JP6975674B2 - Lumber support device for chairs - Google Patents

Description

The present invention relates to a lumbar support device used for the backrest of a chair.

It is widely practiced to install a lumbar support device on the back of a chair. The lumbar support device is equipped with a lumbar pad , and there are those in which the height of the lumbar pad is constant and those in which the height of the lumbar pad can be adjusted.

As an example of a lumbar support device that can adjust the height of the lumbar pad , Patent Document 1 describes the lumbar support device for the backrest with a mesh material on the back frame, which is horizontally long so that the lumbar pad reaches the left and right sides of the back frame. It is disclosed that the guide protrusions formed on the left and right ends of the lumbar pad are engaged with the braking uneven portions formed on the left and right side portions of the back frame.

In Patent Document 1, the guide protrusion has a pin-like shape, but the engaging claw that moves up and down together with the lumbar pad is also engaged with and disengaged from the uneven portion. In this case, the engaging claw bends and deforms against the elasticity to move through the uneven portion.

Japanese Patent No. 5940337

By the way, when the chair is in use, a downward external force may be applied to the lumbar pad. In particular, in the locking state, the difference between the seat, the backrest, and the movement may cause a phenomenon called back slip, and the seated person's body may tend to move downward with respect to the backrest. May be pushed downwards. Therefore, there is a problem that the lumbar pad shifts downward.

To solve this problem, it is conceivable to increase the engagement force by increasing the depth of the unevenness or increasing the elastic force of the connecting claw. However, this coping method requires a strong force to adjust the height of the lumbar pad, which causes a new problem that the height adjustment becomes troublesome. That is, conventionally, there has been a problem that the ease of adjusting the height of the lumbar pad and the certainty of preventing slipping conflict with each other.

In Patent Document 1, when body pressure is applied to the lumbar pad, the guide protrusion is pressed toward the unevenness for braking, so that it is difficult to slide down, but the uneven portion has a corrugated shape to facilitate the movement of the guide protrusion. Therefore, it is doubtful whether the slipping phenomenon of the guide protrusion can be prevented in the fruit, and therefore, it is understood that there remains anxiety about the certainty of sliding down.

The present invention has been made in view of such a situation, and an object thereof is to provide a lumbar support device capable of reliably preventing slipping down without impairing the ease of adjusting the height of the lumbar pad. be.

The lumbar pad device of the present invention is as described in claim 1.
"Lumber pads on which the seater's body pressure is applied via mesh material or other body support members,
The lumbar guide body to which the lumbar pad is attached so as to be able to move up and down,
And height adjusting apparatus capable of changing the height position of the lumbar pad while no hanging body pressure of a seated person before Symbol lumbar pad,
When the body pressure of the occupant is applied to the lumbar pad and a lock device for holding the lumbar pad so as not to move vertically,
The lock device includes a vertically longitudinal lock receiving portion formed on the front surface of the lumbar guide body, and a lock body provided so as to move up and down integrally with the lumbar pad and engage with and disengage from the lock receiving portion from the front-rear direction. The lock body is urged by spring means to disengage from the lock receiving portion. "
It has a configuration that.

The invention of the present application includes various configurations. As an example, in claim 2,
"The height adjusting device is composed of vertically elongated uneven portions formed on the lumbar guide body and engaging claws that engage and disengage from the uneven portions against elasticity, and the engaging claws are said. lumbar pad and that have been arranged so as to move up and down together. "
It is configured as.

In addition, in claim 3, and have you to claim 2,
"The uneven portion is uneven when viewed from the front and is formed in pairs on both sides of the lumbar guide body with the vertically long center line in between, and the left and right engaging claws abut on the lumbar guide body from the left and right outside. On the other hand
The lock receiving portion is arranged between the left and right uneven portions, and the lock receiving portion is formed with lock grooves into which the lock body is fitted and detached in multiple stages at the same pitch as the uneven portion. NS"
It is configured as.

Further, in claim 4, in claim 3,
"The lumbar pad is composed of a pad body and a lumbar frame to which the pad body is attached, and there is a space between the pad body and the lumbar frame through which the lumbar guide body passes.
An elevating guide body provided with the engaging claws is arranged on the front surface of the lumbar frame, and the elevating guide body holds the lumbar guide body relative to each other, and the lock body further holds the lock body. It is placed in front of the elevating guide body and fixed to the lumbar frame.
The elevating guide body and the lock body and the lumbar frame can move relative to each other by a slight dimension in the front-rear direction, and the lock body and the elevating guide body are urged in a direction in which the lock body and the elevating guide body are separated from each other by the spring means. "
It is configured as.

