JP7531318B2 - Fire Screen - Google Patents

Description

The present invention relates to a fire screen used to partition openings and interior spaces in buildings, and in particular to a fire screen that has an openable/closable escape route, allowing people to escape from the escape route in the event of an emergency.

Fire shutters and fire (smoke) screens are installed in buildings to close off compartments in the event of a fire or other emergency. In particular, fire (smoke) screens are made using fire-resistant cloth and are characterized by their light weight and low installation costs.

Some fire screens are equipped with an emergency exit section that can be opened and closed for evacuation, allowing evacuation even when the fire screen is down. Since fire and smoke protection performance must be ensured even when an emergency exit section is installed, the main door screen that serves as the emergency exit section has an overlapping section with other screens, making it less likely for gaps to form. To further improve fire and smoke protection performance, fire screens have been developed that have a sub-door screen that covers the overlapping section on the door edge of the main door screen. In such fire screens, the door edge of the main door screen is sandwiched between a fixed screen and a sub-door screen, and when the emergency exit section is closed, there is no linear gap between the separated compartments, resulting in high fire and smoke protection performance.

In a fire screen having such a main door screen and a sub-door screen, both the main door screen and the sub-door screen must be opened when opening the emergency exit, and when closing, the main door screen must be closed first, followed by the sub-door screen. However, the sub-door screen closes first, making it impossible to sandwich the main door screen between the sub-door screens, resulting in a gap between the main door screen and the sub-door screen, which creates a linear path for flames and smoke between the separated compartments, reducing fire and smoke protection.

To address this issue, Patent Document 1 describes a configuration in which the sub-door weight is formed in an L-shape, the tip of the main door weight is engaged with the protrusion, and the force with which the main door screen closes closes the sub-door screen. Patent Document 2 also provides a stopper mechanism that prevents the open sub-door screen from closing, and when the door is closed, the stopper mechanism is released by the closing force of the main door weight before the sub-door screen closes.

In both Patent Document 1 and Patent Document 2, the sub-door weight is formed in an L-shape and provided with a protrusion, and the tip of the main door weight is configured to abut against the protrusion, so the protrusion is formed at a position away from the rotation axis of the sub-door weight. Therefore, the force of the main door weight pressing the protrusion cannot be efficiently used as a force for rotating the sub-door weight and the sub-door screen. For example, when the main door screen closes slowly, even though the main door weight abuts against the protrusion, it stops at that position, and the sub-door screen does not rotate and does not close. In addition, when the sub-door weight is open, the abutment part is located on the open side of the rotation axis of the sub-door weight, so the sub-door weight starts to rotate before the main door weight closes, and there is also a problem that the main door weight and the sub-door weight hit each other before closing and do not close.

Patent No. 3400384 Patent No. 4427179

The present invention was made in consideration of the above-mentioned circumstances, and aims to provide a fire screen that can be closed securely with little force.

The invention described in claim 1 of the present application is a fire screen made of a non-flammable flexible material and having an openable and closable emergency exit section, the emergency exit section having a main door screen and a sub-door screen that overlaps and covers the door end side of the main door screen, a rotatable main door weight that is provided at the bottom of the main door screen, and a rotatable sub-door weight that is provided at the bottom of the sub-door screen, and a hinge section that serves as the rotation axis of the sub-door weight is provided with an abutment section against which the door end section of the main door weight abuts when the door is closed, causing the sub-door weight to rotate.

The invention described in claim 2 of the present application is a fire screen characterized in that the abutment portion of the invention described in claim 1 of the present application is located near the pivot axis or on the closed side of the pivot axis when the sub-door weight is in an open state, and protrudes toward the emergency exit.

The invention described in claim 3 of this application is a fire screen characterized in that the abutment portion in the invention described in claim 1 or 2 of this application is formed integrally with the bearing portion of the pivot shaft of the sub-door weight.

The invention described in claim 4 of the present application is a fire screen characterized in that the pivot axis of the main door weight in the invention described in any one of claims 1 to 3 of the present application is inclined toward the door end of the main door screen, and further includes a main door biasing means for biasing the main door weight in the closing direction.

