This invention relates to a counterframe for a concealed sliding door with a self-closing device.

The proposal finds particular although not exclusive application in the sector of industry dedicated to the production of counterframes, particularly with respect to closures of the sliding type.

Sliding type closures that provide a counterframe are well known. Such closure solutions, for example with reference to doors of the sliding type, find specific use in building structures in which a division of the internal spaces is positioned in order also to allow the use of the surface which would otherwise be reserved to allow the opening of a conventional hinged door. Schematically, with particular reference to the sliding doors of the concealed type, these doors include a series of fixed elements intended for integration into the wall structure as well as a series of movable parts, intended to be used during the installation stage and then subsequently removed.

A counterframe is to be substantially integrated into the wall structure. The aforementioned fixed elements provided are associated to the wall structure and include at least one case or large case intended to form the hollow structure within which the door panel will be contained once the latter, in relation to the doorway, has been made to slide from the closed to the open position. The counterframe is also part of a door post, intended to be anchored to the wall in correspondence with the vertical profile of the doorframe opposite the positioning profile of the mentioned case, in such a way as to allow, once closed, the door itself to be positioned under it. Moreover, on the upper part of the case, a longitudinal guide is engaged that is screwed to said load-bearing structure. In order to allow the effective opening and closing movement of the door, the presence of a connecting beam is conventionally provided as well as a relative sliding track from which, through convenient means, the door is suspended.

EP0505614 (De Faveri) describes a counterframe for concealed sliding doors, essentially provided with a sliding door, a frame for said door and a rail longitudinally joined to a cross-piece with respect to which the door is movable so that it can be transferred on the interior of the case or the large case. In order to allow the manual opening and closing movement of the door, provision is usually made for the sliding track, arranged in correspondence with the upper part of the doorframe structure, to be equipped with sliding means usually of the trolley type to which, through conventional threaded means, the upper edge of the door is joined by means of the use of suitable support devices. With regard to the case as part of the counterframe, it is noted that it can be made either by a structure to be finished subsequent to installation that is substantially closed on the three sides by a conventional shaped sheet, also obtained by joining two counter-shaped metal sheets, suitable for producing a containing cavity for the door, or alternatively it can be made by a frame instead of the formed case, consisting of stanchions and cross-pieces joined to said stanchions, whose walls are closed by panels made of plasterboard type material or the like.

In patent literature, multiple solutions for self-closing devices for sliding doors are described.

FR2738591 (Mendez et al.) describes an automatic return device for a sliding door. This consists of a cable arranged reciprocally, whose two ends are fixed, respectively: the first in correspondence with the upper edge of the sliding door, the second, returned around a pulley and hinged in correspondence with the upper end of the vertical door slam post profile and integrated into the support cross-piece of the longitudinal guide track of the sliding door that is hooked to a release and elastic recall drum. Said drum is placed in an intermediate and integrated way along the upper cross-piece of the frame, parallel to the upper profile of the sliding door. Furthermore, the drum cooperates with an internal spring, which in one way allows the release of the pulling cable of the sliding door, when this is in an opened position, determining the loading of the spring, while as soon as the door itself is released, the spring of the drum will stretch in order to release itself thus recalling the pulling cable returned through the pulley, and therefore inducing the door to position itself adjacently until it is in abutment with the vertical profile stanchion.

In GB1203218 (Nuttall) a self-closing device for a folding sliding door is proposed. In one sliding door frame, on one hand provision is made for a door that, movable according to a rectilinear motion, is manually moved during the opening and closing of the passage doorway. A pulley projects from the exterior side of the door slam post profile, around which slides a return cable of the door. With a first end the return cable of the door is anchored along the profile of the upper edge of the sliding door, while with the second end it is engaged to a first counterweight that moves vertically and reciprocally in relation to the movement of the sliding door, along a vertical axis that is parallel and positioned behind, and in this case, on the external side of the frame or rather of the door slam post profile. An upper cross-piece has the function of guiding the sliding door, while above said cross-piece, two pulleys are provided at the two ends for the return of a closed loop cable that engages the same anchorage means provided along the upper profile of the edge of the door and that anchors the first end of the return cable of the door. Said closed loop cable drags a trolley along a horizontal axis parallel to the cross-piece, said trolley being provided with a second counter-weight. Due to the effect of the concurrence of the first and the second counter-weight, the sliding door overcomes the force of the first counter-weight during opening, while during closure the path of the sliding door dragged by the first counter-weight is decelerated by the second counter-weight that acts above the cross-piece according to a horizontal motion.

GB451070 (Naylor) proposes a self-closing device for an up-and-over closure, a typical example for garages. Also in this case, as for the previous solution, a counter-weight is provided that acts laterally with respect to said shutter. In this case the shutter is engaged laterally, on each of the two sides, with two shaped guides within which the trolleys slide, hinged at the side with respect to said shutter, facilitating the sliding movement.

