JP2001224459A - Chair with backrest - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a width in up and down direction of a main frame and a backrest frame. SOLUTION: A top end part of an arm part 53 of a backrest frame is connected with a top end of a main frame 3 in a manner that the former is capable of rotating around a center of horizontal axis 61 extending in right and left directions. A cam hole 71 is formed at the top end part of the arm part 53. An axial part 72 is arranged at a top end part of a sitting frame 41 engaged with the cam hole 71 in a movable manner via a roller 73. A movement fixing cam mechanism 70 that reclines the sitting frame 41 accompanying with the rotating of the arm part 53 is constructed with the cam hole 71, the axial part 72 and the roller 73.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair with a backrest whose backrest can be tilted between a work position and a comfortable position.

[0002]

2. Description of the Related Art A conventional chair with a backrest of this type is disclosed in Japanese Patent Application Laid-Open No. 6-253940. This chair with a backrest has a main frame provided at an upper end portion of a support leg, and a front end portion rotatably provided on the main frame, whereby a seatback provided at an upper portion on a rear end side is provided with a work position and a comfortable position. And a seat frame on which a seat is provided. The rear end of the seat frame is pivotally connected to the backrest frame. On the other hand, the tip of the seat frame is connected to the main frame via a positive cam mechanism. The positive cam mechanism includes a cam hole formed in the main frame, and a shaft provided in the seat frame and movably fitted to the cam hole, and the seat frame is rotated with the rotation of the back frame. When the rear end of the seat frame is turned up and down, the entire seat frame is displaced in the front and rear and up and down directions in relation to the turning in the up and down direction, and is tilted up and down.

[0003]

The cam hole of the positive cam mechanism is not only required to move the seat frame in the front-rear direction, but also needs to be displaced and tilted in the vertical direction. . For this reason, the main frame also has to be widened in the vertical direction corresponding to the vertical length of the cam hole, and there is a problem that it is difficult to reduce the size.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a main frame, a seat frame disposed above the main frame, and a front end portion which is horizontal to a front end portion of the chair body. Pivotally connected around the
Thereby, a backrest frame whose rear end can be tilted between a work position and a comfortable position, and a backrest frame provided between the rear end of the seat frame and the backrest frame, with the rotation of the backrest frame A backrest having a displacement mechanism for displacing the rear end portion of the seat frame in the oblique front-rear direction, and a positive cam mechanism for displacing the seat frame in the up-down direction and the front-rear direction in conjunction with the displacement mechanism and tilting the seat frame in the up-down direction. In the chair, the positive cam mechanism is provided between a front end portion of the seat frame and a front end portion of the backrest frame. In this case, the positive cam mechanism has a cam hole and a shaft portion movably inserted in the longitudinal direction of the cam hole, and one of the cam hole and the shaft portion is mounted on the seat. It is desirable to be provided on the frame and the other is provided on the backrest frame. It is particularly desirable that the cam hole be provided in the backrest frame. The displacement mechanism has a lower end rotatably connected to the main frame about a horizontal axis, and an upper end rotatably connected to a rear end of the seat frame about a horizontal axis. A second positive cam mechanism for rotating the link with the rotation of the backrest frame is provided between the upper end of the link and the backrest frame. A second positive cam mechanism is provided on one of the upper end portion of the backrest frame and the link, and a second cam hole provided on the other, and is movably inserted into the second cam hole. It is desirable to have a second shaft portion. The main frame is provided with an engagement member which is engaged with the link so as to be disengageable and prevents the link from rotating when engaged, thereby fixing the position of the backrest frame in the working position. Is desirable. At the tip of the main frame, the lower end of a shielding plate that shields a gap between the tip of the main frame and the seat frame or the seat provided on the seat frame is rotatable about a horizontal axis. When the size of the gap changes according to the displacement of the seat frame, the shielding plate rotates according to the size of the gap,
It is preferable that an upper portion of the shielding plate is connected to a tip of the seat frame.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. FIGS. 1 to 12 show an embodiment of the present invention. As shown in FIG. 3, a chair 1 with a backrest according to this embodiment includes a support 2, a main frame 3, a seat 4, and a backrest. A part 5 is provided.

