JPH0532632Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a shutter fall prevention device that prevents a shutter curtain wrapped around a winding shaft from falling due to its own weight, and particularly relates to The present invention relates to a fall prevention device equipped with an automatic device malfunction release function.

[Prior art]

An electric shutter in which a transmission chain, such as a roller chain, is connected in parallel between a driving sprocket driven by the motor of the opening/closing machine and a driven sprocket fixed to one end of a winding shaft, has the following characteristics: Or, if the braking device of the opening/closing machine malfunctions, the winding shaft becomes free to rotate, causing an accident in which the shutter curtain wound around the winding shaft falls under its own weight.

For this reason, conventional electric opening/closing type or electric winding type shutters are equipped with fall prevention devices as shown in Figures 7 to 9.
(See Publication No. 107092).

That is, FIG. 7 is a front view of a shutter equipped with a conventional drop prevention device, FIG. 8 is a central vertical sectional view of the drop prevention device, and FIG. 9 is a sectional view taken along the line C--C.

FIG. 7 shows a transmission chain between a driving sprocket 41 that is rotationally driven by the electric motor of the opening/closing machine 40 and a driven sprocket 43 fixed to one end of a winding shaft 42 on which the shutter curtain S is wound. 44 is shown, and a fall prevention device R shown in FIGS. 8 and 9 is installed on a bearing plate 45 that pivotally supports one end of the winding shaft 42.

This fall prevention device R is composed of a rotating body 46 fixed to the end of the winding shaft 42, and a stopper 47 fixed to a bearing plate 45 and detachably engaged with the rotating body 46. There is.

The rotating body 46 is provided with claws 50, 50 which are rotatably supported in the radial direction by a pin 48 and are normally biased inwardly by the tensile force of a coil spring 49. Output direction (arrow F in Figure 9)
When a centrifugal force is applied due to abnormal rotation of the winding shaft 42 (as shown in the figure), each pawl 50, 50 projects outward from the periphery of the rotating body 46 against the tensile force of the coil spring 49. ing.

Further, the stopper 47 is formed with a recess 51 that rotatably accommodates the rotating body 46, and the inner peripheral surface of the recess 51 is engaged with the pawl 50 that is projected outward by centrifugal force as described above. A matching notch 52 is formed.

However, if the winding shaft 42 becomes free to rotate due to the transmission chain 44 breaking when opening and closing the shutter, or the braking device of the opening/closing machine 40 failing, etc., the winding on the winding shaft 42 becomes free. The shutter curtain S begins to fall due to its own weight.

At this time, the take-up shaft 42 abnormally rotates at high speed in the unwinding direction of the shutter curtain S, and the claw 50 of the rotating body 46 fixed to the take-up shaft 42
and 50 are projected outward against the biasing force of the coil spring 49 due to centrifugal force, and one of the claws 50 engages with a notch 52 of a stopper 47 fixed to the bearing plate 45.

This prevents the rotation of the winding shaft 42 and stops the shutter curtain S wound around the winding shaft 42 from falling.

[Technical issues to be solved]

By the way, in the case of such a conventional fall prevention device R, the claw 50 of the rotating body 46 is connected to the notch 52 of the stopper 47 even though there has been no accident of cutting the transmission chain 44 or failure of the switch 40. When engaged, the rotation of the winding shaft 42 is stopped, causing a malfunction in which the shutter stops midway through closing.

The cause of this malfunction is, for example, in the case of an electric opening/closing type shutter or an electric winding type self-weight lowering shutter, the elastic force of the coil spring 49 that biases the pawl 50 weakens, resulting in so-called sagging, and the winding shaft 42 If the rotational speed in the unwinding direction changes to become even slightly faster midway through, the claws 50 may tend to protrude outward.

Such malfunctions caused users to complain to the manufacturer, and the manufacturer was forced to carry out maintenance and inspection every time the shutter stopped.

