JPH1014693A - Angle adjusting mechanism of legless chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an angle adjusting mechanism composed of few simple parts with the excellent assembling operability. SOLUTION: A fixed arm 11, a movable arm 13 formed with a saw tooth-like latch 13b and a control plate 14 for controlling the engagement of a spring 12 with the latch 13b are pivotably connected to each other by a hinge pin 15. Both side parts 12a of the spring 12 are supported slidably in the radial direction of the hinge pin 15 in a guide groove 11c formed in the side wall of the fixed arm 11. Both ends of the spring 12 are supported in the fixed arm 11, and the spring 12 is mounted to be bent by the movable arm 13 in the radial direction of the hinge pin 15. The central tip 12b of the spring 12 is engaged elastically with a saw tooth-like latch 13b so that the movable arm 13 is blocked from pivoting in the developing direction of the movable arm 13 relative to the fixed arm 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angle adjusting mechanism for adjusting a tilt angle of a backrest with respect to a seat such as a chair.

[0002]

2. Description of the Related Art As a conventional angle adjusting mechanism for a chair or the like, as disclosed in Japanese Utility Model Publication No. 59-20118, a movable arm having a fixed arm, a latch, and a control plate are rotated by a hinge pin. The pawl, which is rotatably supported by a pin and is rotatably supported by a pin, is engaged with the latch by a spring to prevent the two arms from rotating in the direction in which they are unfolded. If both arms are folded, the control plate latches the arm. There is a configuration in which the engagement of the pole with respect to is released so that the pole can be deployed.

[0003]

The above-described conventional angle adjusting mechanism for a chair or the like has a pole, a pin for supporting the pole, and a spring for urging the pole, which are separate parts. There are drawbacks in that the number of points is increased and the workability of assembling is poor because the spring must be held in an elastically deformed state and assembled. Therefore, an object of the present invention is to provide a low-cost angle adjustment mechanism for a seat and the like, which is configured with a smaller number of parts, is excellent in assembling workability, and is inexpensive.

[0004]

A feature of the present invention to achieve the above object is to provide an angle adjusting mechanism for adjusting a tilt angle of a backrest portion with respect to a seat portion such as a seating chair or the like. A fixed arm to which one of the seat portion and the backrest portion is attached; and a rotatable connection between both side walls of the fixed arm so as to be rotatable around an axis orthogonal to the side wall. A movable arm having a pair of side walls on which a serrated latch is formed to prevent rotation in the folding direction and to which the other of the seat portion and the backrest portion is attached, and which is bent from one metal piece; Both ends of the intermediate portion are slidably supported in the direction toward the axis in guide grooves formed on the inner surface of the side wall of the fixed arm, and both ends are respectively supported by a part of the fixed arm so that the tip of the intermediate portion is Said A spring for elastically engaging the movable arm with respect to the fixed arm to prevent the movable arm from rotating in a developing direction; and a rotatably supported coaxially with the axis between both side walls of the movable arm. A control plate having a restricting portion that engages with a tip of an intermediate portion of the spring to disengage the tip from the latch in the latter half of a pivoting stroke of the movable arm with respect to the fixed arm in a folding direction; It consists of.

[0005]

When the fixed arm is in the expanded state with respect to the movable arm of the angle adjusting mechanism of the present invention, the tip of the spring intermediate portion is elastically engaged with the latch formed on the movable arm. At this time, since the latch is formed in a sawtooth shape that prevents rotation in the developing direction and allows rotation in the folding direction, rotation of the backrest in the developing direction is prevented. When the movable arm is rotated in the folding direction from this state, the tip of the spring intermediate portion is disengaged from the engaged latch tooth and is engaged with the next tooth. That is, the deployment angle of the fixed arm and the movable arm can be adjusted stepwise by successively moving the engagement position between the tip of the spring intermediate portion and the latch.

When the movable arm is rotated in the folding direction and the movable arm and the control plate are engaged, the movable arm and the control plate are thereafter rotated together. The movable arm is pivoted at a predetermined angle in the folding direction so that the tip of the spring middle part rides on the control plate, the engagement of the tip of the spring middle part with the latch is regulated, and the movable arm can freely rotate also in the deployment direction. Become like

Next, when the movable arm is rotated to the most developed position, the movable arm is engaged with the control plate, and both the control plate and the movable arm are rotated in the development direction. When the movable arm is in the most deployed state, the tip of the spring intermediate portion that has been riding on the control plate comes off the control plate and engages with the latch of the movable arm to return to the initial state.

