JPS63139508A - Sitting height adjustable chair cushion body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chair whose seat height can be adjusted so that the seat can be raised and lowered by a lifting device using an X-link mechanism.

[Prior Art] As this type of chair, a type called a so-called piano chair is known. In this chair, the movable part of the barrel seat is supported by the main body of the chair via an X-link mechanism so that it can be raised and lowered.
The chair includes a locking rod fixed to the chair body, and a rotating arm having a plurality of engagement recesses on an edge pivotally connected to the chair body.

By selectively engaging the locking rod with one of the engagement recesses of the rotating arm, the X-link mechanism is fixed at a specific cross angle position, and the height of the seat can be adjusted. This is what I did.

However, since such an adjustment mechanism can only adjust the seat height in steps, a mechanism using a screw feed method as a lifting position adjustment mechanism has recently been devised. In this device, an upper stay is rotatably installed between corresponding link members of a pair of left and right X link mechanisms, and is positioned below the upper stay to connect the corresponding other link member of the X link mechanisms. An X-link that determines the height position of the seat by installing a lower stay rotatably between the two stays and continuously changing the distance between the two stays by advancing and retracting a screw shaft interposed between the two stays. The intersection angle position can be adjusted steplessly.

[Problems to be Solved by the Invention] However, it is difficult to synchronize the left and right X-link mechanisms with just this. That is, since the upper stay and the lower stay are engaged with the screw shaft, both ends thereof must be rotatably connected to the link member, and the function of rigidly connecting the left and right link members is lacking. Therefore, when a load is applied to the sides of the seat, the postures of the left and right X-link mechanisms differ due to the deflection of the members, resulting in a problem that the seat tilts. Therefore, in addition to the stay, a reinforcing bar is required to firmly connect the corresponding link members of the pair of left and right X link mechanisms.

However, such a configuration not only hinders weight reduction, which is one of the advantages of using the X-link mechanism, but also involves problems such as an increase in manufacturing man-hours.

It is an object of the present invention to solve the above-mentioned problems and to provide a chair of this type that has a simple and lightweight structure and ensures rigidity.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a seat height-adjustable chair in which a lifting device is interposed between the chair body and the seat, and the seat height is adjustable. the first, which are interconnected in the center;
A pair of left and right Xs each having a second link member
a link mechanism, an upper connecting bar installed between the upper halves of the corresponding first link members of each of these X link mechanisms, and a corresponding second link member of both X link mechanisms located below the upper connecting bar. A lower connecting bar installed between the lower halves of the link members, an upper pipe and a lower pipe that are externally mounted on the center portions of these connecting bars so as to be rotatable in the circumferential direction but immovable in the axial direction, and this lower pipe. a screw shaft that is screwed into a nut member fixed to the outer periphery of the upper pipe and whose upper end is rotatably but immovably supported in the axial direction by a bearing member fixed to the outer periphery of the upper pipe; and an operation handle for changing the distance between the two connecting bars.

[Operation] With this configuration, when the operation handle of the elevating position adjustment mechanism is operated in a predetermined direction, the screw shaft screws the nut member forward and backward using the bearing member as a foothold, so that the upper pipe and the lower pipe move upward and downward, respectively. While rotating around the lower connecting bar, relative approaching and separating movements are transmitted to the lower connecting bar, thereby changing the cross angle position of the X link mechanism.

Both connection bars firmly connect the corresponding link members and function as reinforcing bars for synchronizing both the left and right X link mechanisms.

In addition, the polymer of the upper connecting bar and the upper pipe sheathed on it functions as an upper stay that connects the upper end of the screw shaft to the left and right link members, and the lower connecting bar and the lower pipe sheathed on it serve as an upper stay that connects the upper end of the screw shaft to the left and right link members. The polymer of this material plays the role of a lower stay that connects the intermediate portion of the screw shaft to the left and right link members.

However, when a load is applied to the seat due to sitting, etc., bending stress is applied to the upper and lower connecting bars, whose central portions are restrained by the screw shaft. The upper and lower pipes are covered and reinforced. Therefore,
The rigidity of the part that supports the seat can be increased without making the connecting bar thick or taking special reinforcing measures.

Furthermore, the bearing member and the nut member that directly engage the screw shaft are fixed to the outer periphery of the upper pipe and the lower pipe, and are eccentric to the axes of the upper connecting bar and the lower connecting bar, so that they do not fit into the seat. When a load is applied, a force in a direction that bends the screw shaft acts on the bearing member and the nut member. Therefore, when the user is seated, the frictional resistance between the screw shaft, the bearing member, and the nut member rapidly increases, and the screw shaft becomes in a locked state or a state close to it.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 6.

As shown in FIGS. 1 and 2, this chair includes a chair body 1, a seat 2 that can be raised and lowered relative to the chair body 1, and a seat 2 that can be raised and lowered between the seat 2 and the chair body 1. It is equipped with a device 3.

