JP2003230452A - Repulsion adjusting mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the whole length of a repulsion adjusting mechanism. <P>SOLUTION: This repulsion adjusting mechanism 1 adjusts the magnitude of the locking repulsion of an energizing spring 5 for returning a supported member 3 supported lockably to a support member 2 to an original position. This mechanism 1 is arranged on the side of the energizing spring 5. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reaction force adjusting mechanism for adjusting the magnitude of a rocking reaction force of a chair or the like capable of rocking a seat or a backrest. More specifically, the present invention relates to a reaction force adjusting mechanism that adjusts the magnitude of reaction force by changing the overall length of a biasing spring that is a reaction force source.

[0002]

2. Description of the Related Art A chair capable of locking a seat or backrest uses a biasing spring such as a compression coil spring or a gas spring to return the seat or backrest to its original position. Then, there is a chair provided with a rocking reaction force adjusting mechanism for adjusting the magnitude of the rocking reaction force according to the physique and usage condition of the seated person.

As the reaction force adjusting mechanism 100, for example, as shown in FIG. 28, a slider 102 capable of pressing one end of an urging spring 101 and an urging spring 10 for urging the slider 102.
1. A wedge-shaped pressing block 103 that can be pressed from the opposite side of 1.
And an adjusting screw 104 for fixing the pressing block 103 by moving the pressing block 103 perpendicularly to the expanding and contracting direction of the biasing spring 101. In this reaction force adjusting mechanism 100, the adjusting screw 1
04 is rotated to move the pressing block 103, and the inclined surface of the pressing block 103 presses the slider 102 and presses the biasing spring 101 to change the initial compression length.
This is to change the initial compression length of the biasing spring 101 to change the initial pressure of the biasing spring 101 and adjust the magnitude of the reaction force of the rocking.

[0004]

However, in the above-mentioned reaction force adjusting mechanism for changing the initial compression length of the biasing spring, since the slider and the movable member of the pressing block are on the extension line of the biasing spring, the biasing force is increased. The total front-rear length of the spring and the reaction force adjusting mechanism is the sum of the front-rear lengths of the urging spring and the reaction force adjusting mechanism, which is very long. Therefore, the length of the guide portion of the seat receiving member that supports the front end portion of the seat so as to be able to move back and forth cannot be sufficiently secured, and the length that the seat can move back and forth is significantly limited. Was insufficient.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a reaction force adjusting mechanism whose total length can be shortened.

[0006]

In order to achieve such an object, the invention as claimed in claim 1 is a rocking counter of a biasing spring for returning a supported member, which is rockably supported by a supporting member, to an original position. In the reaction force adjusting mechanism for adjusting the magnitude of force, the reaction force adjusting mechanism is arranged on the side of the biasing spring.

Therefore, the total front-rear length of the urging spring and the reaction force adjusting mechanism can be suppressed to be slightly longer than the front-rear length of the urging spring. Therefore, the entire front-rear length of the biasing spring and the reaction force adjusting mechanism is much shorter than the conventional length obtained by adding the front-rear lengths of the biasing spring and the reaction force adjusting mechanism. As a result, it is possible to secure a sufficient length of the guide portion of the seat receiving member that supports the front end portion of the seat so as to be able to move back and forth. Can be increased. That is, it is possible to secure a large inclination angle and movement amount of the seat and the backrest between the upright position and the reclining position by sufficiently increasing the back-and-forth movement amount of the seat.

Moreover, since the distance from the front end of the seat to the front end of the seat receiving member can be made sufficiently long, it becomes difficult to see the mechanical portion below the seat when viewed from the front of the chair, and the appearance can be improved. .

According to a second aspect of the present invention, in the reaction force adjusting mechanism according to the first aspect, the reaction force adjusting mechanism changes the entire length of the biasing spring according to the principle of leverage, and the adjusting lever. The adjusting lever is provided with a fixing means for fixing the position, and the adjusting lever is L-shaped with a long side portion located along the biasing spring and a short side portion attached to the biasing spring.

Therefore, the length of the biasing spring can be changed by utilizing the lever principle by operating the adjusting link, so that the reaction force can be adjusted with a light force. Moreover, since the long side portion is along the biasing spring, the biasing spring and the reaction force adjusting mechanism can be compactly assembled as a whole.

Further, the invention according to claim 3 is based on claim 2.
In the reaction force adjusting mechanism described above, the adjusting lever is capable of swinging in the horizontal direction, and the fixing means is an adjusting screw capable of swinging the adjusting lever with the tip of the long side portion as a force point, and the biasing spring It is arranged horizontally on the side. Therefore, since the fixing means and the adjusting lever are horizontally arranged laterally of the biasing spring, the vertical thickness of the seat can be suppressed to be extremely thin.

