JPH0639040Y2 - Brake device for shutter opening and closing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a brake device used in a shutter opening / closing device.

[Prior Art] As is well known, a shutter has a structure in which a slat door body in which a large number of slats are connected is wound around a winding shaft horizontally installed on a ceiling surface and then unwound. And
An automatic closing device and a brake device interlocking with the closing device are attached to the winding shaft to prevent the wound slat door body from falling by its own weight.

In this brake device, as shown in FIG. 4, a brake drum 1 is attached to the end of a winding shaft, and the lower ends of a pair of left and right arcuate brake shoes 2 and 2 can be expanded within the brake drum 1 by a shaft 3. And the outer peripheral edges of the brake shoes 2 and 2,
By attaching the liner 4 and rotating the cam 5 arranged on the diameter line with the rotating shaft 3, the brake shoes 2 and 2 are pressed against the inner peripheral edge of the drum 1 to form a brake lock, and the cam is returned and rotated. The springs 6, 6 adjusted to the inner upper and lower ends of the brake shoes 2, 2 pull back the brake shoes 2, 2 to unlock the brake.

[Problems to be Solved by the Invention] By the way, the above-described conventional brake device operates the opening / closing device in order to unlock the brake when the shutter door body is wound up for several months, for example. Even if it is done, the liner 4 of the brake shoe 2 and the inner peripheral edge of the drum 1 will stick to each other, and the tension of the springs 6, 6 will not reduce the diameter of the brake shoes 2, 2 so that the brake will not be unlocked. There is a drawback that the shutter door cannot be lowered.

[Means for Solving Problems] The present invention has been made in order to eliminate the above-mentioned problems of the conventional type. A rotary shaft is provided on an inner peripheral portion of a brake drum attached to an end portion of a winding shaft of a shutter. A pair of brake shoes, which are designed to be expandable and contractible via a spring, and which are always given a tendency to reduce the diameter by a spring, are provided with a cam between the upper ends of the pair of brake shoes, and the pair of brake shoes is rotated by the cams. In an inner expansion type brake device for expanding and reducing the diameter of a brake shoe, a hook piece is provided at the tip of the brake shoe, and an inner edge portion of the hook piece is brought into contact with an end surface of a cam in a return rotation direction. To do.

[Operation] When the brake is locked from the unlocked state, the brake shoe is expanded by the rotation of the cam, the brake shoe is pressed against the inner peripheral edge of the drum, and when the locked state is unlocked, the cam is released. The hook piece provided on the brake shoe is rotated while being pulled at the front side edge of the cam in the return rotation direction, and the brake shoe is forcibly separated from the drum.

[Embodiment] Hereinafter, the present invention will be described in detail based on an embodiment of the drawings.

FIG. 1 is a schematic front view showing an embodiment of the present invention, FIG. 2 is a transverse cross-sectional view of the same as above, and reference numeral 10 is a brake device.

The brake device 10 is arranged in a brake drum 12 attached to the end of the shutter winding shaft 11.
The pair of brake shoes 13, 13 and the cam 14 are main components. That is, as shown in FIG. 1 and FIG. 2, a pair of substantially semicircular brake shoes 13 having a liner 15 attached to the outer peripheral edge of the liner 15 is attached to the drum.
Arranged so that there is a slight gap with the inner peripheral edge of 12,
The lower ends of these brake shoes 13, 13 are pivotally attached to a frame 18 on the opening / closing machine 17 side by a shaft 16, and springs 19, which are stretched vertically, are provided on these brake shoes 13, 13.
19 always gives an inward tendency.

On the other hand, the upper end surfaces of the brake shoes 13, 13 are in contact with a cam 14 which is rotated by a drive mechanism (not shown) in the opening / closing machine 17.

More specifically, a protector 20 also serving as a sliding plate is attached to the upper end surfaces of the brake shoes 13, 13, and the cam 14 is returned to the protector 20 from the brake locked state to the unlocked state. When you cam
Hook pieces 21, 21 that engage with the end face of the turning direction of 14 are attached so as to face each other vertically, and the tips of the hook pieces 21, 21 are notches provided in the cam 14 in the unlocked state.
It is stored in 22, 22.

Next, the operation of the brake device of the present invention having the above structure will be described.

First, to lock the brake device in the released state as shown in FIG. 1, the manual or electric drive device (not shown) in the opening / closing device 17 is operated to rotate the cam 14 to rotate the brake shoe. Liner attached to the outer peripheral edge of the brake shoes 13, 13 by expanding 13, 13 against the springs 19, 19.
15 and 15 are crimped to the inner peripheral edges of the brake drums 12 and 12 (Fig. 3).

On the other hand, when unlocking the brake device in the locked state, the drive device (not shown) in the opening / closing device 17 is actuated to return and rotate the cam 14 as shown by the arrow in FIG. The shoulder portion 22a of the notch 22 provided on the cam 14 is a hook piece attached to the protector 20 at the end of the brake shoe 13, 13.
It engages with the inner edge portion 21a of 21 and rotates while pulling the brake shoes 13 and 13, and the brake is unlocked by the pulling force of the springs 19 and 19 (Fig. 1).

The present invention is not limited to the above embodiment, and it goes without saying that various modifications and changes can be made.

[Advantages of the Invention] With the above-described configuration of the present invention, even if the drum and the brake shoe adhere to each other during the braking operation, particularly the unlocking operation, the cam forcibly separates the brake shoe from the drum, so that the brake is smoothly applied. Can be unlocked. Moreover, the number of parts is small and the structure is simple, which is extremely practical.

[Brief description of drawings]

FIG. 1 is a schematic front view showing an embodiment of the present invention, FIG. 2 is a transverse sectional view of the same, FIG. 3 is a front view showing an operating state, and FIG. 4 is a view showing a conventional type. 10 …… Brake device, 11 …… Winding shaft, 12 ……
Brake drum, 13 …… Brake shoe, 14 …… Cam,
15 …… liner, 16 …… axis, 17 …… switch, 18 …… frame, 19 …… spring, 20 …… protector, 21 ……
Hook piece, 21a …… Inside edge of hook piece, 22 …… Notch, 2
2a: Notched shoulder.

Claims (1)

[Scope of utility model registration request] 1. An inner peripheral portion of a brake drum used for a shutter opening / closing device, which is attached to an end portion of a winding shaft of a shutter, is expandable and contractable via a rotating shaft, and a spring tends to reduce the diameter at all times. In an inner expansion type brake device, in which a pair of applied brake shoes are arranged, a cam is interposed between the upper ends of the pair of brake shoes, and the pair of brake shoes are expanded and contracted by the rotation of the cams, A brake device for a shutter opening / closing device, wherein a hook piece is provided at a tip of a brake shoe, and an inner edge portion of the hook piece is brought into contact with an end surface of a cam in a return rotation direction.