The present invention relates to an improved fire door.

More specifically, the invention relates to an improved fire door which is suspended in a frame by means of hinges and which can be moved by means of a door handle between a closed position in which the door rests against a door stop or stop strip and an open position in which it does not.

The function of a fire-resistant door is to compartmentalize two sections of a building during a fire.

The frame and the door as a whole must slow down the passage of fire and heat as much as possible, at least for a predetermined time limit of for example 30, 60 or 120 minutes depending on the standards applied, such as the European standard EN1634.

Such a fire door therefore serves as a thermal break, automatically creating a warm zone on one side of the door and a cold zone on the other side of the door.

However, this difference in temperature across the door leads to deformation of the materials used, and these deformations can become so great that the thermal barrier is broken, which is unacceptable.

This problem arises in particular with the combination of a wooden door, a metal frame and a lightweight partition wall of, for example, plasterboard panels on a metal or wooden structure, and more specifically when the fire starts on the side where the door is pulled open.

In that case, the metal frame and wooden door will deform in opposite directions, creating gaps between the door and frame and allowing the fire to break through the barrier.

It is always assumed that in the event of a fire, the door is closed only by a latch bolt of the door lock and not by a dead bolt.

There are a lot of known solutions according to the present state of the art, but they still have a lot of disadvantages .

In some known solutions, the frame is filled with a stony material, such as plaster or something similar.

This slows down the warping of the metal frame, but a disadvantage of this method is that it can only be implemented in the structural work phase and not in the finishing phase of a building.

Also, the risk of damage to the lacquer layer of the frame during the filling is very high.

Pre-casting the frame full with plaster or something similar in a factory is not a good solution either, as this will make the frame extremely heavy, so that the plaster may crack and come off the frame during transport. Mounting such a heavy frame is very difficult as well.

Another well-known solution is to make the doors thicker, so that if they are deformed by fire, there will be a larger or more long-term overlap between the door and frame, and it will take longer to break through the thermal barrier.

This solution again leads to doors that are much too heavy, with mounting and transport problems and the like.

Another known possible solution is to fit the fire- resistant door with locks with, for example, three latch bolts, more specifically in the middle and additionally at the top and bottom.

These can ensure that the door will follow the curvature of the frame in case of fire, so that no gaps are created between the door and the frame.

In practice, however, it is not possible to fit all fire doors with such locks, and certainly not doors that are electrically controlled, for example by a badge reader or an emergency center.

Another known solution is to fit the frame with a thermal break.

A disadvantage of such embodiments is that the thermal break makes it very time-consuming and expensive to fit standard hinges and locks. Another disadvantage of this known solution is that the frame profile must be made of several parts, which reduces the stability of the profile.

This known solution is not optimal from an aesthetic point of view either, as the thermal break remains visible.

Yet another known solution for improving the fire- resistant properties of a door is to use a so-called thermal latch.

This is a bolt that is glued into a housing and mounted in the frame.

When heated by fire, the adhesive dissolves as of a certain temperature, releasing a pin that is pushed down into the door by a built-in spring so as to fix it, preventing the door from warping any further and preventing gaps being formed between the door and the frame, at least that is the theory.

However, the moment at which the pin comes down and fixes the door is unpredictable, and the place where the pin should penetrate the door as a function of the deformations already occurring cannot, therefore, be determined with certainty either, making this fire protection method unreliable.

Another well-known solution is to replace the head of the metal frame by a wooden profile of the same dimensions and appearance, which reduces the burning of the wooden door by the radiation of the glowing metal. A major disadvantage of this solution is that the frame is no longer entirely made of metal.

The vertical jambs of the frame will also continue to warp, and a powder coating finish at the factory is not possible for the wooden part.

Another known solution is to make the wall in which the door is placed as strong as possible and to make the frame on the fire side so weak that the wall can counteract the warping of the frame and the deformations will remain as small as possible.

Some of the disadvantages of these known solutions are the reduced stability of the frame during daily intensive use, the high cost price, the difficulty of installing hinges and locks and the waste of resources.

The present invention therefor aims to provide a solution to the aforementioned and/or other problems.

More specifically, it is an object of the invention to provide an improved fire-resistant door in which the formation of gaps between the frame and the door due to deformations under large temperature differences is counteracted as much as possible, so that an increased fire resistance is obtained.

Another object of the invention is to provide a fire door which can be designed lightly, has elements whose operation is assured to a very high degree and which can be mounted in a simple manner.

An additional object of the invention is to provide a solution for improved fire protection which can be applied to fire doors of all types.

Yet another object of the invention is to ensure that applied mechanisms are easy to maintain and, if necessary, easily replaceable.

A further object of the invention is to provide a simple and relatively inexpensive solution, applicable to various door types and to large-format doors.

