JPH0453711Y2 - - 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 on the seat support part of the chair body via a lifting device, and the lifting device has a pair of left and right X link mechanisms that horizontally connect the seat to the chair body. and a lifting position adjustment mechanism for fixing the seat to the chair body in a height-adjustable manner. As is well known, the elevating position adjustment mechanism for this type of chair is achieved by fixing a locking rod to the chair body and extending downwardly a rotating arm having a plurality of engagement recesses in the seat. The seat is fixed at a specific height position by engaging one of the engaging recesses of the rotating arm with the locking rod. In this device, an operating lever is connected to the rotating arm, and by operating the operating lever to temporarily move the rotating arm away from the engagement position, the locking rod can be connected to the locking rod. The engaging recesses to be engaged can be changed as appropriate, and the vertical position of the seat can be adjusted by operating the engaging recesses.

[Problems to be solved by the invention] However, in such a conventional chair, the engagement recesses of the rotating arm provided intermittently are selectively engaged with the locking rod. , stepless adjustment of sitting height is not possible. Some devices have been able to achieve substantially stepless adjustment by increasing the number of adjustment steps by using a plurality of locking rods, but this method has the problem of complicating the structure.

Furthermore, in this case, 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. It may fall to a certain position and cause 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. One possible measure to prevent such inconvenience is to provide a locking mechanism to the operating lever, etc., but adding such a locking mechanism not only increases the number of parts and complicates the structure. A problem arises in that operations become complicated.

The object of the present invention is to provide a seat height-adjustable chair that can solve the above-mentioned problems and that can quickly raise and lower the seat with a small amount of operation.

[Means for Solving the Problems] In order to achieve the above-mentioned objects, the present invention provides a chair in which a seat is supported on a chair body so that the seat height can be adjusted via a lifting device. , a pair of left and right X link mechanisms, an upper stay installed between the corresponding first link members of both the X link mechanisms, and an upper stay located below the upper stay between the second link members of both the X link mechanisms. a lower stay installed in the lower stay, a screw shaft screwed into a vertical screw hole provided in the lower stay and having its upper end connected to the upper stay in a rotatable but immovable manner in the axial direction; and an operation handle that changes the distance between the two stays by rotating the stay, and the control handle is provided between the pivot point of the first link member and the second link member and the upper end of the first link member. A connection point of the upper stay to the first link member is set in a 1/3 area near the pivot point, and a connection point of the upper stay to the first link member is set in a 1/3 area near the pivot point. The present invention is characterized in that a connecting point of the lower stay to the second link member is set in the region.

In addition, in this specification, the "1/3 area near the pivot point" does not include the "pivot point", and also refers to "the intermediate 1/3 area between the pivot point and the upper end or the lower end". The boundary points with the area of ``area'' are also not included.

[Function] With this kind of configuration, when the operating handle is operated to rotate the screw shaft, the screw shaft will engage with the lower stay and move back and forth, and the lower stay and upper stay will be connected. The interval changes steplessly. As a result, the intersection angle between the first link member and the second link member of the X link mechanism changes, and the height of the seat changes.

Here, the screw shaft is attached to a portion where, when the angles of the first and second link members change, the amount of vertical movement of each link member is small compared to the change. Since the seat is attached to the end farthest from the pivot point of these link members, the amount of elevation of the seat can be increased despite using a screw shaft with a short overall length. If this is not done, the so-called self-locking function will work reliably to prevent the seat from lowering due to the load. In general, if the thread pitch of the screw shaft is made coarser, the distance the shaft moves per one rotation of the shaft (distance the seat lifts and lowers) becomes larger. However, in the case of the screw shaft of the lifting device according to the present invention, the lifting distance of the seat can be increased without roughening the screw pitch.

Furthermore, since the length of the screw shaft is short, the range in which the handle position fluctuates due to lifting and lowering operations is reduced, and therefore the lifting and lowering operations are very easy and the seat can be raised and lowered quickly. Furthermore, when the shaft length is shortened in this way, the weight is reduced, which contributes to the weight reduction of the chair and allows it to be manufactured at low cost.

