"Landing door for a lift"

[0001] The present invention relates to a door assembly, in particular an assembly for a landing door of a lift.

[0002] A common problem in the lifts sector relates to the safety of the landing doors when the cabin of the lift is absent since positioned at another floor.

[0003] In fact, although these doors are structurally sound, there is a real danger that such door may be forced or opened, creating situations of real danger for users of the system who could fall, also from significant heights .

[0004] The mechanisms by means of. which this may occur are mainly the derailing of the panel, . which may, for example, be caused by a stress directed towards the lift shaft, -which causes the exit of the panel from the lower guide (and much more rarely from. the upper guide), or the reciprocal distancing of the panels or the . distancing of the single panel from its respective upright. In such latter circumstances, since the lock which keeps the panel closed over the access opening to the lift shaft acts only at the top, the panel can be moved from the bottom to cause a partial rotation, thereby creating an - abusive - access to the lift, large enough for the passage of an adult or a child. [0005] The present invention falls within such context, proposing to provide a door assembly of increased safety compared to traditional systems, inasmuch as designed specifically to prevent forcing or unauthorised opening of the shaft which the lift is slidably housed in. This way, the present assembly ensures a drastically increased resistance to intrusion of the shaft compared to the prior art systems.

[0006] Such objective is achieved by an assembly according to claim 1, and by means of a lift system according .to claim 14. The dependent claims show preferred embodiment variants .

[0007] The object of the present invention will now be described in detail, with the help of the appended drawings, wherein:

[0008] - figure 1 shows a plan view of an assembly which the present invention relates to, according to a possible embodiment ;

[0009] - figure 2 shows another plan view of an assembly, according to a different embodiment;

[0010] - figures 3a, 3b, 3c, 3d illustrate mutually orthogonal views of a bolt usable in the assembly in figure 2;

[0011] - figures 4, 5, 6 and 7 represent respectively an exploded view, a partial cross-section view, a front view and a side view of the left panel of the assembly in Figure 2, according to a possible embodiment; and

[0012] - figure 6a shows an alternative embodiment of the configuration in Figure 6.

[0013] With reference to the aforementioned drawings, reference numeral 1 globally denotes a door assembly for the landing door of a lift.

[0014] Such assembly 1 comprises an upper translation guide and a lower translation guide 2, parallel to the upper translation guide and defining a longitudinal slot 4 along a sliding direction X.

[0015] In the embodiments shown in figures 4 and 6, the lower translation guide 2 comprises a profile 20, preferably in extruded metal, which realizes a door threshold and which delimits the longitudinal slot 4. According to a preferred embodiment, such profile 20 defines a- further longitudinal slot 28, alongside and preferably parallel to such slot 4.

[0016] The assembly 1 further comprises at least one door panel 6, 6', which acts in conjunction with the upper translation guide and which comprises an end portion 8, 8 ' inserted in a slidable manner in the longitudinal slot 4 between two end-stroke positions.

[0017] As a result, the door panel is inserted in the longitudinal slot 4, the sides 40, 42 of which guide said door between a first and a second end-stroke position.

[0018] In the embodiments shown, the first end-stroke position is a closed position- of an access opening to a lift shaft. For example, the embodiment in figure 1. shows an assembly with a first 6 and a second 6' door panel which, in the aforesaid first end-stroke position, are configured to position themselves so as to close the access opening to the lift shaft. In particular, such panels 6, 6' close the aforesaid opening when they come together in abutment. Alternatively, the first end-stroke position could be achieved with a single panel, when positioned in correspondence to a respective upright.

[0019] According to a further embodiment, the second end- stroke position is a position in which the pair of doo panels 6, 6' is separated, or in which the single panel is distanced from the respective upright, thereby leaving an opening for access to the lift shaft. In conditions of correct operation of the assembly, the second end-stroke position is reached only when an opening of the lift cabin is aligned with the respective access opening closable by means of the present assembly.

[0020] In relation to the construction of the end portion, the embodiment of Figure 4 shows such a portion 8 in the form of plate-shaped lip which extends at the bottom from a panel of the door panel 6, while the variant in figure 1 shows, via the dotted lines, a plurality of flap-shaped end portions, each of which fits into the longitudinal groove 4.

[0021] The door assembly 1 further comprises a transversal component 10 which extends in a direction Y incident to the sliding direction X, for example in an orthogonal direction, and which projects at 'least partially into the longitudinal slot 4 and/or outside thereof. The latter variant will be clarified in the following description.