To this end, the invention concerns an improved fire door provided with a blocking mechanism comprising at least the following elements: blocking means which are movable between a blocked position and an unblocked position corresponding to a closed position and an open position of the door and which, in the blocked position, on the side of the door handle, hold a part of the door at a corner of the door or the parts of the door at the corners of the door against the door stop in the frame or against a stop strip;

- mechanical activating means that include at least one movable pin which, when the door is closed, is moved to a stowed position (for activation of the activating means) by a pressing contact between the door and the door stop or a (e.g. frontal, end side of a) fixed leaf, and in which the movable pin moves to an extended position when the door is opened; and - transmission means which connect the activating means to the blocking means and which, upon activation of the activating means, transfer the movement of pressing the pin to the blocking means in order to move the latter into the blocking position and which, upon opening the door, cause the pins of the activating means and blocking means to move jointly to the extended position and to the unblocked position, respectively.

The blocking devices are adapted to engage, in the blocked position, in one or more apertures provided in one of the following elements: a) in an upper end side of the movable fire door; b) in a frontal end side of the movable fire door on the side of the door handle or lock; c) in a fixed jamb surrounding the fire door.

In the blocked position, the blocking means engage in said aperture (s) in such a way that no or substantially no contact is made between the blocking means and the element in/around the aperture, at least during normal use in the absence of fire (e.g. without exposure to extreme heat).

However, when exposed to heat, the blocking means will clamp in this aperture. In other words, the fire door is adapted to clamp the blocking means in said one or more apertures due to the deformation of the fire door upon exposure to heat during a fire.

A major advantage of such an improved fire-resistant door according to the invention is that it is provided with blocking means which, when the door is closed, are placed in a blocked position, whereby on the side of the door handle, a part of the door at a corner of the door or the parts of the door at the corners of the door will be held against the door stop in the frame or against a stop strip or against a milled door edge by the blocking means.

In this way, the door and frame are held together at all times and the problem of gaps being created that eliminate the door's fire-retardant properties is solved.

In principle, when the door is closed, the door is already held, at the handle, approximately in the middle of the door, against the door stop or against a stop strip or a milled door edge by the latch.

In an improved fire-resistant door according to the invention, it is essential to understand that each time the door is closed, the activating means are activated which bring the blocking means into the blocked state via the transmission means, whereby the door is automatically locked both in the middle at the latch and in the top corner and/or possibly in the bottom corner.

As long as the door remains closed, the door will remain locked on the lock side, at the top and/or bottom and in the middle, so that the door lock remains active while the door is closed, even before a fire has started.

As soon as the door opens, the door is unlocked on the lock side, at the top and/or bottom and in the middle. The locking on the lock side at the top and/or bottom does not interfere with the daily use of the door, since locking and unlocking is done automatically by activating and deactivating the activating means with their pins, without any additional actions by the user.

The blocking mechanism is not a lock and is not intended to keep the door closed.

The aim is not to create an additional lock with the blocking mechanism, to lock the door or to act as burglary protection.

The blocking mechanism merely ensures that the door, when it is sitting against the door stop of the frame or against a stop strip or a milled door edge, cannot warp at the top and/or bottom and come out of the frame.

In order to better explain the characteristics of the invention, the following preferred embodiments of an improved fire-resistant door according to the invention are described below by way of example without being restrictive in any way, with reference to the accompanying figures, in which:

Figure 1 schematically shows a front view of a fire- resistant door in a wall to indicate a number of zones;

Figure 2 shows a section according to the F02-F02 cut through the door and wall from Figure 1; Figures 3 to 8 included are sections similar to those in Figure 2, illustrating the deformations that occur in different fire situations;

Figure 9 shows a front view of various types of fire- resistant doors that can be made as an improved fire- resistant door according to the invention;

Figure 10 shows, in front view, an upper corner on the latch side of a first embodiment of a fire door according to the invention, wherein the blocking mechanism is shown as well in the unblocked position; Figures 11 to 14 included show views and sections according to arrows Fll to F14 included respectively; Figures 15 to 19 included show the fire door in a manner similar to that in Figures 10 to 14 included, with the blocking mechanism in the blocked position; figures 20 to 23 included illustrate the same situation again in a similar manner; figure 24 shows a second embodiment of a fire- resistant door according to the invention in a similar way as in figure 10; figure 25 shows a section according to arrows F25-

F25; figure 26 shows a cross-section according to arrows

F26-F26, corresponding to a closed and blocked position of the fire door; figure 27 shows a cross-section as shown in figure

26, but for the opened and unblocked position of the door; figures 28 to 30 included illustrate again in a similar manner a third embodiment of an improved fire-resistant door according to the invention, more specifically a double, improved fire-resistant door in the open position;

Figures 31 to 33 included show in an analogous manner as in Figures 28 to 30 included the closed position of the double, improved, fire-resistant door;

Figure 34 shows, in a manner similar to that in Figure 10, a fourth embodiment of a fire door according to the invention, this time with the upper half of the figure showing the door in the closed position and the lower half of the figure showing the open position of the door;

Figures 35 to 39 included show sections and views in accordance with arrows F35 to F39 included;

Figures 40 and 41 show the sections identified by F40 and F41 in Figures 28 and 31 respectively to a larger scale;

Figures 42 to 44 included are cross-sections as in Figures 3 to 8 included which, in order to illustrate the operation of an improved fire-resistant door according to the invention, show the deformations which occur in the frame and in the improved fire- resistant door in the event of fire; and,

Figure 45 is an alternative version of Figure 30. Figures 1 and 2 show a known fire door 1 around which a frame 2 is fitted in a wall 3.

