JPH11169252A - Internal tooth type reclining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal tooth type reclining device that can suppress play between a base member and a rotating arm in a locked state so as to prevent a seated person from feeling uncomfortable and improve the value of goods. SOLUTION: Inner teeth 12A and 12B are slidably guided into a recessed part 10 of a base member 1 along guide side walls 9a and 9b, and a cam 16 for sliding the inner teeth 12A and 12B is disposed in the recessed part 10. A bottom face 9e of the recessed part 10 is inclined to the opposite side to a rotating arm toward a center part from the outside. An internal tooth 21a of the rotating arm 2 is inclined outside by a micro angle toward the base member 1 side from its base part. In the locked state of external teeth 13 of the inner teeth 12A and 12B being meshed with the internal teeth 21a in the rotating arm 2, the inner teeth 12A and 12B are therefore inclined to positively bring the external teeth 13 into contact with locking tooth parts 11a, 11b of the base member 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal toothed reclining device for tilting a seat back with respect to a seat cushion, and more particularly, to a base member fixed to the seat cushion and a rotation member for the base member. A rotating arm movably supported and fixed to the seat back;
A sliding engagement portion guided in a recess formed in the base member interposed between the base member and the rotating arm by a side wall thereof so as to be able to advance and retreat, and having external teeth formed at a tip thereof; A rotatable cam for moving a stop between a lock position where the external teeth mesh with the internal teeth formed on the rotary arm and a lock release position where the external teeth are separated from the internal teeth; A reclining device including at least a lever for causing the reclining device.

[0002]

2. Description of the Related Art Conventionally, as this kind of internal tooth type reclining device, those shown in FIGS. 11 (a), (b), (c) to FIG. 14 have been proposed.

[0003] This conventional example is shown in FIGS.
As shown in (c), a base member 1 fixed to a seat cushion, a turning arm 2 rotatably supported by the base member 1 and fixed to a seat back, the base member 1 and the turning A pair of upper and lower inner teeth 12A, 12B guided in a recess 10 formed in the base member 1 interposed between the arms 2 by side walls 9a, 9b so as to be able to advance and retreat and having external teeth 13 formed at the tips; The outer teeth 13 of the inner teeth 12A and 12B are
Between the locking teeth 11a, 11b formed on the rotating arm 2 and the unlock position separated from the locking teeth 11a, 11b and the internal teeth 21a. Rotatable cam 16
And a pivot 4 connected to a lever (not shown) for rotating the cam 16.

On the opposite end surfaces of the inner teeth 12A and 12B on the cam 16 side, a vertical locking portion 14d is provided at the center thereof, and left and right locking portions 14a and 14a are provided at right and left positions of the vertical locking portion 14d. The inner teeth 12A and 12B are moved to the outer locking position by engaging the locking portions 16a, 16b and 16d formed on the cam 16 with the locking portions 14a, 14b and 14d. The external teeth 13 mesh with the internal teeth 21 a of the rotating arm 2, whereby the locked state is maintained in which the rotation of the rotating arm 2 with respect to the base member 1 is prevented.

[0005]

However, in the above-described conventional internal-tooth-type reclining device, when the inner teeth 12A and 12B are brought into the locked position by the cam 16, both the engaging portions 14a, 14b and 14d are not engaged. 16
Since a, 16b and 16d are engaged, the left and right and up and down directions of the inner teeth 12A and 12B are regulated,
When an excessive external force acts on the rotating arm 2 clockwise,
The holding force against the rotational force acting on the sliding locking member can be secured, and the deformation and inclination of the sliding locking member can be reliably prevented, and the guide side wall and the cam can be prevented from being crushed. There are advantages.

However, the guide side walls 9a of the base member 1,
As shown in FIG. 12, the 9b and the side walls of the inner teeth 12A and 12B need a certain clearance in order to absorb the dimensional variation at the time of manufacturing. Therefore, the engagement between the rotating arm 2 and the inner teeth 12A, 12B is ensured, so that the pitch circle of the locking teeth 11a, 11b of the base member 1 is changed as shown in FIGS.
The diameter of the inner teeth 21a is larger than the pitch circle of the inner teeth 21a, and play occurs between the base member 1 and the inner teeth 12A and 12B.

[0007] As described above, when slight play occurs between the base member 1 and the inner teeth 12A and 12B, the play is enlarged to a considerably large play at the upper end of the seat back attached to the rotating arm 2. There is an unsolved problem of giving uncomfortable feeling to a person and lowering the commercial value.

