The present invention relates to a spring hinge kit for swing-doors, particularly for fire doors. The invention also relates to a swing-door comprising such hinge kit.

A drawback of known structures for hinging a fire door leaf to the corresponding door frame is related to the large dimensions of the hinges, caused by the fact that they have to bear a very high cantilevered weight.

The greater amount of metal required, usually concentrated in the pivot structure but also affecting the thickness of the hinge leaves, is a cause of greater heat transmission in case of fire and is therefore disadvantageous.

Moreover, the presence of springs on all the hinges present along the door leaf increases the amount of metal used and the consequent possibility of transmission of the heat deriving from the fire and also the possibility of deformation and therefore malfunction of at least part of the springs due to this heat.

The aim of the present invention is to provide a spring hinge for swing-type fire doors that is capable of improving the prior art in one or more of the aspects mentioned above.

Within this aim, an object of the invention is to provide a hinge that allows the use of a single spring for each swing-type leaf.

Another object of the invention is to reduce, with respect to the prior art, the amount of metal required to provide the hinge for an equal weight of the leaf, thus reducing heat transmission in the event of fire without affecting the capacity of the hinge to bear heavy weights.

A further object of the present invention is to overcome the drawbacks of the prior art in a manner that is alternative to any existing solutions.

Not least object of the invention is to provide a hinge that is highly reliable, relatively easy to provide and at competitive costs. This aim and these and other objects which will become better apparent hereinafter are achieved by a hinge kit according to claim 1, optionally provided with one or more of the characteristics of the dependent claims.

The aim and objects of the invention are also achieved by the door according to claim 10 and optionally claim 11.

Further characteristics and advantages of the invention will become better apparent from the description of a preferred but not exclusive embodiment of the spring hinge kit for swing-doors according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is an exploded view of a spring hinge kit according to the invention;

Figure 2 is an exploded perspective view from below of the spring hinge kit;

Figure 3 is a view of the lower portion of a swing-door with the spring hinge kit according to the invention and with the leaf completely open;

Figure 4 is a perspective view from below of the door portion of Figure 3;

Figure 5 is a front view of the swing-door portion of Figure 3;

Figure 6 is a view similar to Figure 5 but with the leaf in a partially open position;

Figure 7 is a sectional top view of the door of Figure 5;

Figure 8 is a sectional top view of the door of Figure 6;

Figure 9 is a perspective view of a swing-door with a single spring hinge, arranged in a lower region.

With reference to the figures, the spring hinge kit according to the invention, generally designated by the reference numeral 1, comprises a hinge 2 to be fixed on a side wall of a door opening, for example on the post masonry wall. The materials used for the components of the kit 1 are all made of metal, for example steel (optionally galvanized) and preferably of the type used in hinges for fire doors. The hinge 2 comprises a first hinge arm 21 which is adapted to be rendered integral with the side wall of the door opening and therefore will become a fixed arm of the hinge 2.

The first arm 21 is adapted to protrude from an opening 94 of the frame post 93 of the door. For example, it can be fixed in a cantilever manner on a cut portion of a metal sheet 20 which is then fixed internally to the post 93 of a frame along the doorpost of the door opening.

In the case of the figures, the cut portion of metal sheet is a bent tab 20b, on which the first arm 21 is welded and which thus protrudes in a cantilever manner from the opening 20a left by the tab 20b on the metal sheet 20.

The first hinge arm 21 is rotatably mated with a second hinge arm, preferably by means of rolling bodies such as for example balls 21c, accommodated in corresponding annular guides 21a and 22a provided on each of the two arms 21 and 22 so as to face each other. In the illustrated embodiment, the first arm 21 is the male element of the hinge, while the second arm 22 is the female element, with three balls 21c preferably arranged between a pair of mutually facing annular guides 21a and 22a.

To provide the other unsprung hinge structures 100 arranged at higher levels along the leaf 9, the first hinge arm 2G can be the female element of the hinge and the second hinge arm 22' can be the male element (Figure 9).

