JPS6334950B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clutch device used as a free stop mechanism for a roll blind.

There are two types of free stop mechanisms that use centrifugal force to stop the screen of a roll blind at a desired position, and those that do not. Although bones are required, those that do not use centrifugal force have the advantage of not requiring bones at all for operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a clutch device of a non-centrifugal free stop mechanism that is easy to operate.

In order to achieve the above object, the device of the present invention is characterized by a stop counter fixed to the fixed shaft of the roll blind or slidably fitted in the axial direction, a stopper provided on the stop counter, and the stop counter. a cylindrical cam rotatably fitted to a top counter; a heart-shaped cam groove carved on the outer periphery of the cam, the forked upper end and lower end of which extend in opposite circumferential directions; A ball hole in the center of the cam groove, a ball inserted into the ball hole, a U-shaped land portion surrounding the ball hole and corresponding to the forked end of the heart-shaped cam groove, and a roll that engages with the cam groove. It consists of a cam protrusion that is integrated with the pipe, and when the screen is released, the spring of the roll blind reverses the roll pipe and moves the cam protrusion from the forked end of the heart-shaped cam groove onto the ball hole, and the ball moves between the stopper and the cam. The reason is that the roll pipe is pinched by the protrusions to prevent further reversal of the roll pipe.

The apparatus of the present invention will be explained based on embodiments shown in the drawings. As shown in FIG. 1, an end block 2 is fixed to one end of a roll pipe 1, and a round shaft 3 is implanted in the block. The round shaft 3 is rotatably supported by a bracket (not shown). A clutch case 4 is fitted to the other end of the roll pipe 1, and the clutch case is rotatably fitted to a fixed shaft 7 via a bearing receiver 5 and a bearing ball 6. A spring core 9 is fixed to the tip of the fixed shaft 7 with a rivet 8, and a spring mount 25 is fixed to the spring core with a rivet 10. A cover 11 is placed over the spring core, and the position is determined using a collar 12. Both ends of the spring 13 are locked to the clutch case 4 and spring mound 25, respectively.

As shown in FIGS. 1 and 2, a stop counter 14 is spline-coupled to the fixed shaft 7 so as to be slidable in the axial direction, and a cam 15 is rotatably fitted onto the stop counter. Stoppers 16 are protrudingly provided on the circumference of the center of the stop counter 14 at equal arc intervals. The cam cover 17 is fixed to the cam 15 via the setscrew 23, and the stop counter 14 is fixed to the cam 15.
and slide it in the axial direction. A heart-shaped cam groove 18 is carved in the center of the circumferential surface of the cam 15, and a ball hole 19 is provided in the center of the cam groove 18. ball hole 1
9 and the stopper 16 of the stop counter 14 are located on the same cross section. The thickness of the bottom of the cam groove 18 and the height of the stopper 16 are approximately equal to the radius of the ball 20 that fits into the ball hole 19. A cam projection 21 is fixed to the inner peripheral surface of the clutch case 4, and the cam projection 21 is fitted into the cam groove 18. roll pipe 1
When rotates, the cam protrusion 21 connects the stop counter 14, cam 15, and ball 20 via the cam groove 18.
slide in the axial direction as a unit.

As shown in FIG. 3 when the circumferential surface of the cam 15 is expanded, the cam groove 18 has an elongated heart shape, and has a U-shaped land portion 22 in the center. A ball hole 19 is provided between the land portions 22, and a ball 20 is fitted into the ball hole.

As shown in FIG. 4, the stopper 16 of the stop counter 14 is spline-coupled to the fixed shaft 7.
are arranged at equal arc intervals and protrude by a height corresponding to the radius of the ball 20. Since the thickness of the bottom of the cam groove 18 is approximately equal to the radius of the ball 20, the ball hole 1
Ball 20 unless 9 and stopper 16 match.
The cam projections 21 do not come into contact with each other in the circumferential direction. The cam protrusion 21 has a columnar shape from the base to half its height, but is sloped from that point to the tip. The cam projection 21 slides on the peripheral wall of the cam groove 18 with its columnar portion.