Accordingly, the present invention has been made in view of the above-mentioned unresolved problems of the prior art, and it is intended to suppress the play between the base member and the rotating arm in the locked state, thereby preventing the occupant from being seated. It is an object of the present invention to provide an internal-tooth-type reclining device that can prevent pleasure and improve commercial value.

[0009]

According to one aspect of the present invention, there is provided an internal toothed reclining device comprising: a base member fixed to a seat cushion;
A rotating arm rotatably supported by the base member and fixed to the seat back; and a side wall that can be moved back and forth through a recess formed in the base member interposed between the base member and the rotating arm. And a locking position where the external teeth mesh with the internal teeth formed on the rotating arm, and the external teeth are internal teeth. An internal tooth of the rotary arm in a recess of the base member, the internal tooth type reclining device having at least a rotatable cam for moving between unlocked positions separated from the cam and an operation lever for rotating the cam. The internal teeth of the pitch circle slightly larger than the internal teeth of the rotary arm are formed at positions corresponding to the internal teeth of the rotary arm, and the internal teeth of the rotary arm and the external teeth of the sliding locking member meshing therewith are formed. Any one tooth surface Characterized in that the outer teeth of the slide lock member at the locking position is formed on the inclined surface of the small tilt angle to mesh with the locking teeth of the base member.

According to the first aspect of the present invention, the operating lever is operated to rotate the cam, thereby moving the sliding locking member, and the external teeth formed at the tip of the sliding locking member are moved inside the rotating arm. It can be in a locked state in which it meshes with the teeth.

In this locked state, the external teeth of the sliding locking member mesh with the internal teeth of the rotating arm, but either one of the internal teeth of the rotating arm and the external teeth of the sliding locking member. Since the surface is inclined at a small angle, the sliding engagement member is inclined according to the inclination angle, and the external teeth thereof are engaged with the base member having a pitch circle slightly larger than the internal teeth of the rotating arm. The backlash between the rotating arm and the base member is eliminated by meshing with the teeth.

Further, in the internal tooth type reclining device according to the second aspect, in the invention according to the first aspect, the minute inclination angle is set such that the sliding engagement member is in a lock position.
The outer teeth of the sliding engagement member are selected to have an angle that exceeds the pitch circle difference and contacts the engagement teeth of the base member.

According to the second aspect of the present invention, when the sliding locking member is pressed by the cam, when the locking position is attained, the outer teeth of the sliding locking member tilt the inner teeth of the rotating arm. By tilting according to the angle, the sliding locking member is tilted, and its external teeth are securely engaged with the locking tooth portion of the base member having a large pitch circle, and the play can be eliminated. .

Further, in the internal tooth type reclining device according to a third aspect, in the invention according to the first or second aspect, the sliding contact surface in sliding contact with the sliding locking member in the concave portion of the base member is the sliding surface. The locking member is formed on an inclined surface that allows the external teeth to incline along the inclined surface of the internal teeth when the external teeth mesh with the internal teeth of the rotating arm.

According to the third aspect of the present invention, since the sliding contact surface of the base member which is in sliding contact with the sliding engagement member is an inclined surface, the external teeth of the sliding engagement member are locked when the locking arm is locked. When the sliding engagement member is engaged with the internal teeth of the sliding engagement member, the sliding engagement member can be easily inclined, and the engagement between the external teeth of the sliding engagement member and the base member is ensured while ensuring the mechanical strength of the sliding engagement member. Engagement with the pawl portion can be reliably performed.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a reclining device according to the present invention. 1 to 3 are an exploded perspective view, a front view, and a cross-sectional view taken along the line ZZ of an embodiment of the present invention. The base member 1 is fixed to, for example, a left side of a seat cushion (not shown). On the other hand, a turning arm 2 attached to the left side of a seat back (not shown) is held rotatably about a pivot 4 fixed to an operation lever 3.

As shown in FIG. 1, the base member 1 has mounting portions 6a, 6b fixed to a frame of a seat cushion.
And a circular concave portion 8 having an insertion hole 7 through which the pivot 4 is inserted in a central portion formed above it.

At the center of the bottom plate 8a of the circular recess 8, a pair of left and right guide side walls 9a and 9b extending vertically and parallel to a perpendicular passing through the center point of the circular recess 8 and these guide side walls 9 are provided.
A generally rectangular recess 10 is formed by arcuate side walls 9c and 9d, which are arcs centered on the center point and connected to the upper and lower ends of a and 9b.