Further, the invention of claim 4 is the same as claim 1.
In the reaction force adjusting mechanism according to any one of 1 to 3, the reaction force adjusting mechanism is mounted on a rocking device of the chair, and the biasing spring is provided so as to be inclined with respect to the front-back direction of the chair. ing. Therefore, the front-rear length of the biasing spring and the reaction force adjusting mechanism can be further shortened.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of the present invention will be described below in detail based on an example of an embodiment shown in the drawings. As shown in FIGS. 1 to 4, the reaction force adjusting mechanism 1 of the present embodiment includes a back support rod 3 and a seat 4, which are supported members that are rockably supported by a seat receiving member 2 that is a supporting member. The magnitude of the rocking reaction force of the biasing spring 5 for returning the to the original position is adjusted.

The reaction force adjusting mechanism 1 is arranged beside the biasing spring 5. Therefore, the total length L of the urging spring 5 and the reaction force adjusting mechanism 1 is the same as the urging spring 5
The length can be suppressed to be slightly longer than the front-back length. Therefore, the entire front-rear length of the urging spring 5 and the reaction force adjusting mechanism 1 is much shorter than the conventional length obtained by adding the front-rear lengths of the urging spring 5 and the reaction force adjusting mechanism 1. As a result, the length of the guide groove 14 of the seat receiving member 2 that supports the front end portion of the seat 4 so as to be able to move back and forth can be sufficiently secured, so that the amount of back and forth movement of the seat 4 can be made sufficiently long to allow the chair 8 to move. The reclining effect can be enhanced. That is, it is possible to secure a large tilt angle and movement amount of the seat 4 and the backrest 10 between the upright position and the reclining position by sufficiently increasing the back-and-forth movement amount of the seat 4.

Moreover, since the distance from the front end of the seat 4 to the front end of the seat receiving member 2 can be made sufficiently long, it is difficult to see the mechanical portion below the seat 4 when the chair 8 is viewed from the front, and the appearance is good. Can be

Further, the biasing spring 5 is provided so as to be inclined with respect to the front-back direction of the chair 8. Therefore, the biasing spring 5
Also, the front-rear length of the biasing spring 5 and the reaction force adjusting mechanism 1 can be made shorter than when the reaction force adjusting mechanism 1 is provided horizontally.

Further, the reaction force adjusting mechanism 1 includes a biasing spring 5
Adjustment lever 6 that changes the total length of the lever according to the principle of leverage,
A fixing means 7 for fixing the position of the adjusting lever 6 is provided. Therefore, the length of the biasing spring 5 can be changed by utilizing the lever principle by operating the adjusting lever 6, so that the reaction force can be adjusted with a light force. Further, even when a larger reaction force is adjusted, the force required for the adjustment can be suppressed to the same level as in the conventional case.

In this embodiment, the reaction force adjusting mechanism 1 is mounted on a rocking chair 8 as shown in FIGS. The chair 8 includes a leg 9, a seat receiving member 2 supported by the leg 9, a seat 4 supported by the seat receiving member 2 such that a front portion thereof can rotate and move back and forth, a seat receiving member 2 and a seat 4. A back support rod 3 which is rotatably supported with respect to the seat 4 and interlocks with the seat 4, a backrest 10 attached to the back support rod 3, and the back support rod 3 and the seat using the biasing force of the biasing spring 5. A locking device 11 for returning 4 to the initial position and a reaction force adjusting mechanism 1 for adjusting the magnitude of the rocking reaction force of the biasing spring 5 are provided.

The seat 4 is a seat body 12 having a seating surface 12a.
And a seat frame 13 that supports the seat body 12 so as to be movable back and forth from below. The seat body 12 is composed of a seat plate serving as a core, a cushion placed on the seat plate, and an upholstery cloth covering the cushion. An inner guide groove 14 and an outer guide groove 77 are formed at the front end portion of the seat frame 13 with the front and back as the longitudinal direction. A guide hole 78 is formed in the rear portion of the seat frame 13 with the front-back direction as the longitudinal direction. The seat body 12 is supported in the outer guide groove 77 and the guide hole 78 of the seat frame 13 so as to be movable back and forth with respect to the seat frame 13 by using a pin member or a bolt.

The inner guide groove 14 is slidably and rotatably attached to a front support shaft 15 provided at the upper front end of the seat receiving member 2. A rear end portion of the seat frame 13 is rotatably attached to a rear support shaft 16 provided on the back support rod 3. As a result, when the back support rod 3 tilts backward, the seat frame 1
When the rear part of 3 is pulled rearward, the front part rotates and slides rearward at the same time.

As shown in FIGS. 2 to 4, the locking device 11 includes a central support shaft 17 rotatably attached to the central portion of the seat receiving member 2 and a pressing lever 18 which rotates integrally with the central support shaft 17. An urging spring 5 having one end supported by the pressing lever 18 and the other end supported by the seat receiving member 2 via the reaction force adjusting mechanism 1, and a spring mount 19 holding both ends of the urging spring 5. Is equipped with. The biasing spring 5 is a compression coil spring. Therefore, when the central support shaft 17 rotates due to the rearward tilting of the back support rod 3, the pressing lever 18 causes the biasing spring 5 to move.
Can be compressed to obtain a reaction force. When the external force that tilts the back support rod 3 backward is released, the back support rod 3 is returned to its original position by the urging force of the urging spring 5.