Next, a free stop using the apparatus of the present invention will be explained. When the screen of the roll blind is pulled out, the roll pipe 1 rotates in the direction of arrow A in FIG. 4, and the cam protrusion 21 is at the position a in FIGS. At this time, even if the ball hole 19 is directly above the stopper 16, the ball 20 will not be able to reach the cam 1 as shown in FIG.
5 escapes radially outward, so the cam 15
, that is, the rotation of the roll pipe 1 is not prevented.

When the screen is then released, the spring 13 in FIG. 1 rotates the roll pipe 1 in the direction of arrow B in FIG. 4, so that the cam projection 21 comes to point b in FIG. At this time, when the stopper 16 comes under the ball hole 19, as shown in FIG. 6, even if the ball 20 tries to escape to the outside, it cannot escape because of the cam protrusion 21. Therefore, the rotation of the cam protrusion 21 is prevented by the stopper 16 via the ball 20, so that the rotation of the roll pipe 1 is restrained, and the drawn-out screen is stopped at that position.

From there, pull the screen a little and release it, and the screen can easily be rolled up. When the screen is pulled a little, the cam protrusion 21 reaches point c in Figure 3, and when the screen is released, the spring 1 in Figure 1
3 rotates the roll pipe 1 in the direction B in FIG. 4, the cam projection 21 reaches point d in FIG. 3. At this time, the top of the ball hole 19 is always open, and each time the stopper 16 comes below the ball hole while the roll pipe 1 is rotating, the ball 20 escapes outward, so the rotation of the roll pipe 1 is caused by the stopper 16 Undeterred, the screen rolls up.

Although the stop counter in the embodiment is slidably mounted on the fixed shaft, it is also possible to completely fix the stop counter on the fixed shaft. Also, instead of protruding the stopper from the stop counter, a cylindrical stop counter 1 is used as shown in FIG.
A groove 24 with a depth corresponding to the radius of the ball is formed on the circumferential surface of the ball 4.
may be carved at equal arc intervals. In this case, the partition wall 16 between circumferentially adjacent grooves becomes a stopper.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main parts of a roll blind equipped with a device according to an embodiment of the present invention, and FIG.
Figure 3 is a developed view of the cam groove in Figure 2, Figure 4 is a sectional view taken along the - line in Figure 1, Figure 5 is a partial enlargement of Figure 4. 6 is a diagram corresponding to FIG. 5 showing the state of the clutch during braking, and FIG. 7 is a perspective view of a stop counter of another embodiment. 1: Roll pipe, 7: Fixed shaft, 14: Stop counter, 15: Cam, 16: Stopper, 1
8: Cam groove, 19: Ball hole, 20: Ball, 2
1: cam protrusion, 22: land part.

Claims (1)

[Scope of Claims] 1. A stop counter is fitted onto a fixed shaft so as to be fixed or slidable in the axial direction, a stopper protruding in the radial direction is provided on the stop counter, and a cylindrical cam is provided on the stop counter. is rotatably fitted, a heart-shaped cam groove is carved on the outer periphery of the cam, and the bifurcated upper and lower ends extend in opposing circumferential directions, and a ball hole is formed in the center of the cam groove. A ball is inserted into the hole, a U-shaped land portion surrounding the ball hole is provided in the cam groove corresponding to the upper end of the heart-shaped fork, and a cam protrusion integrated with the roll pipe is inserted into the cam groove. When the cam is moved in the axial direction by engaging the cam and the screen of the roll blind is released, the cam protrusion enters between the land portions of the cam groove and presses the ball in the ball hole. When the rotation of the roll pipe is stopped by being sandwiched between the stopper and the cam protrusion and the screen is pulled out, the cam protrusion comes out from between the land portions and releases the balls outward in the radial direction. A clutch device for a roll blind characterized in that it rotates without being restrained by a stopper. 2. A clutch device for a roll blind according to claim 1, wherein the height of the stopper and the thickness of the bottom of the cam groove are each approximately equal to the radius of the ball.