According to the present invention, a pole used in a conventional angle adjusting mechanism and a separate pin for supporting the pole are eliminated, and a portion acting as a pole is formed in an intermediate portion of a spring.
The side wall of the fixed arm slidably supports the hinge pin in the radial direction, and the spring itself functions as a pole and engages with the latch, so that the number of parts is reduced, and a separate pole and a pin supporting the pole are provided. Since the step of assembling can be omitted, it is possible to provide an angle adjusting mechanism such as a seat chair excellent in assembling workability.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of an angle adjusting mechanism 10 such as a seating chair according to the present invention.

The angle adjusting mechanism 10 is rotatably assembled with hinge pins 15 passing through holes 11b and 13c provided with a fixed arm 11 and a movable arm 13, respectively. The fixed arm 11 is made of sheet metal and has a substantially U-shaped cross section. A pair of cut-and-raised grooves 11c is formed inside each side wall toward the center of the hinge pin 15, and a portion 11a for attaching the seat is formed in a pipe shape. It is formed. The movable arm 13 is made of sheet metal and has a substantially U-shaped cross section. The outer periphery of a substantially arc-shaped portion of each side wall is engaged with a tip 12b of a central portion of the spring 12 described below, so that the movable arm 13 moves in the deployment direction. A portion 1 is provided with a saw-toothed latch 13b for preventing the rotation of the backrest portion and allowing the rotation in the folding direction.
3a is formed in a pipe shape.

As shown in FIGS. 1 and 8, the spring 12 is formed by bending a single piano wire, and is formed in a substantially square loop shape capable of engaging and disengaging with the latch 13b of the movable arm 13. And a pair of ends extending from the lower center of the intermediate portion in opposite directions at right angles to the loop. Both side portions 12a of the center portion of the spring 12 are slidably assembled in respective guide grooves 11c formed on both sides of the fixed arm 11. One end of the spring 12 is supported by a projection 11 d cut and raised inside the fixed arm 11, and the other end is supported by the bottom of the fixed arm 11. Therefore, the tip 12b at the center of the spring 12 is directed toward the center of the hinge pin 15, that is, the latch 1 of the movable arm 13.
3b.

The control plate 14 is rotatably mounted on a pair of inner side walls of the movable arm 13 around a hinge pin 15 connecting the arms 11 and 13 as an axis. On the outer peripheral edge of the control plate 14, there are formed a permitting portion 14a for permitting the engagement between the spring 12 and the latch 13b, and a restricting portion 14b for restricting the engagement between the spring 12 and the latch 13b. The radius from the center of the hinge pin 15 to the outer peripheral edge of the permissible portion 13a is formed to be slightly smaller than the radius from the center of the hinge pin 15 to the bottom 13e of the latch 13b. Hinge pin 15
The radius from the center to the outer peripheral edge of the restricting portion 14e is slightly larger than the radius from the tooth tip 13f of the latch 13b. In addition, the movable arm 13 is
The front projection 14d engages with a projection 13d formed by cutting and raising the inside of the movable arm 13 when the movable arm 13 is rotated in the folding direction, and engages with the projection 13d when the movable arm 13 is rotated in the deployment direction. The rear projection 14e is provided.

In the unfolded state shown in FIG. 2, the tip 12b at the center of the spring 12 is engaged with the tooth bottom 13e of the serrated latch 13b which allows rotation in the folding direction and locks rotation in the unfolding direction. ing. As a result, the movable arm 13 can rotate in the folding direction, but is prevented from rotating in the unfolding direction. When the movable arm 13 is rotated in the folding direction from this state, the tip 12
b is pushed by the inclined surface of the latch 13b, so that the spring 1
2 moves away from the hinge pin 15 along the guide groove 11c, and as shown in FIG. 3, the tip 12b at the center of the spring 12 moves so as to ride on the tooth tip 13f of the latch 13b. When the movable arm 13 is further rotated in the folding direction, the tip 12b at the center of the spring 12 becomes the second tooth bottom 1 of the latch 13b as shown in FIG.
3e, the movable arm 13 is prevented from rotating in the developing direction. When the movable arm 13 is further rotated in the folding direction, the engagement positions of the spring 12 and the latch 13b sequentially move, and the movable arm 13 is moved to a position where the tip 12b of the center of the spring 12 engages with each tooth bottom 13e. The rotation of the movable arm 13 with respect to the fixed arm 11 can be adjusted in a stepwise manner.