As shown in FIG. 2, the arcuate side walls 9c and 9d have inner teeth 12A and 12B, respectively, which will be described later.
And has a pitch circle slightly larger than a pitch circle of an internal tooth 21a of the rotating arm 2 described later, and a tooth surface parallel to a cylindrical surface centered on the center of the pivot 4. Stop teeth 11a and 11b are formed.

Further, as the bottom surface 9e, which is a sliding contact surface of the concave portion 10 which makes sliding contact with the inner teeth 12A, 12B to be described later, gradually moves inward from the locking teeth 11a, 11b, it is opposite to the rotating arm 2 side. It is formed in a dish shape so as to be inclined at an inclination angle substantially equal to the inclination angle θ of the internal teeth 21a of the rotating arm 2 described later.

In the recess 10, a pair of upper and lower inner teeth 12A and 12B as sliding engagement members are guided by guide side walls 9a and 9b, and are disposed so as to be able to advance and retreat in the radial direction.

The inner teeth 12A, 12B have a pitch circle slightly smaller than the pitch circle of the internal teeth 21a of the rotating arm 2 described later on the outer peripheral side thereof, and are parallel to a cylindrical surface centered on the center of the pivot. The outer teeth 13 having an appropriate tooth surface are formed, and the cam surface 14 is formed on the inner peripheral side.

The cam surfaces 14 of the inner teeth 12A and 12B are formed point-symmetrically with respect to the center of the insertion hole 7, and are vertically symmetrical at the left and right ends of the inner peripheral surface. Locking portions 14a, 14b inclined outwardly in the direction of approximately 45 degrees, a curved portion 14c formed in a clockwise direction from the locking portions 14a, and a curved portion 14c, and a curved portion 1c.
Locking portion 14 formed at the end of 4c and extending in the horizontal direction
d, and a curved portion 14e which is formed in a hook shape outward from the locking portion 14d in a clockwise direction to the locking portion 14b.

Further, the inner teeth 12A of the recess 10
A cam 16 which is fitted to the two-face width formed on the pivot 4 and is turned is provided between 12B. This cam 16
On the surface facing each inner tooth 12A, 12B, respectively,
Locking portion 1 abutting on locking portions 14a, 14b of cam surface 14
6a, 16b, a curved portion 16c that curves inward in the clockwise direction from the locking portion 16a, a locking portion 16d that abuts a locking portion 14d formed at an end of the curved portion 16c, A cam surface having a projection 16e formed in a hook shape outward in the clockwise direction from the stop 16d, and an inwardly curved portion 16f formed between the projection 16e and the locking portion 16b is formed. Is formed.

The turning arm 2 is composed of a mounting portion 2A having a mounting hole 18 for mounting the seat back on the upper end side, and a rotating portion 2B integrally fixed to the mounting portion by rivets. A cylindrical recess 19 having the same radius as the radius of the arc-shaped side walls 9c and 9d of the recess 10 of the base member 1 is provided on the lower end side of the portion 2B, and the above-described pivot 4 is inserted through the center of the cylindrical recess 19. A hole 20 is formed, and an inner tooth 21a meshing with the outer tooth 13 of the inner teeth 12A, 12B is formed on an inner wall forming the cylindrical concave portion 19.
Are formed.

Here, as shown in an enlarged view in FIG. 4, the inner teeth 21a have a slight inclination angle θ outward so that the tooth surface becomes larger in diameter from the bottom side toward the base member 1 side.
Is only tilted. As will be described later, when the outer teeth 13 of the inner teeth 12A and 12B mesh with the inner teeth 21a, the minute inclination angle θ
A and 12B are inclined toward the base member 1 so that the end of the external teeth 13 on the base member 1 side engages at least with the locking teeth 11a and 11b of the base member 1, for example, 0.5.
It is set to the degree.

Then, the base member 1 and the rotating arm 2
As shown in FIG. 1, a pivot 4 having a two-sided width is inserted from the outside of a base member 1 into an insertion hole 7, a cam 16, and a rotating arm 2.
Is inserted and inserted into the insertion hole 22 of the operation lever 3 while being inserted through the insertion hole 20 of the rotating portion 2B.

Then, a coil spring 25 is inserted between the operation lever 3 and the holder 23 attached to the base member 1, and the operation lever 3 and the pivot 4 are moved counterclockwise in FIG. Being energized.

The rotating arm 2 further includes a spiral return spring 2 having a center end fixed to the holder 23.
The outer peripheral end of the seat back 6 is urged in a counterclockwise direction as viewed in FIG. 1 so as to urge the seat back toward the seat cushion.

