JPH0523083Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a seat height-adjustable chair whose seat can be raised and lowered by a lifting device equipped with an X-link mechanism.

[Prior Art] As this type of chair, a type called a so-called piano chair is known. In this type of chair, the seat is supported by the seat support of the main body of the chair via an elevating device, and the elevating device has first and second link members that are pivotally connected to each other at the center. A pair of left and right X-link mechanisms, and a first and second link member of each of these X-link mechanisms are connected to each other, and both link members are fixed at a constant intersecting angle position, and an operating portion is operated. and a lifting position adjustment mechanism configured to change the fixed angular position.
The elevating position adjustment mechanism of this type of chair includes a locking rod fixedly installed near the rear end of one link member, and a mechanism having a plurality of engaging recesses near the rear end of the other link member. A movable arm is extended downward and pivotally mounted, and one of the engaging recesses of the rotary arm is engaged with the locking rod to fix the seat at a specific height position. ing. In this case, an operating lever is connected to the rotating arm, and the operating lever is operated from the rear of the chair to temporarily move the rotating arm away from the engagement position. The engaging recess that engages with the locking rod can be changed as appropriate, and by this operation, the vertical position of the seat can be adjusted. In addition, in such a chair, the rear end of the link member of each X-link mechanism is pivotally connected to the rear part of the seat and the chair body in relation to the arrangement position of the elevating position adjustment mechanism, and the link member The front end of the seat is rotatably and slidably supported on the seat and the front part of the chair.

[Problems to be solved by the invention] However, such a conventional chair is inconvenient because it is necessary to adjust the sitting height by going behind the chair. In other words, this type of chair is not only used to adjust the sitting height from time to time as the child grows, but it is also often used for children and adults to take turns sitting on it. . In this case, it is necessary to adjust the sitting height each time to suit each person's height, which increases the frequency of sitting height adjustment. Moreover, if you want to adjust a chair that someone else has been using to suit you, you need to change the sitting height many times to find the optimal position. At this time, if the operating section of the elevating position adjustment mechanism is located at the rear of the chair, the user must go around to the back of the chair each time, resulting in the problem of requiring time and effort to adjust the sitting height.

In addition, if the operating part of the lift position adjustment mechanism is located at the rear of the chair, there is a possibility that the sitting height may change unexpectedly due to mischief by others or force majeure while seated, resulting in a lack of sense of security when seated. There is a problem. In particular, in the conventional type described above, when an external force is applied to the operating lever and the engagement recess of the rotating arm and the locking rod are disengaged, the seat falls all at once. Therefore, for example, if another person applies excessive force to the operating lever while sitting on the chair, the rotation arm and locking rod may disengage and the seat may move to the lowest position. fell into position,
It may give a big shock to the person sitting on it. Furthermore, if a hand or foot is inserted between the seat and the chair body at that time, the seat under load may fall, causing irreversible damage.

Furthermore, as described above, in the conventional system, an elevating position adjustment mechanism for connecting and fixing the first and second link members of each X-link mechanism is arranged behind the central pivot point of the X-link mechanism. In addition, since the front end of the link member is slidably supported by the seat and the front part of the chair body, when a large load is applied to the front edge of the seat, the front half of the link member is substantially cantilevered. Easy to bend. especially,
In chairs for study or office use, where people often sit in a shallow position, there is a high possibility that an impactful load will be applied to the front edge of the seat, which may put strain on the link members and cause durability problems.

In addition to these, like the chair lifting device described in Publication of Utility Model Publication No. 11604/1986, it is composed of left and right X-link mechanisms and a horizontal screw shaft arranged parallel to the seat. Things are also known. However, with such devices, the ratio of the force that effectively acts on the operating force applied to the knob to raise and lower the seat plate, so-called power factor, differs depending on whether the seat plate is in a high position or in a low position. If the plate is at a low position, the power factor will be extremely poor. In addition, when a load is applied to the seat plate located at a low position, one end of the lifting arm is screwed into the screw shaft by the screw block and becomes a self-locking state, so depending on the material and material thickness, etc. The X-link mechanism is likely to be pushed outward and expanded. Furthermore, if a load is applied to either the left or right side of the seat plate, the load may cause the seat plate to tilt in that direction.

The present invention aims to solve all of the above-mentioned problems.