Going back to the illustrated embodiment, the second hinge arm 22 is the movable one of the pair of arms 21 and 22 during use and can rotate with respect to the first arm 21 about a hinge axis R which will coincide with the rotation axis of the swing leaf 9 of the door. The second arm 22 comprises a substantially planar end plate 24 which is adapted to be fixed to the leaf 9 of the door in order to allow its rotation about said hinge axis R and is provided with at least one peripheral portion which is contoured, for example so as to have a polygonal shape and, more preferably, with adjacent edges directed at right angles to each other so as to form a substantially rectangular profile. The face 90 of the leaf 9 on which the end plate 24 is fixed is the one directed toward the hinge axis R, which coincides with the rotation axis of the leaf 9.

The second arm 22 can comprise at least two metallic profiles 23 a- 23b in order to support in a cantilever manner the end plate 24 so that it is spaced from the hinge axis R and is substantially parallel to said axis. The two metallic profiles 23a-23b converge toward each other at the hinge axis R.

In the embodiment of Figure 1, the metallic profiles 23a-23b each comprise one of said annular seats 22a for the balls 21c, which are directed toward the similar annular seats 21a which are present on the first hinge arm 21 and with which said annular seats 22a are rotatably mated with the interposition of the balls 21c. The two metallic profiles 23a-23b can be provided and bent one toward each other from the same metal sheet of the end plate 24 and kept mutually integral by a tension member.

The second hinge arm 22 comprises moreover, at the hinge axis R, an engagement element 29 which rotates integrally with the second arm 22 and can be provided directly on, or associated with, the lower metallic profile 23b of the pair.

The engagement element 29 can consists of a contoured recess, for example a cross-shaped or polygonal hollow. Said recess can be provided, for example, with a convenient cut on an additional plate 23 c which is welded to said lower metallic profile 23b. The contoured recess can be optionally flared inside.

The kit 1 also comprises a torsion spring structure 3 which can be fixed to the side wall 93 of the door opening at a distance from the first hinge arm 21, particularly in a point of the side wall 93 that is below the hinging region between the hinge arms 21 and 22 and optionally spaced from the hinge axis R. The torsion spring 35 of the structure 3 is preferably helical and comprises a first end 35a and a second end 35b opposite to the first one. The coils of the helical spring 35 can be advantageously mutually spaced in order to be able to use the helical spring 35 also as a compression spring and allow an adaptation of the spring structure 3 in an axial direction thereto during the assembly step.

The torsion spring structure 3 is provided with a loading shaft 30, which has a substantially rectilinear shape and is coaxial to the torsion spring 35. The loading shaft 30, which is associated with the first end 35a of the torsion spring 35, is rotatably connected to a base 34 of the structure 3. The second end 35b of the torsion spring 35 is fixed on the base 34, particularly at an eccentric position of the base 34.

The torsion spring 35 is adapted to generate, as a consequence of the rotation of the loading shaft 30 with respect to the base 34, a return strength sufficient to rotate the second hinge arm 22, the end plate 24 and the leaf 9 supported thereby at least partially about the hinge axis R, from a position in which the spring 35 is loaded to an initial position with minimum elastic potential energy of the spring 35.

In such initial position, in which the leaf 9 completely closes the door opening, the torsion spring 35 is preferably in a state of torsion preloading. The loading shaft 30 has a central loading axis S about which the shaft 30 rotates in order to modify the elastic energy of the torsion spring 35. Advantageously, the loading shaft 30 can have an arm 33 which is integral with the shaft 30 and protrudes radially so as to fix the first end 35a of the torsion spring 35 in a spaced position with respect to the loading axis S. The loading shaft 30 comprises, at one end thereof, a head 31 which, during use of the hinge structure 2, is mated directly to the engagement element 29 of the second hinge arm 22, so as to load the torsion spring 35 following a rotation of the second hinge arm 22 transmitted to the loading shaft 30 by virtue of the mating between the head 31 and the engagement element 29.

Likewise, the mating between the head 31 and the engagement element 29 allows the loading shaft 30 to produce an inverse rotation of the second hinge arm 22 (and therefore of the leaf 9 connected thereto), in order to discharge the elastic energy of the torsion spring 35, i.e., during use, to bring the leaf 9 to the position for closing the door opening.

The loading shaft 30 passes preferably through the helical spring 35 from side to side and protrudes axially from the spring 35 so as to keep the head 31 exposed and to be able to mate it with the engagement element 29 of the second hinge arm 22.

