JPH0523084Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an adjustable seat height chair in which the seat and backrest can be raised and lowered by a lifting device.

[Prior art] This type of chair is widely used as a study chair, office chair, etc., but in the conventional chair, the leg supports are made expandable and the length of the support is adjustable. Generally, the seat height can be adjusted by using a screw-feed type or gas spring type lifting/lowering position adjustment mechanism.

[Problems to be solved by the invention] However, since the legs of the device using the telescoping support column must be made of metal, it is difficult to significantly reduce the weight.

One possible solution to this problem is to support the seat on wooden legs via an X-link lifting device.

However, in a chair where the backrest is supported by the seat, when a load is applied to the backrest,
A large backward tilting force acts on that seat. Therefore, if an X-link type lifting device is used carelessly, the rearward tilting force acting on the seat will cause
Deflection is likely to occur in the link members, etc., resulting in problems such as loss of rigidity of the chair and failure to ensure sufficient durability.

The object of the present invention is to provide a chair with adjustable seat height that can effectively solve the above-mentioned problems.

[Means for Solving the Problems] In order to achieve the above objectives, the present invention provides a lifting device between a seat with a continuous backrest and a leg with a footrest in the front. A seat height-adjustable chair comprising: a pair of left and right X-link mechanisms comprising first and second link members pivotally connected to each other at the center; and a width of the link members. With approximately the same diameter as the dimensions, near one end of the corresponding link member of both link mechanisms,
and a connecting bar that rigidly connects the vicinity of the other end of the corresponding other link member, respectively, and a lifting position adjustment mechanism, and the rear end of each link member is pivoted to the rear of the seat and the leg. At the same time, the front end of each link member is rotatably and slidably supported by the front part of the seat and the legs, and the elevating position adjustment mechanism is connected to an upper part constructed between the first link members of both X link mechanisms. Stay and
A lower stay is located below the upper stay and is installed between the second link members, and the upper end of the lower stay is screwed into a vertical screw hole provided in the lower stay and is rotatable to the upper stay and has a shaft. The mechanism is provided with a screw shaft that is connected in a direction immovable and an operating section that rotates the screw shaft to change the distance between the two stays, and the elevating position adjustment mechanism is set at the center of the link member. It is characterized by being placed behind the pivot point.

[Function] With this configuration, the lifting position adjustment mechanism with a vertical screw shaft provided between the upper and lower stays is located behind the central pivot point of the link member, so the sitting height can be adjusted. Adjustments can be made from the back of the chair.
Even with a footrest, operability is good, and no matter what height the seat is at, it can be raised and lowered with approximately the same operating force.

Further, since the load is distributed to each link member by the X-link mechanism, each component can be made relatively lightweight and thin compared to a structure in which the load is directly supported. Further, since the legs themselves do not expand or contract, there is no need to make the legs made of metal, and the weight of the entire device can be reduced.

Furthermore, the opposing link members of the left and right X-link mechanisms are rigidly connected by a connecting bar, and their rear ends are pivotally attached to the rear parts of the seat and legs so that they cannot slide, so that the load applied to the seat is received in the axial direction of the screw shaft, so that even if the load applied to the rear part of the seat or the backrest is somewhat large, the rear half of the link members will not bend like a cantilever beam and deform the X-link mechanism. This prevents the backrest from tilting and the user from falling over, and even if an unbalanced load is applied to the seat, the seat will not tilt to the left or right, so high stability can be maintained in various usage situations.

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

As shown in FIGS. 1 and 2, this chair includes a seat 2 with a backrest 21 connected thereto, a leg 1, and a leg 1 provided between the two so that the seat 2 can be raised and lowered relative to the leg 1. It is equipped with a supporting lifting device 3. A plurality of shallow grooves 1b into which footrests 10 made of thick plates are inserted are provided on opposing inner surfaces 1a of the front portions of the legs 1. The footrest 10 is fixed to the leg 1 with screws (not shown) after its both ends are inserted into the left and right grooves 1b, and the mounting height can be changed by selecting the groove 1b to be inserted. It is becoming possible to do this.

Specifically, crossbars 22 are attached to both sides of the seat 2, and the backrest 2 is placed between the upper ends of the crossbars 22.
1 is provided. The seat 2 is supported by the seat support portion 12 of the leg 1 via a lifting device 3. The seat support portion 12 is configured in a frame shape with front and rear horizontal members 14 and 15 installed between left and right side plates 13.