In the present invention, the height adjusting function of the lumbar pad and the locking device for preventing slipping are separately configured. Therefore, the height adjusting device gives priority to the ease of ascending and descending, and ascends and descends with a light force. It can be formed into an operable state. When the occupant puts his / her body against the backrest and the occupant's body pressure is applied to the lumbar pad, the lock device securely holds the lumbar pad so that it cannot be raised or lowered (especially it cannot slide down), and the occupant can move from the backrest. When you release your body, the lock function of the lock function is automatically released.

Therefore, in the present invention, it is possible to reliably prevent the lumbar pad from shifting (particularly slipping down) in a locking state or the like while ensuring the ease of adjusting the height of the lumbar pad. Therefore, the quality of the chair can be greatly improved.

Various modes can be adopted for the height adjusting device and the locking device, but in the present invention, since the locking body directly engages with the lock receiving portion by the body pressure of the seated person, the transition to the locked state can be further ensured. At the same time, the structure can be simplified. Therefore, it is excellent in reliability. In addition, since the locked body is urged in the unlocking direction by the spring means, the transition to the unlocked state is ensured after the seater's body pressure is released, further ensuring the ease of height adjustment. can.

When claim 3 is adopted, the height adjusting device and the locking device can be arranged separately on the left and right, so that the depth of the lumbar support device can be made as small as possible. That is, the height adjusting device and the locking device can be compactly integrated. Therefore, it can be said that the commercial value of the chair can be improved by contributing to the slimming of the backrest design.

In the fourth aspect, first, because the lumbar guide body a space between the pad body and La members frame runs through, can contribute to downsizing. In addition, since an elevating guide body and a lock body, which are separate members from the lumbar frame, are used to have a height adjustment function and a lock function, for example, when an engaging claw is formed on the lumbar frame. Compared to, the freedom of design is high. Therefore, the height adjustment function and the lock function can be firmly secured.

In the figure which shows the embodiment, (A) is an overall perspective view seen from the front, (B) is a partially omitted side view, and (C) is a front view of the lower corner portion of a back frame. (A) is a separated perspective view, and (B) is a partially separated perspective view of the mesh material and the side cover. (A) is a front view and (B) is a rear view. (A) is a plan view, and (B) is a perspective view seen from behind. (A) is a vertical sectional side view centered on the seat portion, (B) is a view seen from the Y direction of FIG. 1 (C), and (C) is a separation view seen from the same Y direction. (A) is a separated perspective view of the back portion, and (B) is a separated perspective view of the hinge portion. It is a vertical sectional front view centering on a lumbar support part. (A) is a detailed view of the part pointed by the arrow A in FIG. 7, (B) is a detailed view of the part pointed by the arrow B of FIG. 7, and (C) is a detailed view of the part pointed to by the arrow C of FIG. Is. (A) is a separated perspective view of the back support and the back frame as seen from below, (B) is a separated perspective view of the connection portion between the back support and the back frame as seen from the back, and (C) is the back support and the back frame. It is a separation perspective view which looked at the connection part with from the front. (A) and (B) are separate perspective views of the back support and the back frame as viewed from below, and (B) is a perspective view of the middle member with the lumbar guide body attached. (A) is a separated perspective view of the lumbar support device as viewed from the front, (B) is a separated perspective view of a part of the lumbar support device as viewed from the back, and (C) is a partial front view of the lumbar guide body. D) is a rear view of the lock body. (A) and (B) are partially omitted separated perspective views of the lumbar support device as viewed from the front, and (B) is a partial perspective view of the lumbar support device. (A) is a partial perspective view of the lumbar support device, (B) is a separated perspective view of the pad body and the lumbar frame, and (C) is a back view of the pad body. (A) is a partial perspective view of the lumbar frame, (B) is a separated perspective view of the lumbar frame and the connecting bar, and (C) is CC of FIG. 11 (C) with the pad body attached to the lumbar frame. It is a cross-sectional view.

(1). Overview Next, embodiments of the present invention will be described with reference to the drawings. First, the outline of the chair will be described mainly based on FIGS. 1 and 2. In this application, the wording of front, back, left and right is used to specify the direction, but this direction is based on the state seen from the person who normally sits on the chair. The front view is the direction facing the seated person.