In a typical application, the door 1 is a wooden door 1 and the frame 2 is a metal frame 2. The wall 3 is in this case a light partition wall 3 made of plasterboard 4 which is mounted on a metal or wooden structure 5.

The door 1 is mounted in the frame 2 by means of hinges 6 on the hinge side 7 of the door 1.

The door 1 is further provided with a door handle 8 which, as usual, is placed approximately at half height in the middle 9 of the door 1 on the latch side 10 of the door 1.

When closing the door 1, the door is locked in the middle 9 of the latch side 10 in an aperture in the frame 2 by means of a latch bolt 11.

The fire door 1 can be moved by means of the door handle 8 between a closed position, in which the door 1 rests against a door stop 12, and an open position in which this is not the case.

As mentioned in the introduction, the purpose of a fire door 1 is to compartmentalize two sections of a building on either side 13 and 14 of the door 1.

The effects in case of a fire 15 are illustrated in Figures 3 to 8.

Figure 3 shows how a metal frame 2 warps or becomes more exactly convex towards the side 16 where the fire 15 is burning . That is because this side 16 of the frame 2 which is heated by the fire 15 expands with respect to the opposite side 17 which is not directly exposed to the fire 15 and which remains at room temperature for a long time.

The light partition wall 3 cannot prevent this deformation and follows the curvature of the metal frame 2.

Figure 4 illustrates that when a wooden door 1 is exposed to flames or fire 15 on one side 16, the moisture on that side 16 of the door 1 will then start to evaporate, causing the wood to shrink.

Since the moisture in the wood on the side 17 of the door 1 which is not directly exposed to the fire does not evaporate or at least evaporates much less quickly and therefore does not shrink or shrinks more slowly, the door 1 will begin to warp, with the door 1 bulging towards the cold side 17.

The deformations of the metal frame 2 and the wooden door 1 thus go in opposite directions, which has different consequences depending on whether the side 16 where the fire 15 is burning is the side 18 on which the door 1 is opened by pushing the door 1, or the side 19 on which the door 1 is opened by pulling the door 1.

The first situation is not problematic and is illustrated in Figures 5 and 6.

Indeed, when the side 16 where the fire 15 is burning is the side 18 of the door 1 where the door 1 is opened by pushing it open, the outer edges 20 of the wooden door 1 will be held against the warping frame 2, which is illustrated in Figure 5, so that no gaps are created between the wooden door 1 and the metal frame 2.

After all, on the hinge side 7, the hinges 6 hold the door 1 against the frame 2; in the middle 9, on the lock side 10 of the door 1, the latch bolt 11 ensures that the door 1 also remains pressed against the door stop 12.

Due to the curvature of the metal frame 2 away from the fire 15, the door 1 is also pressed against the door stop 12 on the upper sections 21 and 22 and the lower section 23 of the door 1 at the corners 24 and 25 of the door 1 on the latch side 10.

In short, the door 1 remains well in place in the frame 2 without any gaps being created, so that foam-forming products can properly seal the chinks between the door 1 and the frame 2.

Figure 6 shows the deformation of the door 1 at the central part 26, and it is clear that the door 1 may still have a concave curvature there on the side 16 of the fire 15.

Figures 7 and 8 illustrate the deformations that occur, on the hinge side 7 and the latch side 10 respectively, when the side 16 of the door 1 where the fire 15 breaks out is the side 19 where the door 1 can be opened by pulling the door 1. On the hinge side 7, the wooden door 1 apparently neatly follows the curvature of the metal frame 2 as in the previous case, thanks to the fastening of the door 1 to the frame by means of the hinges 6.

On the latch side 10, the door 1 remains closed in the middle 9 at the position of the door handle 8 and the lock 27 thanks to the latch bolt 11.

However, in the upper sections 21 and 22 and the lower section 23 of the door 1 at the corners 24 and 25 of the latch side 10, where there are no fixed connections between the frame 2 and the door 1, the deformations go in opposite directions, creating gaps 28 and 29.

As a result, the wooden door 1 is exposed to the fire 15 at the corners 24 and 25, on three sides, namely on the door surface 30, on a crosscut frontal side 31 and on a crosscut upper or lower side 32 or 33, causing the door 1 to burn at an accelerated rate.

Such a condition makes it very difficult to comply with the requirements of imposed standards, such as the European standard EN16034 Eli.

Foam-forming product placed in the door 1 and/or the frame 2 to seal the play between door 1 and frame 2 and to protect the wood against the glowing metal of the frame 2, will no longer be able to fill this play.

This creates an air flow that accelerates the burning process of the wood. This burning away continues exponentially, as the resulting gaps 28 and 29 become larger and larger due to the increasing deformations of the frame and door.

Figure 9 shows a great number of different types of fire doors, all of which can be implemented as an improved fire door 34 according to the invention.

Doors 35 and 36 relate to a single door 35 and a double door 36 respectively, which are surrounded by a frame 2 comprising two vertical jambs 37 and 38 and an upper, horizontal head piece 39.

