JP4294132B2 - Chair recliner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reclining device for a chair, and in particular, can maintain a stable posture in a working posture, and can apply a force to the back to follow the body to obtain a natural reclining reaction force, and further, a backrest and a seat at an arbitrary angular position. The present invention relates to a reclining device for a chair that can be fixed.
[0002]
[Prior art]
Conventionally, a gas spring has been used as means for fixing the backrest of the chair and the reclining state of the seat at an arbitrary angular position. When the gas spring is fixed, the gas spring is locked by operating the lever.
[0003]
Further, in the gas spring, in order to receive an ideal reclining reaction force of the backrest and the seat, a cushion mechanism using a spring is provided separately.
[0004]
[Problems to be solved by the invention]
Therefore, a configuration that uses a gas spring to select and fix the reclining angle increases the cost because the gas spring is expensive and requires a large space for installing the gas spring. In addition to the gas spring, a separate function for obtaining the reclining reaction force is required in addition to the gas spring, which makes the configuration complicated and more expensive and extremely inefficient in terms of space. .
[0005]
On the other hand, office chairs with reclining back frames generally use coil springs as elastic bodies to support the weight of the human body, but those that rely on coil springs are seated when their reaction force is weak As a result, there was a problem that the backrest tilted backwards, and when the reaction force was adjusted strongly, the backrest was difficult to fall down and it was difficult to take a resting posture, and the feeling of spring was felt during reclining and the sitting comfort was poor.
[0006]
The present invention can achieve the reclining structure and the function of obtaining the reaction force without using a gas spring by a single structure, and can simplify the structure, reduce the cost, and effectively use the space. An object of the present invention is to provide a reclining device for a chair.
[0007]
[Means for Solving the Problems]
As means for solving the above-mentioned problems, the present invention provides a pedestal supported by legs, a seat frame whose front end is pivotally supported by the pedestal, and can be tilted rearwardly. A back frame having a backrest that is pivotally supported by a pivot, and a spring mechanism that elastically gives a cushion to the seat frame when it is tilted backward with respect to the cradle, wherein the back frame A shaft inserted and supported so as to be slidable in the width direction,
A cam plate of a plurality of friction plates alternate base portion having a tiltably pivotally supported by the shaft is inserted Rutotomoni the shaft movable arcuate cam hole in the cradle, positioned between the cam plate A washer fitted on the shaft, biasing means for biasing the shaft in the axial direction and pressing the cam plate against the fixing member side to fix the back frame at an arbitrary angle, and the fixed state. A fixed release mechanism for sliding the shaft against a spring bias to release and a pressing portion provided along the tilting side surface of the cam plate and cushioned against the back frame during reclining and possession of the elastic member for providing gender, the unlocking mechanism is fixed mosquito which is fixed to said seat frame and rotating cam which is fixed to an end portion of said shaft And a handle lever inserted into the bearing portion of the rotating cam, the cam plate is engaged with the rotating cam at one position by the operation of the handle lever, and the washer is pushed. The fixed state is set to the pressure-fixed state, and the fixed state can be released by engaging the rotating cam with the fixed cam at another position by operating the handle lever. Depending on the movement position of the shaft in the hole, it is compressed by the pressing portion .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to embodiments shown in the drawings.
FIG. 1 is a cross-sectional view of a state during normal use, FIG. 2 is a cross-sectional view of the reclining state, and FIG. 3 is a horizontal cross-sectional view. 1. A seat frame 3 whose front end is pivotally supported by the cradle 1 with a shaft 2 so as to be tilted rearward. The front end of the cradle 1 is pivotally supported by a shaft 4 so as to be freely tilted rearward and backward. The back frame 5 is provided with a spring mechanism 6 or the like that gives the seat frame 3 a cushioning property when tilting backward with respect to the cradle 1, and the rear portion of the back frame 5 is raised to be a backrest 7.
[0009]
The spring mechanism 6 includes a screw shaft 8 screwed into the center position in the width direction on the lower surface side of the cradle 1, a spring receiver 9 at the tip of the screw shaft 8, and a spring receiver similar to the conventional one. 9 and a coil spring 10 interposed between the cradle 1 and the coil spring 10 by changing the distance between the spring cradle 9 and the cradle 1 by rotating the knob 11 at the lower end of the screw shaft 8. By adjusting the spring force, cushioning that suits the user's preference is obtained.
[0010]
In the present invention, the shaft hole on the cradle 1 side to which the shaft 4 of the back frame 5 is fitted is a long hole 12 that is long in the front-rear direction. A shaft 13 having substantially the same length as the width of the seat frame 3 is provided so as to penetrate in the width direction.
[0011]
A base portion of a plurality of cam plates 14, 14... Is pivotally supported by a shaft 16 between bearings 15, 15 provided on the cradle 1 at a center position in the width direction of the back frame 5.
