JPH09119278A - Clutch device for roll blind - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely release a locked state by certainly locking the lifting of a screen at the desired place of pulling-down while conducting the operation of the screen by slight operating force and downwards pulling the screen. SOLUTION: A braking body 25 is supported to a fixed shaft 15, and a body to be braked 19 with engaging teeth 24, 30 engaged with the braking body 25 is supported to the fixed shaft 15 rotatably and movably in the axial direction. Cam mechanisms 22, 23 are mounted on the body to be braked 19 and a winding shaft 14, and the winding shaft 14 can be rotated when the body to be braked 19 is not engaged with the braking body 25 while the revolution of the winding shaft 14 can be prevented when the body to be braked 19 is engaged with the braking body 25. A rotational permission means capable of turning the braking body 25 together with the winding shaft 14 within the range of the angle of rotation of the winding shaft 14 required for moving the body to be braked 19 from a place, where the body 19 is engaged with the braking body 25, to a place, where the body 19 is not engaged, by the cam mechanism is installed to the braking body 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch device for holding a screen of a roller blind in a desired position in a drawn state.

[0002]

2. Description of the Related Art As one type of roll blind, a twisting coil spring and a clutch device are built in a winding shaft of a screen, and the winding shaft is rotated by the urging force of the twisting coil spring. The screen can be rolled up, and the lower end of the screen can be pulled downward against the biasing force of the torsion coil spring to lower the screen, and the clutch device can resist the biasing force of the torsion coil spring. There is one that can hold the screen in a desired pull-down position.

An example of the above roller blind clutch device is disclosed in Japanese Patent Publication No. 63-8268. In this clutch device, a cam provided on the winding shaft engages with a cam groove provided on the braked body, and the braked body moves along a fixed shaft in the winding shaft as the winding shaft rotates. Is moved axially. By selecting the position where the braked body meshes with the braking body and the position where it does not mesh, the rotation of the winding shaft is prevented against the biasing force of the torsion coil spring, and the screen is pulled down to the desired pulling position. It is selected whether to hold the screen or to wind the screen by rotating the winding shaft by the urging force of the torsion coil spring.

That is, as shown in FIG. 7, when the cam 2 is located at X1 in the cam groove 1, the braked body does not engage with the braking body, and if the screen is pulled down from this state, the cam 2 is moved. Through this, the braked body provided with the cam groove 1 is rotated in the direction of arrow F1.

From the above state, the winding shaft is moved in the screen pulling direction by the urging force of the torsion coil spring,
That is, when the cam 2 is rotated in the direction of the arrow F2, the cam 2 moves to the X2 position in the cam groove 1.

Then, the braked body is moved in the direction of arrow F3 and meshes with the braked body to prevent its rotation, so that further rotation of the winding shaft is prevented. Therefore, the screen is held in the desired lowered position.

When the screen is pulled downward from the above state, the cam 2 moves in the cam groove 1 to the X3 position. Then, the braked body is moved in the direction of arrow F4, disengaged from the braked body, and the winding shaft becomes freely rotatable. When the screen is released in this state, the winding shaft is rotated by the biasing force of the torsion coil spring, and the screen is pulled up. At this time, the cam 2 moves in the cam groove 1 to the X4 position.

When the screen is pulled downward from the above state, the cam 2 moves to the X1 position and the braked body is in a rotatable state, so the winding shaft is rotated and the screen is pulled down. Then, when the screen is released, the cam 2 moves to the X2 position, the braked body meshes with the braking body, and the screen is held at the desired pull-down position.

[0009]

In the clutch device as described above, the braked body rotatably supports the braked body on the fixed shaft in a state of having a predetermined friction. And
By the frictional force, the braked body is axially moved while rotating the braked body based on the rotation of the cam accompanying the rotation of the winding shaft, so that the braked body meshes with the brake body. Further, the braking body is supported by the buffer spring so as to be rotatable in a range of a predetermined angle while having a predetermined frictional force with respect to the fixed shaft.

Then, when pulling down the screen, it is necessary to pull down the screen against the biasing force of the torsion coil spring and the frictional force between the braked body and the fixed shaft, and thus a large operating force is required. To do.

Therefore, if the frictional force between the braked body and the fixed shaft is set to be small in order to reduce the operating force, the braked body tries to mesh with the braked body, and the tip end portions of the teeth of the braked body are attempted. When is contacted with the tips of the teeth of the brake body, the braked body is no longer moved in the axial direction, does not mesh with the brake body, and idles around the fixed shaft. Therefore,
There is a problem that the braked body cannot be reliably meshed with the braked body.