When the front projection 14d of the control plate 14 engages with the projection 13d formed inside the movable arm 13 as the movable arm 13 rotates in the folding direction, the control plate 1
4 rotates together with the movable arm 13, but the control plate 14 allows the top portion 12b of the spring 12 to engage with the latch 13b until the top portion 12b of the spring 12 rides on the restricting portion 14b of the control plate 14. Further, when the movable arm 13 is pivoted to the latter half of the pivoting stroke in the folding direction and the tip 12b at the center of the spring 12 comes off the last tooth bottom portion of the latch 13b, as shown in FIG. The tip 12b is a regulating portion 14 of the control plate 14.
Get on b. As a result, the tip 12b at the center of the spring 12 is lifted from the latch 13b, and the tip 12b at the center of the spring 12 and the latch 13b.
Is disengaged, and the movable arm 13 is also rotatable in the developing direction.

Next, when the movable arm 13 is rotated in the developing direction, the projection 13d formed inside the movable arm 13 is engaged with the rear projection 14e of the control plate 14 as shown in FIG. Rotates together with the movable arm 13 in the developing direction. When the movable arm 13 is further rotated in the developing direction, as shown in FIG.
2b is disengaged from the regulating portion 14b of the control plate 14 and meshes with the latch 13b of the movable arm 13 to return to the state shown in FIG.

In this embodiment, the arm provided with the guide groove for supporting the side of the spring is the fixed arm, and the arm provided with the latch is the movable arm. However, the arm provided with the latch is provided as the fixed arm. The arm having the guide groove for supporting the side of the spring may be used as the movable arm. .

In the angle adjusting mechanism of this embodiment, both sides 12a of the spring 12 are supported by cut-and-raised grooves 11c provided inside a pair of side walls of the fixed arm 11, and the spring 1
Since the top 12b of the second member is configured to function as a pole, the number of parts is reduced, and a step of assembling a separate pole and a pin for supporting the same, which is conventionally required, can be omitted. Can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an embodiment of an angle adjusting mechanism for a seat and the like according to the present invention.

FIG. 2 is a partially broken side view showing a state in which the angle adjusting mechanism of the present invention is deployed most.

FIG. 3 is a partially broken side view showing a state where a movable arm of the angle adjusting mechanism of the present invention is rotated in a folding direction and a spring rides on a tooth tip of a latch.

FIG. 4 is a partially broken side view showing a state where a movable arm of the angle adjusting mechanism of the present invention is rotated in a folding direction and a latch and a spring are engaged.

FIG. 5 is a partially broken side view showing a state where the movable arm of the angle adjusting mechanism of the present invention is rotated in the folding direction and the spring rides on the control plate.

FIG. 6 is a partially broken side view showing a state in which a movable plate of the angle adjusting mechanism of the present invention is rotated in a developing direction and a control plate is in contact with a protrusion formed inside the movable arm.

FIG. 7 is a partially broken side view showing a state immediately before the movable arm of the angle adjusting mechanism of the present invention is rotated in the unfolding direction to release the spring from the control plate and engage with the latch.

FIG. 8 is a sectional view taken along the line AA of FIG. 2;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Angle adjustment mechanism, 11 ... Fixed arm, 11a ... Seat attachment part, 11c ... Guide groove, 11d ... Projection, 12 ... Spring, 12a ... Spring side part, 12b ... Spring top part, 13 ... Movable arm, 13a ... Backrest mounting portion 13b. Latch, 13d. Protrusion, 14. Control plate, 14a. Permitting portion, 14b. Restricting portion, 14d. Front protruding portion, 14e.

Claims (1)

[Claims] An angle adjusting mechanism for adjusting an inclination angle of a backrest portion with respect to a seat portion such as a seat chair or the like, comprising a pair of side walls and a bottom wall, and a fixed arm to which one of the seat portion and the backrest portion is attached. , Between both side walls of the fixed arm, rotatably connected around an axis perpendicular to the side wall,
A movable arm to which a pair of side walls on which a saw-toothed latch for preventing rotation in the developing direction and allowing rotation in the folding direction are formed on the outer peripheral portion, and the other of the seat portion and the backrest portion is attached; , Formed by bending a single metal piece, supporting both sides of the intermediate portion in a guide groove formed on the inner surface of the side wall of the fixed arm so as to be slidable in the direction toward the axis, and both ends of the fixed arm. Partially support each,
A spring that elastically engages with the latch at a tip of the intermediate portion to prevent the movable arm from rotating in the developing direction with respect to the fixed arm; and a coaxial axis between the two side walls of the movable arm. In the latter half of the pivoting stroke of the movable arm with respect to the fixed arm in the folding direction, and engages with the tip of the intermediate portion of the spring to disengage the tip from the latch. An angle adjusting mechanism for a chair or the like, characterized by comprising a control plate provided with a restricting portion for controlling the angle.