Therefore, in this chair, the sitting height can be adjusted steplessly according to the amount of rotation of the operating handle. In addition, since it is possible to provide a self-locking mechanism to the threaded part of the screw shaft,
When the operation is stopped, the seat is automatically locked in that position, so even if an unexpected external force is applied, the seat will not fall suddenly.

By the way, if the connection points of both stays to the link member are set from the center to the end of the link member, the amount of change in the distance between the upper stay and the lower stay becomes close to the amount of elevation of the seat. Therefore, not only is it necessary to make the screw shaft long, but also
The amount of operation relative to the amount of elevation and descent of the seat becomes excessive, resulting in difficulties in operability. On the other hand, in the device of the present invention, the connection point is set in the 1/3 area near the pivot point, so there is a large distance between the connection point and the end of each link member. can be secured. Therefore, the approaching and separating movements of both stays are amplified by the X-link mechanism and transmitted to the seat. Therefore, the seat can be moved up and down by a large amount with a small amount of operation, and quick operation is possible.

[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, and the upper end 41a of the first link member 41 and the upper end 42b of the second link member 42 are connected via the upper bracket 6. Connected to Sagittarius 2 and the 1st
The lower end 41b of the link member 41 and the lower end 42a of the second link member 42 are supported by the seat support portion 12 of the chair body 1 via the lower bracket 7. In addition, specifically, the first link member 41
The upper end 41a and the lower end 42a of the second link member 42 are pivotally connected to the vicinity of the front ends of the corresponding upper bracket 6 and lower bracket 7 via pins 41c and 42c. Further, a pin 42d and a pin 41d are horizontally protruded from the upper end 42b of the second link member 42 and the lower end 41b of the first link member 41, respectively, and the pins 42d and 41d are connected to the rear end of the upper bracket 6. It is rotatably and slidably inserted into a horizontal long hole 61 extending in the front-rear direction provided in the lower bracket 7 and a horizontal long hole 71 extending in the front-rear direction provided near the rear end of the lower bracket 7, respectively. Note that between the parts near the upper end of the first link member 41 and the parts near the upper end of the second link member 42,
Connection bars 44 and 45 are provided respectively to prevent the left and right X link mechanisms 4 from moving differently. The connecting bars 44 and 45 are pipe-shaped and are rigidly attached to the corresponding link members 41 and 42 by welding. The link members 41 and 42 of the X link mechanism 4 constructed as described above are engaged with stays 51 and 52, which will be described later, of the elevation position adjustment mechanism 5.

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 operating handle 5 that rotates the screw shaft 53 to change the distance between the stays 51 and 52.
4. The upper stay 51 is shaped like a rectangular pipe, and has end plates 51a covered on the left and right sides of the upper stay 51.
A connecting pin 51b is provided in a protruding manner. The connecting pin 51b is rotatably connected to a protrusion 41e provided on the first link member 41. The connection point a of the upper stay 51 with respect to the first link member 41 is the pivot point between the pivot point n of the first link member 41 and the second link member 42 and the upper end 41a of the first link member 41. It is set within the area A of 1/3 of the n neighborhood. 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 a protrusion 42e provided on the second link member 42. The connection point b of the lower stay 52 with respect to the second link member 42 is the pivot point between the pivot point n of the first link member 41 and the second link member 42 and the lower end 42a of the second link member 42. It is set in area B of 1/3 of the n neighborhood. In addition, in the center part of this lower stay 52,
A nut (not shown) forming the screw hole 52c
is buried there.

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 rattling and deflection of various parts are ignored, the seat 2 will always rise while being kept horizontal 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.

The seat height can be adjusted steplessly in the above manner, but since the threaded portion of the screw shaft 53 can be provided with a self-locking mechanism, the seat 2 can be adjusted as soon as the operation is stopped. Since it is automatically locked in that position, it is impossible for the seat 2 to suddenly fall even if an unexpected external force is applied.