The head 31 of the loading shaft 30 has a shape which is substantially complementary to that of the engagement element 29, particularly such that it can be inserted in the contoured recess and can engage with it by means of a shape mating (or positive mating) adapted to allow the rigid transmission of the rotation between the loading shaft and the second hinge arm 22 and vice versa. For example, the head 31 can have a cross-like or star-like shape or a polygonal cross-section, so as to engage with a complementary shape (cross-like, star-like or polygonal, respectively) of the recess 29.

Advantageously, the head 31 of the loading shaft 30 has a flared tip 32 adapted to provide a joint which allows said mating between the loading shaft 30 and the engagement element 29 according to a plurality of angles of incidence between the central loading axis S and the hinge axis R. In this manner it is possible to adapt the torsion spring structure 3 to a plurality of positions, allowing position adjustments during assembly.

The base 34 of the torsion spring structure 3 can be rotatably mounted on a bracket 7 to be fixed to the side wall of the door opening, particularly inside the post 93 of the frame of the door.

The bracket 7 can be L-shaped in order to form a ledge 71 for the rotatable resting of the base 34 and a surface 72 that can be fastened to the side wall of the door opening by virtue of screws, for example.

In order to obtain a rotatable mating, the bracket 7 can have a circular opening 73 in which a cylindrical pivot 34b can be inserted which protrudes from the base 34 of the torsion spring structure 3. The cylindrical pivot 34b can be tubular and can be crossed by the end of the loading shaft that is opposite with respect to the head 31.

Between the circular opening 73 of the bracket 7 and the cylindrical pivot 34b there can be optionally a radial clearance in order to allow an adjustment of the inclination of the loading axis S with respect to the engagement element 29 during the installation of the torsion spring structure 3.

Optionally, the bracket 7 can also have a cradle 74 that is bent below the circular opening 73 and is adapted to provide a support for a convex surface arranged on the end of the cylindrical pivot 34b, in order to keep the base 34 spaced from the ledge 71 of the bracket 7 and facilitate the rotation of the base 34 with respect to the bracket 7 and/or the adjustment of the inclination of the loading axis S.

Due to the rotatable mating with the bracket 7, the base 34 of the hinge structure can be used as a preloading tool for the torsion spring 35. In particular, the base 34 can be provided substantially in the shape of a cylinder provided with a plurality of substantially radial holes 34a, in order to set the torsion preloading of the spring 35, when the structure 3 is rotatably mounted on the bracket 7 on one side and mated with the engagement element 29 on the other.

With the second hinge arm 22 in the preferably closed position of the leaf 9 and the bracket 7 fastened at a window 95 provided on a post 93 of the door frame, the torsion spring structure 3 can be mounted between the bracket 7 and the engagement element 29 of the second hinge arm 22, remaining accessible from the outside of the frame. The spring structure 3 thus mounted can be loaded by inserting a key in one of the holes 34a of the base 34 and imposing manually a rotation of the base 34 by means of the key, in order to preload the torsion spring 35, for example clockwise in the case shown in the figures. Once the desired level of preloading of the spring 35 has been reached, a retention element 36 (for example, a grub screw) can be inserted in one of the radial holes 34a so that it abuts against an edge 95a of the window 95 of the post 93 and prevents a return rotation of the base 34 which returns the torsion spring 35 to the resting state.

The same retention element will act also as an element for locking the rotation of the base 34 with respect to the bracket 7 during the rotations of the second hinge arm 22.

The spring hinge kit 1 can comprise furthermore a separate complementary plate 4, which is substantially planar and internally open, can be fixed on the leaf 9 separately from the end plate 24 of the second arm 22 and has an internal edge 40 which is complementarily shaped (i.e., shaped in a substantially complementary manner) with respect to the peripheral portion of the end plate 24, so as to engage said peripheral portion (in particular by means of a shape mating or positive mating) to prevent a mutual rotation between the end plate 24 and said complementary plate 4 when the plate 24 and the complementary plate 4 lie on a same plane and in particular are fixed on the leaf 9.