Similarly, doors 40 and 41 are a single door 40 and a double door 41 respectively which are also provided with a frame 2 that additionally has a lower horizontal piece 42, so that the doors 40 and 41 are completely surrounded by the frame 2.

Doors 43 and 44 are a single door 43 and a double door 44 respectively of the floor-to-ceiling type, the frame 2 comprising only the vertical jambs 37 and 38 this time.

Finally, there are doors 45 and 46 with a fixed top-hung panel 47 and doors 48 and 49 with a top-hung window 50, each in single and double embodiments respectively, wherein the frame 2 has vertical jambs 37 and 38 and an upper horizontal head piece 39 and wherein, in the case of the doors 45 and 46, there is no intermediate frame profile 51 for supporting the panel 47, but there is in the case of the doors 48 and 49 for supporting the window 50.

Figures 10 to 23 included illustrate a first possible embodiment of an improved fire-resistant door 34 according to the invention.

This fire door 34 is provided with a blocking mechanism 52 comprising activating means 53 as well as blocking means 54 and transmission means 55 for transferring the position of the activating means 53 to the blocking means 54 and for activating and deactivating the blocking means 54.

According to the invention, the activating means 53 are preferably mechanical in nature, and the activating means 53 comprise at least one movable pin 56 which, when the fire door 34 is closed, is moved to a stowed position for activating the activating means 53, which is illustrated in Figures 15 to 23 included, and which, when the fire door 34 is opened, moves to an extended position, which is the situation illustrated in Figures 10 to 14.

In the embodiment discussed here, the movable pin 56 of the mechanical activating means 53 extends from a door stop 12 of the fire door 34 in the extended position.

The pin 56 protrudes, for example, 10 mm beyond the draught rubber 76 contained in the door stop 12, as illustrated, for example, in Figure 14. When the fire door 34 is closed, this movable pin 56 is pushed through the door 34 into the door stop 12 in its stowed position.

The pin 56 is herein arranged at the height of the door handle 8, more or less in the middle 9 of the improved fire door 34.

The blocking means 54 can be moved between an unblocked position, shown in Figures 10 to 14 included, and a blocked position, shown in Figures 15 to 23 included, corresponding to an open position and a closed position respectively of the improved, fire-resistant door 34.

According to the invention, in the blocked position, the blocking means 54 hold one or more sections 21 to 23 included of the door 34 against the door stop 12 in the frame 2.

More specifically, in the embodiment discussed above, this concerns a section 21 and/or 22 of the door 34 at an upper corner 24 of the door 34 on the side 10 of the door handle 8 or of the lock 27.

In other embodiments, the blocking means 54, in the blocked position, hold the sections 21 to 23 included of the door 34 at both corners 24 and 25 of the door 34 on the side 10 against the door stop 12 in the frame 2.

As a result, a fire-resistant door 34 in accordance with the invention has improved fire-resistant properties, since, depending on the embodiment, no gap 28 can be created between frame 2 and door 34 or no gaps 28 and 29 can be created between frame 2 and door 34, or only at a much later stage of the fire.

In the first embodiment of an improved, fire-resistant door 34 according to the invention as discussed here, the blocking means 54 are such that, in the blocked position, they engage in an aperture 57 provided in an upper end side 32 of the movable, fire-resistant door 34 at the upper section 21 of the door 34.

The blocking means 54 in this case form a lever system 58 hinged in the frame 2 around a pivot shaft 59.

This lever system 58 further has an ingoing side 60 formed by a plate 60 extending transversely to one end of the pivot shaft 59 and rigidly connected to the latter on the one hand, and it has an outgoing side 61 on the other hand, which in this case is also formed by a plate 61 extending transversely to the other end of the pivot shaft 59 and also rigidly connected to the latter.

By rotating the pivot shaft 59, the lever system 58 tilts and the blocking means 54 are moved from the blocked to the unblocked position or vice versa, depending on the direction of rotation.

The transmission means 55 connect the activating means 53 to the blocking means 54.

When the activating means 53 are activated, the movement of pressing the pin 56 is thereby transmitted to the blocking means 54 so as to put them in the blocked position.

The transmission means 55 are also such that, upon opening the door 34, the pin 56 of the activating means 53 and the pin of the blocking means 54 are moved together, to the extended position and to the unblocked position respectively .

In the embodiment of Figures 10 to 23 included, the transmission means 55 are mechanical transmission means 55, but this need not necessarily be the case according to the invention, and the transmission means 55 may just as well be electrical, pneumatic or electronic in nature or possibly of another nature or a combination thereof.

Preferably, the transmission means 55 comprise at least a rod 62 connecting the activating means 53 to the blocking means 54.

In the case discussed herein, the rod 62 is a rod that is vertically arranged and that can be vertically moved up and down.

In this embodiment, this rod 62 indirectly makes contact with the pin 56 of the activating means 53 at a first end 63, more particularly via a conversion mechanism 64 for transmitting the movement of the pin 56 to the rod 62.

The pin 56 thereby acts directly on a conversion mechanism 64 which in this case takes the form of a lever mechanism 64 hinged in the frame 2 to be rotated about a rotational axis 65 and having an ingoing side 66 and an outgoing side 67, which in this case are the two sides 66 and 67 on either side of the rotational axis 65 of a tilting plate 68 positioned transversely to the rotational axis 65 and mounted as fixed on the rotational axis 65.