[Purpose of invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a shutter fall prevention device that can automatically release the shutter from being stopped due to malfunction.

[Structure of the idea]

In order to achieve this objective, the present invention has developed a method in which a claw provided on a rotary body fixed to the end of the winding shaft absorbs centrifugal force caused by abnormal rotation of the winding shaft rotating in the unwinding direction of the shutter curtain. In the shutter fall prevention device, the shutter fall prevention device is configured to be removably engaged with a stopper that projects outwardly against the biasing force of a spring and prevents rotation of the winding shaft. A switch that is pressed and activated when the pawl is engaged with the stopper is disposed on the stopper side, and the switch outputs an operation signal that once rotates the winding shaft in the winding direction. It is characterized by

[Effect of invention]

According to the present invention, when the claw provided on the rotating body fixed to the winding shaft engages with the stopper that prevents rotation of the winding shaft due to malfunction,
A switch disposed on the stopper side is pressed and activated, and the winding shaft is once rotated in the winding direction by an operation signal output from the switch. As a result, the pawl engaged with the stopper is disengaged from the stopper and returned to its original state by the biasing force of the spring, and the stopped state of the shutter is automatically released.

[Example] Hereinafter, an example of the present invention will be specifically described based on the drawings.

FIG. 1 is a front view showing an example of a fall prevention device according to the present invention, and FIG. 2 is a side view thereof.

The fall prevention device R shown in this example has pawls 3, 3 provided on a rotating body 2 fixed to the end of the winding shaft 1, and stoppers on the upper and lower sides of a bearing plate 4 that pivotally supports the winding shaft 1. Stopper receivers 6, 6 are provided to support the main bodies 5, 5.

Each pawl 3 provided on the rotary body 2 is rotatably supported by a pin 7 at one end in a direction perpendicular to the axial direction of the winding shaft 1, and a coil spring 8 is connected to the other end so that the pawl 3 is always rotated. is urged to be pulled inward by the coil spring 8, and when the rotating body 2 rotates abnormally together with the winding shaft 1 and centrifugal force acts, the rotating body 2 resists the urging force of the coil spring 8. It is configured to protrude outward from the periphery.

Further, each stopper body 5 has a stopper piece 5a protrudingly formed on the front end side facing the peripheral edge of the rotating body 2, which engages with the pawl 3 protruding from the peripheral edge of the rotating body 2 in a detachable manner, and a rear end thereof. Stopper piece 5a on the side
Stopper guide shafts 9, 9 are provided on the stopper receiver 6 so as to be vertically slidable along the direction in which the pressing force of the claw 3 engaged with the stopper receiver 6 acts.
The stopper piece 5a is urged to approach the periphery of the rotating body 2 by a spring 10 such as a disc spring interposed between the stopper piece 5a and the rotor 2.

Further, a micro switch 11 is disposed in each stopper receiver 6, and the claw 3 engages with the stopper piece 5a, so that the stopper body 5 slides toward the stopper receiver 6 against the elastic force of the spring 10. When the stopper body 5 is pressed, a protrusion 12 provided on the stopper body 5 presses an operator 13 of the microswitch 11 to operate the switch 11. This microswitch 11 is connected to the drive circuit of the opening/closing machine shown in FIG. 3, and is configured to output an operation signal for once rotating the winding shaft 1 in the winding direction. Incidentally, FIG. 4 is a time chart showing the operation of the drive circuit shown in FIG. 3.

The drive circuit shown in FIG. 3 consists of a power supply circuit 16 that supplies three-phase alternating current to the electric motor 15, and a control circuit 17 that opens and closes a rise switch Su and a fall switch Sd that are installed in the power supply circuit 16. There is.