The lifting device 3 includes a pair of left and right X-link mechanisms 4 that connect the seat 2 to the legs 1 in order to raise and lower them in a constant posture.
and a lifting position adjustment mechanism 5 for changing the lifting position of the seat 2 by manual operation.

As shown in FIGS. 3 and 4, each X link mechanism 4 includes a first link member 41 in the shape of an elongated plate,
A second link member 42, which is also in the form of an elongated plate, is rotatably connected at the center by a fulcrum pin 43. The rear end 41a of the first link member 41 and the rear end 42 of the second link member 42
A is provided on the rear part of the seat 2 and the leg 1 through the upper bracket 6 and the lower bracket 7.
The front end 41b of the first link member 41 and the front end 42b of the second link member 42 are attached to the leg 1 via the lower bracket 7 and the upper bracket 6. They are rotatably and slidably supported at the front part of the seat 2. Specifically, the rear end 41a of the first link member 41 and the rear end 42a of the second link member 42 are connected to the pin 41.
c and pin 42c to the corresponding rear end portions of the upper bracket 6 and lower bracket 7. Further, the front end 42b of the second link member 42 and the front end 41 of the first link member 41
A pin 42d and a pin 41d are provided horizontally protruding from the pin 42d and 41d, respectively.
d can be rotated and slid into a horizontal long hole 61 extending in the front-rear direction provided near the front end of the upper bracket 6 and a horizontal long hole 71 extending in the front-rear direction provided near the front end of the lower bracket 7, respectively. It is inserted into. A connecting bar 44 is provided between the rear end portion of the first link member 41 and between the front end portion of the second link member 42 to prevent the left and right X link mechanisms 4 from moving differently. , 45 are installed respectively. The connecting bars 44, 45 are pipe-shaped, have approximately the same diameter as the width of the link members 41, 42, and are rigidly attached to the corresponding link members 41, 42 by welding. The portions of the link members 41 and 42 of the X link mechanism 4 constructed as described above are connected to each other by the elevating position adjustment mechanism 5 at the rear of the central pivot point n.

As shown in FIG. 3, the elevating position adjustment mechanism 5 is
The upper stay 51 is installed between the first link members 41 of both the X link mechanisms 4, and the second link member 4 is positioned below the upper stay 51.
A lower stay 52 is installed between the lower stay 52 and the lower stay 52 is screwed into a vertical screw hole 52c provided in the lower stay 52, and its upper end 53a is connected to the upper stay 51 so as to be rotatable and immovable in the axial direction. Screw shaft 5
3, and an operation handle 54 which is an operation section that rotates the screw shaft 53 to change the distance between the stays 51 and 52. Upper stay 51
is in the shape of a rectangular pipe, and connecting pins 51b are provided protruding from end plates 51a covered on the left and right sides thereof. Then, connect the connecting pin 51b to the first link member 4.
It is rotatably connected to 1. This upper stay 5
Connection point a for the first link member 41 of 1
is set between the pivot point n of the first link member 41 and the second link member 42 and the rear end 41a of the first link member 41. The lower stay 52 is shaped like a rectangular pipe, and has connecting pins 52b protruding from end plates 52a covered on the left and right sides thereof. The connecting pin 52b is rotatably connected to the second link member 42. The connection point b of the lower stay 52 with respect to the second link member 42 is set between the pivot point n of the first link member 41 and the second link member 42 and the rear end 42a of the second link member 42. It has been done. Note that a nut (not shown) is embedded in the center of the lower stay 52 to form the screw hole 52c.

Next, the operation of this embodiment will be explained. As shown in FIG. 4, when the seat 2 is lowered, the operating handle 54 is rotated in a desired direction to thread the screw shaft 53 into the screw hole 52c and raise it.
This screw shaft 53 uses the lower stay 52 as a foothold to push the upper stay 51 upward. As a result, as shown in FIG. 3, both link members 41 and 42 of the X-link mechanism 4 operate in the direction of increasing the crossing angle to raise the seat 2. If the rattling and deflection of various parts are ignored, the seat 2 will always rise while maintaining its horizontal position due to the posture maintaining action of the X-link mechanism 4. The operation handle 54
When the screw shaft 53 is rotated in the opposite direction, the screw shaft 53 is screwed into the screw hole 52c and lowered, and the seat 2 is lowered while maintaining a horizontal position by an operation opposite to that described above.