[0022] According to the embodiments shown, the transversal component 10 is a pin which crosses at least partially the thickness of the lower translation guide 2. According to other variants, the transversal component could be a plate resting on the lower translation guide 2 (for example so as to partially close the longitudinal slot) , or a component housed mainly in said longitudinal slot.

[0023] The assembly 1 further comprises a panel component 12, translatable with the door panel 6 and defining a retention loop 14 which, in a first end-stroke position, receives the transversal component 10 to' prevent the derailing of said panel 6.

[0024] In fact, the retention loop 14 is defined at the bottom by a lower edge 30 which, acting in conjunction with the transversal component 10, is configured to prevent a panel derailment. β

[0025] In particular, in the case in which the door panel 6, 6' undergoes stresses such as to cause the exit of the end portion 8, 8' from the longitudinal slot 4 (for example due to a partial lifting of the . panel and/or pursuant to a pushing on it in the direction of the lift shaft) , the retention loop 14 would oppose such exit in that the bottom edge 30 remains attached to the transversal component 10 and would hold the door in the lower translation guide 2.

[0026] Preferably, the panel component 12 is securely fastened to the door panel 6, 6'.

[0027] According to a preferred variant, the end portion 8, 8' forms the panel component 12 and, even more preferably, the panel component 12 is made in one piece with the door panel 6.

[0028] In the embodiment shown in figure 6, the panel component 12 is translatable in the longitudinal slot .4.

[0029] In the embodiment shown instead in figure 6a, the panel component 12 is translatable parallel to the longitudinal slot 4, and in particular along the lower translation guide 2 or along the aforesaid profile 20 forming the door threshold, advantageously along an outer surface of such guide 2 or profile 20. From this figure it can be noted in fact that the transversal component 10 projects externally to the longitudinal slot 4 and externally . to the profile 20, so as to intercept the panel component 12 at the aforesaid said outer surface. This latter component 12 thus also projects laterally from the panel 6 on the same side.

[0030] Optionally, the panel component 12 may be slidingly housed in a further longitudinal slot 28 alongside the longitudinal slot 4. In such case, the aforesaid slot 28, contrary to as shown in figure 4 , should be flanked on the left side of the lower translation guide 2 instead of on the right side.

[0031] According to one embodiment, the panel component 12 extends within the thickness of the door panel 6.

[0032] According to a further embodiment, the panel component 12 is in the form of a plate-like lip which extends downwards from the panel of the door panel 6.

[0033] The door assembly 1 further comprises a bolt 16, joined to the door panel 6 and movable in relation thereto to keep the panel in the first end-stroke position wherein such bolt 16 acts in conjunction with the panel component 12 to block the transversal component 10 in the retention loop 14.

[0034] Indeed, innovatively, in the moment in which the transversal component 10 is jointly imprisoned by the panel component 12 and by the bolt 16, the dangerous movements of the door panel are made safe both in relation to derailment, and to a forced opening of the panel or plurality thereof and in relation to "complex", movements i.e. combining the two previously described.

[0035] It is to be noted that such retention is effective whether the bolt 16 acts in the same space in which the door panel slides or acts laterally to the longitudinal slot 4 (for example inside the slot 28, or along the profile 20 described) , regardless of the seat occupied by the panel component 12.

[0036] Preferably, the bolt 16 is movable between a retention configuration of the panel in which it projects from the panel to act on the transversal component (such configuration being for example shown in figure 1 or 2), and a release configuration of the panel. For example, in the latter configuration, the bolt is partially distanced from the transversal component 10 and in particular from the lower edge 30 of said component.

[0037] Advantageously, the bolt 16 is fitted in a translatable manner to. the aforesaid panel 6 or in a manner rotatable thereto.

[0038] According to a possible embodiment, in one of its configurations (and in particular in the retention configuration) , the bolt 16 overlaps at least partially, for example mainly, an access mouth 18 to the retention loop 14. [0039] According to a further embodiment, in at least one of its configurations (and in particular the retention configuration) , the bolt 16 penetrates the longitudinal slot 4, for example, to overlap with the aforesaid access mouth 18.

[0040] Despite the embodiment in figure 1 showing a single bolt 16 associated with the door panel positioned to the left (marked by number 6) , a further embodiment could provide a bolt for each door panel 6, 6'.