The pin 56 is connected to the ingoing side 66 of the tilting plate 68 by a hinge joint 69, while the first end 63 of the rod 62 is connected to the outgoing side 67 by a hinge joint 70.

Pressing the pin 56 herein causes the ingoing side 66 of the lever mechanism 64 to move and thus rotate, so that the outgoing side 67 is also moved, wherein the rotational movement of the lever mechanism 64 is converted into a rectilinear, vertical movement or nearly rectilinear, vertical movement of the rod 62.

Furthermore, the rod 62 makes direct contact with the blocking means 54 at its second end 71, more particularly by means of a hinge joint 72 which connects this end 71 of the rod 62 to the ingoing side 60 of the lever mechanism 58 in a rotatable manner.

A shift or in this case an upward or downward movement of the rod 62 causes the ingoing side 60 to move and makes the lever system 58 rotate, so that its outgoing side 61 also rotates, which constitutes the actual blocking means 54 since it is the outgoing side 61 which moves in and out of the aperture 57. The operation of the improved fire-resistant door 34 of Figures 10 to 23 included is as follows.

When the fire door 34 is closed, the pin 56 is pushed into the stowed position by the door face 30 of the door 34.

This causes the tilting plate 68 of the lever mechanism 64 to tilt between the pin 56 and the rod 62 of the transmission means 55 so that the rod 62 moves upwardly.

This upward movement of the rod 62 is accompanied by an upward movement of the ingoing side 60 and a downward movement of the outgoing side 61 of the lever mechanism 58 forming the blocking means 54 and provided at the other end 71 of the rod 62.

The downward movement of the outgoing side 61 introduces the blocking means 54 into the aperture 57 provided in the upper end side 32 of the movable, fire-resistant door 34, such that the upper sections 21 and 22 of the door 34 are blocked once the door 34 is closed.

By properly designing the lever mechanism 64 and the lever system 58 at both ends 63 and 71 of the rod 62, a small movement of the pin 56 can be converted into a relatively large displacement of the outgoing side 61 of the lever system 58, which forms the actual blocking means 54.

As shown in more detail in Figure 23, the aperture 57 in the fire-resistant door 34 is covered by a metal cover plate 73, in which a central recess 74 is provided. This metal cover plate 73 may be protected at the top and/or at the bottom by foam-forming product.

As soon as the vertical upward movement of the rod 62 and the downward movement of the outgoing side 61 of the lever system 58 is initiated, this outgoing side 61 penetrates through the central recess 74 into the aperture 57 in the door 34 even before the fire-resistant door 34 is completely closed.

For this reason, the central recess 74 in the metal cover plate 73 is provided with an oblique side 75.

When the door is fully closed and comes into contact with the draught rubber 76, the outgoing side 61 of the blocking means 54 will touch this oblique side 75 of the central recess 74 exactly at point 77, so that there is only minimal play between the blocking means 54 and the central recess 74.

This ensures that the door leaf 30 cannot deform even if a fire 15 breaks out on the side 19 of the door 34 where the door 34 is opened by pulling at it.

The door 34 need not be locked for this purpose, i.e., the deadbolt need not be in the opposite recess.

When the fire door 34 is opened, the force of gravity will make the lever system 58 tilt back in the opposite direction under the weight of the rod 62, thus bringing the blocking devices 54 back into a disengaged position. The outgoing side 61 of the locking means 54 does not hinder the opening of the door 34 since, thanks to the lever system 58 and the lever mechanism 64 and the minimum play between the central aperture 74 and the blocking means 54, the movement of the outgoing side 62 of the blocking means 54 is faster than that of the pin 56.

The first example of a blocking mechanism 52 for a fire door 34 discussed here can be used in single-leaf doors of the types 35, 40 and 48 provided with a frame 2 with an upper head 39 and in doors 34 with a multi-point lock.

It is clear that in the embodiment of an improved fire- resistant door 34 according to the invention as discussed here, the blocking mechanism 52 is mainly integrated in a fixed structure, more specifically in the free space behind the frame 2 surrounding the door 34, wherein the blocking means 54 engage in the movable door 34 in the blocking position.

Consequently, this embodiment can only be used with doors 34 of a type in which the blocking mechanism 52 can be installed behind the jambs of a metal frame 2.

In other words, this embodiment cannot be used in fire doors 1 of the double-leaf type 36, 41 and 49.

In this embodiment, the blocking means 54 are also integrated in the upper head 39 of the frame 2 and the blocking means 54 engage in an aperture 57 provided in an upper end side 32 of the movable fire door 34. Thus, this embodiment is not applicable either to fire doors 1 of types 45 and 46 with a fixed wooden top panel 47 and of the floor-to-ceiling type 43 and 44, since with these types of doors 1, the required upper head piece 39 of the frame 2 is not present or is situated too far from the door 1.

An advantage of this embodiment is that no visible parts are present on the vertical parts of the frame 2 and the door 34.

Another possible embodiment of an improved, fire-resistant door 34 according to the invention is illustrated in Figures 24 to 27.