The adjusting lever 6 of the reaction force adjusting mechanism 1 is L-shaped with a long side portion 20 located along the biasing spring 5 and a short side portion 21 attached to the biasing spring 5. There is. Therefore, since the long side portion 20 is along the urging spring 5, the urging spring 5 and the reaction force adjusting mechanism 1 can be compactly integrated. Also, the biasing spring 5
Are arranged in parallel on both left and right sides with the long side portion 20 of the adjusting lever 6 interposed therebetween. Therefore, as compared with the case where only one urging spring 5 is attached, it is possible to obtain a reaction force that is twice as large as that of the urging spring 5, and the urging spring 5 can be made sufficiently long regardless of the presence of the reaction force adjusting mechanism 1. A large reaction force can be obtained.

The tip of the short side portion 21 of the adjusting lever 6 is rotatably supported by the seat receiving member 2. A spring bearing shaft 22 that engages with the spring mount 19 of the biasing spring 5 is attached to the L-shaped corner of the adjusting lever 6.
Therefore, the adjusting lever 6 is always biased by the biasing spring 5 in the direction of rotating forward. Further, fixing means 7 is attached to the long side portion 20 of the adjusting lever 6. In the present embodiment, the fixing means 7 functions to prevent the adjusting lever 6 from rotating forward.

The fixing means 7 is an adjusting screw capable of swinging the adjusting lever 6. Therefore, since the adjusting lever 6 can be swung by rotating the fixing means 7, the reaction force can be easily adjusted with a light force. In this embodiment, the fixing means 7 is the seat receiving member 2
Is rotatably attached to the bottom portion 2a of the. Further, the fixing means 7 includes an operation knob 23 provided outside the seat receiving member 2 and a male screw portion 24 provided inside the seat receiving member 2. The operation knob 23 may have a flat shape along the longitudinal direction of the male screw portion 24, or a cylindrical shape.

The male screw portion 24 of the fixing means 7 penetrates the through hole 20a formed in the long side portion 20 of the adjusting lever 6. Further, a slider 25 having a female screw portion is screwed into the male screw portion 24 of the fixing means 7. The slider 25 has a rectangular parallelepiped shape and is non-rotatably sandwiched between the left and right side walls of the adjusting lever 6. For this reason,
Even if the fixing means 7 is rotated, the slider 25 slides along the longitudinal direction of the male screw portion 24 without rotating.

As a result, when the slider 25 is lowered downward by tightening the fixing means 7, the adjusting lever 6 rotates rearward to compress the biasing spring 5 and increase the reaction force (in FIG. 3, Shown with a solid line). Further, when the slider 25 is raised upward by loosening the fixing means 7, the adjusting lever 6 is rotated forward by the spring force of the urging spring 5 so that the urging spring 5 extends and the reaction force can be reduced (Fig. 3 is indicated by a chain double-dashed line).

In FIG. 4, reference numeral 26 is an elevating lever for pressing the adjusting pin of the gas spring 28 built in the leg 9, and reference numeral 27 is a cable attached for swinging the elevating lever 26. .

As shown in FIGS. 1 and 2, the back support rod 3 has an L-shape having a substantially horizontal front portion 29 and a substantially upright rear portion 30. The front end of the back support rod 3 is fixed to the central support shaft 17 of the locking device 11 so as to rotate integrally therewith. A rear support shaft 16 to which the rear end of the seat 4 is rotatably connected is formed at the center of the front portion 29 of the back support rod 3.

On the other hand, in this locking device 11, the seat 4
Also, even if the backrest 10 is tilted and the lock is released at the position desired by the user and the lock is released when the user stands, the seat 4
Also, the backrest 10 has a so-called self-holding function in which the backrest 10 is held in an inclined state. This locking device 11
As shown in FIGS. 5 to 10, a locked link 32 provided swingably between the seat frame 13 and the seat receiving member 2 and having a plurality of engaging portions 31, and the seat frame 1 are provided.
The lock member 33 that locks the swing of the seat frame 13 at a position desired by the user when the seat frame 13 is attached to the engagement portion 31 and is urged in the direction in which the lock member 33 is engaged with the engagement portion 31. The first urging means 34, the operating means 35 that is switched between the lock position and the unlock position, and the second urging means 36 provided between the operating means 35 and the lock member 33. .

The locked link 32 has a fan shape as a whole,
A first mounting pin 37 provided near the central angle and a second mounting pin 3 provided closer to the center than the first mounting pin 37
8, a flange portion 39 having a circumferential surface centered on the second mounting pin 38, and an engaging portion 31 formed of a through hole arranged in the flange portion 39 along the circumferential direction. The second mounting pin 38 is rotatably mounted on the seat frame 13 in a horizontal plane. The first mounting pin 37 and the tip of the seat receiving member 2 are connected by a connecting link 40. Therefore, when the seat frame 13 swings, the relative positions of the first mounting pin 37 and the second mounting pin 38 change, so that the locked link 32 rotates.