The chair body 1 is, for example, made of wood and has an integral backrest 11, and has a horizontal seat support portion 1 located below the dust 2.
2 has a frame-like structure with front and rear horizontal members 14 and 15 installed between left and right side plates 13. The lifting device 3 is provided between the seat support portion 12 of the chair body 1 and the dust 2.

As shown in FIGS. 1 to 5, the lifting device 3 removes the dust 2.
A pair of left and right X-link mechanisms 4 that are pivotally connected in order to raise and lower the chair body 1 relative to the chair body 1, and an upper connecting bar 44 that is installed between the upper half portions of the first link members 41 of the respective X-link mechanisms. and a lower connecting bar 45 located below this upper connecting bar 44 and installed between the lower halves of the corresponding second link members 42 of both the X-link mechanisms 4; An upper pipe 51 and a lower pipe 52 are respectively externally mounted in the center so as to be rotatable in the circumferential direction and immovable in the axial direction, and the upper end 53 is screwed into a nut member 55 fixed to the outer periphery of the lower pipe 52.
a bearing member 54 fixed to the outer periphery of the upper pipe 51;
a screw shaft 5 which is rotatable and supported immovably in the axial direction;
3, and by rotating this screw shaft 53, both the connecting bars 44 are connected.
．． 45, and an operation handle 56 for changing the distance between the two.

Specifically, as shown in FIGS. 3 and 4, each X link mechanism 4 includes a first link member 41 in the form of an elongated plate and a second link member 42 in the form of an elongated plate in the center. The upper end 41a of the first link member 41 and the second link member 42 are rotatably connected by a fulcrum pin 43.
The lower end 42a of the first link member 41 is pivotally connected to the seat support portion 12 of the seat 2 and the chair body 1 via the upper bracket 6 and the lower bracket 7, respectively.
b and the upper end 42b of the second link member 42 are supported by the seat support part 12 and the seat 2 of the chair body 1 via the lower bracket 7 and the upper bracket 6, respectively. That is, the upper end 41a of the first link member 41 and the lower end 42a of the second link member 42 are pivotally connected to the front end portions of the corresponding upper bracket 6 and lower bracket 7 via pins 41c and 42c.

Further, pins 41d and 42 are provided at the lower end 41b of the first link member 41 and the upper end 42b of the second link member 42.
d project horizontally, and the pins 41d and 42d are provided in a horizontal elongated hole 71 extending in the front-rear direction provided near the rear end of the lower bracket 7 and in a near rear end of the upper bracket 6. They are respectively inserted into horizontal elongated holes 61 extending in the front-rear direction so as to be rotatable and slidable.

The upper connecting bar 44 and the lower connecting bar 45 are pipe-shaped, and are rigidly attached by welding between the aforementioned corresponding link members, that is, the link members 41 and 41 and the link members 42 and 42, respectively.

The upper pipe 51 is rotatably mounted on the upper connecting bar 44 at a position approximately ⅓ of the center thereof, and both ends 51a of the upper pipe 51 are attached to detent protrusions provided on the outer periphery of the upper connecting bar 44. 44a so that it cannot move in the axial direction. The bearing member 54 is fixed to the outer periphery of the central portion of the upper pipe 51. For example, as shown in FIG. 6, the bearing member 54 has its axis aligned with the upper pipe 5.
Pipe 5 fixed by welding at right angles to the axis of 1
4a, and an end plate 54 that is attached to the open end of this pipe 54a.
It is composed of b. The lower pipe 52 is rotatably mounted on the lower connecting bar 45 at a position of 1/3 of the central passage, and both ends 52a thereof are connected to the lower connecting bar 4.
It is clamped so that it cannot move in the axial direction by a protrusion 45a provided on the outer periphery of the shaft 5 for preventing movement. And this lower pipe 5
The nut member 55 is fixedly provided on the outer periphery of the central portion of 2. For example, as shown in FIG. 6, the nut member 55 includes a vibrator 55a whose axis is perpendicular to the axis of the lower pipe 52 and which is fixed by welding.
a sleeve 55b press-fitted into the inner periphery of the
A female threaded portion 55c is formed on the inner periphery of this sleeve 55b.

Then, the screw shaft 53 is screwed into the inner circumferential female threaded portion 55C of the nut member 55, and the small diameter upper end 53a of the screw shaft 53 is rotatably attached to the end plate 54b of the bearing member 54 in the axial direction. The nut member 5 is inserted in an immovable manner, and by rotating the screw shaft 53 by operating an operation handle 56 connected to the lower end of the screw shaft 53.
5 is screwed forward and backward with respect to the bearing member 54, so that the upper connecting bar 44 and the lower connecting bar 45 to which they are fixed can be moved toward and away from each other relative to each other.