Further, the braking body is supported on the fixed shaft in a state of having a predetermined friction and rotatably within a range of a predetermined angle. Therefore, when the braked body moves in the axial direction and disengages from the state in which the braked body meshes with the braked body, the rotation of the braked body stops at the moment when it disengages from the braked body. .

That is, when the cam 2 moves from the X2 position to the X3 position within the cam groove 1, the braking body stops its rotation when it disengages from the braked body. This stop position is a midway position of the allowable rotation range of the braking body.

Therefore, when the cam 2 moves from the X1 position to the X2 position in the next cycle and reaches the X2 position, the braked body and the braking body are completely meshed with each other, and the braking body is within the allowable rotation range. It is rotated to one end and further rotation is blocked. As a result, further rotation of the winding shaft is prevented and the screen is held in the desired pull-down position.

In the clutch device operating as described above, with the cam 2 positioned at X1, the screen 3 is pulled out to the lowest limit as shown in FIG. 8A, and the cam 2 is moved to the X2 position from this state. As a result, the winding shaft 4 is reversed by the angle θ1 as shown in FIG. 8B until the winding of the screen 3 is prevented. The angle θ1 is an angle at which the winding shaft 4 is rotated when the cam 2 moves from the X1 position to the X2 position.

When the screen 3 is pulled up from this state, it is necessary to rotate the winding shaft 4 in the screen pulling down direction until the cam 2 moves from the X2 position to the X3 position, and the rotation angle is larger than the angle θ1. An angle is needed.

However, even if the screen 3 is pulled downward from the state shown in FIG. 9B, the winding shaft 4 cannot be rotated by the angle θ1 or more, so that the cam 2 cannot be moved to the X3 position. .

Therefore, when the winding of the screen 3 is locked from the state where the screen 3 is pulled out to the lowest limit, the lock cannot be released only by pulling the screen 3 downward, and the screen 3 is slanted. There is a problem that the locked state needs to be released by pulling the winding shaft upward to further rotate the winding shaft or by directly rotating the winding shaft to make the operation complicated.

It is an object of the present invention to securely lock the winding of the screen at a desired lowering position while allowing the screen to be pulled out with a slight operating force, and even if the screen is pulled down to the lowest limit and locked. The purpose of the present invention is to provide a roll blind clutch device capable of reliably releasing the locked state by pulling downward.

[0020]

According to a first aspect of the present invention, a winding shaft having a screen wound around a supporting member is rotatably supported,
A drive source that applies a rotational force in the screen pulling direction to the winding shaft is provided in the winding shaft, and a braking body is supported in the winding shaft by a fixed shaft fixed to the support member. A braked body having engaging teeth that mesh with the braking body is rotatably and axially movably supported on a fixed shaft, and the braked body and the winding shaft are supported on the basis of rotation of the winding shaft. A cam mechanism is provided that reciprocates between a position that meshes with the braking body and a position that does not mesh while rotating the braking body, and enables the winding shaft to rotate when the braked body does not mesh with the braking body. When the braked body meshes with the braking body, the winding shaft can be prevented from rotating, and the braking mechanism requires the cam mechanism to move the braked body from a position where the braking body moves to a position where it does not mesh to a braking body. Within the range of the rotation angle of the take-up shaft, Provided rotation permitting means for rotatable together with the winding shaft.

According to a second aspect of the present invention, the rotation permitting means generates a predetermined friction with the winding shaft to cause the braking body to rotate integrally with the winding shaft, and the braking means. The engaging means engages with the fixed shaft on the basis of the rotation of a predetermined angle to prevent the braking body from rotating.

According to a third aspect of the present invention, the friction means is provided on the spring piece formed along the inner peripheral surface of the rotator fitted in the winding shaft, and at the tip of the spring piece. It is composed of a protrusion that abuts the inner peripheral surface of the rotator.

According to a fourth aspect of the present invention, the engaging means includes a cutout portion formed on the outer peripheral surface of the fixed shaft within a range of a predetermined angle, and an end portion of the cutout portion based on rotation of the brake body at a predetermined angle. And a projection that abuts against.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The roller blind shown in FIG.
The pair of support members 11a and 11b are connected by a mounting base 12, and the mounting base 12 is mounted on the mounting bracket 13.
It is fixed to the wall surface through.