The second mounting pin 38 and the engaging portion 31 are arranged such that the distance between them is larger than the distance between the pins 37 and 38. Therefore, the relative movement amount of the seat frame 13 and the seat receiving member 2 is amplified and the engaging portion 31 is moved. Therefore, when the locked member is directly attached to the seat 4 or the like, a large number of engaging portions 31 cannot be provided, but according to the present embodiment, the number of stages in which the seat 4 and the backrest 10 can be locked can be increased. . For example, in the chair 8 of the present embodiment, since the seat frame 13 moves back and forth by about 30 mm, even if a locked member is directly attached to this, the lock points are provided only in a few steps. Since the movement is amplified, for example, five stages of lock points can be provided. Moreover, since a sufficient margin can be provided between the engaging portions 31, a robust structure can be obtained.

The locked link 32 is provided so as to swing in a horizontal plane. Therefore, the thickness of the locking device 11 in the vertical direction can be reduced, and the locking device 11 can be built in without increasing the thickness of the seat 4.

In the present embodiment, the locked link 3
2 are provided on the left and right. Left and right locked links 32
Theoretically move symmetrically, so that the engaging portions 31 face each other and the lock member 33 penetrates. However, when there is a risk that the left and right locked links 32 may be displaced due to dimensional error or the like, gears that mesh with each other may be provided in each locked link 32 so that the operations are completely the same.

The lock member 33 is slidably attached to the guide cylinder 41 of the seat frame 13 so as to be able to move in and out of the engaging portion 31. Then, when the lock member 33 is fitted into the engaging portion 31, the seat 4 and the backrest 1
Zero swing can be locked. This is because the seat frame 13 and the seat receiving member 2 form a fixed chain by the lock member 33 and the locked link 32. In addition, in the present embodiment, the lock member 33 includes the engaging portion 31.
Although it is mounted so as to slide in and out by sliding, the present invention is not limited to this, and may be set in and out by rotation, for example.

The second urging means 36 transmits the movement of the operating means 35 to the lock member 33 and elastically urges at least the direction in which the lock member 33 is pulled out from the engaging portion 31. Further, the operating means 35 is composed of a lever mechanism and can be held at the unlocked position. Here, the first
The biasing means 34 and the second biasing means 36 are tension coil springs having the same spring constant. Therefore, the components of the first biasing means 34 and the second biasing means 36 can be shared.

Further, a link 42 is connected between the base end of the lock member 33 and the seat frame 13. Then, the lock member 33 is provided so as to appear in and out of the engagement portion 31 as the link 42 swings. Further, the first urging means 34 is attached between the link 42 and the seat frame 13, and urges the lock member 33 in the direction in which it is recessed into the engaging portion 31. A second urging means 36 is attached between the link 42 and the operating means 35. Here, the fulcrum 42a and the action point 42b of the link 42
Since there is a force point 42c between the lock member 33 and the lock member 33 (see FIG. 7), the lock member 33 can be slid by amplifying the movements of the first biasing means 34 and the second biasing means 36.

Therefore, as shown in FIG. 7, the operating means 3
5 is in the lock position and the lock member 33 is fitted in the engaging portion 31 of the locked link 32, the seat frame 13
Since the lock member 33 is present across the guide cylinder 41 and the engaging portion 31, the swing of the seat 4 and the backrest 10 is locked. In this state, if no external force is applied to the seat 4 and the backrest 10 or only a slight external force is applied, the seat frame 13 receives the large reaction force of the biasing spring 5 and returns to the initial position. Is urged by. Here, the inner wall of the engaging portion 31 of the locked link 32 and the lock member 33
Since they are pressed against each other, as shown in FIG.
Even if 5 is operated to the unlock position and the lock member 33 is pulled out from the engaging portion 31 by the urging force of the second urging means 36, the lock member 33 cannot move due to a large friction with the inner wall of the engaging portion 31. . Therefore, the seat 4 and the backrest 1
At the same time that the rocking lock of 0 is maintained, the second urging means 3
6 is stored. As a result, the tilted states of the seat 4 and the backrest 10 are self-maintained.

When an external force that weakens the reaction force of the biasing spring 5 is applied to the seat 4 and the backrest 10 in the self-holding state, a pressing force is applied between the inner wall of the engaging portion 31 and the lock member 33. Becomes smaller and the frictional force weakens. Further, the total amount of this frictional force and the urging force of the first urging means 34 is equal to the second amount.
When the biasing force of the lock member 33 becomes smaller than the biasing force of the lock member 33 in the pull-out direction, the lock member 33 is pulled out from the engaging portion 31 by the second biasing device 36, as shown in FIG. At this time, the lock member 33 is held by the first urging means 34 and the second urging means 36 in a balanced manner so as not to move. Then, the locked state by the lock member 33 and the engaging portion 31 is released, and the seat frame 1
Since 3 becomes unlocked and can swing, the seat 4 and the backrest 10 are returned to the initial position by the urging of the urging spring 5, or the seat 4 is moved to an arbitrary position by the seated person as shown in FIG. It is rocked.