As described above, the sitting height can be adjusted steplessly. In this chair, the first and second link members 4 are pivotally connected to each other at the center.
The rear ends 41a and 42a of 1 and 42 are connected to the seat 2 and the legs 1.
The rear end portions of the left and right first link members 41 are rigidly connected by a connecting bar 44 so that the link members 4
Since the rear parts of the link members 1 and 42 are connected and fixed by the elevating position adjustment mechanism 5, even if an excessive load is applied to the rear part of the seat 2, the rear parts of the link members 41 and 42 are not easily bent. That is, as schematically shown in FIG. 5, a triangular structure in side view is formed by the portion of the link members 41, 42 behind the pivot point n formed by the fulcrum pin 43 and the lifting position adjustment mechanism 5. is formed, and the rear ends 41a and 42a of link members 41 and 42 forming the ends of the structure are non-slidably pivotally connected to the seat 2 and the legs 1, so that the rear ends 41a and 42a of the link members 41 and 42 forming the ends of the structure are non-slidably pivotally connected to the seat 2 and the legs 1. It exhibits particularly high proof strength against the applied load. Therefore, this chair is relatively lightweight, and even if the backrest 21 is pressed backwards and an impactful load is applied to the rear edge of the seat 2, the link members 41 and 42 are unlikely to bend or break. These characteristics can be obtained, and high stability and durability can be ensured.

In addition, since the lifting position adjustment mechanism is a screw type, it is possible to steplessly adjust the sitting height, and the self-locking function of the screw part can be used to automatically connect and fix the link members together at all times. Furthermore, there is an advantage that even children and women can easily adjust the seat by operating the handle.

Note that the cross-sectional shape of each link member can be modified in various ways without departing from the spirit of the present invention.

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

First, since the seat to which the backrest is connected is raised and lowered by an X-link mechanism and screw shafts arranged in the vertical direction of the legs, the weight of the entire chair can be reduced. In addition, the lifting position adjustment mechanism with this screw shaft is located behind the central pivot point of the link member of the X-link mechanism, so the seat height can be adjusted from the back of the chair, making it easy to operate even if there is a footrest. No matter what height the seat is at, you can always raise and lower it with the same operating force.

In such a chair, the backrest is supported by the seat, and the opposing link members of the left and right X-link mechanisms are rigidly connected by a connecting bar, and the rear ends are prevented from sliding into the rear of the seat and legs. Coupled with the fact that it is pivoted to
Since the load applied to the seat is received in the axial direction of the screw shaft, even if the load applied to the rear part of the seat or the backrest is somewhat large, especially if a backward pressing force is applied to the backrest, the rear part of the link member will not be affected. The X-link mechanism will not be deformed by bending like a cantilever beam. That is, the rear half of the link member of the X-link mechanism and the elevating position adjustment mechanism can constitute a structure that can firmly absorb the load acting on the rear edge of the chair.

This prevents the backrest from tilting and causing the user to fall, and even if an uneven load is applied to the seat, the seat will not tilt to the left or right, maintaining high stability under various usage conditions. be able to. Furthermore, it is possible to improve stability and durability without increasing the weight, and it is possible to provide a durable chair that is resistant to breakage even when handled roughly.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a front view, FIG. 2 is a sectional view taken along the line -- in FIG. It is a principle explanatory diagram. 1... Legs, 2... Seat, 3... Lifting device, 4...
X link mechanism, 5... Lifting position adjustment mechanism, 10...
...Footrest, 54...Operation unit (operation handle),
41...first link member, 42...second link member, 41a...rear end, 42a...front end, 4
4, 45... Connection bar, n... Pivotal point.

Claims (1)

[Claims for Utility Model Registration] A chair with an adjustable seat height, comprising a lifting device interposed between a seat with a continuous backrest and legs with a footrest at the front, the lifting device comprising: 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 a corresponding link of both link mechanisms having a diameter substantially the same as the width dimension of the link members. A linking bar that rigidly connects the members near one end to each other and the other end of the corresponding link member to each other, and an elevating position adjustment mechanism, the rear end of each link member being connected to the seat. and the rear part of the leg, and the front end of each link member is rotatably and slidably supported by the seat and the front part of the leg, and the elevating position adjustment mechanism is connected to the first link member of both X link mechanisms. An upper stay installed between them, a lower stay positioned below the upper stay and installed between the second link members, and an upper end portion screwed into a vertical screw hole provided in the lower stay. a screw shaft connected to the upper stay so as to be rotatable and immovable in the axial direction; and an operating section that rotates the screw shaft to change the distance between the two stays, and A seat height-adjustable chair, characterized in that a position adjustment mechanism is disposed behind a central pivot point of the link member.