The control circuit 17 includes a lift control circuit 18 that is connected between the T-phase line and the R-phase line of the power supply circuit 16 and controls opening and closing of a lift switch Su that rotates the winding shaft 1 in the winding direction and opens the shutter. A lowering control circuit 19 that controls opening and closing of a lowering switch Sd that rotates the winding shaft 1 in the unwinding direction and closes the shutter, and a micro switch that is output when the pawl 3 engages with the stopper piece 5a while the shutter is lowering. The timer circuit 20 once rotates the winding shaft 1 in the winding direction based on an operation signal from the winding shaft 11.

The rise control circuit 18 and the fall control circuit 19 are connected in parallel and connected to the T phase line of the power supply circuit 16 via the contact 21 of the micro switch 11 and the stop button Bs, and the rise control circuit 18 has a rise switch.
A relay Ru that opens and closes Su, a rise button Bu that operates the relay Ru, and an upper limit switch Lu that stops energizing the relay Ru when the shutter reaches the upper limit are installed, and the relay Ru self-maintains. A contact 22 is connected in parallel with the rise button Bu. On the other hand, the lowering control circuit 19 includes a relay Rd that opens and closes the lowering switch Sd, a lowering button Bd that operates the relay Rd, and a lower limit switch Ld that stops energizing the relay Rd when the shutter reaches the lower limit position. The self-holding contact 23 of the relay Rd is connected in parallel to the lowering button Bd.

Note that the ascending control circuit 18 and the descending control circuit 19
are connected to the R phase line of the power supply circuit 16 through the off-side contacts of the down switch Sd and the up switch Su, respectively, and when the down switch Sd is on, the up control circuit 18 is cut off and the up switch Su is turned off. When it is on, the lowering control circuit 19 is cut off to prevent the lowering switch Sd and the ascending switch Su from being turned on at the same time.

The timer circuit 20 also includes a relay between the off-side contact of the microswitch 11 and the R phase line.
R ₁ , R ₂ and on-delay timers Tu, Ts, Td are connected in parallel, respectively.
The setting times of Td are set to 5 seconds, 10 seconds, and 15 seconds, respectively.

In addition, in the control circuit 17, 24 is a relay.
A contact of R ₁ , 25 is a b contact of relay R ₂ , 26 is an a contact of timer Tu, 27, 28 is b of timer Ts
Contacts 29 and 30 are a contacts of timer Td, 31
is the b contact of timer Td.

When opening the shutter, press the lift button Bu to close the lift control circuit 18, operate the relay Ru, close the lift switch Su, start the electric motor 15, and rotate the winding shaft 1 in the winding direction. The shutter rises when driven.

Then, when the stop button Bs is pressed or the shutter reaches the upper limit position and the upper limit switch Lu is pressed, the lift control circuit 18 is cut off, the relay Ru is reset, the lift switch Su is opened, and the electric motor 15 is stopped. do.

Next, to close the shutter, press the lowering button Bd to close the lowering control circuit 19 and activate the relay.
Rd is activated, the lowering switch Sd is closed, the winding shaft 1 is rotationally driven in the unwinding direction by the electric motor 15, and the shutter is lowered.

Then, when the stop button Bs is pressed or the shutter reaches the lower limit position and the lower limit switch Ld is pressed, the lowering control circuit 19 is cut off, the relay Ru is reset, the lowering switch Sd is opened, and the electric motor 15 is activated. Stop.

In addition, when the rotational speed of the take-up shaft 1 increases while the shutter is being lowered, for example, the claw 3 may be damaged by centrifugal force.
When it protrudes outward and engages with the stopper piece 5a,
At the same time as the rotation of the winding shaft 1 is stopped,
The stopper body 5 is pressed against the stopper receiver 6 side against the elastic force of the spring 10, and the protrusion 12 attached to the stopper body 5 presses the operator 13 of the micro switch 11, and the contact 21 of the switch 11 is pressed.
is connected to the off side and the timer circuit 20 is energized, and this is used as an operation signal to turn on the timer circuit 20 (t ₁ in FIG. 4).

When the timer circuit 20 is turned on, the relay _R1 is operated and its a contact 24 is closed, and the timer circuit 20 is self-maintained, and the timers Tu, Ts
and Td are energized simultaneously.