A winding shaft 14 is rotatably supported between the support members 11a and 11b. That is, one end of the winding shaft 14 has one end fixed to the fixed shaft 1 fitted and fixed to the support member 11a.
5 is rotatably supported, and the other end is rotatably supported by the support member 11b. The screen 1 is attached to the winding shaft 14.
6 is wrapped around.

A torsion coil spring 17 is arranged in the winding shaft 14, and the torsion coil spring 1 is provided.
One end of 7 is fixed to the fixed shaft 15, and the other end is the winding shaft 1.
4 is fixed. When the take-up shaft 14 is rotated in the rewinding direction of the screen 16, the torsion coil spring 17 stores energy, and the stored force drives the take-up shaft 14 to rotate in the winding direction of the screen 16. It is like this.

A tubular rotator 18 is fitted and fixed inside one end of the winding shaft 14, and the rotator 18 is attached.
Is rotated integrally with the winding shaft 14. In the rotator 18, a braked body 19 is rotatably supported by the fixed shaft 15 via a spacer 20. The spacer 20 is formed in a tubular shape with an opening, and is rotatably supported on the fixed shaft 15 with a certain friction. The ridge 21 formed on the inner peripheral surface of the braked body 19 engages with the opening of the spacer 20 so that the braked body 19 is broken.
And the spacer 20 are integrally rotated. Therefore, the braked body 19 is rotatably supported on the fixed shaft 15 with a certain friction.

A cam groove 22 is formed on the outer peripheral surface of the braked body 19 within a range of about 148 degrees with respect to the center, and a cam 23 protruding from the inner peripheral surface of the rotator 18 is engaged with the cam groove 22. I am fit. As shown in FIG. 4, when the cam 23 is alternately moved in the opposite direction to the cam groove 22, the cam groove 22 orbits the engagement positions P1 to P4 in the cam groove 22 in order. Is configured as follows. Then, when the winding shaft 14 is rotated in the screen pulling direction by the urging force of the torsion coil spring 17, the cam 23 moves in the cam groove 22 in the direction of arrow A, and the winding shaft 1
4 is rotated in the screen pulling direction, the cam 2
3 moves in the cam groove 22 in the direction of arrow B. When the cam 23 moves in the cam groove 22 in the directions of arrows A and B, the braked body 19 moves in the directions of arrows C and D, that is, along the fixed shaft 15 in the axial direction.

Four engaging teeth 24 are formed at one end of the braked body 19 along the outer circumference of the braked body 19. The engaging teeth 24 are composed of a vertical surface 24a and a sloped surface 24b. It

In the rotator 18, a braking body 25 is supported on the fixed shaft 15. As shown in FIG. 3, the braking body 25 has an inner peripheral surface 30
A protrusion 26 is formed in a range of degrees, and a cutout portion 27 is formed on the outer peripheral portion of the fixed shaft 15 corresponding to the protrusion 26 in a range of 180 degrees with respect to the center. Therefore, the protrusion 26 can be moved within the range of the excision portion 27, and the braking member 25 can be moved.
Is rotatably supported on the fixed shaft 15 within a range of approximately 150 degrees with respect to the center.

A spring piece 28 is formed along the outer circumference of the braking body 25, and the projection 2 is formed at the tip of the spring piece 28.
9 are formed. The protrusion 29 elastically abuts the inner peripheral surface of the rotator 18 while having a predetermined frictional force. The frictional force is set to be smaller than the frictional force between the spacer 20 and the fixed shaft 15.

Therefore, in the braking body 25, the projection 26 has the cutout portion 2.
The range of movement from one end to the other end of 7, that is, about 15
It is adapted to rotate integrally with the rotator 18 or the braked body 19 in the range of 0 degree.

Engaging teeth 30 facing the engaging teeth 24 of the braked body 19 are formed on the braking body 25, and when the braking body 19 is moved toward the braking body 25, the engaging teeth 30 are formed. Two
4 and 30 mesh with each other. Engaging teeth 3
0 has the same shape as the engaging tooth 24.

Next, the operation of the roller blind clutch device constructed as described above will be described. Screen 1
When 6 is pulled down against the biasing force of the torsion coil spring 17, the cam 23 is positioned at either P1 or P3 shown in FIG. When the screen 16 is released with the cam 23 positioned at P3, the winding shaft 14 is rotated in the screen pulling direction by the biasing force of the torsion coil spring 17, and the cam 23 moves from the P3 position to the P4 position.