As in the previous example, the blocking mechanism 52 is still mainly integrated in a fixed structure, more specifically in the space behind the frame 2 surrounding the door 34.

The blocking means 54 of the blocking mechanism 52, when in the blocking position, still engage in the movable fire door 34, but this time no longer in an aperture 57 provided in an upper end side 32 of the movable fire door 34 but in one or more, in this case two apertures 78 provided in a frontal end side 31 of the movable fire door 34 on the side 10 of the door 34 where the door handle 8 or the lock 27 is located.

Also the activating means 53 of the blocking mechanism 52 are very similar to those of the preceding embodiment and are again provided with a movable pin 56 which, when extended, extends from a door stop 12 of the fire door 34 and, when the fire door 34 is closed, is pushed into the door stop 12 in its stowed position by the door 34.

However, the manner in which the activation of the activating means 53 is transmitted by pressing the pin 56 and resulting in the actuation of blocking means 54 which engage in the apertures 78 is entirely different in this embodiment .

To this end, the transmission means 55 still comprise a rod 79 which is still vertically arranged behind the frame 2, but this time, however, the rod 79 is suspended in a rotatable manner in the frame 2 by means of supports 80, more particularly in such a way that the rod 79 can be rotated to and fro about its vertical axis in the supports 80.

The rod 79 indirectly makes contact with the pin 56 of the activating means 53, more or less at the center 81, via a conversion mechanism 82 for transmitting the movement of the pin 56 to the rod 79.

In this case, this conversion mechanism 82 comprises a crank or arm 83 which is rigidly connected to the rod 79, and the pin 56 is connected to this crank or arm 83 by a pivot joint 84, such that pressing the pin 56 makes the rod 79 rotate.

The rod 79 also makes direct contact with the blocking means 54, in particular at its two ends 85 and 86, the blocking means 54 in this case being formed by hook-shaped protrusions 87, each rigidly attached to the rod 79 at an end 85 or 86 of the rod 79.

For a proper sealing of the blocking means 54 in the apertures 78 in the blocked position and for achieving a durable cooperation between the blocking means 54 and the apertures 78 in the door 34, the apertures 78 are preferably covered by a metal cover plate 88 in which a suitable central recess 89 is provided.

The different parts of the activating means 53, the transmission means 55 and the blocking means 54 are coordinated such that, when the pin 56 is pushed into the stowed position by closing the door 34, a rotation of the rod 79 about its vertical axis makes the ends of the hook shaped projections 87, which form the blocking means 54, fall perfectly into the apertures 78 in the door 34, more particularly into the central recesses 89 of the cover plates 88 for blocking the corresponding sections of the door 34, in order to avoid any gaps 28 and 29 in case of fire 15.

In the embodiment of Figures 24 to 27 included, the blocking mechanism 52 is also provided with spring devices 90 which are arranged between the frame 2 and a part of the hook-shaped protrusions 87 in order to make the blocking means 54 and the activating means 53 automatically return to an unblocked position and an extended position respectively, when the fire door 34 is opened. The embodiment of an improved fire-resistant door 34 according to the invention shown in Figures 24 to 27 included has the advantage that the fire-resistant door 34, in the closed position, is blocked off in the sections 21 and 22 or 21 to 23 included at the corner 24 or at both corners 24 and 25 on the latch side 10 of the door 34.

The door 34 does not have to be locked, i.e. the dead bolt does not have to be in the opposite recess.

This embodiment can be used with single-leaf fire doors 34 of types 35, 40, 43, 45 and 48 as shown in figure 9.

However, this embodiment of a fire door 34 cannot be used with double fire doors 34 of types 36, 41, 44, 46 and 49, since the frontal end side 31 of such a door 34 does not abut a frame 2 on the lock side 10, in which the blocking mechanism 52 is integrated.

This embodiment cannot be used with doors 34 with a multi point lock either.

A further disadvantage of this embodiment is that visible recesses 89 are made in the frontal end sides 31 of the door 34, which is not always acceptable from an aesthetic point of view.

Also, in this embodiment, the blocking mechanism 52 is not replaceable in an already assembled door unit. Figures 28 to 33 show yet another embodiment of an improved fire-resistant door 34 according to the invention in the form of an improved, double fire-resistant door 91.

In this embodiment, the blocking mechanism 52 is still mainly integrated in a fixed structure or rather in a structure which can be fixed, more particularly in a leaf 92 of the double fire door 91 which can be fixed by means of two flush bolts 93 and 94 at the bottom and top of the leaf 92 respectively.

In the blocking position, the blocking means 54 engage in the movable door or leaf 95, more particularly in apertures 78 provided in a frontal end side 31 of the movable fire door or leaf 95 on the side 10 of the door or leaf 95 with a door handle 8 or lock 27.

These apertures are protected by means of a cover plate 88 in which a central recess 89 is provided.

In this embodiment, the mechanical activating means 53 again comprise a movable pin 56 which, this time however, in the extended position, extends from a frontal end side 96 of the fixed leaf 92 of the double fire door 91 and which, when the fire door 91 is closed, is pushed into the corresponding end side 96 by the door 95 until it is in the stowed position.