The support 2 has a support frame 21. A plurality of casters 22 are provided at the lower end of the support frame 21 so that the support frame 21 can travel on the floor. At the center of the support frame 21, a support cylinder 23 is provided upright. The lower end of the support leg 24 is rotatably inserted into the support cylinder 23. This support leg 24
By a vertical movement mechanism (not shown) using gas pressure, etc.,
The position of the support cylinder 23 can be adjusted in the vertical direction. The main frame 3 is provided at the upper end of the support leg 24, and the main frame 3 is provided with a seat 4 and a backrest 5. Therefore, the seat 4 and the backrest 5
By adjusting the position of the support legs 24 in the vertical direction,
The position can be adjusted vertically.

The main frame 3 is, as shown in FIG.
It has a bottom plate portion 31 and side plate portions 32, 32 erected integrally upward on both left and right side portions of the bottom plate portion 31. A connecting tube 33 is fixed to a rear end of the bottom plate portion 31. The upper end of the support leg 24 is fitted and fixed to the connecting cylinder 33.

As shown in FIG. 3 and FIG.
Is a pair of left and right seat frames 41, 41 (only one seat frame 41 is shown in FIG. 3),
And a sheet 42 supported by the sheet 41. As shown in FIG. 12, the seat frame 41 has a vertical plate portion 43 whose longitudinal direction is oriented in the front-rear direction and whose width direction is oriented in the up-down direction.
A support plate portion 44 protruding outward from the upper end of the vertical plate portion 43 is provided. The support plate 44 is inclined upward as it moves away from the vertical plate 43, but may be horizontal. The respective seat frames 41, 41 are arranged such that the vertical plate portions 43, 43 face the side plate portions 32, 32 of the main frame 3 on the outside thereof, and the support plate portions 44, 44 are located above the side plate portion 32. Have been.

As shown in FIGS. 3 and 4, the backrest 5 has a backrest frame 51 and a seatback 52 provided on the upper rear end of the backrest frame 51. As shown in FIG. 10, the backrest frame 51 includes a pair of left and right arm portions 53, 53 extending in the front-rear direction.
A reinforcing plate 54 spanned between the rear ends of the arms 53, 53, and the arms 53, 53 and the reinforcing plate 5.
Back plate portion 55 fixed to the rear end portion of the rear plate 4 and extending upward.
It is composed of The pair of arms 53, 53
The distal end portion is disposed so as to face the side plate portions 32, 32 of the main frame 3 on the outside thereof. Moreover, as is clear from FIG. 4, the arm portions 53, 53 are arranged outside the vertical plate portions 43, 43 of the seat frames 41, 41. The back plate 55 is provided with a seat back 52.

The seat back 52 of the backrest 5 is
In FIG. 3, the seat back 52 (backrest 5) can be tilted between the work position shown by the solid line and the comfort position shown by the imaginary line. 4 is indicated by a solid line (hereinafter, this position of the seat 4 is also referred to as a work position) and a position indicated by an imaginary line (hereinafter, this position of the seat 4 is also referred to as a comfortable position). It is designed to tilt.

That is, as shown in FIGS. 1, 2 and 4, the distal ends of the side plates 32, 32 of the main frame 3
A horizontal shaft 61 extending in the left-right direction is bridged. Both ends of the shaft 61 protrude outward through the side plate portions 32, 32, to which distal ends of the arm portions 53, 53 of the backrest frame 51 are connected. That is, the distal end of the backrest frame 51 is rotatably connected to the distal end of the main frame 3 via the shaft 61. The seat back 52 tilts in the vertical direction as the backrest frame 51 rotates in the vertical direction about the distal end thereof.

