JPH0354551Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of an operating shaft rotation restraining device for a Venetian blind.

[Prior art] The operating shaft is horizontally supported in the head box,
Venetian blinds use a method in which a winding drum is inserted into the operating shaft, the upper end of a lifting cord is fixed to the winding drum, and the lifting cord is wound onto the winding drum and then unwound to raise and lower the slats. If the bottom rail or slat hits an obstacle while the slat is lowering, not only will the lowering of the hit side stop and the slat will go down on one side, but the lifting cord on the side that stopped will become loose and the winding will not be normally wound on the winding drum. If the film is not rewound, it may cause a malfunction.

In order to eliminate this drawback, a device was developed in 1973 that stops the rotation of the operating shaft when the bottom rail or slat hits an obstacle and the lifting cord becomes loose.
−129152, Utility Model No. 55-96298, Utility Model Kai No. 1987-
Disclosed in No. 135490. In those devices, a ratchet wheel or the like is fixed to the operating shaft, and a pawl that engages with the ratchet wheel is hooked onto a lifting cord. When the lifting cord is tensed, the pawl separates from the ratchet wheel, and when the cord is relaxed, it engages. Since the claws slide horizontally or vertically by friction, there are variations in operation, and reliability and responsiveness cannot always be said to be good. It is also disclosed in Japanese Utility Model Application No. 60-129487 that the claws are rotated instead of sliding, but the member with the claws is extended on both sides around the axis of rotation, with the lifting cord on one side and the claw on the other side. Since they each engage with the vehicle, the structure is complicated and the cost is high.

[Problems to be solved by the invention] The invention was made to solve the above problems, and its purpose is to connect the pawl to the pawl on the operating shaft using a rotating mechanism that has stable operation and good responsiveness. To provide an operating shaft rotation regulating device for a Venetian blind that engages with a vehicle, which has a simple structure and is easy to manufacture and assemble.

[Means for Solving the Problems] In order to achieve the above object, the features of the present invention are such that a stopper is rotatably fixed to a bracket that supports a ratchet wheel, and the stopper is rotated upward. The stopper is provided with a pawl that engages with the ratchet wheel, and a guide roll for passing the lifting cord is attached to the position lined up with the pawl.When the lifting cord becomes tense and the stopper is rotated downward, the pawl When the ratchet wheel comes off and the lifting cord is relaxed and the stopper rotates upward due to the repulsive force of the spring, the pawl and the ratchet wheel engage to prevent the lifting cord from rewinding on the operating shaft. .

[Operation] In the device of the present invention, the stopper rotates upward by the repulsive force of the spring to engage the pawl and ratchet wheel. Since there is no frictional sliding during its rotation, the operation is quick and reliable. When the lifting cord becomes slack, that is, when the slat or bottom rail hits an obstacle, the stopper immediately rotates to stop the rotation of the operating shaft.
Responsiveness and stability are extremely good. If the spring is a leaf spring, it can be molded integrally with the stopper, and since the guide rolls and pawls are arranged on both sides of the stopper, the structure is simple and assembly is easy.

[Example] The apparatus of the present invention will be described based on an example shown in the drawings. As shown in FIG. 1, the operating shaft 10 of the Venetian blind is arranged horizontally inside the top box 13, and the winding drum 12 rotates together with the operating shaft, but can freely slide in the axial direction. mounted on. The lifting cord 14 is wound around the circumferential surface of the winding drum 12, and a male thread is provided on the circumferential surface. Similarly, a winding drum cover 15 is integrally fixed to the operating shaft 10, and the winding cover 15 is rotatably supported by a bracket 11 fixed to the top box 13. The bracket 11 is provided with a screw hole 22 into which the winding drum 12 is inserted, and is engaged with a male thread on the circumferential surface of the winding drum 12.
A stopper 17 is rotatably attached to the end surface of the bracket 11 on the side into which the winding drum 12 is inserted. The stopper 17 is provided with a guide roll 19 on which the lifting cord 14 is hung.