[Means for Solving the Problems] In order to achieve the above-mentioned objects, the present invention provides a seat height-adjustable chair in which a lifting device is interposed between the chair body and the seat. The device is connected to a pair of left and right X-link mechanisms each having a first and a second link member pivotally connected to each other at the center, and a pair of X-link mechanisms having a diameter substantially the same as the width dimension of the link members, and a corresponding one of the two X-link mechanisms. a connecting bar that rigidly connects the vicinity of one end of one of the link members and the vicinity of the other end of the corresponding other link member, and an elevation position adjustment mechanism; is pivotally attached to the front part of the seat and the chair body, and the rear end of each link member is rotatably and slidably supported by the rear part of the seat and the chair body, and the elevating position adjustment mechanism is connected to both X links. An upper stay installed between the first link members of the mechanism, a lower stay positioned below the upper stay and installed between the second link members, and a vertical screw hole provided in the lower stay. A screw shaft that is screwed together and whose upper end is rotatably but immovably connected to the upper stay, and an operating section that rotates the screw shaft to change the distance between the two stays. It is characterized in that the elevating and lowering position adjusting mechanism is disposed in front of the central pivot point of the link member.

[Function] With such a configuration, the operating section of the elevating position adjustment mechanism can be located forward of the center of the chair. Therefore, the operating section can only be operated from the front side of the chair, and it is difficult to operate it from the back side of the chair.

In addition, the front ends of the first and second link members whose central parts are mutually pivotally connected are pivotally connected to the front part of the seat and the chair body so as not to be slidable, and the front parts of the link members are moved by a lifting/lowering position adjustment mechanism. Since the links are connected and fixed, even if a load is applied to the front edge of the seat, the front half of the link member will not bend like a cantilever.

Furthermore, since each link member of the left and right X-link mechanisms is rigidly connected by a connecting bar with the same diameter as the width dimension, the X-link mechanisms always operate in synchronization, and even if an unbalanced load is applied to the seat. The seat never tilts. Since the lifting position adjustment mechanism has a screw shaft arranged in the vertical direction of the chair body, the operating force applied to the operating handle is approximately the same regardless of the height position of the seat. This allows the lift to be lifted and lowered with approximately the same force at all times. In addition, the lifting position adjustment mechanism is disposed forward of the central pivot point of the link member, and the front end of the link member is pivotally connected, which makes it possible to absorb the load applied to the seat from the screw shaft. Since the X-link mechanism is received in the axial direction, even if the load is somewhat large, such as an impact load, the X-link mechanism will not be deformed. Therefore,
High stability can be maintained under various usage conditions.

[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 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.

The elevating device 3 includes a pair of left and right X link mechanisms 4 that connect the seat 2 to the chair body 1 in order to raise and lower it in a constant posture, and an elevating position adjustment mechanism 5 that allows the elevating position of the seat 2 to be changed by manual operation. It is equipped with.

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 front end 41a of the first link member 41 and the front end 42 of the second link member 42
a to the front part of the seat 2 and the seat support part 12 of the chair body 1 via the upper bracket 6 and the lower bracket 7.
The rear end 41b of the first link member 41 and the rear end 42b of the second link member 42 are connected to the rear part of the seat support part 12 of the chair body 1 via the lower bracket 7 and the upper bracket 6. and rotatably and slidably supported at the rear of the seat 2. Specifically, the front end 41a of the first link member 41 and the front end 42a of the second link member 42 are connected to the pin 41.
c and pin 42c to the corresponding front end portions of the upper bracket 6 and lower bracket 7. Further, the rear end 42b of the second link member 42 and the rear 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 into a horizontal elongated hole 61 extending in the front-rear direction provided near the rear end of the upper bracket 6 and a horizontal elongate hole 71 extending in the front-rear direction provided near the rear end of the lower bracket 7, respectively. It is slidably inserted. Furthermore, between the upper end portions of the first link member 41 and between the upper end portions of the second link member 42, there are connecting bars 44 for preventing the left and right X link mechanisms 4 from moving differently. 45 have been constructed 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 by the lifting position adjustment mechanism 5 in front 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 installed between the lower stay 52; and a screw screwed into a vertical screw hole 52c provided in the lower stay 52, the upper end 53a of which is connected to the upper stay 51 in a rotatable but immovable manner in the axial direction. Axis 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 front 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 front end 42a of the second link member 42. There is. 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, both link members 41, 4 of the X link mechanism 4
2 operates 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. When the operation handle 54 is rotated in the opposite direction, the screw shaft 53 is screwed into the screw hole 52c and lowered, and the seat 2 is rotated by the operation opposite to the above.
descends while maintaining a horizontal position.