Next, the operation of this embodiment will be explained. As shown in FIG. 4, when the seat 2 is lowered to the lowest position, the operating handle 56 is rotated in a desired direction to thread the screw shaft 53 into the nut member 55 and raise it. This screw shaft 53 uses the lower connecting bar 45 as a foothold via the nut member 55, and pushes the upper connecting bar 44 upward via the bearing member 54. As a result, the lower end 41b of the first link member 41 and the upper end 42b of the second link member 42 are
The lower ends 42a of the link members are moved forward while respectively sliding on the scaffolding, and both link members 41 and 42 of the X link mechanism 4 operate in the direction of increasing the crossing angle, as shown in FIGS. 2, 3, and 5. Raise seat 2 as shown. When the operation handle 54 is rotated in the opposite direction, the screw shaft 53 is screwed into the nut member 55 and lowered, and the seat 2 is lowered by the operation opposite to that described above.

In addition, with this configuration, the rigidity of the chair can be ensured without installing stays and reinforcing bars as in the past, so it can be configured easily and is expected to last a long time and reduce manufacturing man-hours. I can do it. Furthermore, since the applied load acts at a position a certain distance from the screw shaft 53 that supports it, a bending moment acts on the screw shaft 53 via the bearing member 54 and the nut member 55.

Due to this action, when the chair is in use, the screw shaft is locked and the handle becomes heavy, so that the chair cannot be moved up or down by someone else.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and of course, the bearing member and the nut member may not be fixed in contact with the outer peripheral surfaces of the upper and lower pipes as in the above-mentioned embodiments. As an example, FIG. 7 shows a nut member 155 constituting another embodiment, and a thin iron piece 160 is shown in FIG.
is wound around the lower pipe 152 and welded, and a nut 155a is held between the protruding arms 16Oa, and the arms 160a have a hole 160 through which a screw shaft is inserted.
b is drilled. Even with such a configuration, the same effects as those of the embodiment described above can be achieved.

In addition, various modifications can be made to the bearing member, the nut member, the cross-sectional shape of the pipe, etc. without departing from the spirit of the present invention.

[Effects of the Invention] Since the present invention has the above configuration, the following effects can be obtained.

First, the connecting bar that controls the synchronized operation of the left and right X-link mechanisms and the pipe that is wrapped around the center of the connecting bar can also play the role of the stay described above. Therefore, the structure is much simpler compared to the case where the stay, which needs to be pivotally connected to the left and right link members at both ends by pin shafts, etc., and the reinforcing bar, which rigidly connects the left and right link members, are provided separately. Become. Therefore, it is possible to improve the longevity of the product and to reasonably reduce the number of man-hours required for manufacturing.

Further, the upper pipe and lower pipe that hold the bearing member and the nut member also have the function of reinforcing the central portions of the corresponding upper connecting bar and lower connecting bar, respectively. Therefore, bending deformation of the upper connecting bar and the lower connecting bar can be effectively suppressed without increasing the thickness of the member. Therefore, it is possible to increase the support rigidity of the seat without increasing the weight.

Further, when a load is applied to the seat, the frictional resistance between the screw shaft, the bearing member, and the nut member increases rapidly, so that when the seat is seated, the screw shaft is in a locked state or a state close to it. Therefore, it is possible to eliminate the problem of the seat suddenly falling down due to someone else's mischief or the like.

[Brief explanation of the drawing]

1 to 6 show an embodiment of the present invention, FIG. 1 is a front view, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is an enlarged side view showing the main parts. FIG. 4 is an explanatory view of the operation, FIG. 5 is a perspective view schematically showing the elevating device, and FIG. 6 is a sectional view showing the main parts of the elevating device. Moreover, FIG. 7 is a partial perspective view showing another embodiment. 1...Chair body 2...Seat 3...Elevating device 4...X link mechanism 41...First link member 42...Second link member 44...Upper connecting bar 45...・Lower connecting bar 51...Upper pipe 52.152...Lower pipe 53...Screw shaft 53a...Upper end portion 54
... Bearing member 55.155 ... Nut member 56 ... Operation handle

Claims (1)

[Scope of Claim] A seat height-adjustable chair comprising a lifting device interposed between a chair body and a seat, the lifting device being connected to first and second parts pivotally connected to each other at the center. A pair of left and right X-link mechanisms each comprising a link member, an upper connecting bar installed between the upper halves of the corresponding first link members of each of these X-link mechanisms, and an upper connecting bar located below the upper connecting bar. and the second of both the X-link mechanisms.
a lower connecting bar installed between the lower halves of the link members;
An upper pipe and a lower pipe are mounted on the central part of each of these connecting bars so as to be rotatable in the circumferential direction but not movable in the axial direction, and the upper end of the upper pipe is screwed into a nut member fixed to the outer periphery of the lower pipe. A screw shaft rotatably but immovably supported in the axial direction by a bearing member fixed to the outer periphery of the upper pipe, and an operation handle that rotates the screw shaft to change the distance between the two connecting bars. A chair with adjustable seat height.