JP3358262B2 - Chair tilting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair tilting device, and more particularly to a chair tilting device capable of stably achieving a working posture, a light resting posture and a resting posture.

[0002]

2. Description of the Related Art Conventionally, a seat portion and a backrest portion are interlocked, and the front portion of the seat portion rises and the rear portion descends in accordance with the backward leaning operation of the backrest portion. There has been provided a chair having a structure in which a reaction force against tilting of a seat portion is generated by a single expansion / contraction urging means such as a compression coil spring.

[0003] For example, as disclosed in Japanese Utility Model Publication No. 4-748, a backrest rod is pivotally attached to the rear part of a seat support, and a fixed frame attached to the upper end of a support and a lower part of the backrest rod are linked. On the other hand, a pair of front and rear longitudinally-sided substantially rectangular groove-shaped guide portions are formed on one side of the fixed frame or the seat receiver, and the other is inserted and guided in each of the groove-shaped guide portions. There is provided an inclining device for a chair having a structure in which an engaging pin is provided, and a telescopic urging means is interposed between a front engaging pin and a rear portion of a fixed frame.

In this tilting device, the front and rear groove-shaped guide portions are formed so that the substantially curvilinear shape is upside down, and in the initial stage when the backrest portion is tilted backward, the front portion of the seat portion is raised and the rear portion is raised. The tilting operation is performed so as to descend, and when the backrest is tilted backward, the seat is moved rearward in parallel.

However, in the chair having the above-mentioned structure, the seat portion always performs the vertical tilting operation in conjunction with the back and forth tilting operation of the backrest portion. Therefore, the working posture in which the backrest portion stands up and the backrest portion are maximized. It is easy to realize the resting posture leaning backward, but if you take the light resting posture with the backrest part slightly inclined backward, the seat surface will flutter,
Unnecessary up and down movement of the center of gravity and up and down movement of the line of sight cause an unstable feeling. In particular, this is a problem when the work posture and the light rest posture are frequently repeated.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned situation, the present invention is intended to achieve a working posture in which the backrest is upright and a resting posture in which the backrest is inclined backward at the maximum. Not only that, it is possible to stably take a light resting posture in which the backrest part is slightly inclined backward, and when changing from the working posture to the light resting posture, or vice versa, the vertical movement and tilting of the seat surface An object of the present invention is to provide a tilting device for a chair which can be stabilized without any trouble.

[0007]

According to the present invention, in order to solve the above-mentioned problems, a front portion of a fixed frame attached to an upper end of a column and a front portion of a seat receiving member are pivotally mounted so as to be vertically tiltable. The intermediate portion of the backrest rod is pivotally attached to the rear portion of the seat receiver so as to be capable of tilting back and forth, and an engagement pin is provided at a tip end of an arm portion extending forward and downward from the pivoted portion. A guide groove including an inclined portion along the locus of the engagement pin centered on the pivot portion and a horizontal portion extending forward from the upper end of the inclined portion is formed, and the engagement pin is fitted into the guide groove. Sliding guide,
A tilting device for a chair is provided in which biasing means having compression resistance is interposed between the engaging pin and a front portion of the fixed frame.

[0008]

The tilting device for a chair according to the present invention having the above-mentioned contents has the following effects. First, when the user sits on the seat, the weight of the occupant acts on the seat receiver in the direction in which the rear part descends around the front pivot part which is pivotally attached to the fixed frame. The backrest rod having the intermediate portion pivotally attached to the rear portion of the receiving member is engaged with the engaging pin provided at the distal end portion of the backrest rod via the arm portion from the pivotal portion at the front edge of the inclined portion of the guide groove. The transmission is performed in a direction perpendicular to the front edge of the inclined portion, so that the rear portion of the seat portion does not descend and assumes a stable supported working posture. Further, even if the arm rests slightly on the backrest, the urging means interposed between the engaging pin and the front part of the fixed frame is less than the forward rotational force of the arm centered on the pivotal attachment to the seat receiver. When the compression resistance and the sum of the frictional force of the engaging pin and the inclined portion are superior, the engaging pin is located at the lower end of the inclined portion, and the rear portion of the seat does not descend stably as described above. It is supported. Next, when the backrest is lightly leaned against the backrest, if the forward rotational force of the arm centering on the pivotal portion exceeds the sum of the compression resistance and the frictional force by the urging means, the engaging pin is guided. The backrest rod moves forward and upward along the inclined part of the groove, and the backrest rod inclines backward until the forward rotational force of the arm part and the sum of the compression resistance force and the frictional force by the urging means are balanced. Does not descend, and the backrest part is in a stable lightly resting posture in which the backrest part is slightly inclined backward. If the backrest is further strongly leaned against the backrest, the backrest rod is further inclined backward and the engaging pin reaches the horizontal portion of the guide groove. The pin moves forward along the horizontal portion, and the rear portion of the seat portion descends in conjunction with the backward tilting operation of the backrest portion, and the pin is centered on the rear pivot portion caused by leaning on the backrest portion. The sum of the forward rotational force of the arm portion and the component force of the weight of the occupant seated on the seat and the compression resistance force of the urging means are balanced, or the engaging pin abuts on the front end of the horizontal portion. In any case, a stable resting posture is obtained in which the backrest portion is inclined backward deeply and the rear portion of the seat portion is lowered.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; FIG. 1 is a sectional view showing a typical embodiment of the present invention, FIG. 2 is a conceptual diagram showing a basic operation of the present invention, FIG. 1 shows a working posture, FIG. 3 shows a light resting posture, and FIG. Is shown. In the figure, 1 indicates a seat portion, and 2 indicates a backrest portion.

According to the present invention, the front part of the fixed frame 4 attached to the upper end of the column 3 and the front part of the seat body 5 are pivotably connected to each other so as to be vertically tiltable, while the intermediate part of the backrest rod 6 is connected to the seat body. The arm 5 is pivotally attached to the rear portion of the body 5 so as to be able to tilt forward and backward, and an engagement pin 8 is provided at the tip of an arm 7 extending forward and downward from the pivot. A guide groove 9 comprising an inclined portion 9a along the locus of the engaging pin 8 and a horizontal portion 9b extending forward from the upper end of the inclined portion 9a is formed, and the engaging pin 8 is fitted into the guide groove 9. The gist of the present invention is that, in addition to the sliding guide, a biasing means 10 having compression resistance is interposed between the engaging pin 8 and the front portion of the fixed frame 4.

The seat 1 has a rear seat plate 11 attached to the seat receiver 5 and a front seat plate 13 attached to a fixed portion 12 extending substantially horizontally at the front end of the fixed frame 4. And an integral seat cushion body 14 is attached to the upper surface of the body.
Further, the backrest portion 2 is configured by attaching a back cushion body 16 to a front surface of a backrest plate 15 attached to an upper portion of the backrest rod 6.

More specifically, the fixed frame 4 has a rear end attached to the upper end of a column 3 composed of a gas cylinder or the like, and is supported in a cantilever manner so as to protrude forward. A fixing portion 12 is formed at a front end of the fixing portion 12 and extends forward. Further, the seat receiver 5 is
It is arranged substantially horizontally above the fixed frame 4, and its front end is the front part of the fixed frame 4, which is pivotally attached to the rear of the fixed part 12, and the rear part is vertically moved around the pivoted part 18. It can be tilted. The front portion of the seat cushion body 14 located forward of the pivot portion 18 is connected to the front seat plate 1 as described above.
Since it is attached to the fixed portion 12 of the fixed frame 4 via the fixed member 3, it is fixed even if the rear portion of the seat portion 1 tilts up and down, thereby pressing the lower side of the thigh near the knee of the seated person. There is no.

The backrest rod 6 is formed in a bow shape which rises from the lower part of the seat receiver 5 to the rear upper part.
The intermediate portion is pivotally attached to the rear end of the seat receiver 5 and can be tilted back and forth about the pivoted portion 19. The arm 7 extends forward and downward from the pivot 19 of the backrest rod 6. The arm portion 7 has a distal end branched so as to sandwich both side plates 20 and 20 of the fixed frame 4, and an engaging pin 8 is attached between the branched distal ends.
0, 20 are inserted into a pair of guide grooves 9, 9 formed in the same shape as viewed from the side. Further, an intermediate portion of the engaging pin 8 located inside the hollow portion 17 of the fixed frame 4 and the hollow portion 1
7 and an adjusting device 21 provided at a front end portion of
Is interposed. The biasing means 10 has an elastic resistance that increases as the distance between both ends is reduced, such as a compression coil spring or a cylinder structure using a compression coil spring and a fluid buffer mechanism in combination.

The adjusting tool 21 is for increasing or decreasing the initial elastic resistance of the urging means 10.
An inner surface of the hollow portion 17 of the fixed frame 4 and the moving body 22 form a tapered surface 23 that expands upward, and an inversely tapered member 24 is fitted to the tapered surface 23, and the fixed frame is fixed to the inverted tapered member 24. 4, the adjusting screw 25 inserted from below is screwed, the knob 26 at the lower end of the adjusting screw 25 is rotated, and the reverse taper member 24 is pulled downward, so that the moving body 22 is moved rearward and the attachment is performed. The force means 10 is forcibly compressed.

The operation of each part of the present invention will be described with reference to FIG. 2. First, when the user sits on the seat 1, the seat receiver 5 is centered on the front pivot 18 on the rear part. The weight of the occupant acts in the downward direction, but this stress is
In the state where the engaging pin 8 abuts on the front side edge of the inclined portion 9a of the guide groove 9 from the pivoting portion 19 of the guide groove 9 via the arm portion 7, it is transmitted in a direction perpendicular to the front side edge of the inclined portion 9a. Part 1
The rear part does not descend and assumes a stable supported working posture. This working posture is shown by a solid line in FIG. 2 and corresponds to FIG. Further, even if the backrest 2 is slightly leaned, the force between the engagement pin 8 and the adjusting tool 21 provided at the front portion of the fixed frame 4 is smaller than the forward rotational force of the arm 7 around the pivotal connection 19. When the sum of the compression resistance force of the urging means 10 and the frictional force of the engaging pin 8 and the inclined portion 9a is greater than that of the engaging pin 8, the engaging pin 8 is located at the lower end of the inclined portion 9a,
As described above, the rear portion of the seat 1 is stably supported without descending.

Next, when the backrest 2 is lightly leaned against the backrest 2, the forward rotational force of the arm 7 centering on the pivot 19 overcomes the sum of the compression resistance and the frictional force of the urging means 10. In this case, the engaging pin 8 moves forward and upward along the inclined portion 9 a of the guide groove 9, so that the engaging pin 8 moves along the locus of the radius R ₁ centered on the pivot 19 and the arm 7 The backrest rod 6 inclines backward until the front rotational force of the above and the sum of the compression resistance force and the frictional force by the urging means 10 balance, but the rear part of the seat 1 does not descend, and the backrest part 2 Slightly leaning back to a stable light resting posture. This light resting posture is indicated by a dashed line in FIG. 2 and corresponds to FIG.

When the backrest 2 is strongly leaned against the backrest 2, the backrest rod 6 is further inclined backward and the engaging pin 8 reaches the horizontal portion 9b of the guide groove 9, and the inclined portion 9a Since the support by the front side edge is lost, the engaging pin 8 moves forward along the horizontal portion 9b, and the rear portion of the seat portion 1 descends in conjunction with the backward tilting operation of the backrest portion 2, and therefore, the rear pivot portion. The reference numeral 19 moves along a locus of radius R ₂ centering on the front pivoting portion 18, and the forward rotational force of the arm portion 7 centering on the rear pivoting portion 19 caused by leaning against the backrest portion 2. The sum of the component forces of the weight of the occupant sitting on the seat 1 and the compression resistance force of the urging means 10 are balanced, or the engaging pin 8 is moved to the horizontal portion 9.
b, it comes to a resting state in which the backrest 2 is tilted deeply backward and the rear of the seat 1 is lowered. This resting posture is indicated by a two-dot chain line in FIG. 2 and corresponds to FIG.

Thus, the tilting device for a chair according to the present invention comprises:
As shown in FIG. 2, an operation A is performed in two stages: an operation A from the solid line to the alternate long and short dash line, and an operation B from the alternate long and short dash line. That is, in the operation A, the seat receiver 5 and the seat portion 1 do not tilt up and down at all, and only the backrest rod 6 and the backrest portion 2 tilt back and forth. On the other hand, in the operation B, The rear portion of the seat receiver 5 and the seat 1 tilts up and down in conjunction with the operation of tilting the backrest rod 6 and the backrest 2 back and forth. In this operation B, the distance between the pivot portions 18 and 19, the length of the arm 7 and the guide groove 9
By appropriately setting the angle of the horizontal portion 9b with respect to the seat receiver 5, the tilt angle of the seat portion 1 and the backrest portion 2 can be adjusted to 1: 2, which is considered to realize a comfortable resting posture. It is possible.

FIG. 5 shows another embodiment, in which a second urging means 27 such as a compression coil spring is provided between the front and rear intermediate portion of the seat receiver 5 and the engagement pin 8. To prevent the backrest portion 2 from unexpectedly tilting backward due to a large impact at the time of sitting, and to increase the resistance against the rearward tilting force of the backrest portion 2 when shifting from the working posture to the light resting posture, The shortage of the initial resistance force by the urging means 10 is compensated. That is, the urging means 10 has a relatively large angle with respect to the inclined portion 9 a of the guide groove 9 due to the structural limitation of the fixed frame 4, and the arm portion 7 is tilted backward by the backrest 2. In some cases, the compression is not sufficiently performed due to the forward rotation, and even in such a case, the above-described two-step operation can be performed reliably and stably.

[0020]

The chair tilting apparatus according to the present invention as described above is provided so that the front portion of the fixed frame attached to the upper end of the column and the front portion of the seat receiver are pivotally mounted so as to be tiltable up and down. While pivoting the middle part of the seat receiver to the rear part so as to be able to tilt back and forth,
An engaging pin is provided at a tip end of an arm portion extending forward and downward from the pivot portion, and an inclined portion along a locus of the engaging pin centered on the pivot portion is provided on the fixed frame. A guide groove including a horizontal portion extending forward from the upper end is formed, and the engagement pin is fitted into the guide groove to guide sliding, and a compression resistance is provided between the engagement pin and a front portion of the fixed frame. Because of the interposition of force means, the normal work posture with the backrest standing up, the light resting posture with only the backrest slightly leaning backward while the seat remains intact, and the backward leaning movement of the backrest And a resting posture in which the rear portion of the seat descends in conjunction with. That is, since the change between the working posture and the light resting posture does not involve the vertical movement of the seat portion, the seat surface is fluttered like a conventional chair, unnecessary vertical movement of the center of gravity, and vertical movement of the line of sight. Even if the worker repeatedly takes a work posture and a light rest posture, fatigue can be minimized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a chair employing a tilting device of the present invention in a working posture.

FIG. 2 is a principle diagram for explaining a basic operation of the present invention.

FIG. 3 is a longitudinal sectional view in a light resting posture.

FIG. 4 is a longitudinal sectional view in a resting posture.

FIG. 5 is a longitudinal sectional view showing another embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 seat portion 2 backrest portion 3 support 4 fixed frame 5 seat receiver 6 backrest rod 7 arm portion 8 engagement pin 9 guide groove 9a inclined portion 9b horizontal portion 10 urging means 11 rear seat plate 12 fixing portion 13 front portion Seat plate 14 Seat cushion body 15 Backrest plate 16 Back cushion body 17 Hollow part 18 Pivot part 19 Pivot part 20 Side plate 21 Adjusting tool 22 Moving body 23 Tapered surface 24 Reverse taper member 25 Adjusting screw 26 Knob 27 Second urging means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-86156 (JP, U) JP 4-40512 (JP, Y2) JP 4-748 (JP, Y2) (58) Field (Int.Cl. ⁷ , DB name) A47C 3/026 A47C 7/44

Claims (1)

(57) [Claims] 1. A front portion of a fixed frame attached to an upper end of a column and a front portion of a seat receiver are pivotably connected to each other so as to be vertically tiltable, and an intermediate portion of a backrest rod is tilted forward and backward to a rear portion of the seat receiver. At the end of the arm portion extending forward and downward from the pivot portion, an engagement pin is provided, and the fixing frame is provided along the trajectory of the engagement pin centering on the pivot portion. Forming a guide groove consisting of an inclined portion and a horizontal portion extending forward from the upper end of the inclined portion,
The tilting device for a chair, wherein the engaging pin is fitted in the guide groove to guide the sliding, and a biasing means having a compression resistance is interposed between the engaging pin and a front portion of the fixed frame.