This embodiment is applied to a swivel chair that is frequently used in offices. This chair includes a seat 1, a backrest 2, and a leg device 3 with casters. The leg device 2 has a leg support 4 made of a gas cylinder, and as shown in FIG. 1 (B) (see also FIG. 5 (A)), a fixed base constituting a base portion is provided at the upper end of the leg support 4. 5 is attached.

The moving base 6 is connected to the portion of the fixed base 5 in front of the leg support 4 by the left-right longitudinal first axis 7 (actually, the first axis 7 is hidden by the side view and cannot be seen. See FIG. 5 (A)). ), The back support 8 is fixed to the rear end of the tilt base 6. Therefore, the back support 8 tilts backward with the first axis 7 as a fulcrum. The spine 8 may be made of resin or metal such as an aluminum die-cast product. The tilt base 6 is also made of metal or resin.

The backrest 2 has a structure in which a mesh material 10 is stretched on a back frame 9 opened in the front-rear direction. The back frame 9 is made of synthetic resin, and has a vertically long left and right side member 11, an upper member 12 integrally connected to the upper end thereof, a lower member 13 connected to the left and right side members 11, and left and right side members 12 . It has a middle member 14 connected to the upper part. The middle member 14 has a V shape when viewed from the front, and the lower end portion 14a of the middle member 14 and the upper end portion of the back support column 8 are connected by a second axis 15 extending left and right.

As shown in FIG. 2, the seat 1 is attached to the seat outer shell 16. The seat outer shell 16 includes a main seat outer shell 16a, a front seat outer shell 16b mounted on the front portion thereof so as to be slidable back and forth, and a third axis 17 (left and right longitudinal third axis 17) at the rear end portion of the main seat outer shell 16a. It is composed of a rotary rear seat outer shell 16c connected via FIG. 5 (A)), and the main seat outer shell 16a is fixed to the seat receiving body 18.

As shown in FIG. 2, the front portion of the seat receiving body 18 is connected to the front end portion of the fixed base 5 by a left-right longitudinal fourth axis 19, and the rear portion of the seat receiving body 18 is connected to the left-right longitudinal fifth axis. 20 is connected to the side portion 6a of the tilt base 6. Therefore, when the backrest 2 tilts backward, the seat receiving body 18 tilts backward with the fourth axis 19 as a fulcrum, whereby the seat 1 tilts backward in conjunction with the backward tilting of the backrest 2. However, the degree of backward tilting of the seat 1 is smaller than the degree of backward tilting of the backrest 2.

The rear end of the rear seat outer shell 16c and the lower member 13 of the back frame 9 are connected by a left-right longitudinal sixth shaft 21. The side members 12 of the back frame 9 has an angular portion 11a protruding to the left and right outward in front view with forward projecting the side surface view. The chevron portion 11a can be deformed so that the side view posture and the front view posture change depending on the body pressure of the seated person.

That is, in the non-locking state, when the body pressure of the seated person is applied to the mesh material 10 as shown by the white arrow in FIG. 1, the chevron portion 11a is in the direction of embracing the seated person's body by the pulling action of the mesh material 10. Rotates inward. Therefore, the holdability of the body by the backrest 2 becomes high, and the physical stability of the seated person becomes high.

The backrest 2 is equipped with a lumbar support device. The lumbar support device has a pad body 22 that supports the seated person from behind via a mesh material 10, and a lumbar guide body 23 to which the pad body 22 is adjustable in height. The upper end is connected to the portion where the middle member 14 and the back support 8 are connected, and the lower end of the lumbar guide body 23 is connected to the lower member 13. Further, the lumbar guide body 23 is gently curved as a whole so as to project toward the front in a side view.

In the non-locking state in which the seated person is not leaning against the backrest 2, no external force in the vertical direction acts on the lumbar guide body 23. Therefore, the front-rear position of the pad body 22 does not change, and the body pressure of the seated person is supported via the mesh material 10 (however, depending on the lateral viewing posture of the lumbar guide body 23, the front-rear position also changes when the height changes. It can change together).

When the backrest 2 tilts backward, the second axis 15 descends while retreating, and the sixth axis 21 also descends. Therefore, it changes depending on the distance between the second axis 15 and the sixth axis 21, but in this case, the distance may be widened or the distance may be narrowed, and in this embodiment, the distance is narrowed.

Therefore, the mesh material 10 tends to be slack at the time of locking, but when the distance between the second axis 15 and the sixth axis 21 is narrowed, the degree of bending of the lumbar guide body 23 becomes large and the pad body 22 is pushed toward the front. Acts on. This makes it possible to prevent the mesh material 10 from loosening too much. As a result, it is possible to prevent the holdability for the body from becoming excessively high. Further, when the tension on the mesh material 10 is reduced by locking, the chevron portion 11a of the side member 12 expands to the original posture and tries to be deformed by its own elastic restoring force.