According to the present invention, the force generated when the main door weight abuts the abutment portion can be efficiently used to rotate the sub-door weight and the sub-door screen, and the sub-door screen can be reliably closed after the main door screen is closed with little force.

Also, on the main door screen side, the upper part of the pivot shaft is tilted toward the door end to increase the closing force due to its own weight, and by providing a main door biasing means, the force pushing the abutment part can be increased, facilitating the rotation of the sub-door weight and allowing the sub-door weight and sub-door screen to be closed more reliably.

FIG. 1 is a schematic diagram (front view) of an example of a fire screen according to an embodiment of the present invention. FIG. 1 is a schematic diagram (cross-sectional view) of an example of a fire screen according to an embodiment of the present invention. 1 is a schematic diagram of an example of the vicinity of the seat board of an emergency exit (when the door is closed). 1 is a schematic diagram of an example of the vicinity of the seat board of an emergency exit (when the door is open). FIG. 13 is a schematic diagram (cross-sectional view) of an example of the vicinity of the seat board of an emergency exit. An enlarged view of an example of a sub-door weight 6 portion. An enlarged view of another example of the sub-door weight 6 portion.

Figures 1 and 2 are schematic diagrams of an example of a fire screen according to an embodiment of the present invention. In the figures, 1 is a main door screen, 2 is a sub-door screen, 3 is a back screen, 4 is a seat plate, 5 is a main door weight, 6 is a sub-door weight, 7 is a winding shaft, 8 is a hoist, 9 is a guide rail, 10 is an emergency exit opening and closing section, and 11 is an emergency opening.

The screen body that shields the opening is integrally composed of a main door screen 1, a sub door screen 2, and a rear screen 3. The main door screen 1, the sub door screen 2, and the rear screen 3 are all made of non-flammable flexible materials such as fireproof cloth, and provide fire and smoke protection. In addition, a seat plate 4 is provided at the bottom of the screen body, and the weight of this seat plate 4 pulls the lightweight screen downward, allowing the screen body to be tensioned with the screen body lowered.

The upper end of the integrally constructed screen body is fixed to the winding shaft 7, and the screen body is normally wound up on the winding shaft 7. In the event of an emergency such as a fire, the screen body is lowered along the guide rail 9 by the hoist 8 or by its own weight, closing the opening. Of course, the lowered screen body can be wound up on the winding shaft 7 by the hoist 8 to secure the opening.

The main door screen 1 is provided with an emergency exit opening/closing section 10 that can be opened and closed as an emergency exit. By opening and closing this emergency exit opening/closing section 10, evacuation is possible even in a shielded state. A main door weight 5 is provided at the bottom of this emergency exit opening/closing section 10, and as this main door weight 5 rotates, the emergency exit opening/closing section 10 of the main door screen 1 opens and closes. In addition, as described below, this main door weight 5 is always biased in the closing direction, and the emergency exit opening/closing section 10 is closed even if no special door closing operation is performed.

A sub-door weight 6 is provided at the bottom of the sub-door screen 2. When this sub-door weight 6 rotates, the sub-door screen 2 also opens. As described below, this sub-door weight 6 is biased in the closing direction when the angle is below a certain specified angle, and is biased in the opening direction when the angle is above a certain specified angle. Therefore, when the emergency exit section is closed, it biases the sub-door screen 2 in the closing direction, and when the emergency exit section is open, it biases the sub-door screen 2 in the opening direction.

The relationship between the main door screen 1, the sub-door screen 2, and the back screen 3 in the emergency exit section is shown in Figure 2. The door end side of the emergency exit opening/closing section 10 of the main door screen 1 overlaps with the back screen 3 on one side. The back screen 3 overlaps with the side opposite to the direction in which the emergency exit opening/closing section 10 of the main door screen 1 opens (the closed side). On the other side of the main door screen 1, that is, the side on which the emergency exit opening/closing section 10 opens (the open side), the sub-door screen 2 is provided so as to overlap and cover the door end side of the main door screen 1. As a result, as shown in Figure 2 (A), when the emergency exit section is closed, the main door screen 1 is sandwiched between the back screen 3 and the sub-door screen 2 at the overlapping part. With this configuration, the other side cannot be directly seen between the sections separated by the screens. Therefore, for example, if a fire breaks out in one compartment, the flames cannot be seen directly from the other compartment if the emergency exit is closed, and the direct intrusion of smoke is also prevented.

