JPH0145356Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a support structure for supporting the upper end of a ladder cord that supports the slats of a blind in a head box.

PRIOR ART Ladder cords are usually supported on supports within a headbox. The support part is composed of a coil spring or the like made of a wire with a circular cross section, and is wound around a support shaft that is fitted so as not to rotate relative to the drive shaft for raising/lowering and adjusting the angle of the slat that passes through the head box. A ladder cord is connected to both ends of the coil spring. The coil spring is provided so that friction is generated between the coil spring and the support shaft due to its contraction force toward the center, and as the support shaft rotates, the coil spring is rotated and the slat is tilted. Furthermore, when the slat is tilted to a nearly vertical position, the rotation of the coil spring is restricted to create idle rotation between the coil spring and the support shaft, allowing the slat to move up and down with it closed. .

In such a ladder cord support structure,
Since the coil spring is made of metal, the coefficient of friction is originally low. Moreover, since the coil spring is made of a wire rod having a circular cross section, the contact with the drive shaft is a line contact and the contact area is small. Therefore, the frictional force between the drive shaft and the coil spring is extremely small.
However, in order to adjust the angle of the slat and reliably support it at the desired angle, it is necessary to increase the friction between the coil spring and the support shaft. It is necessary to grip the drive shaft with strong force.
If this is done, it becomes difficult for the spiral spring to rotate idly, and a large operating force is required when lifting or lowering the slat when it is idle, making it difficult to achieve both reliability of slat support and ease of lifting and lowering the slat. Ta.

Purpose The purpose of this invention is to provide a ladder cord support structure with a simple configuration that can stably support a slat at a desired angle and can raise and lower the slat with a slight operating force.

Composition of the Device This device has an arm portion 13 that protrudes from the center tube portion 12 of the cord hook 10 made of a flexible synthetic resin material, shifted to the right in both front and back directions, and has a A separation groove 11 is provided in the tube section 12 so that the inner diameter of the tube section 12 can be expanded and contracted by bending the arm section 13, and the drive shaft 8 is inserted into the tube section 12 of the cord hook 10 in the head box 2. At the same time, arm 1
A blind ladder cord 3 is suspended from the tip of the blind ladder cord 3, and a large frictional force is always interposed between the cord hook 10 and the drive shaft 8 so that the cord book 10 and the drive shaft 8 cannot rotate relative to each other. A regulating piece 7a that comes into contact with the tip of the arm 13 of the cord hook 10 and restricts the rotation of the cord hook 10 is protruded to a lower position of the tube 12, and as the drive shaft 8 and the cord hook 10 rotate together, the arm of the cord hook 10 is rotated. Part 1
3 comes into contact with the regulating piece 7a, the inner diameter of the tube portion 12 is expanded by rotation of the drive shaft 8,
The structure is configured such that the frictional force is reduced to allow relative rotation between the tube section 12 and the drive shaft 8, and the contact surfaces of the tube section 12 and the arm section 13 with the drive shaft 8 are arranged so that the contact surfaces of the tube section 12 and the arm section 13 with the drive shaft 8 are The arm portion 13 has a curved planar shape along the outer circumferential surface, and the tip of the arm portion 13 largely protrudes from the outer circumferential surface of the drive shaft 8.

Embodiment Hereinafter, an embodiment of this invention will be described with reference to the drawings.A blind 1 has a multi-stage slat 4 supported by a ladder cord 3 suspended from both sides of a head box 2. A bottom rail 5 is suspended from the lower end of the ladder cord 3. A lifting tape 6 suspended from the head box 2 is located near the ladder cord support portion of each slat 4.
are penetrated through each, and the lower end of the lifting tape 6 is connected to the bottom rail 5.

The suspension support structure for the ladder cord 3 and the lifting tape 6 in the head box 2 will be explained with reference to FIG. Both ends of a pulley shaft 8 serving as a molded drive shaft are rotatably supported. A rectangular bar-shaped rotating shaft 9 is fitted into the pulley shaft 8 so as not to be relatively rotatable, and one end of the rotating shaft 9 is connected to an output shaft of a motor (not shown) which is capable of forward and reverse rotation. Therefore, the pulley shaft 8 is designed to rotate forward or reverse as the motor operates. The motor is operated by an operation switch S (see FIG. 1) provided on one side of the blind.