The backrest 2 has a portion located above the upper end of the back support column 8. As shown by the black arrow in FIG. 1 (B), the seated person stretches the upper body while the backrest 2 is tilted backward, and the upper part of the backrest 2 is located above the upper end of the back support column 8. In this case, the backrest 2 may tilt backward with the second axis 15 as a fulcrum. That is, after the back support 8 is completely tilted backward, the backrest 2 can be further tilted backward (double locking). Therefore, high comfort can be ensured.

Then, when the backrest 2 tilts backward with the second axis 15 as a fulcrum, the lower end of the back frame 9 tries to rotate toward the front, but the lower end of the back frame 9 is restricted by the sixth axis 21 so that it cannot move forward. Therefore, the chevron portion 11a of the back frame 9 spreads outward and tends to be deformed. Further, when the backrest 2 is tilted backward, the lumbar guide body 23 is deformed to increase the degree of bending, as shown by the black arrow in FIG. 1 (B). As a result, the pad body 22 tends to move forward, and the waist of the seated person is firmly supported.

After all, the backrest 2 can perform primary locking by tilting the back support 8 backward and secondary locking in which only the backrest 2 tilts backward after the back support 8 is completely tilted backward, but the pad body 22 is used during the secondary locking. In order to move forward, it is possible to properly support the seated person's upper body in an extended state and ensure high comfort.

(2). Structure of seat and base The parts will be described below. First, the seat and the base portion will be described. As can be understood from FIG. 2A, the tilting base 6 has side portions 6a located on the left and right sides of the fixed base 5, and the front end portions of the side portions 6a are connected to the fixed base 5.

As shown in FIGS. 2 (A) and 5 (A), the seat receiving body 18 has a left-right longitudinal portion constituting the front portion thereof and a front-rear longitudinal portion located on the left and right, and has left and right portions. The longitudinal portion is connected to the fixed base 5 via the bracket 25. Further, the front-rear longitudinal portion is connected to the tilt base 7 by the fifth axis 20.

A large number of reinforcing ribs are formed on the seat outer shell 16. A seat inner shell 26 is arranged on the seat outer shell 16, and a cushion material 27 (see FIG. 5A) is stretched on the seat inner shell 26.

The seat inner shell 26 has a main seat inner shell 26a fixed to the main seat outer shell 16a , and a front deformable portion 26b that can be rolled down and deformed is integrally connected to the front end of the main seat inner shell 26a. There is. The front end of the front deformed portion 26b is connected to the front end of the front seat outer shell 16b. Therefore, when the back and forth movement of the front-seat outer shell 16b, a front end of the front deformable portion 26b is to go back or caught downward, it is possible to adjust the front end position of the seat 1. Back and forth movement of the front-seat outer shell 16b is effected by a lever 28 shown in FIG. 1 (B), for example.

A rear rotating portion 26c is integrally connected to the rear end of the main seat inner shell 26a via a hinge portion, and the rear rotating portion 26c is engaged with the rear seat outer shell 16c by means of engaging (hook means). It is connected. Therefore, the rear seat outer shell 16c and the main seat inner shell 26a rotate together.

As shown in FIG. 5A, the rear end of the tilting base 6 extends behind the fixed base 5, while as shown in FIG. 1B, the lower end of the back support 8 is behind the tilting base 6. A forward facing portion 8a that overlaps from above is formed at the end portion, and the forward facing portion 8a is fixed to the tilt base 6 with a bolt (not shown).

A locking spring is arranged inside the fixed base 5, but it is omitted in the drawing. The locking spring is a coil spring that expands and contracts in the front-rear direction, and its front end is supported by a front spring receiver 29 shown in FIG. 5 (A).

(3). Back frame and its mounting structure The backrest 2 includes a back frame 9 and a mesh material 10. As shown in FIG. 2B , in the mesh material 10, an edge member 34 such as a resin tape is fixed to the outer peripheral edge of the mesh material 10 by contacting or the like, and the edge member 34 is vertically attached to the edge member 34. The engagement hole 35 is open by jumping.

As described above, the side member 11 of the back frame 9 includes the chevron portion 11a, but as shown in FIG. 1A, for example, the side member 11 continues on the chevron portion 11a. The portion located above the chevron portion 11a also protrudes to the left and right outwards. Therefore, in the upper part of the side member 11, there is a constricted portion 36 inward inward in front view, and the middle member 14 is connected to the constricted portion 36.