As described above, the sitting height can be adjusted steplessly, but in this chair, the operation handle 54 of the elevating position adjustment mechanism 5 is located forward of the center of the chair. Therefore, the operating handle 54 can only be operated from the front side of the chair, and is difficult to operate from the back side of the chair. Therefore, when you are seated, there is no risk of your sitting height changing unexpectedly due to someone else's interference, etc.
It can be used with confidence. Also, first and second link members 4 whose central portions are pivotally connected to each other
The front ends 41a, 42a of the link members 41, 42 are pivotally attached to the front part of the seat 2 and the chair body 1 so as not to be slidable, and the front half parts of the link members 41, 42 are connected and fixed by the elevating position adjustment mechanism 5. Therefore, even if a load is applied to the front edge of the seat 2, the front half portions 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 in front of the pivot point n formed by the fulcrum pin 43 and the lifting position adjustment mechanism 5. is formed, and a link member 4 forming the end of the structure
Since the front ends 41a, 42a of the chairs 1, 42 are non-slidably pivotally connected to the seat 2 and the chair body 1, they exhibit particularly high resistance against the load acting on the front edge portion of the seat 2. Therefore, in addition to being relatively lightweight, the front edge portion of the seat 2 is not easily broken even if an impact load is applied to it, and high durability can be ensured.

Note that the cross-sectional shape of each link member can also 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, each link member of the left and right X-link mechanisms is rigidly connected by a connecting bar with the same width and diameter, so the X-link mechanisms always operate in synchronization, and even if an uneven load is applied to the seat. The seat does not tilt and can be used with confidence.
In addition, since the lifting position adjustment mechanism has a screw shaft arranged in the vertical direction of the chair body, the operating force applied to the operating handle is approximately the same regardless of the height position of the seat. This allows lifting and lowering operations to be performed with the same force at all times, improving operability.

In addition, the lifting position adjustment mechanism is disposed forward of the central pivot point of the link member, and the front end of the link member is pivotally connected, which makes it possible to absorb the load applied to the seat from the screw shaft. Since the X-link mechanism is received in the axial direction, even if the load is somewhat large, such as an impact load, the X-link mechanism will not be deformed, and therefore high stability can be maintained under various usage conditions.

Furthermore, the lifting position adjustment mechanism is placed in front of the central pivot point of the link member so that its operating section can be operated exclusively from the front side of the chair, making it easy to adjust the sitting height frequently. There is the convenience of being able to quickly set the sitting height to a desired height without having to go around to the back of the chair each time. In addition, since it is difficult to touch the operating part of the lifting position adjustment mechanism from behind the chair, the possibility of the sitting height changing unexpectedly due to someone else's prank while sitting is extremely reduced, so you can rest assured. The effect is that it can be used.

In addition, this structure can firmly absorb the load acting on the front edge of the chair by the front half of the link member of the X-link mechanism and the lifting position adjustment mechanism. ,
It is possible to increase the durability without increasing the weight, and it is possible to provide a durable chair that does not easily break even if it is 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. 1, FIG. 3 is an enlarged side view showing the main parts, and FIG. , FIG. 5 is a diagram explaining the principle. 1...Chair body, 2...Seat, 3...Elevating device,
4...X link mechanism, 5...Elevating position adjustment mechanism,
54... Operating unit (operating handle), 41... First
Link member, 42...Second link member, 41
a...front end, 42a...front end, 44, 45...connection bar, 53...screw shaft, n...pivot point.

Claims (1)

[Claims for Utility Model Registration] A seat height-adjustable chair comprising a lifting device interposed between the chair body and the seat, the lifting device being provided with first and second seats pivotally connected to each other at the center. A pair of left and right X-link mechanisms each comprising two link members, and a pair of X-link mechanisms having approximately the same diameter as the width dimension of the link members, and adjacent to one end of the corresponding link members of both the X-link mechanisms, and the corresponding other link member. The link member is provided with a connecting bar that rigidly connects the other ends of each link member to each other, and a lifting position adjustment mechanism, and the front end of each link member is pivotally connected to the seat and the front part of the chair body, A rear end of each of the link members is rotatably and slidably supported by the rear part of the seat and the chair body, and the elevating position adjustment mechanism is connected to an upper stay installed between the first link members of both X link mechanisms; A lower stay is positioned below the upper stay and is installed between the second link members, and the lower stay is screwed into a vertical screw hole provided in the lower stay so that its upper end is rotatable to the upper stay. The elevating position adjustment mechanism is provided with a screw shaft that is connected so as to be immovable in the axial direction, and an operating section that rotates the screw shaft to change the distance between the two stays. A seat height-adjustable chair characterized by being placed forward of the central pivot point.