When opening the emergency exit section, the emergency exit opening/closing section 10 of the main door screen 1 is pushed open. At this time, the main door weight 5 abuts and pushes against the sub-door weight 6, causing the sub-door weight 6 to rotate and open the sub-door screen 2. When the sub-door weight 6 opens beyond a predetermined angle, the sub-door screen 2 is biased toward the opening side and opens fully. This state is shown in Figure 2 (B). When the emergency exit opening/closing section 10 of the main door screen 1 and the sub-door screen 2 open, the emergency opening 11 appears, and evacuation can be performed through this emergency opening 11.

When the emergency exit section is open, the secondary door weight 6 is biased toward the open side, so the secondary door screen 2 remains open. In contrast, the primary door screen 1 is biased toward the closed side by the primary door weight 5 and is also biased toward the closed side by its own weight. Therefore, when the emergency exit section is closed, the emergency exit opening/closing section 10 of the primary door screen 1 and the primary door weight 5 first rotate and move to close the emergency exit section.

Then, just before the emergency exit opening/closing section 10 of the main door screen 1 and the main door weight 5 close, the door end section of the main door weight 5 abuts against an abutment section provided on the hinge of the sub-door weight 6 (described below), causing the sub-door weight 6 to rotate in the closing direction. When the main door weight 5 presses against the abutment section and the sub-door weight 6 rotates below a predetermined angle, the sub-door weight 6 is urged toward the closing side and closes so that it overlaps the main door weight 5. This returns it to the state shown in Figure 2 (A).

Figures 3, 4, and 5 are schematic diagrams of an example of the vicinity of the seat plate of the emergency exit, and Figures 6 and 7 are enlarged diagrams of an example of the sub-door weight 6 portion. Figure 3 shows the state when the door is closed, and Figure 4 shows the state when the door is open. Figure 5 shows cross-sectional views of the door when closed and when open. In the figures, 21 is the main door hinge, 22 is the protrusion, 23 is the closing wire, 24 is the closing auxiliary spring, 31 is the sub-door hinge, 32 is the abutment, 33 is the pivot, 34 is the sub-door auxiliary spring, 41 is a magnet, 42 is a guard plate, 43 and 44 are airtight materials, 45 is a slip, and 46 is a lower sealing material.

The main door weight 5 is attached to the seat plate 4 so as to be rotatable by the main door hinge 21. The pivot axis of the main door hinge 21 is inclined upward toward the door end of the emergency exit opening/closing section 10 of the main door screen 1. This inclination causes the main door weight 5 to pivot diagonally upward toward the opening side, and as shown in FIG. 1, the emergency exit opening/closing section 10 opens in an approximately right-angled triangular shape. In addition, the pivot axis of the main door hinge 21 is inclined, and the main door weight 5 opened to the opening side is biased toward the closing side by its own weight. Furthermore, a closing wire 23 is connected to the main door weight 5, and is biased toward the closing side by the closing auxiliary spring 24. In this example, the main door weight 5 is biased toward the closing side more strongly than before by the biasing force of both the inclined pivot axis of the main door hinge 21 and the closing auxiliary spring 24, ensuring that the door is closed after opening. In addition, when the door is closed, the main door weight 5 strongly abuts against the seat plate 4 and bounces back, preventing it from opening again. As a main door biasing means for biasing the main door weight 5 in the closing direction, various known biasing means other than the closing assist spring 24 may be used.

In addition, in this example, a protrusion 22 is provided on the door end side of the main door weight 5, which abuts against an abutment 32 provided on a sub-door hinge 31 (described later) when the door is closed. Of course, this protrusion 22 may not be provided, and the end of the door end side of the main door weight 5 may be configured to abut against the abutment 32.