Then, 5 seconds after the timer circuit 20 is turned on, the timer Tu operates and the a contact 26 connected in parallel with the rise button Bu is closed, so the relay Ru of the rise control circuit 18 is activated. The lift switch Su is closed, the electric motor 15 is activated to rotate the winding shaft 1 in the winding direction, and the pawl 3 engaged with the stopper body 5 is rotated.
will automatically come off (t ₂ in Figure 4).

At this time, since the stopper body 5 is separated from the stopper receiver 6 by the elastic force of the spring 10, the protrusion 12 provided on the stopper body 5 is detached from the operator 13 of the micro switch 11, and the micro switch 11 is The contact 21 automatically returns to the ON state, and the power supply from the contact 21 to the timer circuit 20 is cut off, but the timer circuit 20 is self-maintained by closing its A contact 24 by relay _R1 . It continues to operate because it is

Then, 10 seconds after the timer circuit 20 is turned on, the timer Ts operates, and the b contact 27 connected in series to the micro switch 11 and the timer
Since the contact 28 connected in series with Tu is opened, the timer Tu is reset, its a contact 26 is opened, and the relay Ru of the lift control circuit 18 is reset, the lift switch Su is turned off, and the drive of the electric motor 15 is stopped. It is stopped (Fig. 4 t ₃ ).

Next, 15 seconds after the timer circuit 20 is turned on, the timer Td operates, and the b contact 31 connected in series with the timer Ts opens to turn on the timer circuit 20.
Since the B contact 27 of Ts closes and the A contact 29 connected in parallel with the lowering button Bu closes, the relay Rd installed in the lowering control circuit 19 operates to turn on the lowering switch Sd, and the electric motor 15 The winding shaft 1 is rotationally driven in the unwinding direction, and the shutter starts to descend again.

Also, at the same time as the shutter starts to descend, the timer
A contact 30 of Td is closed and relay _R2 is activated,
The B contact 28 opens, the relay _R1 returns, and the A contact 24 opens, the timer circuit 20 is turned off, the timer Td returns, and the A contact connected in parallel with the down button Bd Immediately after being turned on, it is turned off (t ₄ in Figure 4).

After that, in the same way as normal opening/closing operations, the stop button Bs is pressed or the lower limit switch is pressed.
When Ld is turned off, the electric motor 15 stops and the shutter stops lowering.

As described above, according to this example, the pawl 3 is moved to the stopper body 5 without a failure of the braking device of the opening/closing machine 40 shown in FIG. If a malfunction occurs in which the stopper body 5 engages, the protruding piece 12 provided on the stopper body 5 presses the operator 13 of the micro switch 11, and the switch 11 temporarily drives the winding shaft 1 to rotate in the winding direction. The pawl 3 engaged with the stopper body 5 is detached from the stopper body 5 and returned to its original state by the biasing force of the coil spring 8, and the shutter is automatically released from its stopped state and immediately lowered. Since the fall prevention device is restarted, complaints due to malfunction of the fall prevention device can be eliminated. Note that if the device of the present invention is activated due to an accident in which the transmission chain is cut, the electric motor 15 will repeatedly rotate in the winding direction and the unwinding direction due to the operation signal from the micro switch 11 that continues to be pressed. Since the power of the electric motor 15 is not transmitted to the winding shaft 11, there is no risk of damaging the winding shaft 1, fall prevention device, etc.

Further, the stopper body 5 that is engaged with the claw 3 is
Since it is vertically slidably supported by the stopper receiver 6 via the spring 10, when the pawl 3 engages with the stopper body 5, the rotary body 2 fixed to the winding shaft 1 and the rotary body 2 are Sudden shocks applied to the pawl 3 and the stopper body 5 are absorbed and alleviated to prevent damage thereto, and the micro switch 11 pressed by the protrusion 12 of the stopper body 5 is
This also prevents damage.

