The present invention relates to a frame for security doors having the characteristics specified in the preamble of independent claim 1, as well as to a frame and false frame assembly comprising a frame of the above-mentioned type.

The support structure of a security door typically consists of a frame and false frame assembly which is installed inside the free opening of the wall intended to accommodate the security door. The false frame (also referred to as counter-frame) is fixed to the wall, for example by means of plugs, and the frame (also referred to as door jamb) is fixed to the false frame, for example by means of screws. The frame and false frame both help to improve the structural strength and the resistance to attacks of the security door. It is known to make the frame as two separate parts, between which at least one thermally insulating seal is arranged. According to the prior art, the frame is preassembled, with the two frame parts and the seal rigidly joined together, and then installed by means of fixing to the false frame.

It is an object of the present invention to provide a frame for security doors which has very high thermal insulation properties and which may be assembled directly at the site where the security door is to be installed. A further object of the present invention is to provide a frame for security door which may be fixed both to a false frame and directly to the wall. Yet another object of the present invention is to provide a frame for security doors which may be easily and rapidly assembled, without the need for welding operations.

This and other objects are fully achieved by means of a frame for security doors as specified in independent claim 1.

Further advantageous features of the invention are indicated in the dependent claims, the contents of which are to be understood as forming an integral and complementary part of the description below.

In short, the invention is based on the idea of providing a frame for security doors comprising a first frame part, or front frame part, a second frame part, or rear frame part, and at least one seal arranged between the front frame part and the rear frame part so as to separate the two frame parts and thus provide a thermal break between them, wherein the right-hand upright and the left-hand upright of the front frame part and of the rear frame part each comprise a flat mounting wall designed to be arranged, in the assembled condition of the door, perpendicularly with respect to a vertical centre plane of the door, wherein the at least one seal is arranged between the mounting walls of the front frame part and of the rear frame part, and wherein the mounting walls of the front frame part and of the rear frame part have respective aligned holes for insertion of screw-type fixing members, in such a manner that, by means of the screw-type fixing members, both a rigid connection between the front frame, the rear frame and the at least one seal, as well as fixing of the frame to the false frame or to the wall, are obtained.

Owing to such a solution, on the one hand high thermal insulation characteristics are achieved, since the two frame parts are separated from each other by the at least one seal, and on the other hand assembly in situ of the frame is possible, since the two frame parts and the at least one seal may be transported separately to the installation site and then rigidly joined together during arrangement of the frame in position. Moreover, the particular configuration of the frame according to the present invention and, more precisely the particular shape of the mounting walls of the two frame parts, are such as to allow fixing of the frame not only to a false frame, but also directly to the wall, this latter possibility being particularly useful in particular in the case of installation of security doors during renovation work.

According to another aspect of the invention, each of the front frame part and the rear frame part comprises a pair of connecting plates which are each designed to be rigidly joined to a respective upright and to the cross-piece by means of mechanical fixing members, such as screws and/or rivets, and/or by means of interlocking engagement.

According to a further aspect of the invention, the frame is designed to be removably joined, preferably by means of quick-fit and quick-release members, such as elastic clips, to additional covering elements. The present invention also relates to a frame and false frame assembly for security doors comprising a frame as specified above, wherein the false frame comprises a right-hand upright, a left-hand upright, a cross-piece designed to connect together the right-hand and left-hand uprights at their top ends, and a pair of locking plates, each designed to rigidly join a respective upright to the cross-piece by means of interlocking engagement.

Further characteristics and advantages of the present invention will become more evident from the following detailed description, given purely by way of a non-limiting example with reference to the accompanying drawings, in which:

Figure 1 shows a perspective view of a frame for security doors according to an embodiment of the present invention;

Figure 2 is a perspective view showing, separated from each other, the front frame part and the rear frame part of the frame of Figure 1 ;

Figure 3 is an exploded view of the front frame part and of the rear frame part of the frame of Figure 1 ;

Figure 4 is a cross-sectional view of one of the two uprights of the frame of Figure i ;

Figure 5 is a perspective view of a false frame which can be used, in combination with the frame of Figure 1 , in order to provide a frame and false frame assembly for security doors;