The sub-door weight 6 is rotatably attached to the seat plate 4 by the sub-door hinge 31, and the sub-door weight 6 rotates around the pivot shaft 33 of the sub-door hinge 31. In addition, a sub-door auxiliary spring 34 is attached between the sub-door weight 6 and the seat plate 4. The pulling force of this sub-door auxiliary spring 34 urges the sub-door weight 6 toward the closing side while the sub-door weight 6 is open to a predetermined angle as described above, so that the door end side of the main door screen 1 is reliably covered by the sub-door screen 2. This urging toward the closing side reduces the gap between the main door screen 1 and the sub-door screen 2, improving fire and smoke prevention performance, and reducing the flapping of the main door weight 5 toward the opening side due to the flapping of the screens such as the main door screen 1. When the sub-door weight 6 opens to a predetermined angle or more, the sub-door auxiliary spring 34 urges the sub-door weight 6 toward the opening side. This prevents the child door screen 2 from closing before the main door screen 1 when the door is closed. The direction of the biasing force applied by the child door auxiliary spring 34 to the child door weight 6 can be changed, for example, depending on whether the child door auxiliary spring 34 is in the closing direction or the opening direction relative to the axis (pivot shaft 33) of the child door hinge 31.

The sub-door hinge 31 is provided with an abutment portion 32 against which the door end of the main door weight 5 abuts when the door is closed. This abutment portion 32 should be provided so as to protrude from the vicinity of the pivot axis or from a position on the closed side of the pivot axis toward the emergency exit side (the emergency opening 11 side, the door end direction of the main door screen 1) when the sub-door weight 6 is open. In the example shown in FIG. 6, an example is shown in which the abutment portion 32 is provided so as to protrude toward the emergency exit side from approximately the position of the pivot axis. Also, in the example shown in FIG. 7, an example is shown in which the abutment portion 32 is provided so as to protrude toward the emergency exit side from a position on the closed side of the pivot axis. When the door is closed, the door end of the main door weight 5, in this example the protrusion 22, abuts against this abutment portion 32 and pushes it toward the closed side, causing the sub-door hinge 31 to rotate, and the sub-door weight 6 to rotate. The abutment portion 32 may be formed integrally with the bearing portion of the sub-door hinge 31, and may have various shapes, such as protruding radially from the pivot shaft, without being limited to the examples shown in Figures 6 and 7.

As described above, the abutment portion 32 is provided on the sub-door hinge 31, and in particular, when the sub-door weight 6 is open, it is preferable to provide it so that it protrudes toward the emergency exit from a position near the pivot axis or on the closed side of the pivot axis. By providing the abutment portion 32 in such a position, the force of the main door weight 5 abutting against the abutment portion 32 can be efficiently used to rotate the sub-door weight 6. For example, even if the force of the main door weight 5 abutting against the abutment portion 32 is weak because the main door weight 5 is closed slowly, the sub-door weight 6 can be reliably rotated, and the sub-door screen 2 can be closed after the main door screen 1 is closed. In addition, the force of the main door weight 5 abutting against the abutment portion 32 is also strengthened by the biasing force of both the inclined pivot axis of the main door hinge 21 and the closing assistance spring 24 as described above, and this biasing force also promotes the rotation of the sub-door weight 6. In addition, after the sub-door weight 6 has rotated to a specified angle, the sub-door auxiliary spring 34 biases the sub-door weight 6 toward the closing side, ensuring that the sub-door screen 2 is closed. It is advisable to adjust the amount of overlap between the abutment portion 32 of the sub-door hinge 31 and the door end portion (projection portion 22) of the main door weight 5 so that the sub-door auxiliary spring 34 biases the sub-door weight 6 toward the closing side before the main door weight 5 reaches the closed position.

