JPS6237918Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blind lifting device, and more particularly to a blind lifting device in which the blind is automatically lowered by its own weight.

BACKGROUND OF THE INVENTION In recent years, a type of blind has been commonly used in which both raising and lowering and tilting of the blind are performed by a single operating means such as an operating cord or an operating chain. In this type of blind, a winding drum for winding the lifting cord is attached to the lifting shaft which is rotated by the operating means, and by rotating the lifting shaft back and forth, The blind is raised and lowered by winding up and unwinding the lifting cord around the winding drum. This kind of blind lifting device not only lifts the blind, but also
Even when lowering the blind, it is necessary to continuously operate operating means such as an operating cord until the blind reaches the desired height.

The present invention eliminates the operational inconvenience of the lifting device in conventional blinds, and when lowering the blind, the blind is automatically moved by its own weight by simply operating the operating means slightly in the direction of lowering the blind. It is an object of the present invention to provide a blind lifting device that allows the blind to be lowered.

The blind lifting device according to the present invention includes an inner cylinder,
The first and second outer cylinders are fitted onto the inner cylinder, and a clutch engagement portion is formed between the first and second outer cylinders. A spring is provided that presses the second outer cylinder against each other,
One of the inner cylinder and the first outer cylinder is connected to a drive shaft, and the other is connected to a blind lifting shaft, and the drive shaft is connected between the second outer cylinder and the inner cylinder in the blind lowering direction. The device is characterized by being provided with an engagement mechanism between an oblique groove and a protrusion that acts to separate the second outer cylinder from the first outer cylinder against the force of the spring when the second outer cylinder rotates. It is.

A detailed description will be given below with reference to the drawings.

1 and 2 illustrate the principle of the blind lifting device according to the invention. In the figure, 1 is an inner cylinder, 2 is a first outer cylinder that fits on the inner cylinder, 3 is a second outer cylinder that fits on the inner cylinder, and the outer cylinder 2 and the outer cylinder are 3
A clutch engaging portion 4 is formed between the outer cylinder 2 and the outer cylinder 2.
A spring 5 is provided that presses the outer cylinder 3 against the inner cylinder 2 so that the outer cylinder 3 and the outer cylinder 3 are always engaged at the clutch engaging portion 4. One of the above-mentioned inner cylinder 1 and first outer cylinder 2 (in the illustrated example, the inner cylinder 1) is connected to the drive shaft 6, and the other (in the illustrated example, the first outer cylinder 2) moves up and down. It is connected to the shaft 7. As is well known, a winding drum (not shown) for winding up the blind lifting cord is mounted on the lifting shaft 7.
Between the second outer cylinder 3 and the inner cylinder 1, when the drive shaft 6 is rotated in the blind lowering direction, the second outer cylinder 3 is connected to the first outer cylinder against the action of the spring 5. An engagement mechanism between the diagonal groove and the protrusion is provided which acts to separate the protrusion from the protrusion. In the illustrated example, the second outer cylinder 3 is formed with an oblique slot 8, and the inner cylinder 1 is provided with a protrusion 9 that engages in the slot.

In the above device, when the drive shaft 6 is rotated in the blind upward direction indicated by arrow A, the inner cylinder 1 is rotated in the direction A, and the protrusion 9 of the inner cylinder 1 is brought into contact with the lower end of the slot 8 of the second outer cylinder 3. engage and rotate the outer cylinder 3 in the A direction,
Along with this, the first outer cylinder 2 is rotated in the A direction via the clutch engaging portion 4, thereby rotating the lifting shaft 7 in the blind lifting direction, and the blind lifting cord is moved to a winding drum (not shown). ) and raise the blind. Next, when the drive shaft 6 is rotated in the blind lowering direction shown by arrow B in FIG. spring 5
It is moved in the direction away from the first outer cylinder 2 against the force, the clutch engaging part 4 is disengaged, and the first outer cylinder 2 becomes free. It will then automatically descend.

A first embodiment that implements the principle of the present invention described above is shown in FIG. In FIG. 3, parts that are the same as those shown in FIGS. 1 and 2 are designated by the same numbers, and their explanation will be omitted.

In FIG. 3, numeral 10 indicates a frame that supports the driving force transmission mechanism shown in FIGS.
A stopper 11 is arranged movably in the axial direction in the first outer cylinder 2 and is pushed toward the left in the drawing by a spring 12, and is engaged with the stopper 11 in the first outer cylinder 2. Ratchet teeth 13 are formed. Further, a protrusion 14 is formed at the end of the stopper 11, and the second outer cylinder 3 is moved from the first outer cylinder 2 against the force of the spring 5 as described later. Ratchet teeth 15 are formed which engage the above-mentioned protrusion 14 when moved in the direction of separation.

In the above-mentioned device, when the drive shaft 6 is rotated in the direction of raising the blind, that is, in the direction indicated by A in the figure, the clutch engagement of the outer cylinders 2 and 3 is maintained, and the lifting shaft 7 is rotated in the direction of raising the blind.