Furthermore, if the connecting points a and b are set in the areas A and B in the vicinity of the pivot point n mentioned above, those connecting points a and b and the end portions 4 of each link member 41 and 42
1a and 42a can be secured.
Therefore, the approaching and separating movements of both stays 51 and 52 are amplified by the X-link mechanism 4 and transmitted to the seat 2. Therefore, compared to a case where the connection point is set from the center to the end of the link member, it is possible to cause the seat 2 to move up and down a large amount with a smaller amount of operation, and quick operability can be obtained.

The chair lifting device 3 also has a lower stay 5.
Since the upper stay 51 is biased by the upper end of the screw shaft 53 screwed into the screw hole 52c of No. 2, the number of parts is small, the structure is simple, and the durability can be increased. At the same time, the number of man-hours required for manufacturing can be reasonably and reliably reduced.

In addition, the cross-sectional shape of each link member and stay is
The chair is not limited to the illustrated embodiment, and the type of chair is not limited to a movable type, but may have legs fixed to the floor or the like. Various other modifications can be made 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, the upper stay and the lower stay are moved toward and away from each other by screwing the screw shafts back and forth, thereby operating the X-link mechanism, which raises and lowers the seat, so the elevation position of the seat can be adjusted steplessly. This can improve the usability of the chair. Moreover, since the screw type mechanism itself can have a self-locking function, it is possible to reliably prevent the inconvenience of the seat suddenly falling to the lowest position due to an erroneous operation. Therefore, the excellent effect of significantly increasing safety can be obtained without adding a separate locking mechanism that would complicate the structure and complicate operation.

Moreover, the connecting point of each stay to the link member is located at 1/1/2 in the vicinity of the pivot point between the pivot point between the link members and the end of each link member.
Since it is set in the area of 3, there is no need for a long screw shaft, and it is possible to make large lifting and lowering movements of the seat with a small amount of operation, creating a chair with the advantage of quick operability. This is something that can be provided.

In other words, when the angles of the first and second link members change, the screw shaft is installed at a location where the amount of vertical movement of each link member is small compared to the change, and the seat Since it is attached to the farthest end of the link member from the pivot point, it is possible to increase the amount of elevation of the seat despite using a screw shaft with a short overall length. A so-called self-locking function works reliably to prevent the seat from lowering due to the load. in general,
If the thread pitch of the screw shaft is coarsened, the movement distance of the shaft per one rotation of the shaft (the lifting distance of the seat) will increase, but for the screw shaft in the seat lifting device,
The load applied to the seat may cause the screw shaft to rotate and degrade the self-locking mechanism, but in the case of the screw shaft of the lifting device invented in this application, it is possible to increase the lifting distance of the seat without roughening the thread pitch. . In addition, since the length of the screw shaft is short, the range in which the handle position changes due to lifting and lowering operations is small, and therefore the lifting and lowering operations are very easy and the seat can be raised and lowered quickly. Further, when the shaft length is shortened in this way, the weight is reduced, contributing to the weight reduction of the chair and making it possible to manufacture the chair at low cost.

[Brief explanation of the drawing]

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. It is. 1...Chair body, 2...Seat, 3...Elevating device,
4... X link mechanism, 41... First link member, 42... Second link member, 41a... Upper end, 42a... Lower end, 51... Upper stay, 52
...Lower stay, 52c...screw hole, 53...screw shaft, 54...operation handle, a, b...connection point, n...pivot point, A, B...1/3 area near the pivot point .

Claims (1)

[Claims for Utility Model Registration] A chair in which a seat is supported on a chair body so that the seat height can be adjusted via a lifting device, the lifting device being a pair of left and right X-link mechanisms,
an upper stay installed between the corresponding first link members of both of these X-link mechanisms; a lower stay located below the upper stay and installed between the second link members of both of the X-link mechanisms; A screw shaft is screwed into a vertical screw hole provided in the lower stay, and its upper end is connected to the upper stay in a rotatable but immovable manner in the axial direction. and an operation handle for changing the distance between the first link member and the second link member, and a 1/3 area near the pivot point between the pivot point of the first link member and the second link member and the upper end of the first link member. A connection point of the upper stay to the first link member is set, and the connection point of the lower stay is set in a ⅓ area near the pivot point between the pivot point and the lower end of the second link member. A seat height-adjustable chair characterized by having connection points for two link members.