The attachment position of the sub-door weight 6 to the sub-door hinge 31 can be adjusted separately from the abutment portion 32. As shown in Figs. 6 and 7, if the sub-door weight 6 is attached to a position slightly away from the rotation axis 33, it can accommodate the thickness of the main door weight 5. In this way, the attachment position of the sub-door weight 6 to the sub-door hinge 31 can be designed according to various conditions, such as the thickness of the main door weight 5 and the position of the rotation axis 33 of the sub-door hinge 31. For example, if an abutment portion is provided on the sub-door weight 6, the sub-door weight 6 must be provided close to the door edge of the main door weight 5 in order to abut the door edge of the main door weight 5 against the abutment portion. However, by providing the abutment portion 32 on the sub-door hinge 31, it is possible to move the sub-door weight 6 to a certain extent away from the door edge position of the main door weight 5 when the sub-door weight 6 is open. In addition, the opening angle when the sub-door weight 6 is opened can also be adjusted separately from the abutment portion 32.

The seat plate 4, which the door edge of the main door weight 5 abuts against when the door is closed, is provided with a magnet 41, a guard plate 42, an airtight material 43, etc. The magnet 41 magnetically attaches the closed main door weight 5 to prevent the main door weight 5 from flapping when the door is not open. The guard plate 42 prevents the main door weight 5 from rising above the magnet 41 when the screen body is rolled up; in this example, when the main door weight 5 tries to rise, the protrusion 22 engages with the guard plate 42, restricting the upward movement of the main door weight 5.

The airtight material 43 closes the gap between the main door weight 5 and the seat plate 4 when the main door weight 5 is closed. When the main door weight 5 is magnetically attached to the magnet 41, the main door weight 5 is pressed against the airtight material 43 by the magnetic force of the magnet 41. The airtight material 43 also functions as a cushioning material that absorbs the impact when the main door weight 5 closes. An airtight material 44 is also provided on the tail side of the main door weight 5, and like the airtight material 43, it closes the gap between the main door weight 5 and the seat plate 4 when the main door weight 5 is closed.

As shown in Figure 5 (A), the upper part of the main door weight 5 is inclined toward the closing side. This allows the main door screen 1 to come into close contact with the rear screen 3 when the main door weight 5 is closed, reducing the gap between the two and improving fire and smoke protection.

As shown in FIG. 5(B), the seat plate 4 of the emergency exit opening/closing section 10 is provided with a slip stopper 45 and has a lower blocking material 46 protruding from it. When the main door weight 5 is closed, the lower blocking material 46 comes into contact with the main door weight 5, preventing flames and smoke from entering from the bottom of the emergency exit opening/closing section 10.

An example of the operation of one embodiment of the present invention will be described. The state in which the emergency exit section is closed is shown in Figures 1 and 2 (A), and the state near the seat plate 4 at that time is shown in Figures 3 and 5 (A). In this state, the opening is closed by the screen. The main door screen 1 has its door end portion of the emergency exit opening and closing section 10 sandwiched between the back screen 3 and the sub-door screen 2. Near the seat plate 4, the main door weight 5 is magnetically attached to the magnet 41 provided on the seat plate 4, and the main door weight 5 is pressed against the airtight material 43 and the airtight material 44 by the magnetic force at that time. Furthermore, the upper part of the main door weight 5 is inclined to the closing side, and the main door screen 1 is positioned on the closing side, so that it is close to and in contact with the back screen 3. Furthermore, the lower sealing material 46 provided on the seat plate 4 and the main door weight 5 are in contact.

Meanwhile, the sub-door weight 6 is biased toward the closing side by the sub-door auxiliary spring 34, and covers the door edge side of the main door weight 5. As a result, the sub-door screen 2 covers the door edge side end of the emergency exit opening and closing part 10 of the main door screen, and as described above, sandwiches the main door screen 1 together with the rear screen 3.

These configurations ensure that when the emergency exit opening/closing section 10 is closed, no linear gaps are created between the sections separated by the screen, and gaps are minimized as much as possible, ensuring fire and smoke protection even when the emergency exit opening/closing section 10 is installed.

