction, the repulsive force is stored while being gradually elastically deformed. Conversely, when the seat 2 shifts from the standing position B to the retreat position C side, as shown in FIG.
The other end 62 is scooped up from the spring engaging recess 53c by the groove bottom of the spring accommodating groove 45a of the rotating portion 4 in a state where the spring 1 is elastically contacted with the spring engaging recess 53b of the fixed portion 5. As it rotates in the same direction, it gradually resiliently deforms and accumulates repulsive force.

The detent mechanism 8 is for stopping the rotating part 4 to the fixed part 5 when the seat 2 is at the upright position B. The detent mechanism 8 is provided on the outer peripheral surface of the semi-cylindrical projecting part 52 of the fixed part 5 in the radial direction. The hole 52c is recessed, and the plunger 8 serving as an engaging element is accommodated in a state in which a spring 81 serving as an urging element is housed in the hole 52c.
2 so as to be able to protrude and retract, and the peripheral wall 42
The plunger 82 is projected and inserted into the engagement recess 42a when the seat 2 is in the upright position B as shown in FIG. When the seat 2 is near the standing position B, the plunger 8
2 is provided with a guide surface 42b that is smoothly continuous with the engaging recess 42a at a position where the plunger 82 protrudes. The reaction force received from the guide surface 42b when the plunger 82 projects causes the plunger 82 to come into contact with the engaging recess 42a. I'm trying to get pulled in.

The first rotation restricting means 7 comprises the first end face 47 in the rotation direction provided on the rotating part 4 side and the first stationary end face 55 provided on the fixed part 5 side. That is, in this embodiment, the seat 2 is preset so that a gap of, for example, about 70 degrees exists between the rotation direction end surface 47 and the stationary end surface 55 in the state of FIG. 8, when the first rotation end face 47 of the rotating part 4 is turned to the first stationary end face 5 of the fixed part 5 as shown in FIG.
5, the rotation unit 4 is prevented from rotating beyond the lying position A, and the seat 2 is stably supported at that position.

The second rotation restricting means 9 comprises the second end face 48 in the rotation direction provided on the rotating part 4 side and the second stationary end face 56 provided on the fixed part 5 side. That is, in this embodiment, it is preset so that a gap of, for example, about 10 to 20 degrees exists between the rotation direction end face 48 and the stationary end face 56 in the state of FIG. When the seat 2 rotates to the retreat position C, the second rotation direction end face 48 of the rotating section 4 comes into contact with the second stationary end face 56 of the fixed section 5 as shown in FIG. Are prohibited from rotating beyond the retreat position C.

Next, the operation of this embodiment will be described. When the seat 2 is in the vicinity of the upright position B shown in FIGS. 3 and 7 due to the action of the spring 6, the plunger 82 provided on the fixed part 5 projects and enters the engaging recess 42 a provided on the rotating part 4. Since the positioning operation is performed, the seat 2 is stably stopped at the standing position B. That is, when the seat 2 is in the upright position B and there is no processing error or the like in each part, both ends 61 and 62 of the spring 6 elastically contact the spring receiving grooves 44a and 45a at both ends of the fixed part 4 at the same time. The springs 6 are also engaged with the spring engaging recesses 53b and 53c at both ends of the rotating portion 5, so that the repulsive force accumulated in the spring 6 causes the seat 2 to move.
Is held in the standing position B in a positioning state. On the other hand, as schematically shown in FIG. 10, both ends 61, 62 of the spring 6 are moved more than the spring engagement recesses 53 b, 53 c of the fixed portion 5 due to a processing error or the like. When preferentially engaging with 45a, the spring 6 is completely supported by the rotating part 4 so that it cannot act on the repulsive force, and the rotating part 4 can rotate with the spring 6 independently of the spring force. Then, as shown in FIG.
2 rotates to a position where it comes into contact with the spring engagement recess 53c of the fixed portion 5 at one side. In addition, as schematically shown in FIG. 11, both ends 61 and 62 of the spring 6 resiliently contact the spring engaging recesses 53 a and 53 b of the fixed portion 5 more preferentially than the spring receiving grooves 44 a and 45 a of the rotating portion 4. At this time, the spring 6 is completely supported by the fixed portion 5 so that no repulsive force can be exerted, and the rotating portion 4 is cut off the edge of the spring 6 and becomes rotatable independently of the spring force. Accordingly, the spring 6 is rotated by its own weight to a position where the spring 6 hits one end. However, in this embodiment, since the moderating mechanism 8 for moderating the rotating section 4 to the fixing section 5 at the upright position B is provided, it is needless to say that there is no processing error and the spring force works effectively. Even if there is backlash due to a processing error or the like, if the moderation mechanism 8 is set to operate within the range of the backlash, the seat 2 can be reliably guided and held at the standing position B.