The complementarily shaped edge 40 of the complementary plate 4 and the peripheral portion of the end plate 24 of the second hinge arm 22 preferably have a substantially polygonal and complementary shape. Moreover, the complementarily shaped edge 40 of the complementary plate is adapted to surround at least partially the peripheral portion of the end plate 24 when the plate 24 and the complementary plate 4 lie on a same plane. In the preferred embodiments, such as the one shown, the complementarily shaped edge 40 is substantially U-shaped and the peripheral portion of the end plate is substantially rectangular.

The peripheral portion of the end plate 24 is preferably provided with at least one tooth 25a and/or a recess 26a which can engage respectively a corresponding recess 46a and/or tooth 45a of the contoured edge 40 of the complementary plate 4, so as to provide said shape mating adapted to prevent the mutual rotation of the end plate 24 with respect to the complementary plate 4.

The tooth 25a or 45a, as well as the recess 26a or 46a, extend substantially parallel to the hinge axis R. In this case, the shape mating is advantageously obtained by means of two edges of the tooth 25a and/or 45a which are parallel to each other and to the hinge axis R and are adapted to be laterally contained and preferably guided parallel to such axis by two corresponding mutually opposite sides of the corresponding recess 46a and/or 26a. In this manner, besides preventing a rotation of the plate 24 with respect to the complementary plate 4, it is possible to use the teeth and the recesses to allow an optional guided translation (of a few millimeters) of the complementary plate 4 with respect to the end plate 24 in a direction that is substantially parallel to the hinge axis R, during the fixing of the leaf 9 (with the complementary plates 4 already fixed along the face 90) to the hinge structures 2 mounted on the side wall of the door opening. In particular it is possible, during the assembly of the leaf 9, to adjust in a guided manner the securing position of the leaf 9 to the end plates 24 in a direction parallel to the rotation axis of the leaf 9.

To this end, the extent of the protrusion of the longer tooth (25a and/or 45a) in a direction that is parallel to the hinge axis R is preferably smaller (by a few millimeters, for example 1-2 mm) than the depth of the corresponding recess 46a and/or 26a, respectively, so that between the plate 24 and the complementary plate 4 there is essentially a clearance (of a few millimeters, for example 2-4 mm) only in a direction that is substantially parallel to the hinge axis R when they lie on a same plane.

Moreover, the end plate 24 can advantageously comprise a slot 28 which is elongated in a direction that is substantially parallel to the hinge axis R and can be crossed by a screw 51 or a rivet adapted to fasten the end plate 24 on the face 90 of the leaf 9. The longitudinal extension of the slot 28 can be substantially equal to the overall guided stroke of the complementary plate 4 with respect to the end plate 24 in a direction that is parallel to the hinge axis R and on the common plane on which the plate 24 and the complementary plate 4 lie (for example the face 90 of the leaf 9).

Preferably, both on the peripheral portion of the end plate 24 and on the complementarily shaped edge 40 of the complementary plate 4 there is a plurality of said teeth and/or recesses, so that the teeth of one engage in the substantially complementary recesses of the other and vice versa. In this case also, each one of these teeth and recesses extends preferably in a direction that is substantially parallel to the hinge axis R.

For example, in the illustrated embodiment, the end plate 24 has two teeth 25a and 25b that protrude from opposite sides of the peripheral portion of the plate 24 and parallel to the hinge axis R. Such teeth 25a-25b of the end plate 24 advantageously incorporate a respective vertex of the substantially rectangular profile of the end plate 24 so as to have a substantially rectilinear common edge, which coincides with an edge 27 of the end plate 24 and is parallel to the hinge axis R.

The teeth 25a-25b (and more generally the rotation-preventing teeth of the plate 24 and/or of the complementary plate 4 of the preferred embodiments of the invention) can have a shape that is substantially rectangular or in any case with two edges which are parallel to each other and parallel to the hinge axis R, for guiding purposes as explained previously. These mutually opposite teeth 25a-25b engage inside the corresponding recesses 46a and 46b, and, by virtue of the parallel edges of the teeth and the parallel sides of the recesses, the teeth can slide within the recesses in order to adjust the mutual position of the plate 24 and the complementary plate 4 during the fastening step.