When opening the emergency exit opening/closing section 10 when the main door screen 1 and the sub-door screen 2 are closed, an evacuee simply pushes open the emergency exit opening/closing section 10 of the main door screen 1 from the closed side to the open side. When the main door screen 1 is pushed to the open side, the main door weight 5 also tries to rotate to the open side. Then, the main door weight 5 comes into contact with the sub-door weight 6 of the sub-door screen 2 that covers the door end side of the main door weight 5, pushing the sub-door weight 6 to the open side. In this way, the sub-door weight 6 also rotates together with the rotation of the main door weight 5. The sub-door weight 6 is biased to the closed side by the sub-door auxiliary spring 34 at the beginning of the rotation, and the sub-door weight 6 opens while being pushed by the main door weight 5.

As the sub-door weight 6 continues to open, the sub-door auxiliary spring 34 biases the sub-door weight 6 toward the open side when it opens beyond a predetermined angle. The pulling force of the sub-door auxiliary spring 34 at this time causes the sub-door weight 6 to rotate to the maximum open angle and stop. For example, if the sub-door weight 6 is biased toward the closed side even after it separates from the main door weight 5, the sub-door weight 6 will close with the main door weight 5 open, and the main door screen 1 will not be able to be sandwiched between the rear screen 3 and the sub-door screen 2 when the door is closed. To avoid such problems, the predetermined angle at which the sub-door auxiliary spring 34 changes its biasing direction must be an angle that can be reached while the main door weight 5 is abutting and pushing the sub-door weight 6 when the door is opened.

The main door weight 5 can continue to rotate even after it is separated from the sub-door weight 6. This rotation of the main door weight 5 is performed around the rotation axis of the main door hinge 21. As described above, the main door hinge 21 has a rotation axis with the upper part tilted toward the door end, and by rotating around this rotation axis, the main door weight 5 rotates diagonally upward on the open side. As a result, the emergency exit opening/closing section 10 of the main door screen 1 opens in a roughly right-angled triangular shape, securing the emergency opening 11. Evacuees can escape through this emergency opening 11. The vicinity of the seat panel 4 with the emergency exit opening/closing section 10 open is shown in Figures 4 and 5 (B).

When the emergency exit opening/closing section 10 is open, the main door weight 5 rotates diagonally upward toward the open side as described above, and therefore attempts to rotate toward the closed side due to its own weight. The main door weight 5 is also biased toward the closed side by the closing assist spring 24 via the closing wire 23. As a result, the main door weight 5 is biased toward the closed side when the emergency exit opening/closing section 10 is open, and after the evacuees have evacuated, the emergency exit opening/closing section 10 of the main door screen 1 is biased in the closing direction even if the evacuees do not close the emergency exit.

When the emergency exit opening/closing section 10 is open, the secondary door weight 6 is biased toward the open side by the secondary door auxiliary spring 34, and the secondary door weight 6 and secondary door screen 2 remain open. As the secondary door weight 6 rotates, the abutment portion 32 provided on the secondary door hinge 31 also rotates, and when the secondary door weight 6 is open, as shown in Figures 6 and 7, the abutment portion 32 protrudes toward the emergency exit section (approximately toward the end of the main door weight 5) and can abut against the door tip of the main door weight 5.

When the door is closed, the main door screen 1 and the main door weight 5 are biased toward the closing side and rotate as described above. Then, just before the main door weight 5 closes, the protrusion 22 provided on the door end side of the main door weight 5 abuts against the abutment portion 32 protruding from the sub-door hinge 31, pushing this abutment portion 32 toward the closing side. As the abutment portion 32 is pushed toward the closing side, the sub-door hinge 31 rotates around the rotation axis 33, and the sub-door weight 6 rotates accordingly. Since the abutment portion 32 is provided on the sub-door hinge 31, the force when the main door weight 5 abuts against the abutment portion 32 can be efficiently used as a rotation force. Therefore, for example, even if the main door weight 5 abuts against the abutment portion 32 gently, the main door weight 5 does not stop in the abutting state, and the sub-door weight 6 can be reliably rotated. The force pushing the abutment portion 32 is also increased by biasing the main door weight 5 toward the closing side by the closing assist spring 24, so that the secondary door weight 6 can be rotated more reliably. In addition, the impact force received by the abutment portion 32 and the secondary door hinge 31 is also mitigated by efficiently utilizing the time when the main door weight 5 abuts against the abutment portion 32.