[0012]
These cam plates 14, 14... Also serve as friction plates. At least the surface is made of a material having a large coefficient of friction, and the tip is drilled in an arc shape from a position farthest from the shaft 16 to a position closest to the shaft 16. The cam hole 17 is provided, and the shaft 13 is inserted into the cam hole 17 as closely as possible.
[0013]
Further, as shown in an enlarged cross section in FIG. 4, washers 18, 18... Interposed between the cam plates 14, 14,. Fixing members 19 and 20 made of a pipe material are fitted on the shaft 13 between the back frame 5. The fixing member 20 passes through the back frame 5 and the seat frame 3 and reaches the outside of the seat frame 3, and the end member 13 a fixed to the outer end of the shaft 13 is a flange portion 20 a at the outer end of the fixing member 20. It is contact | abutted to the outer surface.
[0014]
A compression spring 22 constituting an urging means is interposed between the spring receiver 21 at one end of the shaft 13 and the seat frame 3, and urges the shaft 13 in a direction that always pulls it to the left in FIG. By the spring biasing force, the end member 13a pushes the flange portion 20a of the fixing member 20, and the cam plates 14, 14 ... and the washers 18, 18 ... are strongly pressed against the end surface of the fixing member 19. The cam plates 14, 14... And the washers 18, 18... Are brought into a crimped state, whereby the seat frame 3 and the back frame 5 are configured to be fixed with respect to the cradle 1.
[0015]
An opposite end of the shaft 13 is provided with a fixing release mechanism 23 for releasing the fixed state. The fixing release mechanism 23 includes an annular rotating cam 24 (shown in FIGS. 5A and 5B) that is concentrically fixed to the end of the shaft 13 and a fixed cam that is fixed to the seat frame 3. 25 (shown in FIGS. 6A and 6B), and a handle lever 27 inserted into the bearing portion 26 on one side of the rotating cam 24.
[0016]
As shown in FIGS. 5 and 6, the rotating cam 24 and the fixed cam 25 are formed with a plurality of cams in the circumferential direction of their mating surfaces. The cam shape is shown in FIG. The fixed cam 25 is formed with a plurality of high places 25a and 24a and low places 25b and 24b which can be fitted to the high places 25a and 24a, as shown in a development view of the rotary cam 24 in FIG. The sides that are in contact with each other during rotation are inclined surfaces 25c and 24c, and the opposite side is a vertical surface.
[0017]
A concave portion 24d is formed in the range of the high portion 24a of the rotating cam 24, and a convex portion 25d that is closely fitted to the concave portion 24d is formed in the range of the high portion 25a of the fixed cam 25. When the height 24a of the rotating cam 24 rides on, the convex portion 25d and the concave portion 24d are engaged and held at the stop position as shown in FIG. Note that the convex portion 25d is provided with a taper 25e for smooth fitting into and out of the concave portion 24d.
[0018]
When the high portion 24a of the rotating cam 24 is engaged with the low portion 25b of the fixed cam 25 (shown in FIG. 8B), the shaft 13 is pulled leftward in FIG. Therefore, the end member 13a hits and presses the flange portion 20a of the fixing member 20, and as described above, the washer 18 whose inner end is located at the outer end is pressed to bring the cam plate 14 into the press-contact fixed state. When the height 24a rotates on the height 25a of the fixed cam 25, the rotation cam 24 pushes back through the flange portion 20a of the fixing member 20, so that the cam plate 14 is pressed by the fixing member 20. It has come to be solved.
[0019]
On the front side of the cam plates 14 and 14 located at the outer end, a member having a U-shape in plan view is attached by a pin 28 passing through the plates 14, 14. An elastic body 31 made of block-like rubber constrained by a frame 30 is fixed on the cradle 1 at a position corresponding to the pressing portion 29. The elastic body 31 may be a compression spring, or a tension spring may be stretched on the rear side of the cam plate 14.
[0020]
The elastic body 31 is initially compressed when the shaft 13 is positioned at the upper end of the cam hole 17 of the cam plate 14, and the cam plate 14 is moved downward (reclining) as the shaft 13 descends in the cam hole 17. , 14... Are further compressed as they tilt.
[0021]
1 and 2, reference numeral 32 denotes an attachment boss for attaching the cradle 1 to a leg, and 33 denotes a seat cushion.
[0022]
Next, the operation will be described.
[0023]
During normal use, when the handle lever of the fixing release mechanism 23 is operated to the upper position, the rotating cam 24 rotates in the direction of the arrow in FIG. 8A and the height 24 a rides on the height 25 a of the fixed cam 25. Therefore, the rotating cam 24 pushes the end member 13a through the flange portion 20a of the fixing member 20, and the shaft 13 resists the bias of the spring 22 by the height of the cam as shown in FIG. As a result, the pressing of the cam plate 14 group by the fixing member 19 is released, so that the pressure-bonded state between the cam plates 14, 14... And the washers 18, 18. Can be tilted backwards accordingly.
