Lock for fireproof doors and windows

Abstract

A lock (1) for fireproof doors and windows comprising a boxlike body (2) for containing movement means (3) for a bolt which is kept elastically in a configuration of partial protrusion from the boxlike body (2). The movement means are controlled by an element which can be actuated manually, such as a handle, a knob, a key, and the like. The lock (1) comprises a guiding and supporting element, which is integral with at least one portion of the box-like body (2), for an elastic member (4) which is kept in a fully deformed configuration by means of a shoulder unit (5), which can be coupled rigidly to the guiding element, against which one end (4a) of the elastic member (4) abuts. The shoulder unit (5) is constituted by material that can deteriorate above a predefined threshold temperature: upon the deterioration of the unit (5), the elastic member (4) assumes a less deformed configuration in which one of its ends (4a) abuts, even indirectly, against a portion of the bolt, forcing it into an arrangement of partial protrusion from the boxlike body (2).

Description

[0001] The present invention relates to a lock for fireproof doors and windows.

[0002] Fireproof doors and windows (in particular doors, hatches, door leaves, French doors, and the like) are a particular type of door or window defined to separate spaces in case of fire, so as to confine the flames and prevent their passage from one of the two spaces that they separate to the other.

[0003] Fireproof doors and windows are made of fire-resistant (or generically noncombustible) material and must also ensure a considerable mechanical strength also against the possible deformations that might be induced by the heat of the flames (maintaining their shape and occluding the opening in which they are installed).

[0004] Elements made of intumescent material are normally arranged along their perimeter (the edges that abut against the perimetric surfaces of the installation opening) and, when heated to a temperature that is higher than a threshold temperature, increase their own volume, sealing the gaps between the surfaces between which they are interposed and thus preventing the passage of flames (or of oxygen-rich air from the intact space to the space in which the fire is in progress, which might feed the flames).

[0005] The lock is generally constituted by various metallic alloys which are not resistant to high temperatures: in case of a thermal event, if it were not embedded in intumescent materials it would certainly melt.

[0006] It is furthermore fundamental that these doors or windows, during a fire, cannot be tampered with by people: an accidental opening of the door or window forced by a person (particularly in the early stages of the fire, since as it persists the heat will seize the lock by causing mechanical interference due to the thermal expansions of the various components and / or to the melting of at least part of them) would in fact entail the thwarting of the flame confinement measures. Fireproof doors according to the preamble of claim 1 are e.g. known from US2003 / 079508A1 or US3811717A.

[0007] It is noted therefore that in fireproof doors and windows of the known type a human error might partially thwart the protection offered by the door or window, and this causes a potential risk which must be avoided.

[0008] The aim of the present invention is to solve the problems described above, by providing a lock for fireproof doors and windows that is inherently safe right from the early stages of a fire.

[0009] Within the scope of this aim, an object of the invention is to provide a lock for fireproof doors and windows that avoids accidental opening of the door by a person during a fire in the early stages of a fire in which the lock has not yet undergone any deformation induced by the temperature increase caused by the presence of the flames.

[0010] Another object of the invention is to provide a lock for fireproof doors and windows that has a space occupation that is fully equivalent to that of a traditional lock.

[0011] Another object of the invention is to provide a lock for fireproof doors and windows in which the spring latch remains stably engaged in the respective selvage of the jamb right from the early stages of overheating induced by the fire.

[0012] Another object of the invention is to provide a lock for fireproof doors and windows that is constituted by simple and inexpensive components.

[0013] Another object of the invention is to provide a lock for fireproof doors and windows that is suitable to preserve the closure of the door or window until the various components of the lock mutually seize due to their deformations induced by the heat generated by the flames.

[0014] A further object of the present invention is to provide a lock for fireproof doors and windows that has low costs, is relatively simple to provide in practice and is safe in application.

[0015] This aim and these objects, as well as others which will become better apparent hereinafter, are achieved by a lock for fireproof doors and windows of the type comprising a boxlike body for containing movement means for a bolt which is kept elastically in a configuration of partial protrusion from said boxlike body, said movement means being controlled by an element which can be actuated manually, such as a handle, a knob, a key, and the like, characterized in that it comprises a guiding and supporting element for an elastic member which is kept in a fully deformed configuration by means of a shoulder unit, which can be coupled rigidly to said guiding element, against which one end of said elastic member abuts, said shoulder unit being constituted by material that can deteriorate above a predefined threshold temperature, upon the deterioration of said unit said elastic member assuming a less deformed configuration in which one of its ends abuts, even indirectly, against a portion of said bolt, forcing it into an arrangement of partial protrusion from the boxlike body.