On the other hand, a lumbar support adjusting mechanism 43 for adjusting the protrusion amount of the lumbar support of the backrest 10 is provided at the rear portion of the front portion 29 of the back support rod 3. Backrest 10
The lower portion is supported by the lumbar support adjusting mechanism 43, and the central portion is supported by being screwed to the upper end portion of the rear portion 30 of the back support rod 3.

This backrest 10 is, as shown in FIG.
For example, it is provided with a frame-shaped inner member 44 made of plastic, and a bag-shaped skin member 45 which is made of, for example, an elastomer such as rubber or polyester having elasticity and which wraps the inner member 44. Since the inner member 44 is in the shape of a frame, the back of the seated person is supported only by the skin member 45, so that a high cushioning property can be obtained and the sitting comfort can be improved.

As shown in FIGS. 2 and 11 to 13, the lumbar support adjusting mechanism 43 is fixed to the lower portion of the backrest 10 and can be pushed forward to support the main body 46.
And a support shaft 47 that attaches the support body 46 to the back support rod 3 and supports the back support rod 3 slidably in the front-rear direction.
A rotatable screw shaft 48 provided along the support shaft 47, a slider 49 screwed onto the screw shaft 48, and a link 5 rotatably connecting the slider 49 and the support shaft 47.
It has 0 and.

The support body 46 slides with a mounting portion 51 to which the lower part of the backrest 10 is attached, a support hole 52 through which the support shaft 47 penetrates, and a guide pin 53 formed on the back support rod 3. Guide groove 54, and a seat support portion 55 that is screwed to the rear portion 12b of the seat body 12 and supports the rear portion of the seat 4 from below. A support groove 56 is formed in the back support rod 3 to support the support shaft 47 so as to be movable back and forth. Here, the support groove 56 and the guide groove 54 are formed to have an angle of, for example, about 25 degrees. Therefore, when the support shaft 47 slides in the support groove 56, the support main body 46 also moves back and forth, but at this time, the guide groove 54 moves with an inclination of 16 degrees, so that the support main body 46 as a whole has the support groove 56. Will rotate about a point C where the normals of the guide groove 54 intersect.

Since the lower portion of the backrest 10 and the rear portion of the seat body 12 are fixed to the support body 46, the seat body 12 moves back and forth at the same time as the shape of the backrest 10 changes due to the inclination of the support body 46. The shape of the seat body 12 changes. That is, when the backrest 10 has a relatively flat shape and the seat body 12 is positioned on the front side (shown by a chain double-dashed line in FIG. 12), or the waist portion of the backrest 10 projects and the seat body 12 is It can be changed to a state of being located on the rear side (shown by a solid line in FIG. 12). As a result, when supporting a posture in which the spine has an I shape with a relatively flat shape (see FIG. 1).
4)), or the case where the waist portion projects as a lumbar support and the seat body 12 is pulled backward to support the posture in which the spine is S-shaped (see FIG. 15).

Further, as shown in FIG. 13, the screw shaft 48 is formed with a right-hand thread and a left-hand thread with the central part as a boundary. Then, two sliders 49 are provided so as to sandwich the central portion. Therefore, by rotating the screw shaft 48, the two sliders 49 slide in opposite directions.
Then, when the links 50 are parallel to each other, the support shaft 47 is located at the frontmost position (indicated by a solid line in FIG. 13). When the screw shaft 48 is rotated from this state, the sliders 49 are separated or approached, the links 50 are not parallel, and the support shaft 47 is pulled backward. Along with this, the support body 46 is rotated and the height of the lumbar support can be adjusted. The adjustment of the screw shaft 48 may be performed using a tool such as a screwdriver, or may be performed by operating an operation knob that rotates integrally with the screw shaft 48.

When the chair 8 described above is used, the seated person can perform rocking by leaning on the backrest 10 and leaning it. Then, the reaction force of the rocking can be adjusted by operating the reaction force adjusting mechanism 1.

In this embodiment, since the seat 4 and the backrest 10 are positioned by the engagement of the locked link 32 and the lock member 33, the urging spring is different from the case of using the gas spring with the lock mechanism. It is necessary to increase the spring force of No. 5. However, since the operating force of the reaction force adjusting mechanism 1 here is small, the reaction force can be easily adjusted.

In the present embodiment, the reaction force adjusting mechanism 1 and the biasing spring 5 are short in the front-rear length and the front-rear movement amount of the seat 4 can be made sufficiently long. It is possible to secure a large inclination angle and a large amount of movement of the seat 4 and the backrest 10 between them. Therefore, it is possible to provide the chair 8 that is comfortable to sit on.