The side member 11 is formed in a thin shape (plate shape) whose front-rear thickness is much smaller than the left-right width. Therefore, the chevron portion 11a is deformed so that the shape in the side view can be easily changed. In particular, since the formed thin apex 37 of the mountain-shaped portions 11a, the mountain shape portion 11a is particularly easily bent about its apex 37. Further, the chevron portion 11a is also allowed to be twisted and deformed around the axis. Due to the combined deformation of bending and twisting, the deformation as shown by the alternate long and short dash line in FIG. 1B is allowed.

A side cover 39 is fixed to the front surface of the side member 11. The side cover 39 basically has the same shape as the side member 11, but the substantially upper half portion is narrower than the side member 11.

Although not shown, a vertically elongated groove opened outward is formed between the side member 11 and the side cover 39 over the entire vertical length, and the vertically elongated groove is formed in FIG. 2 (B). The edge member 34 shown is fitted. Further, the upper member 12 is formed with a horizontally long groove that opens upward, and the edge member 34 is fitted in the horizontally long groove.

As shown in FIG. 6, the lower member 13 of the back frame 9 has a gutter-shaped shape that opens forward, but has a large number of reinforcing ribs inside, and basically has a rigid structure that does not deform. There is. A downward bracket portion 13a is formed at both left and right ends of the lower member 13, and the bracket portion 13a is connected to the rear seat outer shell 16c by a third axis 17 as shown in FIG.

As can be inferred from FIGS. 1 (C) and 6, the lower member 13 and the side member 11 are connected by a pin 50. The pin 50 is tilted so as to approach the center of the back frame 9 as it goes upward in the front view. Therefore, when the chevron portion 11a of the side member 11 rotates about the pin 50, the chevron portion 11a changes its shape in the side view as shown by the alternate long and short dash line in FIG. 1B, and also in the front view. The shape of is also changed.

The pin 50 constitutes a hinge means, and as an element of the hinge means, bearing portions 51 and 52 into which the pin 50 is fitted are provided at the lower end of the side member 11 and the left and right ends of the lower member 13. The pin 50 is inserted into the bearing portions 51 and 52 from below, but as can be understood from the comparison of FIGS. 5B and 5C, the pin 50 is prevented from coming off by the protrusion 53 provided on the side cover 39. ing.

The lower cover 54 overlaps the lower member 13 from the front, and the lower cover 54 is fixed to the lower member 13 with a plurality of screws 55 (see FIG. 8B). Then, boss portions 56a and 56b that are fitted to each other are formed in the left and right intermediate portions of the lower member 13 and the lower cover 54, and the lower end portions 22a of the lumbar guide body 23 are fitted into the boss portions 56a and 56b. Therefore, the lower end portion 23a of the lumbar guide body 23 has a hole for fitting the boss portions 56a and 56b. The screw 55 is screwed into the lower member 13 via the boss portions 56a and 56b.

The chevron portion 11a of the side member 11 frequently rotates due to a change in the body pressure of the seated person. Therefore, a moment due to the rotation of the chevron portion 11a frequently acts on the connecting portion at the lower end of the side member 11. Therefore, for example, as shown in FIG. 6, a metal plate stopper 58 having a posture orthogonal to the pin 50 is arranged so as to straddle the front surface of the side member 11 and the lower member 13.

Reference numeral 59 shown in FIG. 6B is formed on the first boss body in which the stopper 58 is fitted so as not to be displaced, reference numeral 60 is formed on the second boss body in which the stopper 58 is slidably fitted, and reference numeral 61 is formed on the stopper 58. It is a guide groove. In FIG. 6B, a part of the edge member 34 is shaded.

As shown in FIG. 8 (B), a lower horizontal groove 62 opened downward is formed on the mating surface of the lower member 13 and the lower cover 54, and the edge member 34 provided at the lower end of the mesh material 10 is lower horizontally long. It is inserted in the groove 62.

(4). Mounting structure of lumbar guide body Next, the lumbar support device will be described mainly with reference to the drawings shown in FIGS. 7 and below. The lumbar guide body 23 is made of a resin or a metal plate and has a long vertical band shape, but as shown in FIG. 7, the lumbar guide body 23 is curved toward the front in a side view as a whole. To be precise, the upper part is curved. Therefore, it can be deformed by an external force applied in the vertical direction. Of the lumbar guide body 23, the portion where the pad body 22 moves up and down is in a substantially linear posture when viewed from the side.