A ratchet wheel 16 is provided at the tip of the winding drum cover 15, and a pawl 26 at the tip of a stopper 17 is attached to the ratchet wheel.
are set so that they interlock. The ratchet wheel 16 is rotatably fitted into the cylindrical portion 25 of the bracket 11 outside the screw hole 22. The lifting cord 14 whose upper end is fixed to the winding drum 12 is unwound on the end face of the bracket 11 and pulled out downward from the top box 13 via the guide roll 19.
The lower end of the bottom rail 4 passes through the slat 30.
It is fixed at 0. A ladder cord 20 for tilting the slat 30 is slidably hung on the circumferential surface of the winding drum cover 15. Since the winding drum 12 is screwed into the screw hole 22 of the bracket 11, when the operating shaft 10 is turned in one direction as shown by the arrow, the winding drum 12 winds up the lifting cord 14 and closes the winding drum cover. When the winding drum 12 is removed from the winding drum cover 15 and turned in the opposite direction, the winding drum 12 enters the winding drum cover 15 while rewinding the lifting cord 14.

As shown in FIG. 2, the operating shaft 10 is a square shaft, and a square hole 21 of the winding drum 12 is slidably fitted into the square shaft. The bracket 11 includes upright walls 31 and 32 arranged in the direction in which the operating shaft 10 extends, and a screw hole 22 is provided in the upright wall 31 on the winding drum 12 side, and a nail 26 of the stopper 17 is inserted below the screw hole 22. A hole 28 is drilled. The stopper 17 is rotatably attached to the end surface of the upright wall 31 of the bracket 11 on the winding drum 12 side via a rivet 23. The stopper 17 is made of synthetic resin and has a leaf spring 18 integrally molded therein, and has a box portion 24 that rotatably supports the guide roll 19 therein, and a ratchet wheel 26 that projects from the box portion toward the bracket 11 side. The bracket 11 is provided with a spring receiver 27, and the stopper 17
When the plate spring 18 is pivoted to the bracket 11, the leaf spring 18 pushes the entire stopper 17 upward by the spring receiver 27. The claw portion 26 enters the claw hole 28 of the bracket 11 and is located between the two upright walls 31,32.
The bottom plate 33 of the bracket 11 is provided with a cord hole 29 through which a lifting cord is passed. A ratchet wheel 16 and a flange 34 are integrally formed at the tip of the winding drum cover 15 which is fitted to the operating shaft 10 for integral rotation, and the tip is connected to a cylindrical portion 35 forming the screw hole 22 of the upright wall 31. Fits freely in rotation. The pawl 16 and the flange 34 fit between the upright walls 31 and 32 to determine the axial position of the take-up drum cover 15. The rotation of the operating shaft 10 causes the winding drum 12 to move in and out of the winding drum cover 15 while rotating. When the winding drum 12 enters the winding drum cover 15, the lifting cord 14 is unwound and the slats are lowered, and when the winding drum 12 comes out of the winding drum cover 15, the lifting cord 14 is wound up and the slats are lowered. will rise. The ratchet wheel 16 and pawl 26 are formed so that, when engaged, they restrict the rotation of the operation shaft 10 in the direction of rewinding the lifting cord 14, but do not restrict the rotation of the lifting cord 14 in the direction of winding it up.

Next, the rotation control of the operating shaft 10 by the device of the present invention will be explained with reference to FIGS. 3 and 4.

As shown in FIG. 3, when the lifting cord 14 is under tension, the lifting cord 14
Rotate the stopper 17 downward through the pawl 26.
is pulled away from the ratchet wheel 16, so the ratchet wheel 16, that is, the operating shaft 10, rotates freely.

When the slat or bottom rail hits an obstacle and stops descending, the lifting cord 14 relaxes, as shown in FIG. When the lifting cord 14 is loosened, the stopper 17 rotates upward due to the elastic repulsive force of the leaf spring 18, and the pawl 26 engages with the ratchet wheel 16.
Rotation of the operating shaft 10 in the direction of rewinding the lifting cord 14 is restrained.