[0041] What is important to note however, is that the presence of only one bolt is already sufficient to solve the technical problem illustrated above in that, even if one of the panels of the door is prevented from rotating relative to the upper translation guide, the gap that is created between the doors or between the single door and the respective upright when forced, is insufficient for a child, and even less for an adult, to pass through.

[0042] In addition, although this is not expressly stated, any variant described regarding the adjacent panel 6" (e.g. with regard to the features as per figures 4-7), is equally applicable to the panel 6 with the bolt 16.

[0043] According to one embodiment, the assembly 1 may comprise a primary lock (not shown) to constrain the panel 6 to a respective upright, the adjacent panel 6' or to the upper translation guide, which acts at the upper translation guide. Preferably, said primary lock is attached to the bolt 16 via transmission means 22, to command the movements thereof between the configurations discussed .

[0044] For example, the above lock blocks or releases the door panel 6 via a rotary motion. According to a variant, the lock may be in accordance with the publication U.S. 6,474,448 Bl in the name of the same applicant.

[0045] As regards the nature of the transmission means, these means 22 preferably comprise a tie-rod which extends, along the door panel, and in particular along a line joining the upper translation guide and the lower translation guide. For example, such tie-rod extends parallel to a side edge 32, 32' of one of the aforesaid panels 6, 6'. According to a possible variant, at least a portion of the tie rod could be inserted in a protective sheath 44 fixed to the panel 6.

[0046] According to an advantageous embodiment, the assembly 1 further comprises elastic means 24 which act constantly in thrust (or in traction) between the bolt 16 and the door panel 6. Preferably, the elastic means work to maintain the retention configuration of the bolt 16.

[0047] As a matter of fact, the elastic means 24 (comprising for example a coil spring) are configured so that when the bolt 16 is free of constraints, it positions itself so as to retain the transversal component 10. In other words, when the primary lock frees the bolt from its constraint, the elastic means 24 convert it automatically and reliably towards the retention configuration.

[0048] With reference to the variant in figure 3, the bolt 16 may include a stem 34 and an annular lip 36, which extends outwardly from the outer surface of the stem. Such annular lip 36 preferably defines an abutment surface for a first portion of the elastic means 2 . Advantageously, the stem 34 is fitted coaxially to the aforesaid coil spring and, preferably, comprises an end portion 34' engaged with the transmission means 22.

[0049] According to a further variant, a second portion of the elastic means works on an abutment bracket 38 constrained to the door panel, and protruding therefrom. For example, the annular lip 36 and the abutment bracket 38 are mutually distanced to exert a pre-compression force on the elastic means 24.

[0050] According to yet a further variant, the bolt 16 defines a cam surface 26 oriented towards the transversal component 10 so that, when the door panel 6 is moved toward the first end-stroke position, such cam surface 26 moves the bolt 16 by passing over the transversal component 10. In fact, such variant provides that, independently of the action of the primary lock, the cam surface temporarily moves the bolt 16 towards the release configuration (i.e. away from the transversal component), to make it pass over such component 10 and to make the bolt 16 reach the retention configuration. Optionally, the aforesaid bypassing occurs in opposition to the action of the elastic means 24, when provided.

[0051] The - present invention further relates to a lift system which comprises a lift shaft for slidingly housing a lift cabin comprising a plurality of access openings to said shaft, each positioned at a different level, and at least one door assembly 1, according to any of the embodiments illustrated above, placed so as to close at least one of the access openings.

[0052] Preferably, each of said access openings comprises a door assembly as described.

[0053] Innovatively, the assembly according to the present invention makes it possible to safely close the lift shaft, and prevent the movement of the panel in any direction.

[0054] Advantageously, the assembly according to the present invention can be implemented in any existing lift door, given its constructive simplicity and reliability.

[0055] Advantageously, the bolt according to the present invention is configured to be controlled by the primary lock. Nevertheless, in case of malfunction, such bolt is suitable to be converted automatically into a safe condition, for reliable locking of the panel.

[0056] A person skilled in the art may make variations or replacements of elements with others functionally equivalent to the aforementioned embodiments of the assembly and the system so as to satisfy specific requirements .

[0057] Such variants are also contained within the scope of protection as defined by the following claims.

[0058] In addition, each variant described as belonging to a possible embodiment may be realised independently of the other embodiments described.