The upper end portion of the lumbar guide body 23 is connected to the lower end portion of the middle member 14. This point will be explained first. As shown in FIGS. 8 to 10, a bearing boss portion 65 is formed at the upper end of the back support column 8 so as to project diagonally upward toward the front, while a bearing boss portion 65 is formed at the lower end portion 14a of the middle member 14. The bearing recess 66 into which the bearing is inserted is formed so as to open downward and rearward. Then, the lower end portion 14a of the middle member 14 and the bearing boss portion 65 are connected by a second shaft 15 (pin).

The left-right width of the bearing recess 66 is larger than the left-right width of the bearing boss portion 65, and a side view angle spacer 67 is provided between the left-right side surface of the bearing boss portion 65 and the left-right inner side surface of the bearing recess 66. , 68 is sandwiched. Spacers 67 and 68 are separated into two large and small parts, both of which are nested. The small spacer 68 is made of a member having a small coefficient of friction and is in contact with the outer surface of the bearing boss portion 65. The large spacer 67 is rotatably held in the bearing recess 66, and the small spacer 68 is non-rotatably fitted to the large spacer 67.

For example, as shown in FIG. 10A, the upper end portion 22b of the lumbar guide body 23 is bent backward, and the upper end portion 23b of the lumbar guide body 23 has two left and right positioning holes 69 , while the middle member 14 On the upper inner surface of the bearing recess 66, two left and right positioning bosses 70 that fit into the positioning holes 69 are projected downward. Therefore, in the present embodiment, the upper end portion 22b of the lumbar guide body 23 is connected to the middle member 14.

In the embodiment, since the upper end portion 23b of the lumbar guide body 23 is held in the bearing recess 66 so as not to be detachable by the bearing boss portion 65, a fixing means such as a screw is not required, and the mounting structure can be simplified accordingly. .. Further, since the lumbar guide body 23 can be formed into a curved shape in a side view by utilizing the fact that the upper end portion 23b thereof is inserted into the bearing recess 66, the ease of deformation can be ensured.

The positioning hole 69 and the positioning boss 70 may be one each, but if two positioning holes 69 are formed on the left and right, there is an advantage that the stability of the lumbar guide body 23 can be improved. Further, the positioning hole 69 and the positioning boss 70 are formed in a long shape in the front-rear direction, which also contributes to the posture stability of the lumbar guide body 23. Of course, the positioning hole 69 and the positioning boss 70 can be formed into various shapes such as a circle and a square.

The second shaft 15 penetrates the lower end portion 14a of the middle member 14. Therefore, the lower end portion 14a of the middle member 14 is provided with a pin hole 71 into which the second shaft 15 is fitted. Therefore, the center cover 72 is attached to the lower end portion 14a of the middle member 14, and the pin holes 71 are covered from the left and right sides by the left and right end portions 72a of the center cover 72. As a result, the second shaft 15 is held so that it cannot be pulled out. For example, as is clearly shown in FIG. 10, the lower end portion 14a of the middle member 14 is formed with a recess 73 into which the left and right end portions 72a of the center cover 72 are fitted.

The center cover 72 is formed in a gate shape when viewed from the front so as not to interfere with the lumbar guide body 23. Then, for example, as shown in FIG. 8A, an engaging piece 72b that enters the bearing recess 69 is formed at the upper end of the center cover 72, and the claw 75 formed in the engaging piece 72b is formed on the bearing recess 66. It is engaged with the engagement bar 76 provided in the above.

Since the upper end edge of the center cover 72 is in contact with the upper surface of the bearing recess 66, the center cover 72 is held so as not to come off. The center cover 72 is attached by utilizing the deformation of the engaging piece 72b. The engaging bar 75 also functions to regulate the upward movement of the upper end portion 22b of the lumbar guide body 23.

(5). Lumber pad and elevating mechanism As shown in FIGS. 13 and 14, for example, the pad body 22 is formed horizontally horizontally, and both left and right ends are rounded. The pad body 22 is made of a soft resin such as an elastomer. The pad body 22 is attached to a lumbar frame 80 arranged behind the pad body 22, and both of them form a lumbar pad. The lumbar frame 80 is curved so as to be recessed toward the front in a plan view, and the left and right side portions are open. Therefore, it is in the shape of glasses ( note that the lumbar frame 80 does not have to be open).

