JPH0446604Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lumbar support device that is disposed on the rear surface of the cushion material of the back of a chair to support the lumbar vertebrae of a seated person.

[Prior Art] Conventionally, many lumbar support devices for chairs have been devised. For example, to explain the lumbar support device of Utility Model Application No. 56-73348 based on FIGS. 11 and 12, the cushion material 1 of the backrest 101 is
A contact plate 103 having an appropriate height and width on the rear surface of 02
A shaft 105 is fixed to the rear end of a shaft bearing plate 104 protruding from the rear surface of the corresponding plate 103, and the shaft 105 is slid up and down on guides 106, 106 fixed to a fixed part of the backrest 101. Support freely,
The amount of extrusion of the abutment plate 103 toward the cushion material 102 is adjusted by rotating the shaft 105, and the height of contact with the lumbar vertebrae is adjusted by vertically moving the shaft 105.

[Problem to be solved by the invention] According to the above-mentioned conventional lumbar support device, the guides 106, 1 adjust the height position of contact with the lumbar vertebrae.
06 and a stop means for fixing the contact plate 103 at an appropriate height position, and in order to adjust the height position of the contact plate 103, the groove 10 of the guide 106 is required.
The cover 108 of the backrest 101 has a cut along the line 7.
There were problems in that the structure required to be formed was complex, resulting in high costs, and the equipment became large.

[Means for Solving the Problems] Therefore, the present invention provides a backrest plate 5 having an appropriate height and width on the rear surface of the cushion material 2 of the backrest 1,
In a lumbar support device for a chair in which the plate 5 is applied to the lumbar vertebrae when sitting, a bearing plate 6 is provided protruding from the rear side of the plate 5, and a long hole 10 is formed in the bearing plate 6. A square shaft 7 is inserted into this elongated hole 10 so that the contact plate 5 rotates integrally with the square shaft 7.
The elongated hole 10 slides to support the abutment plate 5 so that it can slide freely in the front-rear direction.On the other hand, a pin 11 is provided protruding from the elongated hole 10 of the shaft bearing plate 6 at a rear position, and the pin 11 is attached to the back. Groove cam 9 fixed to the fixed part of the stand 1
By engaging with the groove 9a of the groove 9a and tilting the contact plate 5 by rotation of the square shaft 7, the contact plate 5 moves back and forth with respect to the cushion material 2 in accordance with the shape of the groove 9a of the grooved cam 9. Lumbar support device A for a chair
The aim is to provide a solution to the problem.

[Operation] When the square shaft 7 is turned and the contact plate 5 is tilted, the bearing plate 6
The pin 11 is pressed or pulled along the shape of the groove 9a of the grooved cam 9, thereby causing the contact plate 5 to slide back and forth on the square shaft 7. Therefore, the shape of the contact plate 5 and the grooved cam 9
By appropriately combining the shapes of the grooves 9a, it becomes possible to adjust the height position of the contact plate 5 against the lumbar vertebrae simply by rotating the square shaft 7.

[Example] An example of the present invention will be described below with reference to the drawings.

The lumbar support device A of the present invention includes a backrest 1
It is installed between the cushion material 2 and the back cover 3 of the backrest 1, and its height is such that the lumbar vertebrae are in contact with the seat 4 when seated. The lumbar support device A includes a contact plate 5 that supports the lumbar vertebrae;
A bearing plate 6 protruding from the back surface of the corresponding plate 5, a square shaft 7 inserted through the bearing plate 6 to tilt the plate 5, a pin 11 protruding from the rear end of the bearing plate 6, and fixing of the backrest 1. It is generally composed of a grooved cam 9 fixedly attached to the section.

The abutting plate 5 is a single elongated rectangular plate with three convex portions 5a, 5b, and 5c formed in the upper, middle, and lower portions in the longitudinal direction;
It has a curved shape in which the upper and lower convex portions 5a and 5c are bent back toward the back side. A shaft bearing plate 6 is integrally provided at the center of the back surface of this contact plate 5 in a protruding manner. A rectangular long hole 10 is bored in the bearing plate 6 on the center line from the contact plate 5 to the tip of the bearing plate 6, and pins parallel to the longitudinal direction of the contact plate 5 are provided on both sides of the tip of the bearing plate 6. 1
1 and 11 are provided protrudingly.

On the other hand, the square shaft 7 inserted into the bearing plate 6 is attached to the backrest 1.
A circular hole 1 is formed in the back frame 1a with a cylindrical bush 12 fitted into a part of the square shaft 7.
3 is rotatably fitted. The square shaft 7 is inserted into the elongated hole 10 of the bearing plate 6, and when the square shaft 7 is rotated, the bearing plate 6 and the contact plate 5 are also rotated together, and the bearing plate 6 is elongated. It can slide along the hole 10 on the square shaft 7 toward the cushion material 2 side.

Groove cams 9 fixed to the fixed portion of the backrest 1 are screwed 14 to the back frame 1a, and two grooved cams 9 are attached facing the pins 11 of the bearing plate 6.
This grooved cam 9 has an arc-shaped groove 9a whose convex side extends in the same direction as the abutting plate 5, and a pin 11 of the bearing plate 6 is engaged with the groove 9a.