Figure 6 is an exploded view of the false frame of Figure 5;

Figures 7a to 7c are perspective views which illustrate in sequence the operation of interlocking engagement between the cross-piece and one of the two uprights of the false frame of Figure 5;

Figure 8 is a cross-sectional view of a frame and false frame assembly for security doors, comprising a frame according to Figure 1 and a false frame according to Figure 5, in the final installation condition of the security door;

Figure 9 is a cross-sectional view similar to that of Figure 8, relating to the situation where the frame is directly fixed to wall, without the arrangement of the false frame in between; and

Figure 10 is a cross-sectional view of the frame of Figure 5, in the condition where the frame is directly fixed to the wall, without the arrangement of the false frame in between, and the free space between frame and wall is filled with insulating material.

With reference initially to Figures 1 to 4, a frame for security doors according to an embodiment of the present invention is generally indicated 10. The frame 10 comprises basically a first frame part 12, hereinafter referred to as "front frame part", a second frame part 14, hereinafter referred to as "rear frame part", and a seal 16 arranged between the two frame parts 12 and 14 in such a way that the two frame parts 12 and 14 are not in contact with each other, but are separated by the seal 16. The material of the two frame parts 12 and 14 is optionally steel which is galvanized and/or painted and/or lined with PVC film and/or with different surface finishes. The seal 16 is made of heat-insulating material. The seal 16 may be equally well made as one piece or may be formed by two parts, as in the embodiment shown (Figure 3).

The front frame part 12 comprises a right-hand upright 18, a left-hand upright 20, a cross- piece 22 which connects the right-hand upright 18 and the left-hand upright 20 at their top ends, and a pair of connecting plates 24, preferably in the form of a right-angled bracket, each designed to be rigidly joined to a respective upright 18 or 20 and to the cross-piece 22 by means of mechanical fixing members (for example screws and/or rivets, not shown in the drawings) and/or by means of interlocking engagement. Likewise, the rear frame part 14 comprises a right-hand upright 26, a left-hand upright 28, a cross-piece 30 which connects the right-hand upright 26 and the left-hand upright 28 at their top ends, and a pair of connecting plates 32, preferably in the form of a right-angled bracket, each designed to be rigidly joined to a respective upright 26 or 28 and to the cross-piece 30 by means of mechanical fixing members (for example screws and/or rivets, not shown in the drawings) and/or by means of interlocking engagement.

Figures 8 and 9 show two examples of installation of a security door provided with a frame 10 according to the invention, in the case where the frame is fixed to a false frame (indicated by 34) and in the case where the frame is fixed directly to the wall (indicated by W). With reference to Figures 8 and 9, as well as Figure 4, each of the two uprights 18 and 20 (in the abovementioned figures only the upright 18 is shown) of the front frame part 12 comprises a flat mounting wall 36 which in the assembled condition of the door is directed perpendicularly with respect to a vertical centre plane P of the door. Likewise, each of the two uprights 26 and 28 (in the abovementioned figures only the upright 26 is shown) of the rear frame part 14 comprises a flat mounting wall 38 which in the assembled condition of the door is directed perpendicularly with respect to a vertical centre plane P of the door. The seal 16 is arranged between the mounting walls 36 and 38 of the two right-hand uprights 18 and 26 of the front frame 12, as well as between the mounting walls 36 and 38 of the two left-hand uprights 20 and 28 of the rear frame part 14, so as to be sandwiched between these walls. As shown in Figures 8 and 9, the mounting walls 36 and 38 of the front frame part 12 and the rear frame part 14 have respective aligned holes 40 and 42 for insertion of screw-type fixing members 44, in such a way that, by means of the screw-type fixing members, both a rigid connection between the front frame part 12, the rear frame part 14 and the seal 16, as well as fixing of the frame 10 to a false frame 34 or a wall W, are obtained.