At the rear end of the side plates 32, 32 of the main frame 3, a horizontal shaft 62 extending in the left-right direction is provided. A pair of connecting plates (links) are provided at both ends of the shaft 62.
63, the lower ends of which are connected to each other,
Lower ends of the members 3 and 63 are rotatably connected to the main frame 3 via a shaft 62. As shown in FIG. 11, the pair of connecting plates 63, 63 are connected to each other by a reinforcing plate 64, and rotate integrally. A positive cam mechanism (the second cam plate) is provided between each of the upper ends of the connecting plates 63 at an obliquely upper rear and the arm portions 53 of the backrest frame 51 adjacent thereto.
Of the positive cam mechanism) 65 are provided. The positive cam mechanism 65 is provided with a cam hole (second
) And a shaft portion (second shaft portion) 67 bridged between the arm portions 53, 53. Cam hole 66
Extends in the radial direction of the shaft 62, and is arranged and formed in a state of inclining rightward with respect to the arm portion 53. On the other hand, the shaft 67 is horizontally fixed to the arm 53 and is movably fitted in the cam hole 66. Therefore, when the arm 53 rotates, the connecting plate 63 rotates in the same direction as the arm 53 following the rotation.

The upper end of the connecting plate 63 is rotatably connected to the vertical plate 43 of the seat frame 41 via a shaft 68. Therefore, when the connecting plate 63 rotates about the shaft 62, the rear end of the seat frame 41 rotates about the shaft 62. As a result, the rear end of the seat frame 41 is displaced obliquely up and down. In this case, since the shaft 68 is disposed obliquely upward and rearward to the right with respect to the shaft 62, when the backrest frame 51 rotates in the direction of the arrow X in FIG. 1 (the direction from the work position side to the comfort position side), the seat The rear end of the frame 41 is displaced obliquely downward and rearward to the right, and the backrest 51 is positioned at the arrow Y
When the seat frame 41 is rotated in the direction (the direction from the comfort position side to the work position side), the rear end of the seat frame 41 is displaced diagonally to the upper left. As is apparent from this, the connecting plate 63 and the positive cam mechanism 65 constitute a displacement mechanism that displaces the rear end of the seat frame 41 in the oblique front-rear direction with the rotation of the backrest frame 51.

The front end of the seat frame 41 is connected to the backrest frame 5 without being connected to the main frame 3 unlike the conventional one. That is, as shown in FIGS. 1, 2 and 4, each end portion of the arm portion 53 of the backrest frame 51 and the vertical plate portion 43 of the seat frame 41 (a front end portion slightly behind the shaft 61). A positive cam mechanism 70 is provided between them. The positive cam mechanism 70 has a cam hole 71 (see FIG. 10) and a shaft 72 (see FIG. 12). The cam hole 71 is formed at the tip of the arm 53. In this case, the cam hole 71 has a bottom portion without penetrating the arm portion 53, but may be formed as a through hole penetrating the arm portion 53. On the other hand, the shaft 72
Is formed so as to protrude in the horizontal direction on the surface facing the outside of the vertical plate portion 43, and is inserted into the cam hole 71 via the roller 73. The roller 73 can move in the longitudinal direction of the cam hole 71, but cannot move in the width direction. Therefore, when the backrest frame 5 rotates, the front end of the seat frame 41 rotates and displaces accordingly. Moreover, as described above, when the backrest frame 51 rotates, the rear end of the seat frame 41 is displaced, and the entire backrest frame 51 tilts between the working position and the comfortable position. At this time, in relation to the displacement of the rear end portion and the displacement of the front end portion, a tilt displacement is made between the work position and the comfortable position.

As described above, in the chair 1 with the backrest, the positive cam mechanism 70 is not provided between the seat frame 41 and the main frame 3 but is provided between the seat frame 41 and the backrest frame 5.
The cam hole 71 of the positive cam mechanism 70 is formed in the backrest frame 51. Of course,
In this chair 1 as well, the cam hole 71 has a length in the up-down direction, but the lower end (rear end) of the cam hole 71 is adapted to pivot from the work position side of the backrest frame 51 to the comfortable position side. Since the cam hole 71 is displaced downward, the length of the cam hole 71 in the vertical direction is shorter than that when the cam hole 71 is formed in the main frame 3. Therefore, the width in the vertical direction of the backrest frame 51 can be reduced. Moreover, the main frame 3 is
Since no cam hole is formed, the width in the vertical direction can be reduced. Therefore, downsizing of the main frame 3 and the backrest frame 51 can be achieved.