The transmission means 55 are again mechanical transmission means 55 which also comprise a rod 62 connecting the activating means 53 to the blocking means 54 and which, as in Figure 10 for example, is a rod 62 arranged vertically in the fixed leaf 92 and which can be moved vertically up and down therein.

However, in this third embodiment, the vertical rod 62 extends over almost the entire height of the double door 91, whereas in the case of Figure 10, the rod 62 extends only over the top half of the fire door 34.

In this third embodiment, the rod 62, in a first section in the middle 9 of the moving leaf 95 of the double door 91, just above the door handle 8, indirectly makes contact with the pin 56 of the activating means 53 via a conversion mechanism 64 which also bears many similarities to that of Figures 10 and 11 and which also has the form of a lever mechanism 64 which is arranged in a rotatable manner around a rotational axis 65 in the fixed leaf 92 of the double door 91.

The lever mechanism 64 also includes a tilting plate 68, wherein the pin 56 interacts with this tilting plate 68 on an ingoing side 66 via a little shaft 97 extending transversely to the tilting plate 68 and which is rigidly connected to the tilting plate 68, the little shaft 97 extending into a slot 98 provided in the pin 56.

On an outgoing side 70, the tilting plate 68 is connected to the rod 62 via a hinge joint 70.

Pressing the pin 56 by closing the moving leaf 95 of the double fire door 91 makes the ingoing side 66 move and the lever mechanism 64 rotate, causing the outgoing side 67 to move as well, converting the rotational motion of the tilting plate 68 into a rectilinear or nearly rectilinear upward motion of the rod 62.

The rod 62 also makes direct contact, at both ends 85 and 86, with the blocking means 54, which in this case, as for example in the case of Figures 24 and 25, have a single or dual design, at the top and/or at the bottom of the fixed leaf 92 of the double door 91. In this third embodiment, these blocking means 54 are each formed by a lever system 58 which in each case consists of a tilting blade 99 hinged around a rotational axis 100 in the fixed leaf 92 of the double fire door 91 and which has an ingoing side 60 and an outgoing side 61 on either side of the rotational axis 100.

The rod 62 acts directly on the ingoing side 60 via a hinge joint 72, wherein a displacement or in this case a vertical movement of the rod 62 makes the ingoing side 60 move and the lever system 58 rotate, and wherein the outgoing side 61 of the tilting blade 100 extends away from the rotational axis 100 over a certain length.

The outgoing side 61 of the tilting blades 100 rotates downwardly with an upward vertical movement of the rod 62, so that the tilting blades 100 protrude from the frontal end side of the fixed leaf 92 and thus form the actual blocking means 54 which interact with the apertures 78 in the moving leaf 95. Opposite the pin 56, a metal protective plate is incorporated in the moving lock leaf 95 against which the pin presses while the double fire door 91 is being closed. Preferably, the tilting blades 100 and the lever mechanism 64 are each contained in a housing 102 and 103.

Alternatively, these housings 102 and 103 may be connected by means of one long front plate, in which the recesses for the latch bolt 11 and dead bolt 104 of the lock 27 are also provided.

The lock plate 105 opposite the lock 27 then becomes redundant .

As long as the double fire door 91 is not closed, the pin 56 continues to partly protrude from the fixed leaf 95, for example by a length of 8 mm.

Since stop strips 106 and 107 are mounted on both leaves 92 and 95, the protruding pin 56 poses no risk of injury.

Upon closing the door 95, the pin 56 will be pushed in the housing 103 by the metal cover plate 101 in the lock leaf 95, causing the lever mechanism 64 to tilt and the rod 62 to move upwards.

As a result, the tilting knives 100 tilt downward into the central recesses 89 of the metal cover plates 88.

As soon as the vertical movement of the rod 62 and the tilting down of the tilting blades 100 start, these tilting blades 100 enter the apertures 78, even before the double fire door 91 is completely closed.

For this reason, the central recesses 89 in the metal cover plates 88 are provided with an oblique side 108.

When the lock leaf 95 is entirely closed and makes contact with the stop strip 106, the tilting blades 100 will touch this oblique side 108, so that there is only minimal play between the tilting blades 100 and the central recesses 89.

At that point, the door leaf 30 can no longer deform if a fire 15 breaks out on the side 19 where the door 95 is pulled open.

As long as the pin 56 is being pressed, the tilting blades 100 remain in the blocked position and the door 95 cannot warp.

The double fire door 91 need not be locked, i.e., the deadbolt 104 need not be in the opposite recess 109.

When the movable leaf 95 of the double fire door 91 is opened, the force of gravity will cause the blocking means 54 or tilting blades 100 to retract into the fixed leaf 92 by the weight of the rod 62.

This embodiment can be used with double doors 1 of types 36, 41, 44, 46 and 49 and with single doors 1 in a metal frame 2. This embodiment cannot be used with doors 1 with a multi point lock.

There will be visible recesses in the frontal end sides 31 and 96 of both leaves 31 and 96, which is a disadvantage from an aesthetic point of view.

It is possible to combine the first embodiment with the lower part of the third embodiment.

Figures 34 to 39 illustrate yet a fourth embodiment of a fire-resistant door 34 according to the invention.