As shown in FIG. 2, a stopper 17 provided with a pawl 26 is formed integrally with a leaf spring 18 and is fixed via a rivet 23 to a bracket 11 that supports the winding drum 12, and a guide roll 19 is also attached to the stopper. Therefore, the device of the present invention has a simple structure and is easy to assemble. Since the stopper 17 rotates around the rivet 23, the operation is stable and quick, and the response is very good.As soon as the slat or bottom rail hits an obstacle and the lifting cord 14 becomes slack, the operation shaft will stop rotating. be stopped. Therefore, even if the obstacle is removed and the slat is lowered again, a one-sided descent will not occur. Furthermore, when the operating shaft 10 is reversely rotated, the lifting cord 14 is normally wound onto the winding drum. The spring does not necessarily have to be molded integrally with the stopper, nor is it particularly necessary to be limited to a leaf spring. Although not shown, a coil spring may be inserted between the stopper 17 and the spring receiver 27, or a coil spring may be applied between the stopper 17 and the bracket 11 so that the stopper is pulled up by the spring.

[Effects of the invention] As mentioned above, the device of the present invention differs from the conventional device in which the stopper slides frictionally to engage the pawl with the ratchet wheel of the operation shaft, whereas the stopper rotates and engages the pawl with the ratchet wheel of the operating shaft. operation is quick and reliable,
Excellent responsiveness. Also, unlike the known stopper which has a pawl on one side of the rotating shaft and a lifting cord hook on the other side, the stopper pawl and the guide roll are arranged on the same side, so the structure is simple. It is also easy to manufacture and assemble.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the main parts of a Venetian blind equipped with a device according to an embodiment of the present invention, Fig. 2 is an exploded perspective view of the device shown in Fig. 1, and Figs. 3 is a cross-sectional view of the device shown in FIG. 1, FIG. 3 shows a state when the rotation of the operating shaft is not restrained, and FIG. 4 shows a state when the rotation is restrained. In the figure, reference numeral 10 is an operating shaft, 11 is a bracket, 12 is a winding drum, 13 is a top box, 14 is a lifting cord, 15 is a winding drum cover, 16 is a ratchet wheel, 17 is a stopper, 18 is a leaf spring, 19 is a guide roll, 22 is a screw hole, 25 is a cylindrical part, 26 is a pawl, 27 is a spring receiver, 28 is a pawl hole,
31 each indicate an upright wall.

Claims (1)

[Claims for Utility Model Registration] 1. An operating shaft disposed horizontally within a top box, a winding drum integrally rotatable and slidably fitted to the operating shaft, and a male thread of the winding drum. a lifting cord that is wound around the circumferential surface of the winding drum to raise and lower the slat; a bracket that is fixed to the top box and has a screw hole that engages with the external thread of the winding drum; and a bracket that is rotatably fitted to the operating shaft. and a winding drum cover whose position in the axial direction is determined by the bracket, wherein a stopper is rotatably pivoted below the threaded hole on the end surface of the bracket on the side into which the winding drum is screwed. A guide roll is attached to the stopper, a lifting cord is hung on the guide roll, and a claw protrudes from the end surface of the bracket toward the screw hole side at a position of the stopper in line with the guide roll. a cylindrical part coaxial therewith is formed outside the screw hole of the bracket, the tip of the winding drum cover is rotatably fitted into the cylindrical part, and the tip of the winding drum cover An operating shaft rotation restraining device for a Venetian blind, characterized in that a ratchet wheel is formed, and when the pawl and the ratchet wheel are engaged, rotation of the lifting cord in the unwinding direction is restrained. 2. Claims for registration of a utility model characterized in that a leaf spring is integrally formed on the stopper, a leaf spring receiver is provided on the bracket, and the stopper is rotated upward by the elastic repulsive force of the leaf spring. The operating shaft rotation control device for a Venetian blind as described in item 1. 3. A cylindrical part with a screw hole is formed in the upright wall of the bracket, a stopper is attached to the end face of the upright wall via a rivet, and a nail hole is drilled below the screw hole in the upright wall, and the stopper is inserted from there. A slat operation shaft rotation restraining device for a Venetian blind according to claim 2, characterized in that a claw projects downward from the cylindrical portion. 4. A slat operating shaft rotation inhibiting device for a Venetian blind as claimed in claim 1 of the registered utility model claim, characterized in that a coil spring is interposed between the bracket and the stopper to rotate the stopper upwardly. .