The chair 1 with a backrest further includes the following components. To explain these configurations sequentially,
As shown in FIGS. 1 and 2, the shaft 62 is provided with a spring receiver 81 having a circular cross section. A pair of coil springs (only one coil spring is shown in FIG. 1) 82 is wound around one end and the other end of the spring receiver 81. One end of each coil spring 82 is supported by an adjustment shaft 83 provided horizontally on the main frame 3, and the other end is supported by the shaft 68. The coil spring 82 urges the back frame 51 via the shaft 68 and the positive cam mechanism 65 in a direction from the comfortable position to the work position. Therefore, unless a force larger than the urging force of the coil spring 82 is applied to the seat back 52 from the work position to the comfortable position, the seat 42 and the seat back 52 (the seat 4
And the backrest 5) is maintained in the working position. In this case, when the roller 73 abuts on the end of the cam hole 71 on the work position side, the seat 42 and the seat back 5 are moved.
2 is maintained in the working position, but the shaft 67 is
May be maintained in the working position by abutting against the end of the work.

As shown in FIGS. 4, 5 and 9, a pair of guide pieces 34, 34 are fixed upright on both left and right sides of the bottom plate 31 of the main frame 3. Each guide piece 34 is formed with a guide hole 34a extending obliquely upward to the right, and both ends of the adjustment shaft 83 are inserted into each guide hole 34a so as to be movable in the longitudinal direction of the guide hole 34a. . The head 84a of the screw member 84 is fitted to the adjustment shaft 83. The screw portion 84b of the screw member 84 penetrates the bottom plate portion 31 and protrudes downward, and a handle 85 is screwed thereto. The handle 85 is in contact with the bottom plate 31. Therefore, when the handle 85 is rotated, the adjustment shaft 83 moves in the vertical direction. Thereby, the urging force of the coil spring 82 can be adjusted.

As shown in FIGS. 4 and 6, the shaft 61
A rear end portion of the operation lever 86 is rotatably provided at one end side. The operation lever 86 is rotatable between a fixed position indicated by a solid line in FIG. 6 and an adjustment position indicated by an imaginary line, and the distal end of the operation arm 87 is connected. The intermediate portion of the operation arm 87 is rotatably fitted to a shaft 88 bridged between the side plates 32 of the main frame 3. The rear end of the operation arm 87 is vertically opposed to the operation button 25 provided on the upper end of the support leg 24. When the operation lever 86 is turned to the adjustment position, the operation button 25 is pushed down. It has become. When the operation button 25 is depressed, the support cylinder 23
The moving mechanism provided between the support legs 24
Is moved upward to the upper limit position. Of course, by pressing down the sheet 42 against the urging force of the moving mechanism, the support leg 24 can be moved downward. Then, after adjusting the support leg 24 to an appropriate height, the operation lever 86 is returned to the original position, so that the support leg 24 and thus the seat 42 can be fixed at a desired height.

As shown in FIG. 4 and FIG.
On the other end side, a rear end portion of the operation lever 89 is rotatably provided. The operation lever 89 is rotatable between a release position indicated by a solid line in FIG. 7 and an engagement position indicated by an imaginary line, and the operation lever 89 is provided inside one side plate 32 of the main frame 3. The distal ends of the engagement plates (engagement members) 90 arranged along are connected. This engagement plate 90
Move in the front-rear direction with the rotation of the operation lever 89. An engagement plate 90 is also arranged inside the other side plate portion 32 of the main frame 3. This engagement plate 90
Are connected to one engagement plate 90 by a connection plate 91. Therefore, when the operation lever 89 is rotated,
Both engagement plates 90 move integrally in the front-rear direction.