[0016] Further characteristics and advantages of the invention will become better apparent from the description of a preferred but not exclusive embodiment of the lock for fireproof doors and windows, illustrated by way of non-limiting example in the accompanying drawings, wherein: Figure 1 is a schematic exploded perspective view of a portion of a possible embodiment of a lock for fireproof doors and windows according to the invention; Figure 2 is a schematic sectional side view of the lock of Figure 1; Figure 3 is a schematic sectional side view of an enlarged-scale detail of Figure 2, showing the guiding and supporting element associated with the spring latch, which is integral with the front portion of the boxlike body that contains said lock; Figure 4 is a schematic sectional side view of the configuration assumed by the detail of Figure 3 in case of exposure to a high temperature.

[0017] With reference to the figures, the reference numeral 1 generally designates a lock for fireproof doors and windows.

[0018] The lock 1 according to the invention comprises a boxlike body 2 for the containment of movement means 3 for a bolt which is kept elastically in a configuration of partial protrusion from the boxlike body 2.

[0019] The movement means 3 are controlled by an element which can be actuated manually, such as a handle, a knob, a key, and the like.

[0020] With particular reference to the accompanying figures, the movement means 3 can be constituted by the carousel 3a (provided with a cavity in which the shaft of a respective handle engages) and / or by the cylinder 3b (in which it is possible to insert the actuation key).

[0021] The lock 1 comprises a guiding and supporting element for an elastic member 4 which is kept in a completely deformed configuration by means of a shoulder unit 5 which can be coupled rigidly to the guiding element; one end 4a of the elastic member 4 abuts against said shoulder unit 5.

[0022] The guiding and supporting element for the elastic member 4 is associated with the bolt and, according to one embodiment of unquestionable interest in practice and in application, is coupled rigidly to the boxlike body 2 (preferably to its front head directed toward the selvage that is present on the jamb and is designed to accommodate the bolt when the door or window is closed).

[0023] According to the invention, the shoulder unit 5 is constituted advantageously by a material which can deteriorate above a predefined threshold temperature.

[0024] In practice, this material, once it has reached and / or exceeded the threshold temperature, undergoes a deterioration of its own mechanical properties, for example undergoing a softening, a melting, an increase in fragility, a breakup and in general an inability to withstand even very limited loads (in particular the inability to withstand a load that is similar to that of the deformed elastic member 4 which acts, with its end 4a, on said unit 5).

[0025] Therefore, upon the deterioration of the unit 5, the elastic member 4 modifies its own shape, assuming a less deformed configuration in which its end 4a abuts, even indirectly, against a portion of the bolt, forcing it into a an arrangement of partial protrusion from the boxlike body 2.

[0026] It is noted that the bolt against which the end 4a of the elastic member 4 can abut as a consequence of the deterioration of the unit 5 is of a type chosen preferably between a spring latch 6 and a sliding latch 7.

[0027] With particular reference to an embodiment of unquestionable interest in practice and in application, the guiding and supporting element can be conveniently a fixed pin 8 and the elastic member 4 is a helical spring which is fitted coaxially on said pin 8.

[0028] In this case, the shoulder unit 5 is advantageously engaged on the fixed pin 8 directly downstream of the end portion of the helical spring (i.e., the end 4a of the elastic member 4) when the spring is in the compressed configuration: this ensures that the spring is kept in this compressed configuration (as shown by way of non-limiting example in the accompanying Figures 2 and 3).

[0029] It is specified that, again with reference to the embodiment described previously and illustrated by way of non-limiting example in the accompanying figures, the fixed pin 8 can conveniently comprise an annular seat 9 for the accommodation of the shoulder unit 5.

[0030] In this case, the shoulder unit 5 is favorably a component such as a stop ring.

[0031] The lock 1 according to the invention is adapted to be provided according to distinct structures and by using various materials: in particular, the shoulder unit 5 can advantageously be made of a material chosen preferably from polymers, wood, wood derivatives, paper, paper derivatives, low-melting metal alloys, composite materials, and the like.