[0024]
At this time, the shaft 13 moves downward in the cam hole 17 of the cam plate 14 as the back frame 7 tilts backward, and this movement causes the cam plates 14, 14. Tilt while compressing 31. In this tilting cushion, in addition to the spring 10 of the spring mechanism 6, the reaction force of the elastic body 31 obtained according to the tilting angle of the cam plate 14 acts as an auxiliary reaction force. Good reclining reaction force according to the posture can be obtained.
[0025]
In particular, the elastic body 31 has a reaction force that gradually increases as the cam plate 14 starts to tilt, and the reaction force increases, that is, becomes stiffer as the backrest 7 tilts greatly. It has good stability and realizes a good reclining state under the cooperative action with the spring 10. The reaction force by the elastic body 31 can be set to an arbitrary specification by selecting the shape of the cam hole 17.
[0026]
In addition, when it is desired to fix the reclining at an arbitrary angle depending on the work contents and the user's preference, after selecting the desired rear angle of the backrest 7 of the back frame 5, the hand lever of the fixing release mechanism 23 is moved downward. When operated to the position, the high portion 24a of the rotating cam 24 is slid into the low portion 25b of the fixed cam 25 as shown in FIG. 4 presses the flange portion 20a of the fixing member 20, and the cam plate 14 and the washer 18 are pressure-bonded by the fixing member 20 as shown in FIG. The reclining posture at the selected position, that is, the selected position is maintained.
[0027]
【The invention's effect】
As described above, according to the present invention, as a means for fixing the seat frame and the back frame or free for reclining, the cams of the plurality of cam plates pivotally supported by the receiving base on the shaft passing through the back frame. Inserted into the hole, the spring biased against this shaft, with the cam plate as a friction plate, the back frame is placed in a fixed state with respect to the seat frame, and the shaft is slid against the spring bias to release the fixed state and desired After reclining to an angle, if the shaft is returned, it is fixed again, that is, the reclining posture is maintained, and the reclining reaction force at that time is obtained by the cooperative action of the spring and the elastic body acting by tilting of the cam plate. , And can take any reclining posture without using a gas spring as in the past In addition, the elastic body functions as an auxiliary reaction force at that time, and it is possible to obtain a comfortable reclining state, which makes it possible to simplify the structure of the chair and to obtain it at low cost and to be advantageous in terms of space. is there.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of an embodiment of a chair according to the present invention during normal use.
FIG. 2 is a side view of a longitudinal section during reclining.
3 is a horizontal sectional view in the state of FIG.
FIGS. 4A and 4B are enlarged views showing a shaft portion, in which FIG. 4A is a sectional view showing a reclining fixed state, and FIG.
5A and 5B show a rotating cam of a fixing release mechanism, in which FIG. 5A is a front view and FIG.
6A and 6B show a fixed cam, in which FIG. 6A is a front view and FIG. 6B is a plan view.
7A is a development view of a fixed cam, and FIG.
FIGS. 8A and 8B are development views showing that the fixed cam and the rotating cam are not engaged, and FIG.
[Explanation of symbols]
1 Receiving base 3 Seat frame 5 Back frame 6 Spring mechanism 7 Backrest 10 Spring (coil spring)
12 Long hole 13 Shaft 14 Cam plate 17 Cam hole 18 Washers 19 and 20 Fixing member 22 Spring 23 Fixing release mechanism 24 Rotating cam 25 Fixed cam 29 Pressing portion 31 Elastic body

Claims (1)

A pedestal supported by the legs, a seat frame whose front end is pivotally supported by the cradle, and can be tilted rearwardly. A chair having a back frame and a spring mechanism that elastically gives the seat frame a cushioning property when tilted backward with respect to the cradle,
A shaft inserted and supported by the back frame so as to be slidable in the width direction;
A cam plate of a plurality of friction plates alternate base portion having a tiltably pivotally supported by the shaft is inserted Rutotomoni the shaft movable arcuate cam hole in the cradle,
A washer positioned between the cam plates and inserted into the shaft;
A biasing means for biasing the shaft in the axial direction and pressing the cam plate against the fixing member side to fix the back frame at an arbitrary angle;
A fixing release mechanism for sliding the shaft against a spring bias to release the fixed state;
An elastic body provided on the cradle and compressed by a pressing portion provided along a side surface in the tilt direction of the cam plate to provide cushioning to the back frame during reclining ;
The unlocking mechanism includes a rotating cam fixed to an end portion of the shaft, a fixing cam fixed to the seat frame, and a handle lever inserted into a bearing portion of the rotating cam. The rotating cam is engaged with the fixed cam at one position by operating a lever, and the washer is pressed to bring the cam plate into a press-contact fixed state and to the fixed state, and the rotating lever is operated to operate the rotating cam. The fixed state can be released by engaging the fixed cam at another position,
The reclining device for a chair, wherein the elastic body is compressed by the pressing portion depending on a moving position of the shaft in the cam hole .

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