A cord hook 10 is fitted into one end of the pulley shaft 8, and the upper end of the ladder cord 3 is connected to both front and rear ends of the cord hook 10. The details of the cord hook 10 will be explained with reference to FIGS. 3 to 6. The cord hook 10 is molded from nylon, and has a tube portion 12 formed in the center thereof into which the pulley shaft 8 can be inserted. The tube part 12
The upper half is divided into left and right parts by a separation groove 11, and symmetrical arm parts 13 protrude from the upper part diagonally downward in the front and rear directions, respectively, from the outer peripheral surface of the pulley shaft 8. A locking groove 14 is provided at the tip of the arm portion 13. Also, pipe part 1
The inner surfaces of the pulley shaft 2 and the arm portion 13 are curved planes along the outer peripheral surface of the pulley shaft 8.

As shown in FIG. 7, the cord hook 10 configured in this manner has a pulley shaft 8 fitted into its tube portion 12, and the upper ends of the ladder cords 3 are respectively latched into the locking grooves 14 of the arm portions 13. There is. and,
When the weight of each slat 4 and bottom rail 5 acts on the tip of the arm 13 via the ladder cord 3,
The arm portion 13 bends downward to reduce the inner diameter of the tube portion 12, and the contact area between the inner surface of the arm portion 13 and the pulley shaft 8 increases.
The friction between the inner peripheral surface of the tube portion 12 and the pulley shaft 8 increases, and as the pulley shaft 8 rotates, the cord hook 10 is rotated integrally.

Below the cord hook 10, a regulating piece 7a that restricts the rotation of the cord hook 10 is projected upward from the center of the bottom surface of the support box 7. When the cord hook 10 is rotated to a nearly vertical position, the tip of the arm 13 comes into contact with the regulating piece 7a, as shown in FIG. 8, and further rotation of the cord hook 10 is prevented. ing.

As shown in FIG. 2, a pulley 15 is integrally formed on the other end of the pulley shaft 8, and the pulley 15
An elevating tape 6 is wrapped around 5. The lifting tape 6 is wound up or rewound by forward or reverse rotation of the pulley 15 as the motor operates, and the bottom rail 5 and each slat 4 are raised and lowered.

As shown in FIG. 2, the lower end of the support box 7 extends to both the left and right sides, and is inserted into an insertion hole 18 having an oval cross section formed between the extension and the covers 16 and 17 that are fitted from above. A support shaft 19 is inserted so as to be movable back and forth. A roller 20 is rotatably supported at a position below the pulley 15 of the support shaft 19, and a lifting tape 6 suspended from the pulley 15 is hung on the roller 20.

Spring bearings 21 are formed near both ends of the support shaft 19 to extend the insertion hole 18 back and forth.
As shown in Figure a, coil springs 22 are respectively disposed in spring receivers 21 on both front and rear sides of the support shaft 19, and the support shaft 19 is supported between both coil springs 22. And lifting tape 6
When the weight of the bottom rail 5 and slat 4 is acting on the roller 2, as shown in FIG.
Since a horizontal force F acts on 0, Fig. 11a
As shown in , the support shaft 19 is moved in one direction within the insertion hole 18 against the urging force of the coil spring 22,
When the weight of the bottom rail 5 and slat 4 does not act on the lifting tape 6, the coil spring 22
The supporting shaft 19 is positioned at the center of the insertion hole 18 due to the urging force.

As shown in FIG. 2, a switch box 23 is disposed within the head box 2 at a position adjacent to the support box 7. As shown in FIG. Then, as shown in FIG. 9, one end of the support shaft 19 is projected between two sets of contacts 24 provided in the switch box 23, and the back and forth movement of the support shaft 19 causes the contact 25 of the contactor 24 to move. We're starting to come into contact. In addition, when the contact point 25 is in contact, the motor is operated in the blind lowering direction by operating the operation switch S.

In FIG. 2, a lever 26 that hangs down from the switchbox 23 to the outside of the headbox 2 is rotatably supported by a shaft 27 within the switchbox 23. As shown in FIG. When the slat 4 is raised and the uppermost slat 4 pushes up the tip of the lever 26, the base end of the lever 26 presses the push button 28a of the push switch 28 to stop the operation of the motor in the direction of raising the slat. It's getting old.

Next, the operation of the blind constructed in this way will be explained.

When pulling up the slat 4 of the blind 1, when the motor is operated in the slat lifting direction using the operation switch S, the rotating shaft 9 is rotated, the rotation is transmitted to the pulley shaft 8, and the lifting tape 6 is wound around the pulley 15. The bottom rail 5 is pulled up, and the slats 4 are pulled up in order from the bottom by the bottom rail 5. Then, when the uppermost slat 4 is pulled up and the lever 26 is pushed upward, the push switch 28 is activated and the motor is stopped.