Next, the operation of the above embodiment will be described.
Now, as shown in FIG.
And is engaged with the holder 23 in the counterclockwise direction. In this state, the locking portion 1 of the cam 16
As shown in FIG. 5 (a), 6a, 16b and 16d are locking portions 1 of the cam surfaces 14 of the inner teeth 12A and 12B, respectively.
4a, 14b and 14d assume a counterclockwise rotation position abutting thereon.

For this reason, the inner teeth 12A, 12B
Are guided by the guide side walls 9a and 9b of the concave portion 10 of the base member 1 and slid outward, respectively, and the external teeth 13 formed at the distal end thereof are first rotated by the rotary arm 2 as shown in FIG. It meshes with the bottom side of the internal teeth 21a of the portion 2B.

Next, the inner teeth 12A and 12B are further pressed by the cam 16 against the inner teeth 21a of the rotating arm 2, and further, the bottom surface 9e of the concave portion 10 in the base member 1.
Are inclined outward toward the center, so that the inclination of the inner teeth 12A, 12B toward the base member 1 is allowed, so that the inner teeth 12A, 12B
Are inclined along the bottom surface 9e of the base member 1, and the external teeth 1
3 is an inclined surface when viewed from the front as shown in FIG.

For this reason, the inner teeth 12A, 12B
The external teeth 13 of the rotary arm 2 shift to a positive meshing state along the inclination angle θ of the tooth surface of the internal teeth 21a of the rotating arm 2, and the inclination of the inner teeth 12A, 12B at this time causes the base member of the external teeth 13 to move. 1 are the locking teeth 11a, 11
b, and the external teeth 13 on the bottom 9e side of the recess 10 are engaged with the locking teeth 1 of the base member 1 as shown in FIG.
1a and 11b are reliably engaged with each other.

As a result, the inner teeth 12A, 12B
As shown in FIG. 9, the external teeth 13 of the rotary arm 2 and the internal teeth 21a of the rotary arm 2 and the locking teeth 11a and 11b of the base member 1 are securely engaged with each other. Even if the pitch circles of the locking teeth 11a and 11b of the base member 1 are set slightly larger, play may occur between the inner teeth 12A and 12B and the base member 1 and the rotating arm 2. Can be reliably prevented,
The locked state between the base member 1 and the rotating arm 2 can be reliably ensured.

When the operating lever 3 is rotated clockwise as viewed in FIG. 1 from the locked state against the coil spring 25, the cam 16 is also rotated clockwise as shown in FIG. 5B. By rotating, the locking portion 16 of the cam 16 is rotated.
a, 16b and 16d are inner teeth 12A and 12B
Of the cam surface 14 with the locking portions 14a, 14b and 14d.

When the seat back is tilted to a desired tilt angle in the unlocked state, the rotary arm 2 is rotated accordingly, and the force transmitted from the internal teeth 21a to the inner teeth 12A, 12B. As a result, the inner teeth 12A and 12B slide inward, respectively, and the meshing state between the internal teeth 21a and the outer teeth 13 of the inner teeth 12A and 12B is released, whereby the locked state is released and the seat back is tilted as desired. Can be tilted to a corner.

When the tilting of the seat back to the desired tilting angle is completed, the rotation of the operation lever 3 is released, and the cam 16 rotates counterclockwise, so that the inner teeth 12A and 12B are respectively moved. By sliding outward in the radial direction, the external teeth 13 are
By engaging the locking teeth 11a, 11b and the internal teeth 21a of the rotating arm 2 in the above, the locked state is restored.

In this locked state, if an excessive rearward impact force acts on the seat back due to, for example, a collision accident, this impact force is transmitted to the rotating arm 2 and this will rotate clockwise. And The clockwise turning force of the turning arm 2 is transmitted to the inner teeth 12A and 12B in which the outer teeth 13 mesh with the inner teeth 21a, and a clockwise turning force acts on these.

Thus, each inner tooth 12A, 1
When a clockwise rotation force acts on 2B, for example, in the inner tooth 12B, the left and right side portions 1 of the inner tooth 12B
On the inner peripheral surface on the upper end side of 2a, 12b, locking portions 14a,
14b and 14d are in contact with the locking portions 16a, 16b and 16d of the cam 16, respectively.
b reliably restricts the upward movement and inward movement of the left part 12a, and the locking parts 14a and 16a reliably restrict the upward movement and inward movement of the right part 12b. The upward movement of the central portion 12c where the external teeth 13 are formed is restricted by the locking portions 14d and 16d.