The above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, the lumbar support adjustment mechanism 43 adjusts the height of the lumbar support by moving the support body 46 fixed to the lower portion of the backrest 10 as shown in FIGS. 2 and 11 to 13. However, it is not limited to this. For example, as shown in FIGS.
The lumbar support adjusting mechanism 43 is provided with a guide rail 57 that supports the lower part of the backrest 10 so as to be able to move up and down, and an operation lever 58 that is supported so as to be vertically swingable with respect to the back support rod 3, A part of the lever 58 may be connected to the lower portion of the backrest 10 so that the lower portion of the backrest 10 is guided by the guide rail 57 and moves up and down as the operation lever 58 moves up and down.

In this embodiment, the guide rails 57 are provided on the left and right back support rods 3 and each of the guide rails 57.
A connecting member 59 for connecting the above is provided. The operation lever 58 is provided on the left and right from the central portion of the connecting member 59. The inner end 58a of each operating lever 58 is rotatably provided at the center of the connecting member 59, and the outer end 58b is provided through the guide rail 57 so as to be operated from the outside. Further, the lower portion of the backrest 10 is attached to the central portion 58c of each operation lever 58. Here, a laterally long through hole 60 is formed in the lower portion of the backrest 10 (see FIG. 18), and the backrest 10 is screwed to the operation lever 58 with a bolt penetrating the through hole 60.

Therefore, when the operating lever 58 is at the lowermost position, the lower portion of the backrest 10 is also at the lowermost position (FIG. 17).
(A)). At this time, the backrest 10 has a relatively flat shape, which is suitable for supporting the posture in which the spine is I-shaped (FIG. 14). When the operating lever 58 is at the uppermost position, the lower portion of the backrest 10 is also at the uppermost position (FIG. 17).
(B)). At this time, the waist portion of the backrest 10 is projected, which is suitable for supporting the posture in which the spine is S-shaped (FIG. 15).

In the above-described embodiment, as shown in FIG. 11, the center portion of the backrest 10 is attached to the upper part of the back support rod 3 which is about half the height of the backrest 10 by screwing. Not limited to For example, FIGS. 14, 15, and 1
As shown in FIGS. 8 to 20, a back support rod 3 having the same height as the backrest 10 may be swingably provided in the central portion in the front-rear direction. In this case, as shown in FIG. 18, the back support rod 3 includes a lower half portion 61 attached to the seat receiving member 2 and an upper half portion 62 rotatably attached to the lower half portion 61. . Here, the upper half portion 62 has a frame shape. Upper half 6
2 and the lower half part 61 are rotatably attached to the front and back by left and right connecting pins 63.

The backrest 10 is provided with, for example, a frame-shaped inner member 44 made of plastic, and a bag-shaped skin member 45 which is made of an elastomer such as rubber or polyester having elasticity and which wraps the inner member 44. . A horizontal opening 64 is formed in the center of the back surface of the skin member 45. The upper skin member 65 above the opening 64 is formed in a bag shape larger than the inner member 44. The upper half 62 is hidden inside the upper skin member 65. Therefore, the appearance of the backrest 10 can be improved.

The lower portion of the upper half 62 is screwed to the inner member 44 of the backrest 10 as shown in FIG. The upper end portion of the upper half portion 62 is engaged with the inner member 44 of the backrest 10 as shown in FIG. The mode of engagement is not particularly limited, and a convex portion 66 and a concave portion 67 that completely fit each other are formed as shown in FIG. 7A, or a mountain portion that is simply caught as shown in FIG. 68 and the valley portion 69 may be formed. Thus, by fixing the upper half portion 62 to the inner member 44 of the backrest 10,
It is possible to prevent the upper half 62 from falling.

According to the backrest 10 and the back support rod 3,
As the lower part of the backrest 10 is moved up and down by the lumbar support adjusting mechanism 43, the upper half of the backrest 10 swings so that the shape of the backrest 10 changes.

In the embodiment shown in FIGS. 18 and 19, the upper part of the back support rod 3 is hidden inside the upper skin member 65, but the invention is not limited to this. For example, as shown in FIG. 21, an outer cover 70 that hides the upper half portion 62 of the back support rod 3 between the backrest 10 and the backrest 10 may be attached from the rear.

Although the adjusting lever 6 is rotated in the vertical direction in the above-described embodiments shown in FIGS. 1 to 4, it is not limited to this and may be in the horizontal direction. For example, as shown in FIGS. 23 and 24, the adjusting lever 6 can be horizontally swingable. In this case, the fixing means 7 is an adjusting screw capable of swinging the adjusting lever 6 with the tip of the long side portion 20 as a force point, and is provided horizontally to the side of the urging spring 5 to adjust the urging spring 5. Lever 6
Since the fixing means 7 and the fixing means 7 can all be arranged in the horizontal direction, the thickness t in the vertical direction can be made thinner than when these are arranged in the vertical direction. This makes it possible to reduce the thickness of the seat while shortening the entire front-rear length of the biasing spring 5 and the reaction force adjusting mechanism 1.