On the outer peripheral surface of the connecting plate 63 facing the engaging plate 90, a large number of engaging teeth 63a are formed at a predetermined pitch in the circumferential direction. Engaging plate 9 facing the outer peripheral surface of connecting plate 63
A plurality of engagement teeth 90a are formed on the rear end face of the zero 0 at the same pitch as the engagement teeth 63a. Engaging teeth 63a, 90a
Are engaged with each other when the engaging plate 90 is moved rearward.
Moreover, the rear end of the engagement plate 90 is prevented from moving in the vertical direction by the shaft 92. Therefore, the engagement teeth 63
When the a and 90a are engaged with each other, the connecting plate 63 becomes unrotatable, and the backrest frame 51 is fixed in position. In this case, the back frame 51 is provided with the engaging teeth 6 of the engaging teeth 90a.
By changing the meshing position with respect to 3a, not only can the position be fixed to the working position or the comfortable position, but also the position can be fixed between them at every pitch of the engaging teeth 60a, 90a.

As shown in FIG. 8, the operation levers 86, 8 provided on the seat 42 of the seat 4 and the distal end of the main frame 3 are provided.
9, a gap is formed. The vertical interval of the gap is relatively large when the seat 42 is located at the office position, but becomes smaller when the seat 42 is rotated to the comfortable position.
For this reason, when the seat 42 is rotated from the work position to the comfortable position with a finger inserted between the seat 42 and the operation levers 86 and 89, the seat 42 and the operation levers 86 and 89 are rotated.
There is a danger of injury due to the fingers being pinched.

In order to prevent such inconvenience, the chair 1 of this embodiment is provided with a shielding plate 92 for shielding a gap formed between the seat 42 and the operation levers 86 and 89. . This shielding plate 92 is
There is provided a shielding portion 93 for shielding between the control levers 86 and 89, and connecting portions 94 are formed at both front ends of the shielding portion 93. The connecting portion 94 is connected to the shaft 6
1 and is rotatably connected to the first member. An operation section 95 is formed on both sides of the rear end of the shielding section 93.
5 is provided with a cam hole 95a. This cam hole 95
A shaft portion 45 formed in the vertical plate portion 43 of the seat frame 41 so as to be orthogonal to the vertical direction is inserted into “a” so as to be movable in the longitudinal direction of the cam hole 95a. The shaft portion 45 and the cam hole 9
A positive cam mechanism is constituted by 5a. This positive cam mechanism is configured to maintain the gap between the upper end of the shielding portion 93 and the sheet 42 at a constant size such that a finger cannot enter regardless of the position of the sheet 42.

The present invention is not limited to the above embodiment, but can be changed as appropriate. For example, in the above embodiment, the cam hole 7 of the positive cam mechanism 70
1 is formed on the back frame 51 and the shaft portion 72 is formed on the seat frame 41.
1 and the shaft portion 72 may be formed on the backrest frame 51. The same applies to the cam hole 66 and the shaft 67 of the positive cam mechanism (second positive cam mechanism) 65.

In the above embodiment, the connecting plate 63 and the seat frame 41 are connected by the shaft 68. However, as in the embodiment shown in FIG. The connecting plate 63 and the seat frame 41 are
May be connected. In this case, since the postures of the connecting plate 63 and the seat frame 41 change with the rotation thereof, at least one of the connecting plate 63 and the seat frame 41 and the shaft 67 are rotatably connected. . Other configurations in FIG. 13 are the same as those in the above-described embodiment.

In the above embodiment, the operating levers 86 and 89 are provided at the tip of the main frame 3.
Since the pair of seat frames 41, 41 are arranged outside the main frame 3, the shielding plate 92 is operated by operating levers 86, 89.
And the seat 42, the operation lever 8
In the case where the main frame 3 and the seat frame 41 are not provided and the support plates 44 of the seat frames 41 are integrally connected to face the main frame 3, the shielding plate 92 is not provided. And provided between them.

[0026]

As described above, according to the present invention, it is possible to reduce the width of the main frame, the seat frame or the backrest frame in the vertical direction, thereby reducing the size of each frame as a whole. The effect is obtained.

[Brief description of the drawings]

FIG. 1 is a partially omitted vertical sectional side view showing a state in which a backrest frame is rotated to a work position according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view similar to FIG. 1 showing a state in which the backrest frame is rotated to a comfortable position.

FIG. 3 is a side view showing the whole of the embodiment.

FIG. 4 is a cross-sectional view taken along line XX of FIG.