The lumbar frame 80 is largely curved in a plan view, while the pad body 22 is substantially flat. Therefore, only the left and right ends of the pad body 22 are attached to the lumbar frame 80 in a state where both ends are supported. Then, as the mounting structure of the pad body 22, for example, as clearly shown in FIGS. 13 (B) and 14 (C), the lumbar frame 80 is formed with the engaging claws 81 protruding outward in multiple stages, while the pad body is formed. The pocket portion 82 into which the engaging claw 81 enters is formed in the 22.

For example, as clearly shown in FIGS. 14A and 14C, the lower ends of the lumbar frame 80 are connected by a joint bar 83. The joint bar 83 is formed with a hook portion 84 that engages with the engaging claw 81 at the lowermost end. The presence of the joint bar 83 prevents the lumbar frame 80 from spreading and deforming, and also prevents the lower end edge of the pad body 22 from bending and deforming. When the seated person's body pressure is applied, the pad body 22 can be stretched and deformed so as to be recessed backward, but the pad body 22 is not deformed at the lower end edge, and is more easily deformed as it goes up.

For example, as shown in FIGS. 11 and 12, a guide wall portion 85 composed of a group of ribs is formed in the left and right intermediate portions of the lumbar frame 80, and the lumbar guide body 23 is placed between the left and right guide wall portions 85. An elevating guide body 86 to be held is arranged. Therefore, the elevating guide body 86 is provided with left and right dovetail grooves that hold the lumbar guide body 23. The portion of the lumbar guide body 23 that fits into the dovetail groove of the elevating guide body 86 is formed to be slightly thin (may be of equal thickness).

The lumbar guide body 23 is located on the front side of the elevating guide body 86, and the elevating guide body 86 is provided with left and right engaging claws 87 located on the front side of the lumbar guide body 23. Further, as shown in FIGS. 12 (B) and 12 (B), a plurality of upper and lower outward ribs 86a are projected on the left and right side surfaces of the elevating guide body 86. On the other hand, the guide wall portion 85 of the lumbar frame 80 is composed of a group of ribs, and therefore, a groove is formed between the adjacent ribs, but the groove of the guide wall portion 85 is outside the elevating guide body 86. The facing rib 86a is fitted so that it can slide back and forth. Therefore, the elevating guide body 86 is attached to the lumbar frame 80 so that it cannot move up and down and can move back and forth.

The lower end of the engaging claw 87 is a free end, and the lower end is a chevron protruding inward. On the other hand, the left and right uneven portions 88 to which the engaging claws 87 engage and disengage due to deformation against the elasticity of the lumbar guide body 23 are projected forward (the concave and convex portions 88 are formed on the vertically elongated ribs). ing.).

(6). Elevating lock mechanism Further, a lock body 89 is arranged in front of the elevating guide body 86, and the lock body 89 is fixed to the guide protrusion 85 of the lumbar frame 80 by left and right screws 90. .. There is a certain distance (several mm) between the lock body 89 and the elevating guide body 86, and the lock body 89 and the lumbar frame 80 have only a certain size with respect to the elevating guide body 86 and the lumbar guide body 23. Can move back and forth.

Further, as shown in FIGS. 12B and 12C, left and right springs (coil springs) 91 are arranged between the lock body 89 and the elevating guide body. Therefore, the lock body 89 is urged in a direction away from the elevating guide body 89 and the lumbar guide body 23, and when the body pressure of the seated person is applied to the pad body 22, the lock body 89 comes into close contact with the lumbar guide body 23. do. A spring receiver 92 is formed between the lock body 89 and the elevating guide body 23. Instead of the coil spring 91, another elastic body such as rubber may be used.

Then, as can be understood from, for example, FIGS. 12 (A) and 11 (C), side-viewing angle-shaped lock grooves 93 composed of forward ribs are provided in multiple stages on both sides of the front surface of the lumbar guide body 23 with the vertically long center line sandwiched. On the rear surface of the lock body 89 , a vertically elongated rib 94 located between the left and right engaging grooves 93 and a vertically elongated rib 94 outside the vertically elongated rib 94, as shown in FIGS. 12 (A) and 11 (D). The upper and lower lock claws 95 protruding in the direction are formed. The lock device is composed of the lock body 89, the lock groove 93, and the lock claw 95. Further, the group of the lock grooves 93 becomes the lock receiving portion described in the claim.

The vertical pitch of the lock groove 93 is the same as the pitch of the uneven portion 88, and the distance between the upper and lower lock claws 95 is an integral multiple of the pitch of the lock groove 93 and the uneven portion 88. When the lock claw 95 and the lock groove 93 are fitted, the lumbar frame 80 and the pad body 22 are held so as not to be able to move up and down.