[Example] Next, FIG. 5 is a front view showing another example of the fall prevention device according to the present invention, and FIG. 6 is a side view thereof.

In this example, the stopper receiver 6 is formed in a case body that accommodates and holds the stopper body 5 in a vertically movable manner, and is located between the rear end side of the stopper body 5 housed in the case body and the stopper receiver 6. A retractable L-shaped buffer member 14 is sandwiched between the operator 13 of the micro switch 11 provided on the stopper receiver 6 and the protruding piece 12 provided on the stopper body 5 on the line on which the pressing force of the claw 3 acts. Buffer member 14
They are arranged so that they face each other with the two sides in between.

When the pawl 3 protrudes outward from the periphery of the rotating body 2 and engages with the stopper piece 5a of the stopper body 5 protruding from the stopper receiver 6 formed on the case body, the pressing force of the pawl 3 is received. Stopper body 5
compresses the buffer member 14, and the protrusion 12 provided on the stopper body 5 moves toward the micro switch 11 and presses the operator 13 of the switch 11.

As a result, as in the case of the embodiment, the micro switch 11 outputs an operation signal that once rotates the winding shaft 1 in the winding direction.
The engagement state between the pawl 3 and the stopper body 5 is released, and the stopped state of the shutter is automatically released.

Furthermore, since the impact generated when the pawl 3 engages with the stopper body 5 is absorbed and alleviated by the elasticity of the buffer member 14, not only the pawl 3 and the stopper body 5 are damaged, but also the micro switch 11 is prevented from being damaged. Prevented.

Note that the switch according to the present invention is not limited to the micro switch 11, but may be a pressure-sensitive switch that converts a change in pressure into an electrical signal and outputs the electrical signal.

Further, the installation location of the switch is not limited to the stopper receiver 6, but may be the stopper body 5,
In short, it is sufficient if it is provided not on the rotating body 2 side but on the stopper side including the stopper body 5 and the stopper receiver 6.

Furthermore, the present invention is not limited to electric opening/closing type shutters, but can also be applied to electric hoisting type shutters for lowering their own weight.

[Effect of idea]

As described above, in the shutter drop prevention device according to the present invention, when the claw provided on the rotating body fixed to the take-up shaft engages with the stopper that prevents the rotation of the take-up shaft due to malfunction, the stopper stops. The switch installed on the side automatically operates and the winding shaft is once rotated in the winding direction, so the pawl that has engaged with the stopper disengages from the stopper and the shutter is automatically released from its stopped state. This has the excellent effect of eliminating the need for maintenance and inspection due to malfunction of the fall prevention device.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an example of a fall prevention device for a shutter according to the present invention, FIG. 2 is a side view thereof, and FIGS. 3 and 4 are exploded views showing the operation of the fall prevention device, respectively. Time chart, 5th
The figure is a front view showing another embodiment of the present invention, Figure 6 is a side view thereof, Figure 7 is a front view of a shutter equipped with a conventional fall prevention device, and Figure 8 is a central longitudinal section of the fall prevention device. The top view and FIG. 9 are cross-sectional views taken along the line C--C. Explanation of symbols, 1... Winding shaft, 2... Rotating body, 3... Claw, 5... Stopper body, 6... Stopper receiver, 8... Coil spring, 11... Micro switch, 12... Projection piece .

Claims (1)

[Scope of utility model registration request] The claws provided on the rotating body fixed to the end of the take-up shaft move outward against the biasing force of the spring due to the centrifugal force caused by abnormal rotation of the take-up shaft that rotates in the unwinding direction of the shutter curtain. Being made to stand out,
In a shutter fall prevention device configured to be removably engaged with a stopper that prevents rotation of a winding shaft, a switch is pressed and activated when the pawl is engaged with the stopper. A fall prevention device for a shutter, which is disposed on the stopper side, and is configured to output an operation signal from the switch to once rotate the winding shaft in the winding direction.