JPH0414967B2 - - Google Patents

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, a movable barrel seat is supported by the chair body through an X-link mechanism so that it can be raised and lowered, and the raising and lowering position adjustment mechanism that adjusts the height of the seat is connected to a lock that is fixed to the chair body. The rotary arm includes a rod and a pivot arm having a plurality of engagement recesses on the edge thereof which is pivotally connected to the seat. By selectively engaging the locking rod with one of the engagement recesses of this rotating arm, the X-link mechanism is fixed at a specific crossing angle position, and the height of the seat can be adjusted. This is what I did to get it.

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. A lower stay is rotatably installed in between, and the height position of the seat is determined by continuously changing the distance between the two stays by screwing the screw shaft interposed between the two stays forward and backward. The cross angle position of the X link 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 such a 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 impedes 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. is installed between a pair of left and right X-link mechanisms each comprising first and second link members pivotally connected to each other at the center, and the upper half of the corresponding first link member of each of these X-link mechanisms. a lower connecting bar located below the upper connecting bar and installed between the lower halves of the corresponding second link members of both the X-link mechanisms; An upper pipe and a lower pipe having a length of 3 and externally mounted on the central part of each of these connecting bars so as to be rotatable in the circumferential direction and immovable in the axial direction, and a nut member fixed to the outer periphery of the lower pipe. A screw shaft that is screwed together and whose upper end is supported rotatably and immovably in the axial direction by a bearing member fixed to the outer periphery of the upper pipe, and the screw shaft is rotated to adjust the distance between the connecting bar. It is characterized in that it is equipped with an operation handle that can be changed.

[Function] With this configuration, when the operation handle of the elevation 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.
The upper pipe and the lower pipe rotate around the upper and lower connecting bars, respectively, and transmit relative approaching/separating movements to them, thereby changing the crossing 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 will act on the upper connecting bar and the lower connecting bar, whose central portions are restrained by a screw shaft, but these connecting bars are reinforced by having an upper pipe and a lower pipe wrapped around each intermediate portion. It is becoming a state. Therefore, the rigidity of the portion supporting the seat can be increased without making the connection bar thick or taking special reinforcement 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 a horizontal seat support part 12 located below the seat 2 has front and rear horizontal members 14 between left and right side plates 13, 15 is constructed in the form of a frame. And, the seat support part 1 of this chair body 1
2 and the seat 2, the lifting device 3 is provided.

As shown in FIGS. 1 to 5, the elevating device 3 includes:
A pair of left and right X link mechanisms 4 pivotally connected to raise and lower the seat 2 relative to the chair body 1, and a first link member 4 corresponding to each of these X link mechanisms.
an upper connecting bar 44 installed between the upper halves of 1;
The corresponding second link members 42 of both X-link mechanisms 4 are positioned below this upper connecting bar 44.
A lower connecting bar 45 is installed between the lower halves, and an upper pipe 51 and a lower pipe 52 are mounted on the central portions of the connecting bars 44 and 45, respectively, so as to be rotatable in the circumferential direction and immovable in the axial direction. , a nut member 55 fixed to the outer periphery of this lower pipe 52
is screwed into the upper pipe 5 and its upper end 53a is connected to the upper pipe 5.
A screw shaft 53 is rotatably but immovably supported in the axial direction by a bearing member 54 fixed to the outer periphery of the screw shaft 53, and by rotating the screw shaft 53, the two connecting bars 44,
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 lower end 42a of the second link member 42 are rotatably connected by a fulcrum pin 43.
are pivotally connected to the seat 2 and the seat support part 12 of the chair body 1 via the upper bracket 6 and the lower bracket 7, respectively, and the lower end 41b of the first link member 41 and the upper end 42 of the second link member 42.
b is supported by the seat support portion 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 connected to the pin 41c and the pin 4.
2c to the respective ends of the upper bracket 6 and lower bracket 7, respectively. Further, a pin 4 is provided at the lower end 41b of the first link member 41 and the upper end 42b of the second link member 42.
1d and 42d project horizontally, and the pins 41d and 42d are located near the rear end of the lower bracket 7 and extend in the front-rear direction through a horizontal elongated hole 71 and the rear end of the upper bracket 6, respectively. A horizontal long hole 6 extending in the front-rear direction provided in
1 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 to the corresponding link members described above, that is, between the link members 41 and 41 and between the link members 42 and 42, respectively.

The upper pipe 51 has approximately 1/3 the length of the upper connecting bar 44, is rotatably mounted on the central portion of the upper connecting bar 44, and has both ends 51a connected to the upper connecting bar 44. It is clamped so that it cannot move in the axial direction by a projection 44a provided on the outer periphery of the shaft 44 for preventing movement. 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 includes a pipe 54a fixed by welding with its axis perpendicular to the axis of the upper pipe 51;
An end plate 54b attached to the open end of this pipe 54a
It is composed of.