With respect to that disclosed above, it is reasonable to consider as known:

• A counterframe to be joined to a wall that is made up essentially of a case or large case integrated into the wall or coating in order to constitute a wall itself, said case being hollow, it houses the door or the window, of the air type, engaged on the upper part by means of trolleys with a guide track, connected to a cross-piece that joins, defining the doorway to be closed again, the case with the door slam post profile opposite the entrance of said case;
• A self-closing device for a sliding door, including a cable, hooked to a first end along the upper profile of the edge of the door, and with a second end returned around a pulley, hooked to a counter-weight that is movable along an axis parallel to the door slam post profile;
• A sliding door which is manually movable in the opening position by overcoming the effect of the counter-weight hooked to the cable, and self-closing once the door has been released due to the effect of the counter-weight.

At the website www.edilportale.com, the counterframe Eclisse® mod. Unilaterale is found that proposes a counterframe for a sliding door provided with a self-closing device that allows the door, once opened, to close itself again automatically. In this case, the closing action occurs by means of a counter-weight that is can be moved along a vertical seat provided along the internal side of the door slam post profile. The counter-weight, by means of a connection cable and a return clearance by means of a pulley, is connected to the upper edge of the sliding door.

Until today a large part of the solutions mentioned in the background art highlight how those solutions provided with a self-closing device are not integrated into a counterframe for a sliding door.

Only in the Eclisse® proposal, mentioned as the prior art most similar to the invention, is a self-closing device solution applicable to a counterframe described. In this hypothesis, the provided cooperation of the return cable, connected to the upper edge of the sliding door and on the other side to a conventional counter-weight, fails to make the device particularly manageable or easy to use. In other words, the use of the counter-weight, although achieving the automatic closure of the door, is not practical since the door, released by the user, tends to move suddenly and it is difficult to adjust with respect to intensity, even if it acts on the weight quantity of the counter-weight. Therefore, a door is obtained that tends to close too quickly or too slowly, in the first case tending to close with excessive force along the door slam post or alternatively the complete closing of the door is not achieved.

A second disadvantage relates to the dimensions necessary to obtain the seat suitable for the sliding action of the counter-weight along the door slam post. In this case the counterframe requires notable dimensions that essentially jeopardize the appearance of the moment whose orientation is related to maintaining the minimal possible visibility of the counterframe and the frame understood as a whole. Similar dimensioning and concealment problems of the device would be present if in the case of the conventional Eclisse solution, the cooperation of a deceleration device was provided, for example that noted in GB1203218 (Nuttall).

In relation to that considered, the need emerges to find alternative and more functional solutions with respect to those in existence at present.

The aim of this invention is to prearrange a counterframe for a concealed sliding door with a self-closing device through which it is possible to guarantee the efficient sliding of the door avoiding at least the drawbacks mentioned.

This and other aims are achieved by means of the present invention according to the characteristics of the annexed claims that resolve the arising problems by means of a counterframe for a concealed sliding door with as self-closing device, made up of:

1. a) a case, whose vacant space defined in this way houses the door in an open position of the doorway that is to be closed again, a door slam post profile opposite the introduction entrance of the door on the interior of the case, said door slam post profile being joined to the case by means of a connecting upper cross-piece that supports a sliding track to which the sliding door is engaged by means of trolleys;
2. b) a self-closing device, consisting of a translation cable whose first end is engaged along the upper edge of the sliding door, while a second end is returned by means of at least one pulley along the door slam post profile, towards the return body of the door in the closing position of the doorway;

In this way, through a notable creative contribution, the effect of which constitutes an immediate technical progress, certain advantageous aims are achieved.

A first advantageous aim consists in producing a counterframe provided with a self-closing device, in which the movement of the door, due to the concurrence of the spring and sheave with the interaction of the return pulleys of the translation cable, the user carrying out both the opening and release of said door, is particularly calibrated and smooth, achieving in the latter case a perfect closure behind the door slam post profile.

A second aim consists in reducing globally the noisiness of the door during the sliding motion thus avoiding the need to resort to a counter-weight and optimising definitively the sliding of the door-sheave assembly, both during opening and, when released, following closure.

A third aim relates to the fact that maintenance and adjustment is easier when it is necessary to carry out interventions to modify the conventional parameters configured by the manufacturer.

A fourth aim relates to obtaining a significant reduction of encumbrances, particularly in correspondence with the housing seat of the return body of the sliding door.

These and other advantages will appear from the following detailed description of at least one preferred solution with the aid of the enclosed schematic drawings, whose details are not to be considered limitative but only as illustrative.

Figure 1 represents a global view of the counterframe with the door in an open position, showing the positioning of the self-closing device.
Figure 2 represents a detailed and global view of the return pulley of the translation cable of the door provided in correspondence with the door slam post profile and the cross-piece connecting the case to said profile.
Figure 3 represents a detailed and global view of the sheave, movable along the profile rabbet stanchion.
Finally, Figure 4 is a detailed view of the upper edge of the sliding door along which the first end of the translation cable is hooked.