Therefore, even if a rotational force acting on the inner tooth 12B causes a force to move upward on the left portion 12a, this force is surely prevented by the locking portions 14b and 16b, and the left portion 12a is similarly moved to the left by the right portion 12b. Even when a force to move the outer teeth 1 is reliably prevented by the locking portions 14a, 16a, the external teeth 1 are prevented by the locking portions 14d, 16d.
3 is reliably prevented from being lifted upward, so that the deformation and inclination of the inner tooth 12B can be reliably prevented.

Since the inner tooth 12A is also symmetrical with respect to the inner tooth 12B, deformation and inclination due to an impact force can be reliably prevented as in the case of the inner tooth 12B.

As described above, according to the above embodiment, the locked state of the rotating arm 2 can be securely held without rattling, so that the uncomfortable feeling of the occupant can be reliably prevented. In addition, the commercial value can be improved. Also, since the bottom surface 9e of the concave portion 10 of the base member 1 is an inclined surface, the inner teeth 12A, 12
Without reducing the thickness of B, the inner tooth 12A,
12B tilt can be tolerated, inner tooth 1
The mechanical strength of 2A and 12B can be secured.

Although the above embodiment has been described with reference to the case of having the pair of inner teeth 12A and 12B, the present invention is not limited to this, and one of the inner teeth 12A and 12B may be omitted. Can,
Further, three or more sets of inner teeth may be provided radially at predetermined angular intervals.

Further, in the above-described embodiment, the case where the bottom surface 9e in the concave portion 10 of the base member 1 is inclined to allow the inclination of the inner teeth 12A, 12B is described, but the present invention is not limited to this. Alternatively, the contact surface on the bottom surface 9e side of the concave portion 10 of the inner teeth 12A, 12B may be gradually inclined toward the rotating arm 2 toward the center.

Further, in the above-described embodiment, the case where the tooth surface of the internal teeth 21a of the rotating arm 2 is an inclined surface has been described. However, the present invention is not limited to this. The portion of the outer teeth of the inner teeth 12A and 12B that meshes with the inner teeth 21a may be gradually inclined inward, that is, toward the center as the rotation arm 2 moves from the bottom surface to the base member 1 side. In short, the locking teeth 11a and 11b of the base member 1 and the internal teeth 21 of the rotating arm 2
The inner teeth 12A and 12B may be inclined to such an extent that the pitch circle difference between the inner teeth 12a and 12a can be eliminated, and the outer teeth 13 may be engaged with the locking teeth 11a of the base member 1.

Further, in the above embodiment, the case where the locking portions 14a, 14b and 16a, 16b are provided on the inner teeth 12A, 12B and the cam 16, respectively, has been described, but the present invention is not limited to this. Alternatively, any one of the locking portions may be omitted.

Further, in the above embodiment, the case where the bottom corresponding to the concave portion 10 of the base member 1 is formed in a dish shape is described, but only the bottom surface 9e may be an inclined surface.

Further, in the above embodiment, the case where the pitch circle of the outer teeth 13 of the inner teeth 12A and 12B is set smaller than the pitch circle of the inner teeth 21a of the rotary arm 2 is described. Instead, the pitch may be set to be equal to or larger than the pitch circle of the internal teeth 21a.

Further, a base member 1, a rotating arm 2,
The shapes of the operation lever 3, the inner teeth 12A, 12B, and the cam 16 are not limited to those in the above-described embodiment, and can be set to any shape.

Further, in the above embodiment, the case where the reclining mechanism is provided on one side of the seat cushion and the seat back has been described. However, the present invention is not limited to this, and as shown in FIG. The base member 1 and the rotating arm 2 are also provided on the opposite side of the back.
May be arranged symmetrically, and these pivots may be connected by connecting rods 30 to provide locking mechanisms on both sides of the seat.

[0051]

As described above, according to the internal-tooth-type reclining device according to the first aspect, when the reclining device is in the locked state, the external teeth of the sliding locking member and the internal teeth of the rotating arm are reliably formed. And the sliding locking member is inclined toward the base member so that its external teeth are meshed with the locking teeth of the base member, so that the rotating arm and the base member are locked in the reclining device locked state. In this way, it is possible to reliably prevent backlash that occurs between the vehicle and the vehicle, to reliably prevent the uncomfortable feeling of the occupant, and to improve the commercial value.