Next, an adjustment device for adjusting the rotation angle of the square shaft 7 will be explained. The square shaft 7 has one end protruding from the back cover 3 of the backrest 1, and the lever 1 is attached to the protruding end of the square shaft 7.
5 is installed. The lever 15 is attached to the back cover 3
A square hole 15b having the same shape as the square shaft 7 is formed at the center of the cylinder section 15a, and the square shaft 7 is inserted into the square hole 15b to connect the lever 15 and the square shaft 7. rotate integrally, and the square shaft 7
The lever 15 can slide in the axial direction. A retaining ring 16 is attached to the end of the square shaft 7 located inside the lever 15.
is attached to lock the lever 15 so that it does not come off the square shaft 7, and furthermore, a spring 17 is interposed between the bush 12 of the square shaft 7 and the cylindrical portion 15a of the lever 15, so that the lever 15 is normally attached to the square shaft 7. It is adapted to be pressed into contact with the retaining ring 16 of. On the other hand, a movable pawl 15 in the shape of a quarter arc gear is provided at the tip of the cylindrical portion 15a.
A fixed claw 1b is formed on the back frame 1 and engages with the movable claw 15c. This movable claw 1
5c and the fixed claw 1b engage with each other when the lever 15 is pressed outward of the backrest 1 by the spring 17, and when the lever 15 is manually pressed toward the backrest 1 side, the movable claw 15c
slides in the axial direction of the square shaft 7 to be disengaged. Therefore, when the lever 15 is pressed, the square shaft 7 can be rotated, and when the lever 15 is released at any rotational position, the movable claw 15c slides under the action of the spring 17 and engages with the fixed claw 1b. The rotation of the square shaft 7 is fixed at that rotation angle.

A pair of upper and lower supporting plates 5d, 5d protruding from the left and right positions of the shaft support plate 6 on the back surface of the contact plate 5, and a piece supported between the supporting plates 5d, 5d and rotating integrally with the square shaft 7. The members 18, 18 are for reinforcing the backing plate 5.

Next, the effect will be explained.

FIG. 1 shows a state in which the pin 11 is located at the center of the groove 9a of the grooved cam 9. In this state, the plate 5
The central convex portion 5b protrudes most, and the lumbar vertebrae are supported by this convex portion 5b.

From this state, move the lever 15 in the manner described above.
When the square shaft 7 is rotated clockwise in FIG. 1 while pressing, the bearing plate 6 and the contact plate 5 are also rotated together, and the convex portion 5c below the contact plate 5 projects forward. At this time,
Since the pin 11 of the bearing plate 6 and the groove 9a of the grooved cam 9 are engaged, the bearing plate 6 is pulled by the pin 11 and retreats. As a result, the lower convex portion 5c is shown as a solid line in FIG.
This means that the lumbar vertebrae can be supported at a position lower than the position of the central convex portion 5b indicated by the chain line in the same figure, without protruding too much toward the cushion material 2 side.

Similarly, when the square shaft 7 is turned counterclockwise, the convex portion 5a on the upper part of the contact plate 5 protrudes toward the cushion material 2, and the amount of protrusion increases from the pin 1 as shown in FIG.
1 and the grooved cam 9, and moreover, the lumbar vertebrae can be supported at a position higher than the central convex portion 5b indicated by the chain line in the figure.

[Effect of the invention] As described above, the lumbar support device A of the invention
According to the above, by appropriately setting the combination of the shape of the backing plate 5 and the shape of the groove 9a of the grooved cam 9, the height of the backing plate 5 can be adjusted as in the present embodiment, and for example, the height of the backing plate 5 can be adjusted.
If the plate 5 is rotated clockwise to project the corresponding plate 5 forward, it can also be applied to adjust the strength of contact with the lumbar vertebrae, and this can be done only by rotating the lever 15. There is no need to provide vertical grooves in the guide 106 or the back cover 108 of the backrest 101 as in the prior art, and therefore manufacturing is easy and the installation space can be reduced.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Figure 1 is a side sectional view of the main parts, Figure 2 is a side view of the chair, and Figure 3 is a side view of the chair.
Figure 4 is a rear view of the chair, Figure 4 is a rear view of the main parts partially cut away, Figure 5 is a perspective view of the backing plate, Figure 6 is a sectional view taken along the line X-X in Figure 4, Figure 7 The figure is Y- in Figure 4.
Y-line sectional view, Figure 8 is a Z-Z line sectional view of Figure 1,
9 and 10 are side sectional views showing the operation, FIG. 11 is a perspective view showing a conventional example, and FIG. 12 is a side sectional view of the backrest portion thereof. 1... Backrest, 2... Cushion material, 5... Back plate, 6... Bearing plate, 7... Square shaft, 9... Groove cam,
9a...Groove, 10...Elongated hole, 11...Pin, A...
...Lumbar support device.

Claims (1)

[Scope of Claim for Utility Model Registration] A lumbar support device for a chair in which a plate with an appropriate height and width is provided on the rear surface of the cushion material of the backrest, and the plate is applied to the lumbar vertebrae when seated. In addition to providing a bearing plate protruding from the rear side of the said plate,
A long hole is bored in the bearing plate, and a square shaft is inserted into the long hole so that the plate rotates integrally with the square shaft, and the long hole of the bearing plate slides on the square shaft. The support plate is supported so as to be able to slide freely in the above-mentioned direction, and on the other hand, a pin is provided protruding from the long hole of the bearing plate at a rear position, and the pin is fixed to the fixed part of the backrest. The chair is characterized in that the backing plate is moved back and forth with respect to the cushion material in accordance with the groove shape of the grooved cam by engaging with the square shaft and tilting the backing plate by rotation of the square shaft. Lumbar support device.