The present invention relates to a method for the interconnection of components of sheet metal in-wall frames for sliding doors.

Currently, it is known to provide doors and windows which entail the use of an in-wall frame, placed firmly inside a wall or between plasterboard panels, within which a door, or a door panel, is slidingly associated and is also referred to as an "in-wall sliding door.”

This solution makes it possible to reduce the space occupation of the door or door panel within a room by virtue of the possibility to make it slide within the in-wall frame: thus, it is possible to use the space adjacent to the passage opening/room that would instead be occupied by doors of the type hinged laterally to a frame.

In the background art, the in-wall frame - embedded in the wall or between plasterboard panels - forms a containment casing for a sliding door or door panel and is usually constituted by a plurality of profiled elements, including an abutment post, two center posts and a rear post, between which said door or door panel slides, an upper crossmember and a transom, all defining the passage or room that can be closed by means of said door or door panel.

A track is placed, in a concealed manner, at the upper crossmember and at the transom.

Two or more carriages are slidingly associated within the track and the upper edge of the door or door panel is coupled thereto in a downward region to allow it to slide within the in-wall frame.

In order to fix the track to the upper crossmember, holes are provided in both profiles and standardized screws are placed therein; when inserted, said screws protrude from the upper crossmember.

One problem encountered in the use of these solutions resides in that the operation of screwing the track inside the upper crossmember during the preassembly step in production requires a considerable use of workers, who due to the large number of units that are marketed always repeat the same movement, since there is a continuous repetitiveness of the gesture which, in addition to be arduous as it is also necessary to apply a certain pressure and attention in the gesture, can lead to failure to screw in the screws according to the best manufacturing practice; in fact, it is enough to apply slightly excessive pressure to the power screwdriver to strip the screws, and this can occur easily if one acts sequentially on metal sheets of different hardness and also if one acts sequentially on a same batch of sheet metal.

The pressure and precision required during the screwing step, being the result of the manual activity of the operator, cause a large number of rejects, with consequent waste of material and time.

The aim of the present invention is therefore to solve the technical problems that have been highlighted, eliminating the drawbacks of the cited background art and thus devising a method that allows the operator, during the preassembly step in production, to achieve the coupling according to best manufacturing practice, by means of screws, between a sliding track for supporting carriages for a door or door panel and an upper crossmember of an in-wall frame for sliding doors, preventing the screws from stripping, with consequent reduction of rejects and of production times.

Within this aim, an object of the invention is to achieve the cited coupling according to best manufacturing practice regardless of the thickness and hardness of the sheet metal.

Another object is to provide a method that allows an installation worker to replace rapidly and easily the sliding track arranged inside an upper crossmember of an in-wall frame for sliding doors that is already installed, without stripping the screws.

Another object is to provide a method that allows to obtain an upper crossmember of an in-wall frame for sliding doors to which it is possible to couple quickly and easily and according to best manufacturing practice a track for a supporting carriage for a door or door panel.

Another object is to devise a method that allows the operator, during the preassembly step in production, to achieve the coupling according to best manufacturing practice regardless of the type and quality of the screws.

Not least object is to provide a method that can be industrialized easily.

This aim and these and other objects which will become better apparent hereinafter are achieved by a method for the interconnection of components of sheet metal in-wall frames for sliding doors provided with an upper crossmember, provided with a first flat base, within which a sliding track provided with a second flat base is arranged for at least one supporting carriage for a door or door panel, characterized in that it comprises the steps of

- providing a plurality of studs which are provided longitudinally to said first flat base of said upper crossmember and protrude externally from it

- providing a plurality of first holes, which are mutually equidistant like said plurality of studs and are obtained on said second flat base of said sliding track

- obtaining, on each one of said studs, a second central hole from which two or more slits or cuts of equal length and width, which are not aligned along the longitudinal axis of said upper crossmember, extend radially.

Further characteristics and advantages of the invention will become better apparent from the detailed description of a particular but not exclusive embodiment, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a perspective view of an in-wall frame for a sliding door or door panel according to the present invention;

Figure 2 is a partially sectional perspective view of an upper crossmember, a track and a supporting carriage for a door or door panel according to the present invention;

Figure 3 is a detail view of a stud which protrudes from an upper crossmember not coupled to a track;

Figure 4 is a detail view of a stud which protrudes from an upper crossmember coupled to a track by means of a screw;

Figure 5 is a sectional view, taken along the plane V-V of Figure 4;

Figure 6 is a view, similar to the preceding one, in which the screw has been omitted.

In the exemplary embodiment that follows, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other exemplary embodiments.

With reference to the figures, an in-wall frame constituted by a plurality of profiled elements, including an abutment post 2, two central posts 3a, 3b and a rear post 4, is designated by the reference numeral 1.

To connect the upper ends of said abutment posts 2, two central posts 3a, 3b, there is an upper crossmember 5 and, between the upper ends of said two central posts 3a, 3b and said rear post 4, there is a transom 6.