The maximum distance between the mutually opposite teeth 25a-25b (measured in a direction that is parallel to the hinge axis R) is advantageously shorter than the maximum distance between the mutually facing bottoms of the corresponding recesses 46a-46b. Moreover, the maximum distance between the mutually opposite teeth 25a-25b is such that, in the two possible stroke limiting positions, the teeth cannot disengage from the respective recesses, i.e., the parallel edges of the teeth remain always laterally contained by the sides of the corresponding recesses in which they engage.

The mutually opposite teeth 25a-25b of the end plate 24 are advantageously flanked by a respective recess 26a-26b of the end plate 24 and can be formed indeed by cutting those two portions of the end plate 24 which, after their removal, leave on the plate 24 the recesses 26a and 26b. The recesses 26a-26b also have two inner sides which are mutually opposite and parallel to the hinge axis R.

Likewise, the mutually opposite recesses 46a-46b are flanked by mutually facing teeth 45a-45b, which have a shape that is substantially complementary to the corresponding recesses 26a-26b of the end plate 24.

The hinge structure 2 described above can be used, but without the torsion spring structure 3 and without the engagement element 29, to provide the hinges arranged along the face 90 of the leaf at higher levels with respect to that of the hinge structure 2 described above.

Such “upper” hinges 100 are, however, preferably provided in an alternative manner, keeping the end plate 24 and the complementary plate 4 as described herein, but with the first hinge arm 2G provided as a female element and the second hinge arm 22' provided as a male element (as in Figure 9). In this case, the first hinge arm 2G is provided, for example, by bending two flaps 6 la-6 lb from a cut metal sheet 20', which can be fixed to or integrated with the post 93 of the frame of the door opening. The two flaps 6 la-6 lb face each other along the hinge axis R.

The two metallic profiles 23a'-23b' of the second hinge arm 22’ converge from the end plate 24 until they substantially mutually abut and engage rotatably their external end faces with the end faces of the ends of the female type 6 la-6 lb of the first hinge arm 2G, with similar interposition of balls which roll within, for example, cylindrical sleeves 62a-62b which are coaxial to the hinge axis R.

The method for assembling the swing-leaf 9 along a side wall of a door opening by using the hinge kits according to the invention is evident from what has been described above.

In particular, with reference to the lower hinge, one proceeds with the fixing of the first hinge arm 21 on the side wall of the door opening, for example by fixing the metal sheet 20 (which supports the arm 21) inside a post 93 of the door frame, at an opening 94 already provided in the post 93. The first arm 21 comprises, in an already assembled condition, the second hinge arm 22 associated rotatably therewith and, after fixing to the frame, the hinge axis R coincides with the desired rotation axis of the leaf 9.

It is furthermore possible to fix, along one or more additional openings of the post arranged vertically above the opening 94, other hinge structures 2 or 100, for example by fixing the metal sheet 20' (which supports the first hinge arm 2G) inside the post 93 at each of said additional openings of the post 93.

The method preferably provides, furthermore, the fixing of one or more complementary plates 4 along the face 90 of the leaf 9, one for each hinge structure 2 and 100.

A hole is also provided in the face 90 of the leaf 9 in order to obtain one or more holes 91 for a screw 51 with which each end plate 24 must be fastened to the face 90 of the leaf 9. Subsequently, the leaf 9 is moved closer to the end plates 24 of the second hinge arms 22 mounted along the vertical wall of the door opening so as to engage the peripheral portion of the end plate 24 with the complementarily shaped edge 40 of the complementary plate 4.

In particular, each tooth 25a, 25b, 45a and/or 46b engages within the corresponding recess 46a, 46b, 26a and/or 26b, respectively.

In the lower region of the frame post 93, below the opening 94 for the lower hinge, there is the window 95, along the base of which the bracket 7 has been fixed prior to the installation of the post 93 along the door opening.

By inserting the torsion spring structure 3 between the engagement element 29 and the bracket 7 it is possible to set the preloading of the spring as described above and fix it by means of the grub screw 36.

In practice it has been found that the invention achieves the intended aim and objects.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may furthermore be replaced with other technically equivalent elements.

In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art.

The disclosures in Italian Patent Application No. 102021000019118 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.