In this state, the engaging teeth 24 of the braked body 19
Does not mesh with the engagement teeth 30 of the braking body 25. Therefore, the winding shaft 14 is rotated by the biasing force of the torsion coil spring 17, and the screen 16 is wound up.

At this time, the braking body 25 rotates together with the rotator 18 until the projection 26 of the braking body 25 comes into contact with one end of the cutout portion 27 of the fixed shaft 15, and after the projection 26 comes into contact with one end of the cutout portion 27, The rotation is blocked and the rotator 18
Rotates idly while rubbing against the braking body 25.

Then, when the screen 16 is pulled down,
The cam 23 moves from the P4 position to the P1 position as the winding shaft 14 rotates. In this state, the engaging teeth 24,
Since 25 does not mesh with each other, the braked body 19 rotates around the fixed shaft 15, and the screen 16 is rewound from the winding shaft 14.

At this time, the braking body 25 rotates together with the rotator 18 until the projection 26 of the braking body 25 comes into contact with the other end of the cutout portion 27 of the fixed shaft 15, and after the projection 26 comes into contact with one end of the cutout portion 27, , Its rotation is blocked.

When the screen 16 is released after the screen 16 is pulled down to the desired position, the torsion coil spring 1
The winding shaft 14 is rotated in the screen pulling direction by the urging force of 7, and the cam 23 moves from the P1 position to the P2 position. Then, the braked body 19 rotates and the braking body 2 rotates.
5, the engaging teeth 24 mesh with the engaging teeth 30.

At this time, the braking member 25 has the engaging teeth 24, 30.
Rotate integrally with the rotator 18 until they engage with each other, and when the engaging teeth 24 start to engage with the engaging teeth 30, the braking body 25 rotates together with the braked body 19 and the engaging teeth 24 engage with the engaging teeth 30.
Mesh smoothly and deeply. Then, when the protrusion 26 of the braking body 25 reaches one end from the other end of the cutout portion 27 of the fixed shaft 15, further rotation of the braking body 25 is blocked, so that the braked body 19 and the winding shaft 14 rotate. Are blocked and the screen 16 is held in the desired position.

Accordingly, by the time the cam 23 reaches the P1 position to the P3 position and the rotation of the winding shaft 14 is blocked, at least the projection 26 of the braking body 25 of the winding shaft 14 is cut off.
After being reversed by 150 degrees or more, which is the angle from the other end to the one end, it is locked.

Then, when the screen 16 is pulled down,
When the winding shaft 14 is rotated, the cam 23 moves from the P2 position to the P3 position.
Move to the position. Then, the braked body 19 becomes the brake body 25.
The engagement teeth 24 and 30 are disengaged from each other. If the screen 16 is released from this state, the winding shaft 14 is rotated based on the biasing force of the torsion coil spring 17, and the cam 23 moves from the P3 position to the P4 position. At the P4 position, the engaging teeth 24 and 30 are held in a state where they do not mesh with each other, so that the winding shaft 14 winds up the screen 16 to the upper limit.

By repeating the above operation,
The screen 16 can be held at a desired position, and the screen 16 can be pulled up to the maximum upper limit by the biasing force of the torsion coil spring 17.

With the clutch device as described above, the following operational effects can be obtained. (B) When the cam 23 is positioned at P1, the screen 1
When 6 is released to engage the braked body 19 with the brake body 25, the brake body 25 rotates together with the rotator 18,
The braked body 19 also moves toward the braking body 25 while rotating together with the rotator 18.

Therefore, when the engagement teeth 24 and 30 are engaged with each other, there is almost no friction between the engagement teeth 24 and 30, so that the engagement teeth 24 and 30 can be smoothly engaged with each other. (B) Since the engaging teeth 24 and 30 are formed in a sawtooth shape from the vertical surface and the inclined surface, the meshing is further facilitated. (C) Since the engaging teeth 24 and 30 can be engaged with each other without generating friction, friction between the braked body 19 and the fixed shaft 15 moves the braked body 19 in the axial direction. Therefore, the operating force for pulling down the screen 16 can be reduced. (D) The cam 23 moves from the P1 position to the P2 position,
When the rotation of the winding shaft 14 is locked, at least after the braking body 25 and the winding shaft 14 are reversed by 150 degrees, the rotation of the braking body 25 is blocked and the winding body 19 meshed with the braking body 25 is wound. The take-up shaft 14 is locked.

Then, as shown in FIG. 6A, even when the winding shaft 14 is locked from the state where the screen 16 is pulled down to the lowest limit, as shown in FIG. 14 is locked at least 150 degrees reversed.