In this fourth embodiment, the blocking means 52 is mainly integrated in a movable structure which in this case is formed by the fire door 34 itself, but which in an alternative embodiment may be, for example, the movable leaf 95 of a double fire door 91.

In this case, in the blocking position, the blocking means 54 engage in a fixed structure either in a frame 2 surrounding the fire door 34 (as is the case in Figures 34 to 39 included) or in a leaf 92 of a double fire door 91 which can be fixed.

More particularly, the blocking means 54 are such that, in the blocked position, they engage in apertures 110 provided in a fixed door jamb 111 surrounding the fire door 34.

In this embodiment, the activating means 53 comprise one or more, for instance a pair of movable pins 56, which, this time however, in the extended position, extend from one end side 112 of the movable, fire-resistant door 34 on the side 7 of the hinges 6.

When the fire door 34 is closed, these movable pins 56 will be pushed in the door 3 by a door jamb 113, into the stowed position.

The transmission means 55 comprise one or more, for example a pair of rods 114, which connect the activating means 53 to the blocking means 54, wherein these rods 114 are this time arranged horizontally in the fire door 34, at the height of the upper section 22 and/or the lower section 23 of the door 34 respectively.

The rods 114 can be moved horizontally back and forth in the fire door 34.

At a first end 63, the rods 114 make direct contact with a corresponding pin 56 of the activating means 53 for transmitting the movement from the pin 56 to the respective rod 114.

Each pin 56 herein presses directly against the relevant rod 114, and by pressing the pins 56, the rods 114 are displaced horizontally.

At a second end 71, the rods 114 make direct contact with corresponding blocking means 54, each of which forms a lever system 58 in the form of hook-shaped elements 115, each of which is hinged about a pivot shaft 59 in the fire door 34. Each lever system 58 has an ingoing side 60 and an outgoing side 61 which are this time on the same side of the pivot shaft 59.

Each rod 114 acts directly on the ingoing side 60 of the corresponding lever system 58 in that it is connected to a hook-shaped element 115 at its end 71 by a hinge joint 72.

A horizontal displacement of a rod 114 makes the ingoing side 60 move, thereby rotating the lever system 58 and making the hook-shaped elements 115 move from the frontal end side 31 of the fire door 34 into the apertures 110 in the door jamb 111.

The outgoing side 61 of the hook-shaped elements 115 located furthest from the pivot shaft 59 thus form the actual blocking means 54.

The blocking mechanism 52 is also provided with spring means 90 which are provided between the hook-shaped elements 115 and the fire door 34 which, when the door 34 is opened, automatically bring back the blocking means 54 and the activating means 53 into an unblocked position and extended position, respectively.

The fire door 34 need not be locked in this case, i.e. the dead bolt need not be in the opposite recess.

This fourth embodiment can be used with all types of doors 1 shown in Figure 9. The blocking mechanism 52 can be implemented with a single rod 114 and, by adjusting the blocking means 54, it can also be ensured that, in the blocked position, they protrude from an upper end side 32 of the door 34 to engage in an aperture provided in an upper head piece 39 of the frame 2 or in the intermediate profile 51 or in the lower end of the top panel 47.

This embodiment cannot be used in combination with a multi-point lock if it is mounted in the vertical side of the door 34.

The blocking mechanism 62 can also be arranged in a mirrored position, so that the ingoing side 60 and the outgoing side 61 switch positions.

For proper operation, high leverage and very precise adjustment are necessary.

The aim here is that the length by which the pins 56 protrude from the door 34 can be adjusted in an already mounted door assembly.

A further disadvantage of this embodiment is that visible recesses have to be made in the frontal end side 31 of the door 34.

It is possible to combine the first embodiment with the lower part of the fourth embodiment.

Figures 42 to 44 included show the deformations which occur in an improved fire-resistant door 34 according to the invention when the side 16 where a fire 15 breaks out is the side 19 where the door 34 can be opened by pulling at it.

Figure 42 shows the deformation on the hinge side 7 where the door face 30 is being held in the frame 2 by the hinges 6.

Figure 43 illustrates the situation on the lock side 10 wherein the improved fire-resistant door 34 is constructed as shown in Figures 10 to 23 and is provided with a blocking mechanism 52 which holds the door face 30 in the upper sections 21 and 22 against the frame 2, but wherein the lower section 23 moves slightly out of the frame 2.

Finally, Figure 43 shows the situation on the lock side 10 for an improved, fire-resistant door 34 according to the invention wherein the blocking mechanism 52 holds the door 34 against the frame 2 both at the top in the sections 21 and 22 and at the bottom in the section 23.

Figure 45 illustrates another variant of the situation shown in Figure 30, wherein the fire door 95 rests in its closed position against a milled door edge 116 instead of against a stop strip 106 and wherein the blocking means 54, in the blocked position, hold the door 95 against this milled door edge 116.

In this case, the milled door edge 116 functions as a door stop.

The invention is by no means limited to the fire doors 34, 91 according to the invention, described by way of example and illustrated with reference to the figures; on the contrary, such fire doors 34, 91 can be realized in other ways while still remaining within the scope of the invention.