JPH089358Y2 - Shutter curtain fall prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a shutter curtain fall prevention device for a building shutter, particularly a heavy shutter.

[Prior Art] A heavy shutter or the like uses an opening / closing device that uses a motor or the like as a drive source to open and close the shutter curtain.

 The switchgear will be briefly described in FIG.

A shutter curtain 2 is mounted on a winding drum 1 which is rotatably supported.
Is wound up. A sprocket 4 is fixed to a shaft portion 3 of the winding drum 1, and the sprocket 4 is connected to a pinion sprocket 6 fixed to an output shaft of a motor 5 by a chain 7.

When the motor 5 is driven and the winding cylinder 1 is rotated through the pinion sprocket 6, the chain 7 and the sprocket 4, the shutter curtain 2 can be rolled up or rolled down.

Here, the self-weight of the shutter curtain 2 is supported by the driving force of the motor 5 when the motor 5 is driven and by the brake attached to the motor 5 when the motor 5 is stationary. Therefore, when the chain 7 that connects the sprocket 4 and the pinion sprocket 6 is cut due to fatigue or the like, it does not stop the rotation of the winding cylinder 1, so that the winding cylinder 1 rotates freely and the shutter curtain falls. Resulting in. This falling speed is high, and the shutter curtain is a heavy object, which is very dangerous.

Therefore, some types of heavy shutters are provided with a fall prevention device.

FIG. 6 shows an example of a conventional fall prevention device, in which an idler sprocket 8 is meshed with a chain 7, and the idler sprocket 8 is rotatably supported by an arm 9 biased in a direction to apply tension to the chain 7. It is provided.
A detector such as a limit switch is provided at the center of the arm 9 so as to detect when the arm 9 is out of the normal position.

In the conventional example, when the chain 7 is cut due to fatigue or the like, the arm 9 rotates counterclockwise in the figure, and this rotation is detected by the limit switch described above. That is, the applied brake is actuated to brake the winding cylinder 1.

Further, although not particularly shown, as another conventional example, a mechanical stopper is provided on the rail so that the rail is mechanically locked when it is wound up to the uppermost position of the shutter curtain, and this lock cannot be released except during the hoisting and lowering operation. There are things I do like this.

[Problems to be Solved by the Invention] However, the conventional device described above has the following problems.

That is, the former one has a complicated and expensive structure such as an idler sprocket, a supporting mechanism thereof, a detector, a detection circuit, and a brake provided on the body.

The latter is not effective when the chain breaks during the winding operation or the lowering operation. Furthermore,
A mechanism or an electric circuit for locking and unlocking the stopper corresponding to the opening / closing operation is required, which is inevitably expensive.

The present invention has been made in view of the above circumstances, and has a simple structure and is reasonably inexpensive, and further, when the chain is broken when the hoisting and lowering operation is performed or when the chain is stationary, the chain is reliably wound. An object of the present invention is to provide a shutter curtain fall prevention device that restrains the rotation of the body.

[Means for Solving the Problems] In the present invention, a winding cylinder is rotatably provided on a side bracket, a flange is fixed to a shaft portion of the winding cylinder, and a lock claw is eccentrically provided on the flange toward a rear end side from a gravity center position. The lock claw is pivotally attached at a fixed position so that the tip of the lock claw can project from the outer shape of the flange and the rear end of the lock claw abuts the shaft while the tip of the lock claw protrudes by a required amount to rotate the lock claw. It is characterized in that the stopper block is provided on the side bracket side so as to be brought into contact with the flange so that the stopper block engages with the protruding lock claw tip portion when the winding cylinder is rotated a predetermined number of times or more.

[Operation] When the shutter curtain begins to fall due to chain disconnection, motor failure, etc., and the rotation of the winding cylinder rises, centrifugal force acts on the lock claws, causing the lock claws to expand and the lock claws to protrude from the normal rotation trajectory. And engages with the stopper block to restrict the rotation of the winding cylinder and prevent the shutter curtain from falling.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

The same parts as those shown in FIG. 5 are designated by the same reference numerals in FIGS. 1 and 2.

In the figure, 10 is a shutter curtain fall prevention device, which is a flange 11 and 12 fixed to the shaft portion 3 with a required space therebetween, and a pin 13 is interposed between the flanges 11 and 12 to form a bead-shaped lock claw 1.
Pivot 4 The lock claw 14 has a long tip 14a and a short rear end 14b, and the center of gravity of the lock claw 14 is eccentric to the tip side 14a with respect to the pivot point. or,
The front end portion 14a of the body portion 14c of the lock claw 14 is on the center side (reduction direction).
When it rotates, it has a shape that interferes with the shaft part 3 to restrict its movement, and the rear end part 14b rotates more than a predetermined angle in the direction in which the front end part 14a moves away from the center (enlargement direction) Is a stopper that abuts the shaft portion 3 and restrains the movement.

