JP2543474Y2 - Shutter fall prevention device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutter fall prevention device for preventing a shutter curtain from dropping rapidly.

[0002]

2. Description of the Related Art As this type of shutter fall prevention device, the following device is conventionally known.

[0003] That is, in this shutter fall prevention device, there is provided a rotating plate directly connected to a winding shaft for winding the shutter curtain and integrally rotating with the winding shaft. The rotating plate is provided with claws around it,
When the rotation speed of the rotating plate reaches a predetermined value, the claw protrudes radially outward from a state along the peripheral surface of the rotating plate due to centrifugal force acting on the claw, and is fixed to the housing on which the winding shaft is mounted. Meshed with the internal tooth ratchet,
As a result, the rotation of the take-up shaft is prevented, the drawing out of the shutter curtain is stopped, and a rapid descent of the shutter curtain caused by an abnormal increase in the rotational speed of the take-up shaft is avoided.

[0004]

However, in the above-described conventional shutter drop prevention device, since a claw and an internal ratchet are used, a large impact force is generated due to sudden stop of the winding shaft. . Particularly, in the case of a large shutter, the impact force is further increased, so that it is difficult to mount the device.

The present invention has been made in consideration of the above-described circumstances, and has as its object to provide a shutter drop prevention device capable of reducing an impact force accompanying the rotation prevention when the rotation of the winding shaft is prevented.

[0006]

In order to achieve the above object, the present invention provides a rotating member which rotates together with a winding shaft for winding a shutter curtain, and a rotation of the rotating member which is transmitted through a friction member so as to rotate the shutter curtain. A shutter drop prevention device comprising: a rotatable member rotatable together with the rotatable member; and a stop unit for stopping rotation of the rotatable member when the rotation speed of the rotatable member reaches a predetermined value or more. Is what you do.

[0007]

With the above arrangement, the rotation of the rotating member is normally transmitted to the rotated member via the friction member, and the rotated member rotates according to the rotation speed of the winding shaft. When the rotation of the rotating member is accelerated, the rotation speed of the rotated member increases accordingly, and when the rotation speed reaches a predetermined value, the stopping means operates to stop the rotation of the rotated member. The stop of the rotation of the rotated member is not directly transmitted to the rotating member but is transmitted to the rotating member via the friction member. Therefore, the rotating member does not stop integrally with the rotated member because the friction member serves as a buffer, but stops rotating by decelerating so as to slide relatively to the rotated member. As a result, the rotation of the winding shaft is prevented, and a rapid drop of the shutter curtain is avoided. As a result, when the rotation of the winding shaft is prevented, the impact force accompanying the rotation is reduced, and the impact force is sufficiently reduced even with a large shutter.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a shutter fall prevention device according to the present invention will be described in detail with reference to FIGS.

FIG. 2 is a schematic diagram of an electric shutter to which the present embodiment is applied. As shown in FIG. 1, a frame 12 is disposed along and above the lintel portion 10, and brackets 14, 16 are provided on both ends of the frame 12.
The brackets 14 and 16 are rotatably mounted on the brackets 14 and 16 at both ends of a winding shaft 18 having a body 20 for winding a shutter curtain 22 indicated by a chain line in FIG. ing. Winding shaft 18
At one end, the right end in FIG. 2, is driven to rotate via a chain 30 by a motor 28 attached to the bracket 14 on the same end side. For example, the shutter curtain 22 is lowered by forward rotation of the motor 28, The shutter curtain 22 can be raised by the reverse rotation of the motor 28.

The shutter curtain 22 is formed by connecting a plurality of slats.
The left and right ends of the shutter 2 are guided by guide rails 26 extending from the lintel portion 10 to the floor surface 24 when the shutter curtain 22 is moved up and down.

At the other end of the winding shaft 18, that is, at the left end in FIG. 2, a rectangular box-shaped casing 32 is mounted on the wall of the building. As shown in FIG. The end penetrates through one side wall 34 of the casing 32 and enters the casing 32. A rotating shaft 36 is disposed in the casing 32 and parallel to and below the other end of the take-up shaft 18 therein. Rotating shaft 36
Is rotatably supported by the side wall 34 via a bearing 38, and the other end of the rotating shaft 36 is rotatably supported by the side wall 35 opposite to the side wall 34.

At the center of the rotating shaft 36, a rotating disk 40 constituting a rotating member is fitted using a key member 41. The rotating disk 40 has a casing 3 on the bearing 38 side.
A gear 44 meshed with a gear 42 fitted to the tip of the winding shaft 18 that has entered the inside 2 is integrally formed, and is rotatable together with the winding shaft 18.

A rotating disk 46 constituting a member to be rotated can slide along the rotating shaft 36 toward the side wall 35 so as to face the rotating disk 40. They are fitted so as to be relatively rotatable.
A compression coil spring 66 is interposed between the rotated disk 46 and the side wall 35 of the casing 32 so as to fit into a boss 64 formed on the rotated disk 46. The compression coil spring 66 is provided on one of the opposing surfaces of the rotating disk 46 and the rotating disk 40, or on each of the opposing surfaces, via a brake lining 68 that constitutes a friction member. 46 is constantly pressed against the rotating disk 40,
A frictional force is applied between the rotated disk 46 and the rotating disk 40. The rotation of the winding shaft 18 is transmitted to the rotating disk 46 via the brake lining 68, and the rotating disk 46 rotates at a speed corresponding to the rotation speed of the winding shaft 18. The brake lining 6
8 can be applied to a single plate or multiple plates.