The upper crossmember 5 has, in a transverse cross-section, a substantially Q (omega)-shaped configuration, so as to form a first flat base 7 and a pair of first wings 8a, 8b between which there is a sliding track 9, which runs within the upper crossmember 5 and the transom 6.

The sliding track 9 is substantially C-shaped in transverse crosssection, so as to form a second flat base 10, which has smaller dimensions than said first flat base 7, and a pair of second wings I la, 11b, which are slightly higher than said first wings 8a, 8b and are provided with means, such as two facing pairs of guides 12a, 12b, 12c, 12d, for the sliding of adapted pairs of wheels 13a, 13b which are associated with at least one carriage 14, which supports in a lower region a door or door panel (not shown).

The method entails providing, longitudinally to said first flat base 7 of said upper crossmember 5, preferably at the central axis, a plurality of studs 15 which protrude externally with respect to the first base 7, in the opposite direction with respect to said second flat base 10.

Such plurality of studs 15 is advantageously arranged so that they are mutually equidistant.

The method entails providing, at said second flat base 10 of said sliding track 9, preferably at the central axis, a plurality of first holes 16 which are mutually spaced by an extent equal to that of said plurality of studs 15.

The method further entails providing, on the cambered surface 17 of each one of said studs 15, a second central hole 18 from which two or more slits or cuts 19, each having equal length and width, extend radially.

Furthermore, each one of said slits or cuts 19 has a constant width along their entire length.

Such two or more slits or cuts 19 are not aligned with respect to the longitudinal axis of said upper crossmember 5.

The two or more slits or cuts 19 are preferably three and are mutually angularly offset, preferably but not necessarily, by approximately 120°.

Advantageously, the surface 17 of each one of said studs 15 has such a concavity that said two or more slits or cuts 19 are oriented at a chosen angle with respect to the axes X and Y of said upper crossmember 5.

Preferably, the angle is approximately 14-16 degrees.

The interconnection of the sliding track 9 to the overlying upper crossmember 5 occurs by arranging the two components so that the first and second holes 16, 18 have the same axis; then a screw 20 is inserted therein and its vertex is arranged axially to the second hole 18 and is guided, in its insertion and in subsequent screwing, by the slits or cuts 19, which keep it centered so that it is screwed at right angles to the second flat base 10 of the sliding track 9 and to the upper crossmember 5.

The width of the slits or cuts 19 is such that it does not allow the screw 20 to penetrate between said slits or cuts 19, thus forcing it to remain inside the second central hole 18.

The screws 20 can be of the desired type, for example of the flat point type.

Each slit or cut 19, which as mentioned has a constant width starting from the second central hole 18, preferably has a width equal to approximately 0.8 mm.

Each second central hole 18 has a diameter preferably approximately equal to 2.7 mm.

The shape and arrangement of the slits or cuts 19 and their width in fact prevent the screw 20 from penetrating between said slits, moving away from the axis of each second hole 18, since the "top regions” (i.e., the flaps that form between one slit or cut 19 and the adjacent one), located proximate to the axis of the second central hole 18, between one slits or cut 19 and the other, during screwing adapt to the helical thread of the screws 20, avoiding the stripping of the screws 20.

Such shape furthermore allows, during screwing, to drag the stud 15 downward, thus perfecting the coupling between the upper crossmember 5 and the sliding track 9.

A method has thus been obtained which allows an operator in production to achieve quickly, easily, according to best manufacturing practice and while maximally limiting rejects, the coupling by means of screws 20 of a sliding track 9 (for supporting carriages 14 for a door or door panel) to an upper crossmember 5 of an in-wall frame 1 for sliding doors.

By virtue of the presence of the studs and of their particular shape, said coupling has the advantage of being independent of the thickness and hardness of the sheet metal, as well as of the type and quality of the screws, which may also be of different brands and not perfectly identical, therefore with mutually different qualities.

The fact that the slits or cuts 19 have the same width along their entire length, from the second central hole 18 up to the opposite end, prevents the screw 20 from penetrates in said slits or cuts 19, thus remaining at the center, allowing the screw 20 to be screwed in at right angles.

Advantageously, the diameter of each second central hole 18 is smaller than the diameter of the thread of each screw 20, the diameter of each screw 20 being also greater than the width of each one of said slits or cuts 19.

In particular, the angle of the slits or cuts 19 is such as to avoid/not allow/prevent the sliding of the sliding track 9 longitudinally, inside the upper crossmember 5, so as to allow to maintain the matching of the axes of the first holes 16 and of the second holes 18, which are mutually equidistant like said plurality of studs 15.

The slits or cuts 19 are therefore oriented in such a way that none of the three slits is arranged longitudinally with respect to the crossmember 5, to avoid said sliding during screwing.

Obviously, the invention is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

The materials used, as well as the dimensions that constitute the individual components of the invention, may of course be more pertinent according to the specific requirements.

The various means for performing certain different functions need not certainly coexist only in the illustrated embodiment but can be present per se in many embodiments, including ones that are not illustrated.

The characteristics indicated as advantageous, convenient or the like may also be omitted or be replaced with equivalents.

The disclosures in Italian Patent Application No. 102021000027803 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.