When the sub-door weight 6 is initially rotated when the door is closed, it is biased toward the open side by the sub-door auxiliary spring 34, but once a certain angle has passed, it is biased toward the closed side and the sub-door weight 6 rotates toward the closed side. At this point, the main door weight 5 has already moved toward the closed side beyond the sub-door hinge 31, so the sub-door weight 6 closes to cover the edge of the closed main door weight 5. As the sub-door weight 6 is biased toward the closed side and rotates, the abutment portion 32 provided on the sub-door hinge 31 also rotates. When the sub-door weight 6 is closed, the abutment portion 32 is released from abutment with the main door weight 5 and is stored between the sub-door hinge 31 and the seat plate 4 that engages the rear screen.

In this way, the sub-door weight 6 can be closed after the main door weight 5 is closed. As for the screens, the sub-door screen 2 can be closed after the main door screen 1 is closed, so that the rear screen 3, main door screen 1, and sub-door screen 2 overlap normally in this order, and the edge of the main door weight 5 can be closed by being sandwiched between the rear screen 3 and the sub-door screen 2.

If the secondary door screen 2 closes first, the compartment on the opposite side will be visible through the gap between the main door screen 1 and secondary door screen 2. In this state, if a fire breaks out in one compartment, the flames will be directly visible from the other compartment, and smoke will also enter directly through the gap, reducing fire and smoke prevention performance. For this reason, when closing the doors, it is necessary to close the main door screen 1 before closing the secondary door screen 2, and this invention ensures that the doors are closed in this order.

When the main door weight 5 reaches the closed position, it is magnetically attached to the magnet 41 and is biased toward the closed side by the closing auxiliary spring 24, and the sub-door weight 6 is biased toward the closed side by the sub-door auxiliary spring 34. As a result, even if the rotational force of the main door weight 5 is strong, the recoil when it is closed is reduced by these biasing forces toward the closing side, preventing the door from opening due to the recoil when it is closed. In addition, these biasing forces toward the closing side prevent the main door screen 1 and main door weight 5 from opening even if some wind pressure is applied from the closing side, and the main door weight 5 is pressed against the airtight materials 43, 44, improving fire and smoke resistance.

1...Main door screen, 2...Sub-door screen, 3...Rear screen, 4...Seat plate, 5...Main door weight, 6...Sub-door weight, 7...Winding shaft, 8...Winching machine, 9...Guide rail, 10...Emergency exit opening/closing section, 11...Emergency opening, 21...Main door hinge, 22...Protrusion, 23...Closing wire, 24...Closing auxiliary spring, 31...Sub-door hinge, 32...Abutment section, 33...Pivot shaft, 34...Sub-door auxiliary spring, 41...Magnet, 42...Guard plate, 43, 44...Airtight material, 45...Slip, 46...Lower sealing material.

Claims (4)

A fire screen made of a non-flammable flexible material and having an openable and closable emergency exit section, the emergency exit section having a main door screen and a sub-door screen that overlaps and covers the leading edge of the main door screen, a rotatable main door weight that is provided at the bottom of the main door screen, and a rotatable sub-door weight that is provided at the bottom of the sub-door screen, and a hinge that serves as the pivot axis of the sub-door weight has an abutment that the leading edge of the main door weight abuts against when the door is closed, causing the sub-door weight to rotate. The fire screen according to claim 1, characterized in that the abutment portion is located near the pivot shaft or on the closed side of the pivot shaft when the sub-door weight is open, and protrudes toward the emergency exit. The fire screen according to claim 1 or 2, characterized in that the abutment portion is formed integrally with the bearing portion of the pivot shaft of the sub-door weight. The fire screen according to any one of claims 1 to 3, characterized in that the pivot axis of the main door weight is inclined toward the door end of the main door screen, and further includes a main door biasing means for biasing the main door weight in the closing direction.

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