Taking Figure 1 as a reference, it is observed that the object of the invention consists of a counterframe 10 for a sliding door 20 that is concealed, provided with a self-closing device of the sliding door 20 that essentially includes:

• a translation cable 30;
• a stirrup 70 that supports two pulleys 701 ,702;
• a movable sheave 80 to which are joined two pulleys 801 and 802;
• a spring 90
• a pulley 71 that is hinged to the door slam post profile, on the internal side, in a position between the stirrup 70 and the movable sheave 80.

The counterframe 10 essentially includes a case 100, on the interior of which is defined the housing of the door 20 in an open position of the doorway that is to be closed again, at least one cross-piece 101 horizontal and higher than the case 100 for the connection of the latter to the door slam post profile 102, facing and opposite the access entrance to the case 100. The upper cross-piece 101 is of the type prearranged to support a guide track 40 on the interior and along which slides at least one trolley 50 that is engaged along the upper edge 200 of said door 20 thus making it of the suspended type. With respect to the structural part of the case 100, this can be of the type consisting of at least one sheet of metal folded on its three sides, or rather two specular metal sheets joined along the vertical edge in correspondence with the end part of the case 100 that defines the housing. Behind the metal sheet of the case 100, on the external side and in correspondence with the façades themselves, transverse profiles 104 are provided that are anchored to the end lateral stanchions 103, said profiles having a cross section essentially at omega, obtaining definition, and in one case allowing the anchorage of the plaster fixing lath. In a second case, the function of said transverse profiles at omega 104 is to allow the support of buffer panels, for example of the type made of plasterboard, suitable for allowing the production of the relative seat for the housing of the door 20 and for allowing the execution of the finishing work of at least one of the two external façades.

The self-closing device of the door 20 in a counterframe 10, for a concealed sliding door (Figures 1 and 4), consists of a translation cable 30, made of textile material or metal strands, that with a first end 301 is engaged in an adjustable way along the upper edge 200 of the sliding door 20 by means of an anchorage stirrup 60 to which said first end 301 of the translation cable 30 is secured. The translation cable 30 is thus horizontally distributed, parallel and below, namely on the interior of the track 40 or alternatively in a seat, not illustrated, integrated into the track 40. The translation cable 30, extends across a section from the sliding door 20 until reaching a point in correspondence with the door slam post profile 1 02 on the top of which is fixed, on the internal side of the door slam post profile 102, a plate 70 to support two pulleys 701 and 702 that are oriented perpendicularly to each other. Respectively (Figure 2), the first pulley receives the translation cable 30 directly from the sliding door, in order then to return it vertically downwards until intercepting the pulley 801 of the movable sheave 80 placed behind, in a central position, along the internal side of the door slam post profile 102. In Figure 3, the movable sheave 80 consists of two flat metal sheets that are coupled to each other by means of screws and counter-shaped in such a way as to hold between them the two pulleys, respectively 801 ,802, aligned with respect to each other and the first 801 having a larger diameter with respect to the second 802. The lower end of the movable sheave 80 anchors the upper end 901 of the helicoidal spring 90 that is positioned below the movable sheave 80. The lower end 902 of the helicoidal spring 90 is anchored to the door slam post profile 102, in a position corresponding approximately to the median longitudinal axis, not represented (Figure 1).

The translation cable 30 returned by the pulley 701 towards the pulley 801 of the movable sheave 80 is thus subsequently returned upwards to be turned around the pulley 702 of the plate 70 and therefore to be returned again downwards to be turned around the second pulley 802 of the movable sheave 80. At this point the translation cable 30 from the second pulley 802 of the movable sheave 80 is directed towards the pulley 71 which is hinged to the door slam post profile, on the internal side, in a position between the stirrup 70 and the movable sheave 80, to be turned around and descend again towards the movable sheave 80 with the second end 302 engaging the upper end of said movable sheave 80, if necessary in an adjustable way.

The assembly of the self-closing device is carried out in such a way that, with the sliding door 20 in a maximum opening position of the doorway to be closed again, a certain return effect of the spring 90 remains that is therefore mounted in a preloaded way, namely it is preliminarily tensioned to the point necessary to overcome the point of inertia to start the closing function of the sliding door 20. Furthermore, at least the assembly made up of a movable sheave 80 to which are joined two pulleys 801 and 802, a spring 90 and a pulley 71 which is hinged to the door slam post profile 1 02, on the internal side, is placed almost behind and along the profile of the door slam post between two vertical shoulders so that the removable cover element, not illustrated, made up of the rabbet jamb, will rest and fix itself to the underlying door slam profile 102, concealing from view said components that therefore will be included in the vertical interspace obtained in this way.