On the other hand, when the seated person's body pressure is not applied to the pad body 22, the lock claw 95 is separated from the lock groove 93, so that the engaging claw 87 can be elastically deformed and adjusted to an arbitrary height. It is done with a light force. Therefore, the pad body 22 can surely prevent the pad body 22 from shifting (particularly, sliding down) due to the body pressure of the seated person without impairing the ease of height adjustment. When the vertically long rib 94 is provided on the lock body 89 as in the embodiment, the lock body 89 can be accurately positioned, so that there is an advantage that the lock operation can be ensured.

The upper end portion 23b of the lumbar guide body 23 can also be connected to the bearing boss portion 65 of the back support column 8. Various other structures can be adopted for the height adjusting mechanism and the locking mechanism of the pad body 22. The lower end of the engaging claw 87 moves left and right to move the uneven portion 88, but the lock claw 95 is fitted into the space outside the engaging claw 87 to prevent elastic deformation of the engaging claw 87. By doing so, the locked state can be secured. As the height adjusting means, it is also possible to adopt a ball catch structure in which the ball is urged by a spring instead of the engaging claw.

Further, as the form of the pad body and the lumbar guide body, various forms can be adopted as long as they have the function. For example, the lumbar guide body can be in the form of a pipe or a gutter (the lumbar guide body can also be composed of two left and right members). The lumbar pad may be a single structure without a pad body. Alternatively, it is also possible to form a body support portion on the lumbar frame and put a cushioning material on the surface thereof.

The invention of the present application can be embodied in a chair. Therefore, it can be used industrially.

2 Backrest 9 Back frame 10 Mesh material 11a Crest as a deformation allowable part 22 Pad body that constitutes a lumbar pad 23 Lumbar guide body 80 Lumbar frame that constitutes a lumbar pad 81 Engagement claw 82 Engagement hole 85 Guide wall part 86 Lifting and lowering Guide body 87 Engagement claws constituting the height adjusting means 88 Concavo-convex portion constituting the height adjusting means 89 Locking body constituting the locking device 91 Spring as an example of the urging means 93 constituting the lock receiving portion of the locking device Lock groove
94 Vertical rib 95 Lock claws that make up the locking device

Claims (4)

A lumbar pad on which the seated person's body pressure is applied via a mesh material or other body support member,
The lumbar guide body to which the lumbar pad is attached so as to be able to move up and down,
And height adjusting apparatus capable of changing the height position of the lumbar pad while no hanging body pressure of a seated person before Symbol lumbar pad,
When the body pressure of the occupant is applied to the lumbar pad and a lock device for holding the lumbar pad so as not to move vertically,
The lock device includes a vertically longitudinal lock receiving portion formed on the front surface of the lumbar guide body, and a lock body provided so as to move up and down integrally with the lumbar pad and engage with and disengage from the lock receiving portion from the front-rear direction. The lock body is urged by a spring means to disengage from the lock receiving portion.
Lumber support device for chairs. The height adjusting device is composed of a vertically elongated uneven portion formed on the lumbar guide body and an engaging claw that engages and disengages with the uneven portion against elasticity, and the engaging claw is the lumbar. that have been arranged so as to lift the pad and integrated,
The lumbar support device for the chair according to claim 1. The uneven portion is uneven when viewed from the front and is formed as a pair on both sides of the lumbar guide body with the vertically long center line interposed therebetween, and the left and right engaging claws are in contact with the lumbar guide body from the left and right outside. on the other hand,
The lock receiving portion is arranged between the left and right uneven portions, and in the lock receiving portion, lock grooves into which the lock body is fitted and detached are formed in multiple stages at the same pitch as the pitch of the uneven portions. Yes,
The lumbar support device for the chair according to claim 2. The lumbar pad is composed of a pad body and a lumbar frame to which the lumbar pad is attached, and there is a space between the pad body and the lumbar frame through which the lumbar guide body passes.
An elevating guide body provided with the engaging claws is arranged on the front surface of the lumbar frame, and the elevating guide body holds the lumbar guide body relative to each other, and the lock body further holds the lock body. It is placed in front of the elevating guide body and fixed to the lumbar frame.
The elevating guide body and the lock body and the lumbar frame can move relative to each other by a slight dimension in the front-rear direction, and the lock body and the elevating guide body are urged in a direction in which the lock body and the elevating guide body are separated from each other by the spring means. ,
The lumbar support device for the chair according to claim 3.

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