Next, it is assumed that a person who is going to sit on the seat 2 urges the seat 2 toward the lying position A shown in FIGS. 3 and 8 from the standing position. The spring 6 has the other end 62
With one end 61 being in elastic contact with the spring engaging recess 53 c of the fixed portion 5.
It is scooped up from the spring engagement recess 53b by the groove bottom of 4a, and accumulates a repulsive force while gradually elastically deforming. Then, when the seat 2 reaches the lying position A, the repulsive force becomes maximum. When the occupant leaves the seat, the spring 6 urges the seat 2 toward the upright position B via the rotating portion 4 while releasing the repulsive force. When the seat 2 reaches the standing position B and tries to pass through it, this time the spring 6 has one end 61.
Is resiliently contacted with the spring engaging recess 53b of the fixed portion 5, and the other end 62 is scooped up from the spring engaging recess 53c by the groove bottom in the spring accommodating groove 45a of the rotating portion 4, and the repulsive force in the opposite direction is stored. I do. For this reason, even if the seat 2 can pass through the standing position B transiently, the standing position A
Pulled back to the side.

Conversely, suppose that a person trying to pass forward from the standing position B urges the seat 2 toward the retreat position C shown in FIGS. As a result, the spring 6 has one end 61 elastically contacting the spring engaging recess 53b of the fixed portion 5 and the other end 62 having the spring engaging recess 53c formed by the groove bottom of the spring receiving groove 45a of the rotating portion 4. It is scooped up and accumulates repulsive force while gradually deforming elastically. When the seat 2 reaches the evacuation position C, the repulsive force becomes maximum. When the pedestrian leaves, the spring 6
Urges the seat 2 toward the upright position B via the rotating part 4 while releasing the repulsive force. When the seat 2 reaches the standing position B and tries to pass therethrough, the spring 6
2 is elastically contacted with the spring engaging recess 53c of the fixed portion 5,
The one end 61 is scooped up from the spring engaging recess 53b by the spring accommodating groove 44a of the rotating portion 4, and accumulates a repulsive force in the opposite direction. Therefore, even if the seat 2 can pass through the standing position B transiently, the seat 2 is pulled back to the vicinity of the standing position B again.

When the seat 2 stops near the standing position B by the action of the spring, the plunger 82 is moved along the guide surface 42b by the protruding force of the plunger 82 of the detent mechanism 8 as described above. Since the rotating portion 4 is rotated to a position protruding into the engagement recess 42a, the seat 2 can always be stably returned to the upright position B described above.

As described above, according to the present embodiment, it is possible to always apply a force to the seat 2 to return to the standing position B, even though the rotating part 4 and the fixed part 5 are directly associated with each other through the spring 6. As a result, the function of stably stopping the seat 2 at the standing position B can be effectively realized without using the intermediate portion as in the related art, so that the tip of the seat 2 of an empty seat where no person is seated can be neatly displayed. Can be aligned. Then, it is possible to effectively reduce the number of parts and the manufacturing cost. In particular, in the present embodiment, the return operation to the standing position B is caused only by the single spring 6, so that such an effect is particularly remarkable. In addition, in the present embodiment, the positioning to the standing position B is performed by the moderation mechanism 8, so that even if the spring 6 is loosely formed or assembled, the seat 2 can be reliably moved up and down. Can be performed.