On the other hand, in the embodiments shown in FIGS. 1 to 4 described above, the reaction force adjusting mechanism 1 is provided with the adjusting lever 6 and the fixing means 7, but it is not limited to this. For example, as shown in FIG. 25, a slide lever 71 slidable along the expansion / contraction direction of the biasing spring 5, a rack 71a formed on the slide lever 71, and a pinion 72 that rotates by meshing with the rack 71a are provided. It may be equipped. In this case, the rack 71a is assumed to be along the extension / contraction direction of the biasing spring 5. As a result, the slide lever 71 slides along the expansion / contraction direction of the biasing spring 5 as the pinion 72 rotates, so that the biasing spring 5 can be expanded / contracted.

Further, as shown in FIG. 26, a slide lever 73 slidable along the extension / contraction direction of the biasing spring 5, and a slide lever 73 formed on the slide lever 73 and located laterally of the biasing spring 5. The slide block 74 and a pressing block 75 that presses the slide block 74 from the side by the slope.
And an operation screw 76 for pressing the pressing block 75. In this case, since the pressing block 75 slides the slide block 74 by operating the operation screw 76, the biasing spring 5 can be expanded and contracted.

Further, in this case, as shown in FIG. 26, the pressing direction of the pressing block 75 may be the direct direction of the biasing spring 5, or as shown in FIG. 27, the pressing direction of the pressing block 75 may be the biasing spring. It can be deviated from 5. This makes it possible to select a structure suitable for the structure of the locking device in which the reaction force adjusting mechanism 1 is mounted.

Further, in the locking device 11 shown in FIGS. 5 to 10 described above, the locked link 32 is used, but the locking link 32 is not limited to this and may be a locked gear or the like.

Further, in the above-described embodiment, FIGS.
As shown in FIG. 5, the operation means 35 can be held in the unlocked position, and the first urging means 34 moves the seat frame 13
And the lock member 33, and the second urging means 36 is attached between the operating means 35 and the lock member 33. When the operating means 35 is held in the unlock position, the first urging means is urged. The means 34 and the second urging means 36 are balanced to hold the lock member 33 in the unlock position, and when the operating means 35 is brought to the lock position, the first urging means 34 holds the lock member 33 in the lock position. However, it is not limited to this.

For example, as shown in FIG. 22, operating means 35
Can be held in the lock position, and the lock member 3
The second urging means 36 for urging the locking member 33 in the direction of pulling out the engaging portion 31 is attached between the seat frame 13 and the lock member 33, and the locking member 33 is engaged in the engaging portion 31. The first urging means 34 for urging may be attached between the operating means 35 and the lock member 33. In this case, when the operating means 35 is held at the lock position, the first biasing means 34 and the second biasing means 36 balance and the lock member 33 is held at the lock position, and the operating means 35 is set at the unlock position. Then, the lock member 33 is held at the unlock position by the second biasing means 36. In this case also, even if the operating member 35 is operated to the unlock position and the lock member 33 is pulled out from the engaging portion 31 in the locked state where the operating member 35 is set to the lock position and the lock member 33 is fitted in the engaging portion 31, The lock member 33 cannot move due to a large friction with the inner wall of the engaging portion 31, and the tilting lock of the seat 4 and the backrest 10 is maintained and self-held.

Further, although the rocking device 11 is applied to the rocking chair in each of the above-mentioned embodiments, the invention is not limited to this, and the rocking device 11 supports the supported member in a swingable manner, particularly the supported member. The present invention can be generally applied to those in which the support member and the support member are swung so as to sandwich the rotary shaft between them. For example, it can be used for a table, a drawing table, etc. of a personal computer desk having a considerable weight. Since such a table top has a considerable weight, a large reaction force is applied to balance it. In this case, by using the reaction force adjusting mechanism 1, the entire locking mechanism 11 can be downsized. Further, by using the reaction force adjusting mechanism 1, the rocking reaction force can be adjusted with a light force. Furthermore, when the operating lever is operated to the unlock side when the table plate is not loaded, the table plate is held by itself, so that it is possible to prevent the phenomenon that the table plate suddenly jumps up.

[0064]

As is apparent from the above description, according to the reaction force adjusting mechanism of the first aspect, the overall longitudinal length of the biasing spring and the reaction force adjusting mechanism is the same as the biasing spring and the reaction force adjusting mechanism. It is much shorter than the conventional length, which is the sum of the front and rear lengths. As a result, it is possible to secure a sufficient length of the guide portion of the seat receiving member that supports the front end portion of the seat so as to be able to move back and forth. Can be increased. That is, it is possible to secure a large inclination angle and movement amount of the seat and the backrest between the upright position and the reclining position by sufficiently increasing the back-and-forth movement amount of the seat. This makes it possible to improve the sitting comfort.

Moreover, since the distance from the front end of the seat to the front end of the seat receiving member can be made sufficiently long, the mechanical portion below the seat becomes difficult to see when viewed from the front of the chair, and the appearance can be improved. .

According to the reaction force adjusting mechanism of the second aspect, since the length of the biasing spring can be changed by operating the adjusting link by utilizing the principle of leverage, the reaction force can be adjusted with a light force. become. Moreover, since the long side portion is along the biasing spring, the biasing spring and the reaction force adjusting mechanism can be compactly assembled as a whole.