[0032] The polymers, depending on whether they are of the thermoplastic type (for which softening occurs above a predefined temperature) or of the thermosetting type (for which instead vitrification occurs, with consequent rapid increase in fragility and reduction of the breaking load, above a predefined temperature), must be selected in order to ensure a loss of mechanical strength once a threshold temperature has been reached and / or exceeded. Likewise, the same conditions apply also for composite materials, since normally they comprise a polymeric matrix which will undergo degradation above predefined temperatures.

[0033] As regards wood, woods derivatives, paper and paper derivatives, it is specified that they are subject to combustion when raised above a certain temperature and this causes the drastic reduction (to elimination) of their breaking load and of their mechanical strength.

[0034] As regards low-melting metal alloys, finally, it is specified that generally they are the ones that melt at temperatures below 100°C: among all low-melting alloys, it is possible to select the ones that undergo such a softening as to no longer be able to withstand a load that corresponds to the load applied by the end 4a of the elastic member 4 already at temperatures that correspond to the threshold temperature.

[0035] With particular reference to the accompanying figures, the bolt (by way of example but not exclusively, when this component coincides with the spring latch 6 of the lock 1) can advantageously comprise a protruding tab 10 which is arranged along the stroke of the end 4a of the elastic member 4: the movement of the end 4a of the elastic member 4 that makes it abut against the tab 10 occurs upon the transition from the deformed configuration of the elastic member 4, maintained by the shoulder unit 5, to the less deformed configuration that follows the deterioration of the shoulder unit 5 (which can occur, according to the invention, as a consequence of its exposure to a temperature that is not lower than the predefined threshold temperature identified previously).

[0036] In greater detail, the bolt can rigidly support a bracket 11 which is provided with a specific protruding tab 10 which interferes with a fixed pin 8 which constitutes the guiding and supporting element for the elastic member 4.

[0037] The tab 10 interferes with the possible stroke of the end 4a of the elastic member 4, which is constituted by a helical spring fitted coaxially on the fixed pin 8. In this case, upon the transition of the elastic element 4 from a deformed configuration to a less deformed configuration, the elongation of the spring along the pin 8 and the abutment of its end 4a against the tab 10 occur.

[0038] It is specified that in this specific embodiment the protruding tab 10 can conveniently comprise a through hole 12, within which the fixed pin 8 that constitutes the guiding and supporting element for the elastic member 4 shaped like a helical spring is accommodated.

[0039] The tab 10, by virtue of the hole 12, can slide along the pin 8 during the normal operation of the lock 1 (translations of the spring latch 6 actuated by said movement means 3): in case of fire, the overheating induced by the presence of the flames will cause the deterioration of the shoulder unit 5 with consequent release of the elastic member 4 (the helical spring), which with its end 4a will push the tab 10 toward the base of the pin 8, forcing the spring latch 6 into its extracted arrangement in which a portion thereof protrudes outside the box-like body 2.

[0040] In relation to the exemplary embodiments shown in the accompanying figures, the fixed pin 8 conveniently can comprise a threaded axial end cavity.

[0041] By virtue of the presence of said threaded cavity it is possible to adopt corresponding threaded means 13, which are accommodated within a hole 14 of the boxlike body 2 and can be screwed and tightened inside said threaded axial cavity in order to lock the pin 8.

[0042] It is specified that if the bolt is a spring latch 6, then the lock 1 can also conveniently comprise a sliding latch 7, also controlled by the movement means 3 (preferably by the cylinder 3b).

[0043] Advantageously, the present invention solves the problems described previously, proposing a lock 1 for fireproof doors and windows that is inherently safe right from the early stages of a fire. The lock 1, by virtue of the presence of the elastic member 4 and of the shoulder unit 5 (which loses the ability to bear a mechanical load above a predefined threshold temperature), determines the assured retention of the lock 1 in the configuration for closing the door or window in which it is installed, well before the metallic components of said lock 1 seize due to the deformations induced by the heat of the flames.

[0044] Conveniently, the lock 1 according to the invention avoids the accidental opening of the door or window by a person during a fire, especially during the first steps of said fire, during which the lock 1 has not yet undergone any deformation induced by the temperature increase caused by the presence of the flames.

[0045] The forcing, due to the action of the elastic member 4, of the bolt (for example of the spring latch 6) in the configuration in which it is extracted from the boxlike body 2 ensures that the fireproof door or window is retained so as to close the opening in which it is installed.