FIG. 5 is a cross-sectional view similar to FIG. 1, showing a configuration for urging the backrest frame from the comfort position side to the work position side and a configuration for adjusting the urging force according to the embodiment;

FIG. 6 is a sectional view similar to FIG. 1, showing a configuration for adjusting the height of the support leg according to the embodiment;

FIG. 7 is a cross-sectional view similar to FIG. 1, showing a configuration for locking the connecting plate of the embodiment in a working position.

FIG. 8 is a cross-sectional view similar to FIG. 1, illustrating a configuration for blocking a gap between a seat and an operation lever according to the embodiment.

FIG. 9 is a view showing a main frame used in the embodiment, and FIG. 9 (A) is a plan view thereof, FIG.
FIG. 10B is a sectional view taken along line BB of FIG.

FIG. 10 is a view showing a backrest frame used in the embodiment, wherein FIG. 10 (A) is a plan view thereof, and FIG. 10 (B) is a side view thereof.

FIG. 11 is a view showing a connecting plate used in the embodiment, and FIG. 11 (A) is a front view thereof, FIG.
(B) is a side view thereof.

12A and 12B are views showing a seat frame used in the embodiment, wherein FIG. 12A is a plan view thereof, FIG. 11B is a side view thereof, and FIG. FIG.

FIG. 13 is a sectional view similar to FIG. 1, showing another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 chair with backrest 3 main frame 41 seat frame 42 seat 51 backrest frame 63 connecting plate (link) 65 positive cam mechanism (second positive cam mechanism) 66 cam hole (second cam hole) 67 shaft portion (second cam hole) 2 Shaft) 70 Positive cam mechanism 71 Cam hole 72 Shaft 90 Engagement plate (engagement member) 92 Shielding plate

Claims (6)

[Claims] 1. A main frame, a seat frame disposed above the main frame, and a front end portion rotatably connected to a front end portion of the main frame around a horizontal axis, whereby a rear end portion is provided. A backrest frame that can be tilted between a work position and a comfortable position, and a backrest frame that is provided between a rear end portion of the seat frame and the backrest frame. The backrest frame is rotated with the rotation of the backrest frame. A displacement mechanism for displacing the end portion obliquely in the front-rear direction, and a chair with a backrest having a positive cam mechanism for displacing the seat frame in the vertical direction and the front-rear direction in conjunction with the displacement mechanism and tilting the seat frame in the vertical direction; A chair with a backrest, wherein the positive cam mechanism is provided between a front end of the seat frame and a front end of the backrest frame. 2. The positive cam mechanism has a cam hole and a shaft portion movably inserted in a longitudinal direction of the cam hole, and one of the cam hole and the shaft portion is provided. The chair with a backrest according to claim 1, wherein the chair is provided on the seat frame, and the other is provided on the backrest frame. 3. The chair with a backrest according to claim 2, wherein the cam hole is provided in the backrest frame. 4. The displacement mechanism has a lower end rotatably connected to the main frame about a horizontal axis, and an upper end pivotally connected to a rear end of the seat frame about a horizontal axis. It has a link movably connected,
A second positive cam mechanism for rotating the link with the rotation of the back frame is provided between the upper end of the link and the back frame, and the second positive cam mechanism is A second cam hole provided in one of the upper end of the backrest frame and the link;
The chair with a backrest according to any one of claims 1 to 3, further comprising a second shaft portion provided on the other side and movably inserted into the second cam hole. 5. The main frame has an engaging member which is engaged with the link so as to be able to be disengaged and prevents the link from rotating when engaged, thereby fixing the position of the backrest frame in the working position. The chair with a backrest according to claim 4, wherein the chair is provided. 6. A lower end of a shielding plate for shielding a gap between the leading end of the main frame and the seat frame or a seat provided on the seat frame has a horizontal axis at the leading end of the main frame. It is provided rotatably as the center,
The upper portion of the shielding plate is connected to the tip of the seat frame so that the shielding plate rotates according to the size of the gap when the size of the gap changes according to the displacement of the seat frame. The chair with a backrest according to any one of claims 1 to 5, characterized in that: