JP2001017258A - Legless chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a legless chair in which the angle of the back rest can be continuously adjusted by simple operation, and which has no danger of the sudden fall of the backrest and is profitable in terms of production costs. SOLUTION: Connection parts 3A and 3B between a seat side metal fitting 11 of a seat frame 1 and a back side metal fitting of a back frame 2, outer gears 6a, inner gears 6b, and rotary operation shafts 7A and 7B which penetrate both the gears 6a and 6b constitute a taumel mechanism, and a concentric shaft part 71 and an eccentric shaft part 72 for a rotary shaft line are formed between opposing flange parts 8A and 8B of the shafts 7A and 7B. The outer gear 6a and the inner gear 6b are sandwiched between both the flanges 8A and 8B in the engaged state, and the concentric shaft part 71 is fitted to one of the gears 6a and 6b, and the eccentric shaft part 72 is fitted to the other, and the back frame is inclined in the front and rear directions by rotary operation of the shaft 7A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair which can adjust the angle of a backrest steplessly.

[0002]

2. Description of the Related Art As a means for adjusting the angle of a backrest of a chair, a ratchet system has been widely used. In a typical structure, a cam plate that regulates the engagement between the ratchet and the locking claw is pivotally supported on a pivot connecting the seat-side metal fitting provided with the locking claw and the back metal fitting provided with the ratchet. The backrest can be rotated in the forward direction to stand up and the angle can be adjusted step by step. At the end of the forward rotation, the locking pawl is disengaged by the cam plate. By returning the backrest to the engageable state, the angle can be adjusted again by turning the backrest forward.
Nos. 1-488, 42-3313, 54-3133
No. 1, No. 59-20118).

[0003] In addition, a dovetail-shaped long hole is provided in a back side metal fitting provided with a ratchet, a pivot shaft passing through the long hole is supported by a seat metal fitting having a locking claw, and both metal fittings are pulled by a spring. By biasing in the direction, the same angle adjustment can be performed without the cam plate (for example, Japanese Patent Application Laid-Open No. H11-37139), or the cam curved surface of the back side metal fitting and the seat side metal fitting can be adjusted. There has also been proposed one in which the angle adjustment by the forward rotation of the backrest can be performed steplessly by the engagement of a roller loaded between the roller and the concave arc surface.

[0004]

However, in the conventional angle adjusting means, since the angle of the backrest can be adjusted only on the forward rotation side, the angle of the backrest is more inclined than the angle once set. In the case of a large state, the backrest portion is folded to the end of the front rotation, and then the backrest is tilted backward and then rotated forward to the required angle again,
There was a problem that operation was very troublesome. Also,
In the ratchet mechanism, the angle adjustment range of the backrest portion is limited to a maximum of about 5 to 6 steps, and there is also a problem that the angle cannot be finely adjusted according to the user's preference or situation.

According to the present invention, in view of the above-mentioned circumstances, the angle of the backrest can be adjusted steplessly by an extremely simple operation, and there is no danger that the backrest may be inadvertently fallen. It also aims to provide an advantageous sitting chair.

[0006]

In order to achieve the above object, the invention according to claim 1 comprises a seat bracket fixed to the rear left and right sides of a seat frame, and a back fixed to the lower left and right sides of a back frame. In the chair in which the side fittings are pivotally connected, at least one of the left and right seat-side fittings and the pivotal connection between the back-side fittings are provided with an outer gear provided on the outer periphery of the circular convex portion on the side of one of the fittings, and the other. An inner gear provided on the inner periphery of the circular concave portion on the side surface of the metal fitting and having a larger diameter and a larger number of teeth than the outer gear, and a rotary operating shaft penetrating both gears constitute a taumel mechanism. The shaft has a pair of opposed flange portions, and has a concentric shaft portion and an eccentric shaft portion with respect to the rotation axis between the two flange portions, and the outer gear and the inner gear are sandwiched between the two flange portions in a meshing state. And placed on one of both gears Mandrel portion and the other to the eccentric shaft portion is fitted with fitted, the back frame is adapted to tilt in the longitudinal direction with respect to the seat frame by the rotation operation of the rotary operation shaft.

[0007] In the seat chair having the above-described structure, since the Taumel mechanism is employed in the pivotally connecting portion between the seat frame and the back frame, the outer frame can be provided regardless of the angle of the back frame with respect to the seat frame. When the rotating shaft is rotated, the back frame is moved in one of the forward and rearward tilting directions depending on the direction of rotation of the rotating shaft. It is tilted and displaced steplessly at an angular velocity corresponding to the difference in the number of teeth of both gears per rotation. However, since the outer gear and the inner gear are sandwiched between the flange portions of the rotating shaft in a meshing state, a force in a direction different from the rotation direction or a force in the twisting direction is applied to the back frame. Also, the opening of both gears is prevented from opening by the flanges on both sides,
Therefore, there is no concern that the gears may be disengaged from each other.

According to a second aspect of the present invention, in the seat chair of the first aspect, the flange portion on the concentric shaft portion side of the rotary operating shaft is formed of a plate with a hole separate from the rotary operating shaft. One end side of the operating shaft following the concentric shaft portion forms a smaller-diameter thin shaft portion, and the plate with a hole fitted to the fine shaft portion is provided at a boundary step between the fine shaft portion and the concentric shaft portion. They are fixed by welding in contact with each other. That is, in assembling and manufacturing a seat chair, at the time of fitting the outer gear and the inner gear to the rotary operation shaft, at least the flange portion on the concentric shaft portion side is a separate plate with a hole, and after fitting both gears, Although it is necessary to fit and fix the plate with the hole by welding, the positioning can be performed at the boundary step when the plate with the hole is fixed by welding, so that a light movement of both gears is guaranteed between both flange portions. Can be set reliably.

According to a third aspect of the present invention, in the seat chair according to the first or second aspect, both the left and right pivotally connected portions constitute a taumel mechanism, and the rotational operation shafts of the taumel mechanisms on both sides form a connection shaft. It is configured to be integrally connected via In this case, the back frame is held so as not to be tiltable on both right and left sides by the engagement of the outer gear and the inner gear of the Taumel mechanism. Since the rotating shafts on both sides are integrated by the connecting shaft, the angle can be changed by rotating the rotating shaft on one side.

According to a fourth aspect of the present invention, in the seat chair according to the first or second aspect, only one of the left and right pivotally connected portions constitutes a taumel mechanism, and the taumel mechanism comprises two outer gears and two inner gears. And a double meshing structure. In this case, the set angular attitude of the back frame is maintained only on one side of the taumel mechanism, but since the taumel mechanism has a large fixing force due to the double mesh structure, the back frame is stably held only by fixing one side. it can.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a seat chair according to the present invention will be specifically described with reference to the drawings. FIG.
4 to 4 show a first embodiment, and FIG. 5 shows a second embodiment.

As shown in FIG. 1, the seat chair according to the first embodiment has a tongue-shaped seat vertically erected on both left and right sides of a rear part of a rectangular metal frame-shaped seat frame (1). Side bracket (11) (1
1) and a strip-shaped back metal fittings (21) (21) projecting obliquely forward provided on the lower left and right sides of a metal pipe-shaped back frame (2) having a U-shaped frame. It has a connecting shaft (4) extending on both sides of the pivot connection (3A) (3B), and has an operating handle (3A) on one side (right side when the user is sitting). 5) is attached. In addition, the whole of the seat frame (1) and the back frame (2) are covered with the cushion layer and the cover as shown by the imaginary line in the figure, with only the operation handle (5) being exposed to the outside.

As shown in FIG. 2, the left and right pivot connection portions (3
(A) and (3B) constitute a symmetrically arranged taumel mechanism having a substantially similar structure. Each of the taumel mechanisms includes an outer gear (6a) on the outer periphery of a circular convex portion (11a) formed by pressing from one side on the side surface of the seat-side fitting (11), and a press on the side surface of the back-side fitting (21). The inner gear (6b) on the inner periphery of the circular recess (21a) formed by the rotary shaft (7) penetrating both gears (6a) (6b).
A) or (7B).

The inner gear (6b) has one or more teeth than the outer gear (6a) and has a diameter slightly larger than the height of one tooth of the outer gear (6a). It is set larger than the diameter. Each of the rotary operation shafts (7A) and (7B) has a small-diameter flange portion (8A) and a large-diameter flange portion (8B) arranged opposite to each other, and has a small diameter between the two flange portions (8A) and (8B). The eccentric shaft (71) on the flange (8A) side and the large-diameter flange (8
B) side concentric shaft portion (72). And
The outer gear (6a) and the inner gear (6b) are fitted between the flange portions (8A) and (8B) of the rotating shafts (7A) and (7B) in a mutually meshed state. ) Has an eccentric shaft (71) and an inner gear (6).
In (b), concentric shaft portions (72) are fitted concentrically with the gear center. The small-diameter flange portion (8A) is located in a circular recess (11b) on the opposite side of the seat-side bracket (11) from the outer gear (6a) side.

In such a Taumel mechanism, as shown in FIG. 3, the eccentric shaft portions (7A) of the rotary operating shafts (7A) and (7B).
The outer gear (6a) fitted to 1) is connected to the eccentric shaft (7).
The eccentric side of (1) meshes with the inner gear (6b), but the other parts are separated from the inner gear (6b), and the eccentric shaft ((7A), (7B) rotates with the rotation of the rotary operation shafts (7A, 7B). Since the center P of (71) moves around the center O of the concentric shaft portion (72), the meshing position with the inner gear (6b) also moves in the circumferential direction. However, both gears (6a) (6
Since the outer gear (6a) having a difference in the number of teeth in b) and having a small number of teeth is provided on the seat-side bracket (11) which is a fixed side, the outer gear (6a) is used for rotation of the rotation operating shafts (7A) and (7B). Accompanying
The inner gear (6b) rotates in the same direction by the difference in the number of teeth per rotation, and the back frame (2) integrated therewith tilts back and forth.

On the other hand, even if an external force is applied to the back frame (2) in the direction of tilting back and forth, the rotary operating shafts (7A) and (7B) cannot be rotated by the torque from the gear side in the Taumel mechanism. Therefore, the meshing position between the outer gear (6a) and the inner gear (6b) does not change, so that the back frame (2) does not tilt and maintains a predetermined angular posture.

The small-diameter flange portion (8A) of the rotary operation shafts (7A) and (7B) is formed integrally with the shaft itself. However, as shown in FIG.
a) When fitting the inner gear (6b) and the inner gear (6b), the large-diameter flange portion (8B) is formed by fitting and welding and fixing a separate donut plate-shaped perforated plate (80). . Thus, the inner end side following the concentric shaft portion (72) of the rotary operation shafts (7A) and (7B) is formed into a smaller shaft portion (73) having a smaller diameter, thereby welding the large-diameter flange portion (8B). At the time of fixing, the perforated plate (8
0) at the boundary step (7) between the concentric shaft portion (72) and the thin shaft portion (73).
4) and positioned, and then both flanges (8
A certain interval (s) is secured between A) and (8B) to ensure light movement of the outer gear (6a) and the inner gear (6b) (see FIG. 4).

As shown in FIG. 2, the left and right rotation operating shafts (7A) and (7B) are non-circular in that the distal end (73a) of each of the thin shafts (73) is partially cut away on the peripheral surface. This tip (73a) is inserted into the end (4a) of the connecting shaft (4) made of a metal pipe, which is similarly processed into a non-circular cross section, and a stopper pin (41) is fitted to the fitting portion. By penetrating, they are interconnected so as to rotate integrally. The rotation operation shaft (7A) on the pivot connection portion (3A) side is set to be longer on the outer end side than the rotation operation shaft (7B), and its tip (75) is used for operation indicated by a virtual line in FIG. Handle (5)
It is formed in the shape of a square axis for attaching the.

In the chair having the above structure, the seat frame (1)
(3A) (3B)
The rear frame (2) set at a required angle is fixed to the left and right sides so as not to be tiltable by the engagement of the outer gear (6a) and the inner gear (6b). It is held stably in the angular posture. On the other hand, when the operation handle (5) is rotated, the left and right rotation operation shafts (7A) and (7B) rotate integrally, and with this rotation, the back frame (2) tilts in the same rotation direction. Therefore, the angle of the back frame (2) can be adjusted steplessly in any of the front and rear directions.

The tilt of the back frame (2) is an angular velocity corresponding to the difference in the number of teeth between the two gears (6a) and (6b) per rotation of the operating handle (5), for example, the outer gear (6a). When the number of teeth is 20, the inner gear (6
If the number of teeth in b) is 19, which is one difference, the ratio of 18 degrees (360 degrees / 20) for one rotation of the operating handle (5), and 36 degrees if the number of teeth is 18 is also two different.

By the way, when the chair is used, a force in a direction different from the rotation direction or a force in the twisting direction is often applied to the back frame (2). Gear (6a) and inner gear (6b)
When the overlap of the gears is opened, the gears (6a) and (6b) are disengaged from each other, and there is a risk that the back frame (2) may fall down carelessly. However, in the chair having the above configuration, both gears (6a)
(6b) is sandwiched between the flange portions (8A) and (8B) of the rotary operating shafts (7A) and (7B) in a meshing state, and the two gears (6a) and (6) are sandwiched by these flange portions (8A) and (8B).
Since the movement of opening the overlap of b) is prevented, the back frame (2)
Even if the above-mentioned external force acts on the two gears (6a) (6
The meshing of b) is not disengaged, and there is no concern that the back frame (2) will fall carelessly during use.

In the above-described first embodiment, the Taumel mechanism is used for the pivotally connected portions (3A) and (3B) on the left and right sides of the seat frame (1) and the back frame (2). Only one side of the pivotally connected portions (3A) and (3B) may be a taumel mechanism, and the opposite side may simply be pivotally connected to a seat-side fitting and a back-side fitting without a locking function. Thus, when only one side of the left and right pivot connection parts (3A) (3B) is used as a Taumel mechanism, in order to improve the stability of the back frame (2), as in the second embodiment described below. It is recommended that the Taumel mechanism be of a double type, that is, a double mesh structure.

In the chair of the second embodiment, the frame structure of the seat frame (1) and the back frame (2) is the same as that of the first embodiment. However, as shown in FIG. 4, in one of the pivotally connected portions (3A), the seat-side fitting (12) is formed by connecting two of the seat-side fittings (11) of the first embodiment to the outer gear (6a). And a back metal fitting (22) corresponding to this, the back metal fitting (21) of the first embodiment is also replaced by an inner gear. (6b) The structure is arranged with the side facing inward, and the rotation actuating shaft (7) is held with the back-side bracket (22) sandwiching the seat-side bracket (12) from both sides.
C) penetrates to form a double-meshed taumel mechanism, and an operation handle (5) is attached to the outer end of the rotation operating shaft (7C) as shown by a virtual line.

The rotary operating shaft (7C) has a wide eccentric shaft (71) between two opposed large-diameter flanges (8B) (8B) and a pair of concentric shafts located on both sides thereof. It has shaft portions (72) and (72), and the eccentric shaft portion (71) corresponds to the outer gears (6a) and (6a), and the concentric shaft portions (72) and (72) correspond to the inner gears (6b) and (6b). Are fitted concentrically with the gear center. In addition, in this rotation operation shaft (7C),
At the time of assembling the pivot connection part (3A), two pieces each of the outer gear (6a) and the inner gear (6b) are fitted from both sides with the eccentric shaft part (71) at the center. Both the large-diameter flange portions (8B) and (8B) are formed by welding and fixing a perforated plate as in the first embodiment. Also,
The inner and outer ends of the rotary operating shaft (7C) are thin shaft portions (73) smaller in diameter than the concentric shaft portions (72), and each large-diameter flange portion (8B).
At the time of welding fixation, the perforated plate is
2) A position where the seat-side fitting (12) and the back-side fitting (22) can move lightly between the flanges (8B) and (8B). An interval is secured.

In the taumel mechanism of the pivotally connected portion (3A), the two shafts fitted to the eccentric shaft portion (71) of the rotary operating shaft (7C) are used.
The two outer gears (6a) and (6a) mesh with the inner gears (6b) and (6b) on the eccentric side of the eccentric shaft portion (71), and the rotation is similar to that of the first embodiment. The meshing position is moved in the circumferential direction by the orbital movement of the center point of the eccentric shaft portion (71) accompanying the rotation of the operating shaft (7C), and the inner gear (6b) rotates the outer gear (6B) per rotation of the rotating operating shaft (7C). 6a) in the same direction as the number of teeth, and the back frame (2) integrated therewith tilts back and forth.

On the other hand, the opposite pivotally connected portion (3B) is such that the seat-side bracket (13) and the back-side bracket (23), both of which have a flat plate shape, can simply rotate relative to each other via the pivot pin (31). , And does not have a locking function such as the Taumel mechanism on the side of the pivotally connected portion (3A). (31a) is a retaining flange formed by welding on the distal end side of the pivot pin (31).

In the chair according to the second embodiment, the angle of the back frame (2) can be steplessly adjusted in any of the front and rear directions by rotating the operation handle (5) as in the first embodiment. However, since the Taumel mechanism is used for only one of the left and right pivot connection parts (3A) (3B), the set angular posture of the back frame (2) is held by only one side. However, the Taumel mechanism has two outer gears (6a).
Since the (6a) and the inner gears (6b) and (6b) have a double meshing structure simultaneously meshed, the back frame (2) can be sufficiently held on only one side so as not to be tilted by the large fixing force. In such one-side fixing, in order to prevent the back frame (2) from being twisted and deformed, it is desirable that the back frame (2) has a rigid frame structure.

Also, in the chair of the second embodiment, the outer gear (6a) and the inner gear (6b) are provided at one of the pivotal connecting portions (3A) using the Taumel mechanism.
In a state where the sheets are engaged, both flange portions (8
B) and (8B), these gears (6a)
(6a) (6b) Since the movement of opening of the overlap of (6b) is prevented, a force in a direction different from the rotation direction or a force in the twisting direction may be applied to the back frame (2) in use. However, the gears (6a) and (6b) are not disengaged from each other, and there is no concern that the back frame (2) will fall down carelessly.

In the present invention, the pivotally connecting portion of the seat frame (1) and the back frame (2) using the Taumel mechanism is provided on the outer side of the back side metal fitting, contrary to the first and second embodiments. The gear (6a) may have a structure in which an inner gear (6b) is provided on a seat-side fitting. In this case, the rotation direction of the rotation operating shaft and the rotation direction of the back frame (2) are opposite. The eccentric shaft portion (71) and the concentric shaft portion (72) of the rotary operation shaft are the same as the first and second embodiments, and the former (71) is the inner gear (6).
b), the latter (72) may be configured to be fitted to the outer gear (6a), respectively, and the operation is exactly the same. Further, the double-meshed taumel mechanism as in the second embodiment may have a configuration in which two back-side brackets are combined and sandwiched between the seat-side brackets from both sides, in reverse of the embodiment.

In addition, according to the present invention, when a Taumel mechanism is used for the left and right pivotally connected portions, the rotary operating shafts and the connection shafts on both sides are connected by welding, and separate to the seat side metal fitting and the back side metal fitting. The outer gear (6a) and the inner gear (6b) made of members are fixed by welding or screwing,
The design of the detailed configuration can be variously changed in addition to the embodiment.

[0031]

According to the first aspect of the present invention, since the seat chair uses a Taumel mechanism for the pivotally connecting portion between the seat frame and the back frame, it is extremely simple to rotate the rotary operation shaft. With this operation, the angle of the backrest can be adjusted steplessly in any of the front and rear directions, and the outer gear and the inner gear that constitute the taumel mechanism are interposed between a pair of flange portions of the rotary operation shaft. Therefore, even if a force in the direction different from the rotation direction or a force in the twisting direction is applied to the backrest during use, the movement that disengages the two gears is prevented, and the backrest is inadvertently There is no danger of falling down, and a structurally simple and advantageous in terms of manufacturing cost is provided.

According to the second aspect of the present invention, as the above seat chair, when assembling the Taumel mechanism portion, the interval between the pair of flange portions of the rotary operating shaft can be reliably set at a constant interval. The light movement of the backrest is ensured, so that the angle of the backrest can be adjusted more smoothly.

According to the third aspect of the present invention, in the above chair, both the left and right pivotal connecting portions constitute a Taumel mechanism, and the rotational operating shafts of the Taumel mechanisms on both sides are integrated via the connecting shaft. Therefore, there is an advantage that the set angular posture of the back frame can be stably maintained by fixing the left and right sides, and the angle of the backrest can be changed by rotation of the rotation operating shaft on one side.

According to the fourth aspect of the present invention, in the above chair, a Taumel mechanism is used only in one of the left and right pivotal connecting portions, and the Taumel mechanism is a double mesh structure and is largely fixed. Because of the strength, there is an advantage that the set angular posture of the backrest can be stably held only by fixing one side.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a frame structure of an entire chair according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional front view of a pivotal connection between a seat frame and a back frame of the chair.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a longitudinal sectional front view of the pivotable connecting portion in an exploded state.

FIG. 5 is a vertical sectional front view of a pivotally connected portion of a seat frame and a back frame of a chair according to a second embodiment of the present invention.

[Explanation of symbols]

 1 ····· Seat frame 11 to 13 ··· Seat side fitting 11a ······ Circular convex part 2 ····· Back frame 21 to 23 ··· Seat side fitting 21a ··· ··· Circular recess 3A, 3B ··· Pivot connection part 4 ····· Connection shaft 5 ····· Operation handle 6a ····· Outer gear 6b ···· · Inner gears 7A to 7C ··· Rotating shaft 71 ··· Eccentric shaft 72 ··· Concentric shaft 73 ··· Fine shaft 74 ··· Boundary Step 8A: small-diameter flange 8B: large-diameter flange 80: perforated plate O: center of concentric shaft (rotation axis) P ... Center of eccentric shaft

Claims (4)

[Claims] 1. A seat chair in which a seat-side bracket fixed to both left and right sides of a rear portion of a seat frame and a back-side bracket fixed to left and right sides of a lower portion of a back frame are pivotally connected to each other. The pivotal connection between the side fitting and the back fitting has an outer gear provided on the outer periphery of the circular convex portion on one side of the fitting, and an inner gear provided on the inner circumference of the circular recess on the other side of the fitting and has a diameter larger than that of the outer gear. And the inner gear having a large number of teeth, and a rotary operating shaft that penetrates both gears constitute a Taumeru mechanism, the rotary operating shaft includes a pair of opposed flange portions,
A concentric shaft portion and an eccentric shaft portion with respect to the rotation axis are provided between the two flange portions, and the outer gear and the inner gear are interposed between the two flange portions in a meshing state, and a concentric shaft is provided on one of the two gears. The seat chair is configured such that the back frame tilts in the front-rear direction with respect to the seat frame by the rotation operation of the rotation operation shaft. 2. A rotary operating shaft, wherein a flange portion on the concentric shaft portion side is formed of a plate with a hole separate from the rotary operating shaft, and one end of the rotary operating shaft following the concentric shaft portion has a smaller diameter. 2. The thin shaft part according to claim 1, wherein the plate with a hole fitted in the thin shaft part is fixed by welding in a state of being in contact with a boundary step between the thin shaft part and the concentric shaft part. Chair. 3. The seat according to claim 1, wherein the left and right pivotally connected portions together form a Taumel mechanism, and the rotary operating shafts of the Taumel mechanisms on both sides are integrally connected via a connecting shaft. Chair. 4. A taumel mechanism comprising only one of the left and right pivotally connected portions, wherein the taumel mechanism has a double meshing structure of two outer gears and two inner gears.
Chair.