The lower pipe 52 has approximately 1/3 the length of the lower connecting bar 45, is rotatably mounted at the center of the lower connecting bar 45, and has both ends 52a connected to the lower connecting bar 45. It is clamped so that it cannot move in the axial direction by a projection 45a provided on the outer periphery of the shaft 45 for preventing movement. The nut member 55 is fixed to the outer periphery of the central portion of the lower pipe 52. For example, as shown in FIG. 6, the nut member 55 is a pipe 55a fixed by welding with its axis perpendicular to the axis of the lower pipe 52.
and a sleeve 55b press-fitted into the inner periphery of this pipe 55a, and a female threaded portion 55c is formed on the inner periphery of this sleeve 55b.

Then, the inner peripheral female threaded portion 5 of the nut member 55
5c, and the small diameter upper end 53a of the screw shaft 53 is screwed into the shaft bearing member 5.
The nut member is inserted into the end plate 54b of No. 4 so as to be rotatable but immovable in the axial direction. 55 is screwed forward and backward with respect to the bearing member 54, and the upper connecting bar 44 and the lower connecting bar 4 to which they are fixed are connected.
5 can be moved toward and away from the base.

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 is the nut member 5
The upper connecting bar 44 is pushed upward via the bearing member 54 using the lower connecting bar 45 as a foothold via the shaft bearing member 54. As a result, the first link member 41
The lower end 41b of the second link member 42 and the upper end 42b of the second link member 42 are connected to the upper end 4 of the first link member
1a and the lower end 42a of the second link member are moved forward while sliding on the scaffold, and both link members 41 and 42 of the X link mechanism 4 are operated in the direction of increasing the crossing angle, as shown in FIGS. 2, 3 and 3. Raise the seat 2 as shown in FIG. 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 easily configured, reducing weight and 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 bearing member 54 and a nut member 5 are attached to the screw shaft 53.
A bending moment will act through 5. Due to this action, when the chair is in use, the screw shaft is locked and the handle becomes heavy, so that the seat cannot be raised or lowered by someone else.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and of course it does not matter if, for example, the bearing member and the nut member are not fixedly installed in contact with the outer peripheral surfaces of the upper and lower pipes as in the above-mentioned embodiments. FIG. 7 shows, as an example, a nut member 155 constituting another embodiment, in which a thin iron piece 160 is wrapped around the lower pipe 152 and welded, and its protruding arms 16
A nut 155a is held between the two arms 160a, and a hole 160b through which a screw shaft is inserted is bored in both arms 160a. 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 screw shaft screws forward and backward through the nut member fixed to the lower pipe using the shaft support member fixed to the upper pipe as a foothold, and the upper pipe and lower pipe rotate around the upper and lower connecting bars, respectively. However, since it is configured to transmit relative approaching and separating movements to them and change the intersection angle position of the X link mechanism, each connecting bar can be rigidly attached to the corresponding link member by welding etc. Therefore, even if the members bend, there will be no difference in the postures of the left and right X-link mechanisms, and problems such as those caused by tilting the seat can be prevented.
Therefore, there is no need for a reinforcing bar to firmly connect the corresponding link members of the left and right X link mechanisms. 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, compared to the case where a stay that requires both ends to be pivotally connected to the left and right link members by a pin shaft, etc. and a reinforcing bar that rigidly connects the left and right link members are provided separately,
The structure becomes much simpler, and therefore the weight can be reduced, and the number of man-hours required for manufacturing can be reasonably reduced.

In addition, the upper pipe and lower pipe that hold the bearing member and nut member also have the function of reinforcing the center part of the corresponding upper connecting bar and lower connecting bar over 1/3 of the length of the connecting bar. There is. Therefore, bending deformation of the upper connecting bar and the lower connecting bar can be effectively suppressed without increasing the thickness of each connecting bar. Therefore, it is possible to increase the support rigidity of the seat without increasing the weight.

Furthermore, 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.

[Brief explanation of drawings]

1 to 6 show one embodiment of the present invention, FIG. 1 is a front view, FIG. 2 is a cross-sectional view of FIG. 1, FIG. 3 is an enlarged side view showing main parts, and 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, 5
5,155...Nut member, 56...Operation handle.

Claims (1)

[Scope of Claims] 1. A seat height-adjustable chair comprising a lifting device interposed between a chair body and a seat, the lifting device being connected to a first and a second chair which are pivotably 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. a lower connecting bar installed between the lower halves of the second link members of both the X-link mechanisms; An upper pipe and a lower pipe that are externally rotatable in the direction but not movable in the axial direction; and a shaft bearing that is screwed onto a nut member fixed to the outer periphery of the lower pipe and whose upper end is fixed to the outer periphery of the upper pipe. It is characterized by comprising a screw shaft rotatably but immovably supported in the axial direction by a member, and an operation handle that rotates the screw shaft to change the distance between the two connecting bars. A chair with adjustable seat height.