Therefore, if the operation switch S is continued to be operated in the slat upward direction, the motor will be automatically stopped when the blind 1 is raised to the maximum limit, that is, until the uppermost slat 4 approaches the lower surface of the head box 2.

When lowering the slat 4 that has been pulled upward, operate the operation switch S to operate the motor in the direction of lowering the slat 4. The lifting tape 6 wound around the pulley 15 is rewound, and the bottom rail are gradually lowered and supported by the ladder cord 3 in order from the upper slat 4. Then, the bottom rail 5 is lowered to the lowest limit, and from the state where it is suspended by the ladder cord 3, the pulley 1
5 is rotated, the lifting tape 6 becomes loose, so that the weight of the bottom rail 5 and the slat 4 does not act on the lifting tape 6, and no force in the direction of the arrow F acts on the roller 20. Then, the 10th
As shown in the figure, the support shaft 19 is moved to the center of the insertion hole 18 by the urging force of the coil spring 22.
Along with this, the pressure on the contactor 24 by the tip of the support shaft 19 is released, the contact point 25 is separated, and the operation of the motor in the downward direction of the slat is stopped. Therefore, even if the operation switch S is continued to be operated in the direction of lowering the slat, the bottom rail 5 reaches the lowest limit and the blind 1
When the is fully closed, the motor operation is automatically stopped.

Furthermore, even if the bottom rail 5 comes into contact with some kind of obstacle before reaching the lowest limit, the lifting tape 6 will loosen in the same way as when the bottom rail 5 reaches the lowest limit, and the motor operation will be automatically stopped. .

In such a blind raising/lowering operation, the seventh
As shown in the figure, when the cord hook 10 is held horizontally and each slat 4 is held horizontally via the ladder cord 3 and starts moving up and down, the slats 4 and bottom rail 5 are attached to both ends of the cord hook 10. As the weight acts and the diameter of the tube portion 12 is reduced, the contact area between the arm portion 13 and the pulley shaft 8 increases, the frictional force between the two 13 and 7 increases, and as the pulley shaft 8 rotates. Tsute cord hook 1
0 are rotated together. That is, since the inner circumferential surface of the tube portion 12 is flat, the inner circumferential surface and the pulley shaft 8
There is a surface contact with the slat 4, and the point of application of the weight with the slat 4 is the arm part 13 which is separated from the pipe part 12.
Since it is at the tip, a large moment acts on it, causing a large amount of friction between the cord hook 10 and the pulley shaft 8, and the contact area between the arm 13 and the shaft 8 increases. Since nylon has a high coefficient of friction, the pulley shaft 8 is made of synthetic resin, and both 8,
The frictional force between the cord hooks 13 is larger than when one of them is made of metal, so that there is no slippage between the two, and the cord hook 10 is reliably rotated as the rotating shaft 9 rotates, and at the same time the slat 4 is tilted. be done. In this specification, the fact that the tip of the arm portion 13 largely protrudes from the outer circumferential surface of the pulley shaft (drive shaft) 8 means that the arm portion 13 can be bent downward, and due to the bending, the arm portion 13 This is the amount of protrusion that increases the contact area with the pulley shaft 8.

When the cord hook 10 is tilted to a nearly vertical position, the arm portion 13 as shown in FIG.
The tip comes into contact with the regulating piece 7a of the support box 7, and further tilting is prevented. At this time, the regulating piece 7
A reaction force acts in the direction of arrow A on the arm 13 that abuts a, and a force in the direction of arrow B acts on the other arm 13 due to the rotational force of the pulley shaft 8. Since these forces act in the direction of bending the arm portions 13 in the directions of arrows A and B, respectively, and expanding the inner diameter of the tube portion 12, the friction between the inner peripheral surface of the tube portion 12 and the pulley shaft 8 is reduced, and the cord hook 10 The pulley shaft 8 is in a state where idle rotation is likely to occur.

Therefore, when the cord hook 10 is not in contact with the regulating piece 7a, a large frictional force acts between the cord hook 10 and the pulley shaft 8, and no idle rotation occurs, so the motor is operated to move the slat 4. Even when the angle is adjusted obliquely, the cord hook 10 and the pulley shaft 8 do not slip, and can be reliably held at a desired position.
When the cord hook 10 comes into contact with the regulating piece 7a, the friction between the cord hook 10 and the pulley shaft 8 decreases, and in order to make it easy for idle rotation to occur between the two, the load on the motor during the slat lifting operation is reduced. It is possible to reduce current consumption, prevent motor deterioration, etc. Note that the ladder cord support structure as described above is not limited to electric blinds.
It can also be applied to manually operated blinds.

