JPS62510Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a stepwise variable adjustment device for the angle of the backrest of a chair or a simple foldable bed called a desk chair.

Conventionally, as this type of device, for example,
As shown in No. 20440, No. 45-31331, and Japanese Patent Publication No. 42-16156, etc., a rotating plate having pawl teeth is pivotally attached to the metal body, and a locking pawl is engaged with the pawl tooth. Many joint fittings are used in combination with a plate cam that disengages the locking pawl when the moving plate is rotated to a predetermined position. However, the conventional metal joints described above are generally of the so-called one-way type, in which the angle of the backrest can be changed one step at a time in the direction of raising the backrest, but it is possible to change the angle of the backrest one step at a time in the direction of raising the backrest. To change the angle, first tilt the backrest completely forward to put the cam in the working position, then tilt the backrest all the way back to return the cam to the non-working position, and then tilt the backrest upward. It required a troublesome operation to raise it to a predetermined angle. In addition, in rare cases where such joint metal fittings are used, the backrest may suddenly move backwards when one puts their weight on the backrest due to a mistake in the user's operation or the operation of the joint metal fitting itself. There was a danger that the user could fall over and hit his or her head on the back wall. Furthermore, as mentioned above, when adjusting the angle, it is necessary to tilt the backrest backward until it reaches a substantially horizontal position, which has the disadvantage that it cannot be used in a narrow space.

In addition, in the case of a chair that uses this type of articulated hardware, if a child or the like accidentally leans against the backrest from behind, the backrest will pivot forward and fold onto the seat. Not only was there a risk of falling and getting injured, but in cases where the entire backrest was covered with thick cushioning material, the cushioning material near the joints could be damaged by forcibly folding the backrest onto the seat. There were also problems with cracking or early damage.

This invention eliminates the above-mentioned drawbacks and further improves practical convenience.

Therefore, as shown in the illustrated embodiment, this invention has the following features:
A main body hardware 1 having a pair of side wall plates 11, 11 parallel to the rear end of the seat frame A is provided, and a metal body 1 is provided at the lower end of the back frame B, located between the side wall plates 11, 11, and pivoted thereto. A rotary metal fitting 2 is provided with plate-shaped branches 21, 21, and selectively engages with a plurality of claw teeth 22 provided on the lower arcuate periphery of the plate-shaped branches 21, 21. A spring-biased locking pawl 3 is attached to the side wall plate 1.
1 and 11, and further presses the locking pawl 3 between the side wall plates 11 and 11 in the direction of separating from the pawl teeth 22, and applies a forward tilting force to the back frame B. An engagement release member 4 is disposed to restrict further rotation when the front wall of the rotating hardware 2 comes into contact with the back frame B to hold the back frame B at a predetermined angle slightly tilted forward from the upright state, and The disengagement member 4 rotatably passes through the side wall plate 11 of the metal body 1 and is rotatably connected to a pivot shaft 6 having a handle 5 at one end on the outside thereof. .

The side wall plates 11, 11 of the main body hardware 1 have a substantially circular rear part that protrudes upward, and a front part that is connected to the upper wall 12.
and are connected by a lower wall 13.

The plate-like supports 21, 21 of the rotating hardware 2 are also 2
It consists of two parallel fan-shaped plates, and is pivoted to the main hardware 1 by a shaft 7 at the center of its arcuate periphery.

The locking claw 3 has its base end attached to both side wall plates 1 of the main body hardware 1.
It is pivotally connected between 1 and 11 by a shaft 8, and is constantly urged upward by a spring 9 wound around the shaft 8.
The tip is adapted to be elastically engaged with the pawl teeth 22.

The disengagement member 4 is plate-shaped, and its rear lower surface abuts the upper surface of the locking pawl 3, and its front lower end abuts the base end of the locking pawl 3 to maintain a stable position. . In addition, the rear part thereof is projected upward, and when a forward tilting force is applied to the back frame B, the front wall of the rotating hardware 2 comes into contact with it, causing the back frame B to be slightly tilted forward from the upright state. Further rotation is restricted to maintain the angle at a predetermined angle. The rotation shaft 6 of the disengagement member 4 is made of a polygonal shaft such as a hexagonal cross section, and rotatably passes through the side wall plate 11 of the main body hardware 1. It passes through the rectangular hole 10 and is integrally connected thereto only in a rotational manner.