[0046] Advantageously, the lock 1 according to the invention has a space occupation which is fully equivalent to that of a traditional lock, ensuring its simple installation in the dedicated seats of doors or windows, which generally have standardized shapes and dimensions.

[0047] Positively, the lock 1 according to the invention is constituted by simple and inexpensive components.

[0048] Usefully, the lock 1 according to the invention is suitable to preserve the closure of the door or window until the various components of the lock mutually seize due to their deformations induced by the heat generated by the flames.

[0049] Efficiently, the lock 1 according to the invention ensures that the spring latch 6 remains stably engaged in the respective selvage of the jamb from the very early stages of the overheating induced by the fire.

[0050] Validly, the lock 1 according to the invention is relatively simple to provide in practice and is low in cost: these characteristics make the lock 1 according to the invention an innovation of assured application.

[0051] The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the accompanying claims; all the details may furthermore be replaced with other technically equivalent elements.

[0052] In the exemplary embodiments shown, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other exemplary embodiments.

[0053] In practice, the materials used, as well as the dimensions, may be any according to the requirements and the state of the art.

[0054] 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.

Claims

1. A lock for fireproof doors and windows of the type comprising a boxlike body (2) for containing movement means (3) for a bolt which is kept elastically in a configuration of partial protrusion from said boxlike body (2), said movement means being controlled by an element which can be actuated manually, such as a handle, a knob, a key, and the like, characterized in that it comprises a guiding and supporting element (8), which is integral with at least one portion of said box-like body (2), for an elastic member (4) which is kept in a fully deformed configuration by means of a shoulder unit (5), which can be coupled rigidly to said guiding element, against which one end (4a) of said elastic member (4) abuts, said shoulder unit (5) being constituted by material that can deteriorate above a predefined threshold temperature, upon the deterioration of said unit (5) said elastic member (4) assuming a less deformed configuration in which one of its ends (4a) abuts, even indirectly, against a portion of said bolt, forcing it into an arrangement of partial protrusion from the boxlike body (2).

2. The lock according to claim 1, characterized in that said bolt is of the type preferably chosen from a spring latch (6) and a sliding latch (7).

3. The lock according to one or more of the preceding claims, characterized in that said guiding and supporting element is a fixed pin (8) and said elastic member (4) is a helical spring which is fitted coaxially on said fixed pin (8), said shoulder unit (5) being engaged on said fixed pin (8) directly downstream of the terminal end (4a) of said helical spring when said spring is in the compressed configuration, in order to keep said spring in said compressed configuration.

4. The lock according to one or more of the preceding claims, characterized in that said fixed pin (8) comprises an annular seat (9) for accommodating said shoulder unit (5), said shoulder unit (5) being of the type of a stop ring.

5. The lock according to one or more of the preceding claims, characterized in that said shoulder unit (5) is made of a material chosen preferably from polymers, wood, wood derivatives, paper, paper derivatives, low-melting metal alloys, composite materials, and the like.

6. The lock according to one or more of the preceding claims, characterized in that said bolt comprises a protruding tab (10) which is arranged along the stroke of said end (4a) of said elastic member (4) that is performed upon its transition from said deformed configuration, maintained by said shoulder unit (5), to said less deformed configuration, which follows the deterioration of said shoulder unit (5) as a consequence of its exposure to a temperature that is not lower than the predefined threshold temperature.

7. The lock according to one or more of the preceding claims, characterized in that said bolt rigidly supports a bracket (11) provided with a protruding tab (10) which interferes with a fixed pin (8) which constitutes said guiding and supporting element, said tab (10) interfering with one end (4a) of said elastic member (4), constituted by a helical spring which is fitted coaxially on said fixed pin (8), upon a transient step of transition of said elastic member (4) from a deformed configuration to a less deformed configuration.

8. The lock according to claim 7, characterized in that said protruding tab (10) comprises a through hole (12) in which said fixed pin (8) which constitutes said guiding and supporting element is accommodated.

9. The lock according to one or more of the preceding claims, characterized in that said fixed pin (8) comprises a threaded axial end cavity, corresponding threaded means (13) being accommodated within a hole (14) of said boxlike body (2) and being tightened in said threaded axial cavity for the locking of said pin (8).

10. The lock according to one or more of the preceding claims, characterized in that said bolt is a spring latch (6) and in that it comprises a sliding latch (7) which also is controlled by said movement means.

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