Further, in this embodiment, since the moderation mechanism 8 is constituted by a combination of the plunger 82 and the engaging concave portion 42a, the moderation stopping operation at the standing position B can be reliably performed on the seat 2 by a simple structure. Since the guide surface 42b is provided in the vicinity of the engagement recess 42a, the seat 2 can be reliably guided to the upright position B.

Further, the seat 2 is stably held at the lying position A,
Alternatively, in order to prohibit unnecessary rotation beyond the retreat position C, the rotation direction end faces 44, 4
Since the stationary member 5 is brought into contact with the stationary end surfaces 55 and 56 provided on the fixed part 5, it is possible to ensure the proper use state of the chair and the undulating operation using the rising mechanism component itself.

In addition to this function and effect, in this chair, a rotating part 4 fixed to the side of the seat 2 is attached so as to surround a fixed part 5 provided on the support 1, and a spring 6 and Since the moderation mechanism 8 is accommodated in the seat, the seat can be configured without providing a penetrating support shaft in a seat or bringing in complicated element parts into the seat as in a conventional chair. For this reason, a sufficient degree of freedom can be ensured in designing the shape of the seat 2, and even if the width dimension and the arrangement pitch of the seat 2 are different, different standards as in the case of using the through shaft are used. Therefore, it is not necessary to prepare each time, and it is possible to give versatility that can flexibly cope with various aspects. In particular, since the rotation restricting means 7 and 9 are included between the rotating part 4 and the fixed part 5, between the rotating end face 47 and the stationary end face 55, or between the rotating end face 48 and the stationary end face 56.
It is possible to avoid the inconvenience of clothing or the like being sandwiched between the two, and at the same time, to eliminate the unsightly appearance when the mechanism is exposed.

The specific configuration of each part is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0036]

The present invention is embodied in the form described above and has the following effects. That is, in the chair of the present invention, the seat is supported on the support via the rising mechanism, and when the seat is moved up and down between the evacuation position and the evacuation position by the rising mechanism, the rising mechanism is A fixed portion, a rotating portion, a spring, and a detent mechanism are configured so that a force for returning to the upright position always acts on the seat even if the seat rotates in any direction from the upright position. Although the intermediate portion is not used, the function of stably stopping the seat at the standing position can be effectively exerted, so that the leading end of the seat of an empty seat where no person is seated can be neatly arranged with good appearance. As a result, it is possible to effectively reduce the number of parts and the manufacturing cost. In particular, since the present invention is constituted only by a single spring, such an effect is particularly remarkable. Moreover, since the present invention is provided with a moderation mechanism, it is possible to reliably hold the seat in the expected standing position even if there is some backlash without requiring high accuracy in processing and assembling the spring. Can be. Also,
Since the present invention can be configured without providing a rising mechanism and a penetrating support shaft inside the seat, the degree of freedom in designing the seat can be largely secured, and at the same time, the width dimension and arrangement pitch of the chair are reduced. Different cases can be easily handled.

In particular, when the moderation mechanism is constituted by a combination of the engaging element and the engaging concave portion, the moderation stopping operation at the upright position on the seat can be reliably performed by a simple structure. When the guide surface is provided in the vicinity, the seat can be reliably guided to the upright position.

In order to stably hold the seat in the lying position or to prohibit unnecessary rotation beyond the retreat position,
If the end face in the rotating direction provided on the rotating part is brought into contact with the stationary end face provided on the fixed part, it is possible to ensure the proper use state of the chair and the undulating operation using the rising mechanism itself. Become. In particular, by enclosing the rotation restricting means constituting the rising mechanism between the rotating part and the fixed part, the inconvenience that clothes and the like are sandwiched in the mechanism part, and the mechanism part is exposed to the outside and has a good appearance. The inconvenience that is impaired can be effectively eliminated.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a plan view showing the embodiment.