Next, when the drive shaft 6 is rotated in the blind lowering direction shown by arrow B, the outer cylinder 2 is stopped from rotating by the engagement between the stopper 11 and the ratchet teeth 13.
That is, the rotation of the outer cylinder 2 due to the weight of the blind applied to the lifting shaft 7 is stopped, and the rotation of the outer cylinder 3 is stopped. Therefore, only the inner cylinder 1 rotates, and the inner cylinder 1
The protrusion 9 moves along the slot 8, and the second outer cylinder 3
is moved in the direction of separating it from the first outer cylinder 2. When the outer cylinder 3 moves to a certain extent, the ratchet teeth 15 engage with the protrusion 14 of the stopper 11, and rotation of the outer cylinder 3 in the direction B is prevented.
Thereafter, as the inner cylinder 1 rotates, the outer cylinder 3 moves while pushing the stopper 11 to the right in the figure. As a result, the engagement between the outer cylinder 2 and the ratchet 13 of the stopper 11 is released, and the engagement between the outer cylinder 2 and the outer cylinder 3 is also released, so that the outer cylinder 2 becomes free against rotation in the B direction, and the blind Due to its own weight, it rotates in direction B while descending the slat.

4, 5 and 6 show a second embodiment of the present invention. In these figures, parts similar to those in the embodiment shown in FIG. 3 are indicated by the same numerals, and detailed explanation thereof will be omitted.

In the second embodiment, a clutch drum 16 is arranged on one end of the inner cylinder 1, and a spring 17 is arranged thereon, which allows the clutch drum to rotate in one direction but prevents it from rotating in the opposite direction. Ru. As shown in FIG. 5, one end of the clutch spring 17 is bent at a right angle to form an engaging portion 17', and the frame 10 is formed with a protrusion 18 against which the engaging portion 17' abuts. . When the clutch drum 16 rotates in the blind raising direction, that is, in the A direction, the clutch spring 17 is loosened, so that the clutch drum 16 can rotate freely, or when the clutch drum 16 rotates in the blind lowering direction, that is, in the B direction, one end of the clutch spring 17 is rotated. Since the engaging portion 17' is stopped by the projection 18, the clutch spring 17 is tightened on the clutch drum as the clutch drum 16 rotates, thereby preventing the clutch drum from rotating. Therefore, the second outer cylinder 3 has an axial protrusion 1.
9 is formed which slidably engages a recess 20 in the clutch drum 16.

In the second embodiment described above, when the drive shaft 6 is rotated in the blind rising direction, that is, in the A direction, the clutch spring 17 is loosened, so that the clutch drum and the second outer cylinder 3 can freely rotate in the A direction. Similarly to the above, the second outer cylinder 3, second outer cylinder 2, and lifting shaft 7 rotate together to lift the blind. Next, when the drive shaft 6 is rotated in the blind lowering direction, the rotation of the second outer cylinder 3 is prevented by the action of the clutch drum 16 and the clutch spring 17, so that as the inner cylinder 1 rotates, the outer cylinder 3 moves away from the outer cylinder 2, and when the outer cylinder 3 moves to a certain extent, the clutch engagement between the outer cylinder 3 and the outer cylinder 2 is disengaged, and the outer cylinder 2 freely descends due to the weight of the blind. It becomes like this.

As mentioned above, according to the blind lifting device according to the present invention, when lowering the blind, by just slightly operating the operating means such as the operating cord, the blind automatically lowers by its own weight, and the blind is lowered. Operation becomes extremely easy.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams showing the principle of the present invention;
FIG. 3 is a side view showing the first embodiment of the present invention, FIG. 4 is a side view showing the second embodiment of the present invention, and FIG.
This figure is a front view showing the structure of the clutch spring and clutch drum shown in FIG. 4, and FIG. 6 is a plan view of the device shown in FIG. 4. DESCRIPTION OF SYMBOLS 1... Inner cylinder, 2... First outer cylinder, 3... Second outer cylinder, 4... Clutch engaging part, 5... Spring, 6... Drive shaft, 7... Lifting shaft, 8...Slot hole, 9...Protrusion, 10...Frame, 11...Stopper, 12...Spring, 13...Ratchet tooth, 14...Protrusion, 15...Ratchet tooth,
16... Clutch drum, 17... Clutch spring, 18... Protrusion, 19... Axial protrusion,
20……Concavity.

Claims (1)

[Scope of utility model registration request] It includes an inner cylinder and first and second outer cylinders that fit onto the inner cylinder, and forms a clutch engagement part between the first outer cylinder and the second outer cylinder, and is always , a spring is provided that presses the first and second outer cylinders against each other, one of the inner cylinder and the first outer cylinder is connected to a drive shaft, the other is connected to a blind lifting shaft, and the second Between the outer cylinder and the inner cylinder, there is an inclined surface that acts to separate the second outer cylinder from the first outer cylinder against the force of the spring when the drive shaft is rotated in the blind lowering direction. A blind lifting device characterized by having an engagement mechanism between a groove and a protrusion.