Effects As detailed above, this invention has an arm portion 13 that protrudes from the center tube portion 12 of the cord hook 10 made of a flexible synthetic resin material and is shifted to the right in both front and rear directions. A separation groove 11 is provided in the tube section 12 between the arm sections 13 so that the inner diameter of the tube section 12 can be expanded and contracted by bending of the arm section 13, and the cord hook 10 is driven into the tube section 12 within the head box 2. At the same time as the shaft 8 is inserted, the ladder cord 3 of the blind is suspended from the tip of the arm portion 13, and a large frictional force is always interposed between the cord hook 10 and the drive shaft 8 to connect the cord hook 10 and the drive shaft 8. A regulating piece 7 configured to be relatively unrotatable and abuts against the tip of the arm portion 13 of the cord hook 10 to restrict rotation of the cord hook 10.
a to the lower position of the tube portion 12, and when the tip of the arm portion 13 of the cord hook 10 comes into contact with the regulating piece 7a as the drive shaft 8 and the cord hook 10 rotate together, the rotation of the drive shaft 8 causes the tube to close. The inner diameter of the section 12 is enlarged, the frictional force is reduced, and relative rotation between the tube section 12 and the drive shaft 8 is permitted. The frictional force between the cord hook 10 and the drive shaft 8 is reduced by making the contact surface of the cord hook 10 have a curved plane shape along the outer circumferential surface of the drive shaft 8, and by making the tip of the arm portion 13 largely protrude from the outer circumferential surface of the drive shaft 8. becomes larger and when the cord hook 10 does not come into contact with the regulating piece 7a, it is possible to stably support the slat 4 at a desired angle, and when the slat is raised or lowered, the tip of the arm 13 comes into contact with the regulating piece 7a, and the same occurs. The friction between the cord hook 10 and the drive shaft 9 is reduced, and it is possible to provide a ladder cord support structure for a blind with a simple configuration, which allows the slat 4 to be raised and lowered with a slight operating force.

[Brief explanation of the drawing]

Figure 1 is a front view of a blind related to this invention, Figure 2 is a front view of a ladder cord support structure embodying this invention, Figure 3 is a front view of a cord hook, Figure 4 is a plan view of the cord hook, and Figure 5 is a front view of a ladder cord support structure embodying this invention. Figure 6 is a side view of the cord hook, Figure 6 is a central vertical sectional view of the cord hook, Figure 7 is a sectional view showing the cord hook in use, Figure 8 is a sectional view showing the cord hook in a tilted state, and Figure 9 is a sectional view of the cord hook. A plan view showing the inside of the switchbox, Figures 10a, b, and 11a, b are a plan view and sectional view showing the operating state of the support shaft, and Figure 12 is a schematic diagram showing the relationship between the support shaft and the lifting tape. It is a diagram. 1...Blind, 2...Headbox, 3
...Ladder code, 7...Support box, 7a...
...Regulation piece, 8... Drive shaft, 10... Cord hook, 12... Pipe section, 13... Arm section.

Claims (1)

[Scope of utility model registration request] An arm portion 13 protrudes from the center tube portion 12 of the cord hook 10 made of a flexible synthetic resin material, shifted to the right in both front and back directions, and a separation groove 11 is provided in the tube portion 12 between both arm portions 13. is provided so that the inner diameter of the tube section 12 can be expanded and contracted by bending the arm section 13, and the head box 2
Inside, the drive shaft 8 is inserted into the tube part 12 of the cord hook 10, and the ladder cord 3 of the blind is suspended from the tip of the arm part 13, so that a large frictional force is always maintained between the cord hook 10 and the drive shaft 8. The cord hook 10 and the drive shaft 8 are interposed so that they cannot rotate relative to each other, and the arm portion 1 of the cord hook 10
A regulating piece 7a that contacts the tip of the cord hook 10 and restricts the rotation of the cord hook 10 is projected to a lower position of the tube portion 12, and as the drive shaft 8 and the cord hook 10 rotate together, the tip of the arm portion 13 of the cord hook 10 is When it comes into contact with the regulating piece 7a, the inner diameter of the tube portion 12 is expanded by the rotation of the drive shaft 8, and the frictional force is reduced to allow relative rotation between the tube portion 12 and the drive shaft 8. In addition, the contact surfaces of the tube portion 12 and the arm portion 13 with the drive shaft 8 are made into a curved plane shape along the outer peripheral surface of the drive shaft 8, and the arm portion 1
A ladder cord support structure for a blind, characterized in that the tip of the cord 3 protrudes largely from the outer peripheral surface of the drive shaft 8.