FIG. 3 is a side view showing the same embodiment.

FIG. 4 is an enlarged schematic sectional view showing an X part in FIG. 1;

FIG. 5 is an exemplary exploded perspective view showing a main part of the embodiment;

FIG. 6 is an operation explanatory diagram for explaining the operation of the embodiment.

FIG. 7 is an enlarged sectional view taken along line YY in FIG. 4;

FIG. 8 is an operation explanatory view corresponding to FIG. 7;

FIG. 9 is an operation explanatory view corresponding to FIG. 7;

FIG. 10 is a schematic diagram showing a state of a spring at a standing position according to the embodiment.

FIG. 11 is a schematic diagram showing a state of a spring at a standing position according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Support body 2 ... Seat 3 ... Rising mechanism 4 ... Rotating part 5 ... Fixed part 6 ... Spring 7 ... First rotation restricting means 8 ... Moderation mechanism 9 ... Second rotation restricting means 42a ... Engaging concave part 42b ... Guide surface 47 ... First rotational direction end surface 48 ... Second rotational direction end surface 55 ... First stationary end surface 56 ... Second stationary end surface 61 ... One end 62 ... Other end 81 ... Biasing element (spring) 82 ... Engaging element (plunger) A: Falling position B: Standing position C: Retreat position

Claims (6)

(57) [Claims] 1. A chair having a structure in which a seat is supported on a support via a rising mechanism, and the seat can be raised and lowered between a standing position, a standing position, and a retreating position by the rising mechanism. A rotating portion integrally provided with the rising mechanism with its axis aligned with the center of rotation of the seat, a fixed portion provided around the center of rotation on the support side, and both ends elastically connected to the fixed portion. When the seat is shifted from the standing position to the lying position side, the other end is in elastic contact with the fixed portion, and one end is engaged with the rotating portion, and the seat is separated from the elastic contact position. It is configured to accumulate repulsive force while being elastically deformed by entrainment, and when the seat moves from the standing position to the retracted position side, one end is elastically contacted with the fixed portion and the other end is engaged with the rotating portion. In the direction away from the elastic contact position A single spring configured to accumulate repulsive force while elastically deforming, and a detent mechanism for detently stopping the rotating part on the fixed part when the seat is in the upright position. Chair featuring. 2. An engaging member provided with a detent mechanism on one of a rotating portion and a fixed portion so as to be able to protrude and retract in a radial direction, an urging element for urging the engaging member in a protruding direction, 2. The chair according to claim 1, further comprising an engaging recess provided on the other side of the fixing portion and opened at a position where the engaging element can be inserted when the seat is in the upright position. 3. A guide surface which is smoothly continuous with the engaging concave portion at a position where the engaging member abuts when the seat is in the vicinity of the upright position, and a reaction force received from the guiding surface when the engaging member protrudes. 3. The chair according to claim 2, wherein the engaging element is configured to be drawn into the engaging recess. 4. A first rotation restricting means for prohibiting the seat from rotating beyond the lying position, the first rotation restricting means being provided in a first rotation direction set on the rotating part side. 2. The chair according to claim 1, further comprising an end surface, and a first stationary end surface which is set on the fixed portion side and in which the end surface in the rotation direction abuts on the seat in the down position. 5. A second rotation restricting means for prohibiting the seat from rotating beyond the retreat position, the second rotation restricting means being provided in a second rotation direction set on the rotation unit side. The chair according to claim 1 or 4, further comprising an end surface, and a second stationary end surface set on the fixed portion side and brought into contact with the end surface in the rotation direction at the retracted position of the seat. 6. The chair according to claim 4, wherein the rotation restricting means is included between the rotating part and the fixed part.