Further, the invention according to claim 3 is based on claim 2.
In the reaction force adjusting mechanism described above, the adjusting lever is capable of swinging in the horizontal direction, and the fixing means is an adjusting screw capable of swinging the adjusting lever with the tip of the long side portion as a force point, and the biasing spring It is arranged horizontally on the side. Therefore, since the fixing means and the adjusting lever are horizontally arranged laterally of the biasing spring, the vertical thickness of the seat can be suppressed to be extremely thin.

Further, according to the reaction force adjusting mechanism of the fourth aspect, the longitudinal length of the biasing spring and the reaction force adjusting mechanism can be further shortened.

[Brief description of drawings]

FIG. 1 is a central vertical cross-sectional side view showing an overview of a chair equipped with a reaction force adjusting mechanism of the present invention.

FIG. 2 is an exploded perspective view showing a main part of a chair equipped with a reaction force adjusting mechanism.

FIG. 3 is a central longitudinal sectional view showing a reaction force adjusting mechanism and a locking device.

FIG. 4 is a perspective view showing a reaction force adjusting mechanism and a locking device.

FIG. 5 is a perspective view showing a state in which a seat frame is attached to a seat receiving member.

FIG. 6 is a perspective view showing a state where the seat frame is viewed from below.

FIG. 7 is a plan view showing the locking device when the seat and the backrest are locked.

FIG. 8 is a plan view showing a locking device when a seat and a backrest are self-held.

FIG. 9 is a plan view showing the locking device when the seat and backrest are unlocked.

FIG. 10 is a plan view showing the locking device when the seat and the backrest are locked.

FIG. 11 is a perspective view showing a back support rod and a backrest.

FIG. 12 is a side view of a central longitudinal section showing a back support rod and a backrest.

FIG. 13 is a plan view showing a main part of a lumbar support adjusting mechanism.

FIG. 14 is a side view showing a state where the spine is seated in an I-shaped posture.

FIG. 15 is a side view showing a state where the spine is seated in an S-shaped posture.

FIG. 16 is a perspective view showing another embodiment of the lumbar support adjusting mechanism.

FIG. 17 is a front view showing another embodiment of the lumbar support adjusting mechanism, (A) showing a low lumbar support state, and (B) showing a high lumbar support state.

FIG. 18 is a perspective view showing another embodiment of the back support rod and the backrest.

FIG. 19 is a side view of a central longitudinal section showing another embodiment of the back support rod and the backrest.

FIG. 20 is a central longitudinal cross-sectional side view showing a connection structure of a back support rod and a backrest, (A) engaging a concave portion and a convex portion, and (B) engaging a mountain portion and a valley portion, respectively.

FIG. 21 is a perspective view showing another embodiment of the back support rod and the backrest.

FIG. 22 is a plan view showing another locking device.

FIG. 23 is a plan view showing a reaction force adjustment mechanism including an L-shaped horizontal adjustment lever.

FIG. 24 is a schematic side view showing a reaction force adjusting mechanism including an L-shaped horizontal adjusting lever.

FIG. 25 is a schematic view showing another embodiment of the reaction force adjusting mechanism.

FIG. 26 is a schematic view showing another embodiment of the reaction force adjusting mechanism.

FIG. 27 is a schematic view showing still another embodiment of the reaction force adjusting mechanism.

FIG. 28 is a side view of a central longitudinal section showing a conventional reaction force adjusting mechanism.

[Explanation of symbols]

1 Reaction force adjustment mechanism 2 Seat receiving member (supporting member) 3 Back support rod (supported member) 4 seats (supported members) 5 biasing spring 6 Adjustment lever 7 Fixing means 20 Long side 21 Short side

Claims (4)

[Claims] 1. A reaction force adjusting mechanism for adjusting the magnitude of a rocking reaction force of a biasing spring for returning a supported member, which is rockably supported with respect to a supporting member, to an original position.
The reaction force adjusting mechanism is arranged laterally of the biasing spring. 2. The reaction force adjusting mechanism includes an adjusting lever that changes the entire length of the biasing spring according to the principle of leverage, and a fixing unit that fixes the position of the adjusting lever. L having a long side portion located along the biasing spring and a short side portion attached to the biasing spring
The reaction force adjusting mechanism according to claim 1, wherein the reaction force adjusting mechanism has a letter shape. 3. The adjusting lever is capable of swinging in a horizontal direction, and the fixing means is an adjusting screw capable of swinging the adjusting lever with a tip portion of the long side portion as a force point, and the biasing means. The reaction force adjusting mechanism according to claim 2, wherein the spring is provided horizontally on a side of the spring. 4. The reaction force adjusting mechanism is mounted on a rocking device of a chair, and the biasing spring is provided so as to be inclined with respect to the front-rear direction of the chair. Item 4. The reaction force adjusting mechanism according to any one of items 1 to 3.