Since this invention has the above-mentioned configuration, when the backrest is in the upright position as shown in Fig. 5, if you want to tilt it further backwards at a predetermined angle to achieve the desired comfortable state, you can While sitting on the seat, pull up the handle 5 in the direction of arrow F in Figure 1. Then, due to the rotation of the rotation shaft 6, the engagement release member 4 presses the locking pawl 3 downward against the spring 9.
As shown in FIG. 6, the engagement with the pawl teeth 22 is released, and the rotating hardware 2 is placed in a free state. Therefore, in this state, after tilting the back frame B to the desired angle, turn the handle 5.
When released, the locking pawl 3 engages with the pawl tooth 22 at the corresponding position by the force of the spring 9, and the back frame B is held at a predetermined angle.
On the other hand, when raising the back frame B from the collapsed state as shown in FIG. The back frame B can be set at an angle of .

This invention is based on the above-mentioned, and the back frame B can be freely rotated upward at any time and stopped at an angle where the locking claw 3 engages with any claw tooth 22 along the way. When folding the frame B, simply disengaging the locking pawl 3 from the pawl teeth 22 by operating the handle 5 allows it to be tilted to any angle in one motion and stopped, unlike the conventional method. In particular, when folding the backrest, you can easily pivot the back frame forward and backward and then adjust it to any desired angle. The angle of the backrest can be easily adjusted in any direction, there is no risk of the backrest falling too far backwards, and it can be installed and used in a relatively narrow space without any problems, and its relatively simple structure prevents mistakes. Not only is there no risk of operation or failure, but the forward rotation of the back frame B is regulated by the engagement release member 4 at a predetermined angle position slightly tilted forward from the upright position, so that a person cannot lean against the backrest from behind. In such a case, there is no danger of the device being accidentally folded in half and falling, resulting in injury, and the cushion material covering the area around the device can be prevented from being damaged or torn, making it safe and secure. It is convenient to use and has excellent effects.

[Brief explanation of drawings]

The drawings show an embodiment of this invention; Fig. 1 is a perspective view of the entire chair frame, Fig. 2 is a side view of the main parts,
Figures 3 and 4 are the same rear view and plan view, Figure 5 is a vertical sectional view of the main parts with the back frame upright, and Figure 6 is equivalent to Figure 5 when the back frame is folded down. FIG. DESCRIPTION OF SYMBOLS 1... Body hardware, 2... Rotating hardware, 3... Locking claw, 4... Engagement release member, 5... Handle, 6...
...Rotation shaft, 9...Spring, 11...Side wall plate, 21...
...Plate-like branch, 22...Claw teeth, A...Seat frame, B...
Back frame.

Claims (1)

[Claims for Utility Model Registration] (1) A pair of side wall plates 11, 1 parallel to the rear end of the seat frame A.
A rotating hardware 2 is provided at the lower end of the back frame B with plate-shaped support pieces 21, 21 pivotally attached to the side wall plates 11, 11. is provided, and the plate-shaped support piece 2
A spring-biased locking pawl 3 that selectively engages with a plurality of pawl teeth 22 provided on the lower arcuate periphery of the side wall plates 11, 21 is pivotally attached to the lower portion between the side wall plates 11, 11, and When the locking pawl 3 is pressed in the direction of separating from the pawl teeth 22 and a forward tilting force is applied to the back frame B, the front wall of the rotating metal fitting 2 comes into contact between the side wall plates 11, 11, and the above-mentioned An engagement release member 4 is arranged to restrict further rotation in order to hold the back frame B at a predetermined angle slightly tilted forward from the upright state, and the engagement release member 4 is arranged on the side wall plate of the main body hardware 1. A backrest angle adjusting device for a chair or the like, which is rotatably connected to a rotating shaft 6 which rotatably passes through a shaft 11 and has a handle 5 at one end of the outer side thereof. (2) The rotating shaft 6 is formed of a polygonal cross-sectional shaft, and is passed through a corresponding polygonal hole of the unlocking member 4 so that both are rotationally engaged. Backrest angle adjustment device for chairs, etc.