A pair of claws 48 are provided around the rotating disk 46 so as to face each other via the rotating shaft 36. Nail 4
8 is rotatably supported by a claw shaft 52 disposed in parallel with the rotation shaft 36 in a concave portion 50 formed on the peripheral surface of the rotated disk 46, with the claw shaft 52 as a center. As shown by the solid line in FIG. 3, the claw 48 mostly enters the recess 50 except for a part of its tip, and the tip of the claw 44 is rotated in a clockwise direction indicated by an arrow A in FIG. The rotation between the state in which it is positioned along the peripheral surface of the plate 46 and the state in which the claw 48 projects radially outward from the peripheral surface of the rotating disk 46 as shown by a chain line in FIG. It is possible to move. At the tip of the claw 48, an enlarged portion 54 wider than the concave portion 50 is formed, and the enlarged portion 54 is rotated along the peripheral surface of the rotated disk 46 as shown by a solid line in FIG. It comes into contact with the peripheral surface of the plate 46. In addition, the claw shaft 52 includes
As shown in FIG. 1, a torsion coil spring 56 is fitted,
The torsion coil spring 56 constantly urges the claw 48 to rotate in a clockwise direction indicated by an arrow B in FIG. 3 in a state indicated by a solid line in FIG.

On the other hand, a stopper member 60 is fixed in the casing 32 so as to face the peripheral surface of the rotating disk 46. As shown in FIG. 3, a plurality of, for example, eight, internal tooth ratchets 62 are arranged at predetermined angular intervals on the inner peripheral surface of the stopper member 60. Each internal tooth ratchet 62
Is formed at an acute angle in a clockwise direction indicated by an arrow A in FIG. 3, and when the rotation speed of the rotated member 46 rotating in the same direction reaches a predetermined value, as shown by a chain line in FIG. As the rotation speed of the torsion coil 46 increases, the claw 48 that pivotally projects based on the centrifugal force acting on the claw 48 against the urging force of the torsion coil spring 56 can be locked. In the state where the claw 48 is locked to the internal ratchet 62, the rotated disk 46 cannot rotate clockwise as indicated by A in FIG.
The rotation is stopped. Further, the locked state of the claw 48 is maintained irrespective of the stop of the rotation of the rotated disk 46. Thus, the pawl 48 and the internal tooth ratchet 62 constitute a stopping means for stopping the rotation of the rotated disk 46. The direction indicated by the arrow A in FIG. 3 is the direction of rotation of the rotated disk 46 that is rotated by transmitting the rotation of the rotating disk 40 via the brake lining 68 when the shutter curtain 22 is lowered.

Next, the operation of this embodiment will be described. Motor 2
When 8 rotates, the winding shaft 18 rotates and the shutter curtain 22 moves up and down.

Normally, as the winding shaft 18 rotates,
The rotating disk 40 rotates via the gears 42 and 44, and further,
Via the brake lining 68 interposed between the rotating disk 40 and the rotating disk 46, the rotating disk 46 rotates integrally with the rotating disk 40 according to the rotation speed of the rotating disk 40.

If the take-up shaft 18 exhibits an abnormally high rotational speed in the direction in which the shutter curtain 22 is lowered, the rotating disk 46 which rotates clockwise as indicated by arrow A in FIG. The rotation speed also increases. This allows
The centrifugal force acting on the pawl 48 increases, and the torsion coil spring 5
6, the pawl 48 gradually rotates counterclockwise as indicated by an arrow C in FIG. 3 and projects from the peripheral surface of the rotated disk 46. When the rotation speed reaches a predetermined value, as shown by a chain line in FIG. As a result, the rotation of the rotating disk 46 is stopped, and the stop is transmitted to the rotating disk via the brake lining 68 interposed between the rotating disk 40 and the rotating disk 46, and the rotation of the rotating disk 40 is stopped. The brake lining 68 serves as a buffer, so that it does not stop integrally with the rotated disk 46 irrespective of the sudden stop of the rotated disk 46, and resists the frictional force of the brake lining 68. The rotation is decelerated so as to slide relative to 46, and then stopped. Thereby, the winding shaft 18 stops without suddenly stopping. In this way, abnormal lowering of the shutter curtain 22 is avoided. At this time, the impact force generated when the winding shaft 18 is prevented from rotating is reduced, and the impact force is sufficiently reduced even in a large-sized shutter.

Although the embodiment has been described above, the present invention is not limited to the above-described embodiment, and can be variously modified.

[0020]

As described above, according to the shutter fall prevention device of the present invention, when the rotation of the winding shaft is prevented, the impact force accompanying the rotation can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of an embodiment of a shutter fall prevention device according to the present invention.

FIG. 2 is a schematic front view of an embodiment in which the shutter fall prevention device according to the present invention is applied to an electric shutter.

FIG. 3 is a partially cutaway left side view of FIG. 1;

[Explanation of symbols]

 Reference Signs List 18 winding shaft 22 shutter curtain 40 rotating disk (rotating member) 46 rotated disk (rotating member) 48 pawl (stopping means) 62 internal ratchet (stopping means) 68 brake lining (friction member)

Claims (1)

(57) [Scope of request for utility model registration] A rotating member that rotates together with a winding shaft that winds a shutter curtain; a rotating member that is rotatable with the rotating member by transmitting rotation of the rotating member via a friction member; A shutter drop prevention device comprising: a stop unit for stopping rotation of a rotated member when a rotation speed of the rotation member reaches a predetermined value or more.