According to the internal tooth type reclining device according to the second aspect, the relative inclination angle of the sliding locking member and the rotating arm is such that the sliding locking member is in the sliding position in the locked position. Since the angle of the external teeth of the locking member is selected to be such that the external teeth of the locking member mesh with the locking teeth of the base member, when the sliding locking member is pressed by the cam, it slides when the locking position is reached. The external teeth of the locking member are reliably engaged with the locking teeth of the base member beyond the pitch circle difference between the internal teeth of the rotating arm and the locking teeth of the base member, and the play is reliably eliminated. Is obtained.

Furthermore, according to the internal tooth type reclining device according to the third aspect, the sliding contact surface of the base member, which is in sliding contact with the sliding engagement member, is an inclined surface. When the external teeth mesh with the internal teeth of the rotating arm,
The sliding locking member can be easily inclined, and the engagement between the external teeth of the sliding locking member and the locking teeth of the base member is ensured while ensuring the mechanical strength of the sliding locking member. The effect that can be performed is obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of an internal-tooth reclining device according to the present invention.

FIG. 2 is a front view showing an embodiment of the internal-tooth-type reclining device according to the present invention.

FIG. 3 is a sectional view taken along the line ZZ in FIG. 2;

FIG. 4 is an enlarged view of a portion A in FIG. 3;

5A and 5B are views showing a connection state of a base member and a rotating arm of the internal-tooth-type reclining device according to the present invention, wherein FIG. 5A is a front view showing a locked state, and FIG. Front view.

FIG. 6 is an enlarged view showing a meshing state between the internal teeth of the rotating arm and the external teeth of the inner tooth at the start of locking.

FIG. 7 is an enlarged view of the external teeth when viewed from the front when the inner tooth is inclined in the locked state.

FIG. 8 is an enlarged view showing a meshing state of the outer teeth of the inner tooth and the locking teeth of the base member in a locked state.

FIG. 9 is an enlarged view showing a meshing state of the outer teeth of the inner tooth, the inner teeth of the arm member, and the locking teeth of the base member in the locked state.

FIG. 10 is an exploded perspective view showing another embodiment of the internal-tooth-type reclining device according to the present invention.

11A and 11B are explanatory views showing a conventional internal-tooth-type reclining device, wherein FIG. 11A is a front view, and FIG. 11B is Y in FIG.
FIG. 2C is a sectional view taken along line Y-Z, and FIG.

FIG. 12 is an enlarged view of a portion C in FIG. 11 (c).

FIG. 13 is an enlarged view of a portion B in FIG. 11 (b).

FIG. 14 is an enlarged view of a portion A in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base member 2 Rotating arm 3 Operation lever 4 Axis 9a Guide side wall 9b Guide side wall 9e Bottom surface (sliding contact surface) 11a Locking tooth portion 11b Locking tooth portion 12A Inner tooth 12B Inner tooth 13 External tooth 14 Cam surface 14a Lock Part 14b Locking part 14d Locking part 16 Cam 16a Locking part 16b Locking part 16d Locking part 21a Internal teeth

Claims (3)

[Claims] 1. A base member fixed to a seat cushion, a pivot arm rotatably supported by the base member and fixed to a seat back, and interposed between the base member and the pivot arm. A sliding locking member which is guided in a recess formed in the base member by a side wall thereof so as to be able to freely advance and retreat and has external teeth formed at a tip thereof; and the sliding teeth are formed on the rotating arm by the external teeth. Internal toothed reclining device comprising at least a rotatable cam for moving between a locked position meshing with the set internal teeth and an unlocked position for separating the external teeth from the internal teeth, and an operation lever for rotating the cam In the concave portion of the base member, at a position corresponding to the internal tooth of the rotary arm, an internal tooth of a pitch circle slightly larger than the internal tooth of the rotary arm is formed. tooth And a slight inclination angle such that one tooth surface of the external teeth of the sliding locking member meshing with the locking teeth is engaged with the locking teeth of the base member at the locking position. An internal-tooth-type reclining device characterized by being formed on an inclined surface. 2. The small inclination angle is such that, when the sliding locking member is in the locked position, the external teeth of the sliding locking member contact the locking teeth of the base member beyond the pitch circle difference. The internal toothed reclining device according to claim 1, wherein the angle is selected as follows. 3. A sliding contact surface in sliding contact with the sliding locking member in the recess of the base member, the sliding locking member being inclined when its external teeth mesh with the internal teeth of the rotating arm. The internal-tooth-type reclining device according to claim 1 or 2, wherein the reclining device is formed on an inclined surface that allows inclination along a surface.