With reference now to Figures 5 and 6, the false frame 34 comprises a right-hand upright 46, a left-hand upright 48, a cross-piece 50 which connects the right-hand upright 46 and left-hand upright 48 to each other at their top ends, and a pair of locking plates 52 each designed to rigidly join, by means of interlocking engagement, a respective upright 46 or 48 to the cross-piece 50 (for example according to the sequence of operations shown in Figures 7a, 7b and 7c). The false frame 34 may also comprise one or more spacers 54 (three spacers, in the embodiment shown) having the dual function of making the movement of the false frame and its positioning for the installation work easier and of ensuring that the false frame remains squarely aligned both during the movement and handling operations and for all the time needed to allow setting and drying of the mortar used to fix the false frame in the wall. Preferably, the components of the false frame 34 are made of steel which is galvanized and/or painted and/or with different surface finishes. The false frame may be fixed to the wall by means of plugs inserted into through-holes 56 provided in the two uprights 46 and 48 and/or by means of extractable cramps-irons 58 integrally formed by the two uprights 46 and 48.

With reference, finally, to Figure 10, the particular shape of the profiles of the uprights of the two front and rear frame parts allows the introduction of filling material with heat- insulating and/or sound-proofing properties between frame and wall (or between frame and false frame, in the case where the false frame is provided for) in the areas indicated by F, and therefore an improvement in the thermal insulation and noise damping performances of the door.

In the light of the description provided above, the advantages which can be achieved with a frame for security doors according to the present invention are evident.

Owing to the fact that the frame comprises a front frame part, a rear frame part and a seal which are made as components separate from each other and which can be joined together by means of the same fixing members (in particular screw-type fixing members) used to fix the frame to a false frame or directly to the wall, it is possible to transport one by one the components of the frame to the installation site and assemble the frame components directly during arrangement of the frame in position. This allows obvious savings in terms of costs for transportation and handling of the frame components, as well as easier assembly of the frame and disassembly thereof, if necessary, for example in order to replace any damaged parts.

Furthermore, the frame for security doors according to the invention allows joining together of the frame and leaf of the security door independently of the size (height and width) of the door itself. As shown in Figure 10, the hollow zone indicated by H is in fact designed to accommodate the bolts, latch, riders and generally all the parts of the locking system of a security door, independently of the height relative to the plane of the floor at which these parts are mounted. This results in advantages of an economic and commercial nature, owing to the possibility of combining the same frame with door leaves having different configurations, as well as advantages in terms of production flexibility and supply logistics. Moreover, owing to the fact that all the closing points, including the hinges, may be housed and fixed inside the hollow zone H, the frame is reversible, in that it may be used as such for security doors having an opening direction equally well of the left-hand type or right-hand type. The same applies to assembly with a pushing action or pulling action where the frame (or false frame, if present) is inserted as such in either direction inside the free opening of the wall which must accommodate the security door. Moreover, the frame for security doors according to the invention offers a considerable degree of flexibility in terms of adaptation to door leaves of different thicknesses. In fact, the rear frame part may be made in various sizes so as to allow the frame to be easily adapted to different thicknesses of the security door. By varying only the profile of the rear frame part (which, owing to the shape of its cross-section, is simpler to modify than the front frame, part), the dimensions of the front frame part may be kept unchanged. The profile of the rear frame part may be made using conventional technology, such as bending, which offers some flexibility in the final dimensions of the profile obtained.

Furthermore, with the frame for security doors according to the invention optimization of the materials may be achieved. In fact, owing to the division of the frame into two parts, it is possible to use different thicknesses and types of materials for each of the two parts. This results in the possibility of varying the configurations of the frame structure depending on the intended use and the performances required for the security door. For example, for a more effective performance in terms of resistance to attacks, it is possible to vary the materials and/or the thicknesses of one or both of the profile frame parts.

Also, some embodiments of the frame for security doors according to the invention may be designed so that they can be combined with additional aesthetic covering elements. Such embodiments of the frame are designed to accommodate the special features needed for additional aesthetic covering elements which are mounted using quick-fixing and quick- release systems, such as elastic clips, and which have the advantage of covering entirely each visible part of the frame and concealing any connecting components (such as screws and/or rivets).

Naturally, the principle of the invention remaining unchanged, the embodiments and the constructional details may be greatly varied with respect to those described and illustrated purely by way of a non-limiting example, without thereby departing from the scope of the invention as defined in the accompanying claims.