Therefore, in the subsequent operation, the screen 16
The winding shaft 14 is at least 1
Since the cam 23 is rotated by 50 degrees and the cam 23 is reliably moved to the P3 position, the locked state can be reliably released.

The angle of the cam groove 22 and the cutout portion 2
The angle of 7 is not limited to the angle described in the above embodiment, but can be set to any angle based on the diameters of the rotator 18, the braked body 19, and the like.

The technical ideas other than the claims that can be understood from the above-described embodiment will be described below along with their effects. (1) In claim 2, the braked body is rotatably supported on the fixed shaft through a spacer in a state of having a predetermined friction, and the friction means of the brake body includes the braked body and the fixed shaft. It was set to generate a friction smaller than that of. Since the braking body and the braked body mesh while rotating in the same direction, and the friction of the friction means is smaller than the friction between the braked body and the fixed shaft, the friction between the braked body and the fixed shaft is set small, It is possible to surely engage the braked body with the braking body while reducing the operating force. (1) In claim 1, engaging teeth are respectively provided on the braked body and the braking body, and the engaging teeth are formed in a sawtooth shape with a vertical surface and an inclined surface. The braked body and the braking body can be smoothly meshed with each other.

[0050]

As described above in detail, according to the present invention, the screen can be pulled out with a slight operating force, the winding of the screen can be reliably locked at the desired pulling position, and the screen can be pulled down to the lowest limit. It is possible to provide a roll blind clutch device in which the locked state can be reliably released by pulling the screen downward even when the screen is locked rearward.

[Brief description of the drawings]

FIG. 1 is a sectional view of a roller blind.

FIG. 2 is a perspective view showing a braked body and a braked body.

FIG. 3 is a cross-sectional view of a braking body.

FIG. 4 is a development view of a cam groove.

FIG. 5 is a cross-sectional view showing a state in which the braked body meshes with the braking body.

FIG. 6 is an explanatory diagram showing an operation of locking the screen after pulling it out to the lowest limit.

FIG. 7 is an explanatory diagram showing the operation of a conventional cam.

FIG. 8 is an explanatory diagram showing an operation of locking the screen after pulling it out to the lowest limit in the conventional example.

[Explanation of symbols]

11a, 11b Support member 14 Winding shaft 15 Fixed shaft 16 Screen 17 Drive source (torsion coil spring) 19 Braked object 22,23 Cam mechanism (cam groove, cam) 24, 30 Engaging tooth 25 Braking element 27, 28,29 Rotation allowance means (removal part, spring piece,
Projection)

Claims (4)

[Claims] 1. A winding source having a screen wound around a support member is rotatably supported, and a drive source for imparting a rotational force in a screen pulling direction to the winding shaft is provided in the winding shaft. A braking body is supported on a fixed shaft fixed to the support member in the take-up shaft, and a braked body having engaging teeth that mesh with the braking body is rotatably and axially movable on the fixed shaft. A cam mechanism is provided for supporting the braked body and the take-up shaft to reciprocate between a position where the braked body is engaged and a position where the braked body is not engaged while rotating the braked body based on the rotation of the take-up shaft. When the braked body does not mesh with the braking body, the winding shaft can rotate, and when the braked body meshes with the braking body, the rotation of the winding shaft can be blocked, and the braking body has the cam. The mechanism causes the braked body to bite from the position where it meshes with the braking body. A roll blind clutch device comprising rotation permitting means for allowing the braking member to rotate together with the winding shaft within a range of a rotation angle of the winding shaft required to move to a position that does not match. 2. The rotation permitting means generates a predetermined friction with the winding shaft to rotate the braking body integrally with the winding shaft, and a predetermined angle of the braking body. The clutch device for a roller blind according to claim 1, wherein the clutch device engages with the fixed shaft on the basis of rotation to prevent rotation of the braking body. 3. The friction means is provided on a spring piece formed along an inner peripheral surface of a rotator fitted in the winding shaft, and is provided at a tip end portion of the spring piece, and The clutch device for a roller blind according to claim 2, wherein the clutch device is formed of a protrusion that abuts on the peripheral surface. 4. The engaging means abuts on a cutout formed on the outer peripheral surface of the fixed shaft within a range of a predetermined angle and an end of the cutout based on rotation of the brake body at a predetermined angle. The clutch device for a roller blind according to claim 2, wherein the clutch device is formed of a projection.