The flange 1 is located at a position close to the flanges 11 and 12.
A stopper block (15) is fixed to a side bracket (16) at a position facing horizontally the centers of (1, 12).

In FIG. 3, the direction of rotation of the winding cylinder is the direction of arrow A, which is the winding direction of the shutter curtain, and the direction of arrow B, which is the direction of winding the shutter curtain.

 The operation will be described below.

In FIG. 3, when the lock claw 14 is on the lower side, the tip end portion 14a projects from the outer peripheral surfaces of the flanges 11 and 12 due to gravity acting on the center of gravity.

When rotating from this state in the direction of arrow A, the lock claw 14 is in sliding contact with the stopper block 15 and the stopper block 15
The locking claw 14
When is on the upper side, it is completely stored under its own weight. When it is further rotated in the direction of arrow A, the tip 14
a projects. These operations are repeated and the hoisting operation is performed without any trouble.

Next, when the lock claw 14 is rotated from the lower side in the direction of the arrow B, the lock claw 14 rises, and this rise causes the lock claw 14 to move in the storage direction (clockwise direction in the drawing) from the position of the pivotal point and the center of gravity of the lock claw 14. The moment acts, and the tip portion 14a is completely retracted when passing through the stopper block 15. Therefore, the lowering operation can be performed without any trouble.

In the above-mentioned winding and lowering operations, the rotation speed of the winding cylinder is slow, and the centrifugal force hardly acts on the lock claws 14 or the movement thereof does not affect the movement of the lock claws 14. .

However, when the chain 7 is cut, the winding drum 1
Rotates at high speed due to the fall of the shutter curtain 2.
The rotation direction in this falling state is the direction of arrow B in FIG. 3, and when the tip portion 14a expands or the storage time is delayed due to the action of centrifugal force, the tip portion 14a engages with the stopper block 15, and this engagement Becomes stronger as the winding cylinder 1 rotates, and is instantly locked as shown in FIG.

As described above, the rear end portion 14b serves as a stopper for the lock claw 14, and the movement of the winding cylinder is completely restrained by the engagement of the front end portion 14a with the stopper block 15, and the shutter curtain is locked once. Due to its own weight, a clockwise rotating force is always acting on the winding cylinder 1, and therefore it is not released.

Needless to say, the lock can be easily released by rotating the winding drum 1 counterclockwise.

Although the two flanges are fixed to the shaft portion in the above embodiment, it goes without saying that a ring block in which a groove for storing the lock claw 14 is formed may be fixed to the shaft portion. It may be 2 or 3.

In the above embodiment, the lock pawl is only supported so as to be freely movable, but when the spring force or the frictional force is applied to the lock pawl, the lock pawl 14 is moved when the centrifugal force exceeds a predetermined value. It may be configured to project. Further, a plurality of holes may be formed in the lock claws 14 and 19 and the holes may be appropriately filled to adjust the center of gravity. Further, the position where the lock claw is provided may be any position on the winding drum.

[Advantages of the Invention] As described above, according to the present invention, the rotation of the winding cylinder can be reliably restrained when the rotation of the winding cylinder rises, so that the shutter curtain can be prevented from dropping, and the structure is simple and mechanical parts Since it has only the structure, it has an excellent effect that it is inexpensive and can be easily added to an existing shutter.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a perspective view of the embodiment, FIGS. 3 and 4 are operation explanatory views, and FIG. 5 is an explanatory view of a conventional example. Reference numeral 1 is a winding drum, 2 is a shutter curtain, 10 is a shutter curtain fall prevention device, 14 is a locking claw, and 15 is a stopper block.

Claims (1)

[Scope of utility model registration request] 1. A winding barrel is rotatably provided on a side bracket, a flange is fixed to a shaft portion of the winding barrel, and a lock claw is pivotally attached to the flange at a position eccentric to a rear end side from a center of gravity. The tip of the locking pawl is allowed to project from the outer shape of the flange, and the rear end of the locking pawl comes into contact with the shaft to restrain the rotation of the locking pawl with the front end protruding a required amount. A shutter curtain fall prevention device, characterized in that a stopper block with which the protruding lock claw tip portion engages after a predetermined rotation or more is provided so as to be in contact with the flange on the side bracket side.