Technical field

This invention relates to a concealed hinge for opening doors relative to a frame.

More specifically, this invention addresses the sector of concealed hinges having the characteristic of allowing the rotation up to 180° and as well as a sash for example of a door, of a window, of a piece of furniture or an electrical household appliance, even if the sash is provided with the so-called contact with overlapping on the frame.

For clarity of description, the term "concealed hinge" is used to mean a hinge which is completely recessed in the structure, for example of the doors or windows on which it is mounted, in such a way that it completely invisible when the door is closed with respect to the structure.

Background art

Generally speaking, the concealed hinges are applied in the cases in which each additional extension is to be avoided and in cases in which, for example, for aesthetic or safety reasons, it is preferable that the hinge is not visible when the door is closed.

Again for clarity of description, the term "contact with overlapping on the frame" is used to mean that special structure in which the peripheral slot between door and the frame is not visible.

This feature is very important as a door/frame structure having a contact with overlapping has much higher performance levels from different points of view: acoustic insulation, thermal insulation, greater anti- burglary protection, as well as a better aesthetic appearance.

Some prior art types of concealed hinges are known which allow an opening of approximately 180° and which, at the same time, can also be used on doors with contact with overlapping on the frame.

An example of a prior art concealed hinge is described in patent documents DE 20 2005 000064 in the name HAHN GMBH & CO KG DR and IT B020 100 311 Al in the name of BLINDATO EFFEPI s.r.l. which introduced control of the sequence of rotation of the axes of the concealed hinge by means of pins sliding in slots or cams operating relative to coupling teeth.

However, the change of axis of rotation made according to the above-mentioned patents is abrupt, uncertain and difficult to synchronise between the hinges mounted on the same door, due to the rigidity of the system for controlling the movement of the components which determine the occurrence of the various steps of operation of the hinge, and in particular the fact that the locking elements are fixed on the constraining means which control them.

Another example of a prior art concealed hinge is described in Italian patent application 102017000041649 entitled: concealed hinge, which is also in the name of the same Applicant as this invention.

The above-mentioned patent application describes a concealed hinge which by means of an optimised mechanism makes it possible to obtain a sequence of rotations, relative to two separate axes, allowing the door to rotate by 180° relative to its frame.

At the same time, this prior art solution does not expose the mechanism which controls the sequence of rotation relative to the two axes towards the gap for passage of the door or of the window.

However, this prior art solution is also not free of drawbacks.

One drawback lies in the fact that this prior art solution does not allow a perfect and precise control of the movement of the two portions of the hinge both during the opening step and during the closing step.

This drawback may cause, during operation of the hinge, the occurrence of jolts in the movement, non-fluid movements up to a possible mistiming between the various hinges installed on the same sash (upper, lower and central, where present).

Aim of the invention

The aim of the invention is to provide a concealed hinge which overcomes the above-mentioned drawbacks of the prior art.

A further aim of the invention is to provide a concealed hinge operating on two axes of rotation in sequence in which the change of axis of rotation is progressive, without sudden and noisy jolts.

Another aim of this invention is to provide a concealed hinge which, when the door on which it is mounted is partly or fully open relative to the frame, is free of components which extend towards the gap passage of the door or window on which the hinge is mounted. A further aim of the invention is to improve the reliability and precision of the sequence for changing the axes of rotation of the concealed hinge both during the opening and closing step.

These and other aims are substantially achieved by a concealed hinge as described in one or more of the appended claims.

Further features and advantages are more apparent from the detailed description of non-limiting embodiments of a concealed hinge according to this invention.

The dependent claims correspond to possible embodiments of the invention.

Brief description of the drawings

The description is provided below with reference to the accompanying drawings, which are also non-limiting and provided by way of example only, in which:

- Figure 1 is a perspective view of a concealed hinge according to the invention in a condition of opening to 180°,

- Figures 2a, 2b, 2c, 2d illustrate a sequence of operation in which a concealed hinge according to the invention passes from the completely closed condition on the frame (Figure 2a) to the fully open condition at 180° (Figure 2d),

- Figure 3 shows a concealed hinge according to the invention in the fully open condition at 180°,

- Figure 4 shows the concealed hinge of Figure 3 in the completely closed condition,

- Figure 4a shows an enlarged detail of the hinge of Figure 4.

Detailed description The reference numeral 1 denotes in its entirety a possible solution of a concealed hinge for opening of doors relative to a frame according to the invention.

The hinge 1 comprises a first body 2 which can be fixed to the door or to the frame and a second support 3 which can also be fixed to the door or to the frame.

The hinge 1 also comprises a connecting means 4, substantially U-shaped and designed to connect the first support 2 with the second support 3.

The connecting means 4 is pivoted on the first support 2 by means of a first pin 5 and on the second support by means of a second pin 6.

In particular, the connecting means 4 can rotate:

- relative to a first axis of rotation 101, defined by the first pin 5, and

- relative to a second axis of rotation 102, defined by the second pin 6.

The connecting means 4 comprise a first slot 1004.

The hinge also comprises constraining means 7 for the second support 3 relative to the connecting means 4, relative to which the second support 3 is operatively connected.

The constraining means 7 comprise a second slot 1007.

The concealed hinge 1 according to the invention also comprises a locking element 9 having an axis of symmetry 2005 which is movable in a respective guide 14, positioned on the first support 2, and inserted both in the first slot 1004 of the connecting means 4 and in the second slot 1007 of the constraining means 7. The locking element 9 is configured to move inside the first slot 1004 along a first trajectory 3004 and inside the second slot 1007 along a second trajectory 3007. According to the embodiment illustrated in the drawings, the locking element 9 is a pin inserted free to slide in the guide 14, the latter being in the form of two grooves 12, 13.

In particular, the two grooves 12, 13 are made on the upper containment panel 16 and on the lower containment panel 17 of the first support 2.

The first support 2 is therefore formed in its most basic geometry by the two containment panels 16, 17 which are held together by respective connection elements 18 thereby defining a practically box-shaped body.

The box-shaped body, that is to say, the first support 2, thus defined is advantageously insertable inside a frame or door as described above.

The guide 14 has a first portion 12 and a second portion 13 which are contiguous and having different directions of extension.

Inside the portions 12, 13 the radial movement relative to said first axis of rotation 101 of the locking element 9 allows a relative movement between the constraining means 7 and the second support 3 so as to release the constraining means 7 from the second support 3 and therefore allow the rotation of the second support 3 relative to the second axis of rotation 102.

The radial movement of the locking element 9 inside the guide 14 also allows the rotation of the connecting means 4 to be locked or unlocked relative to said first axis of rotation 101. The constraining means 7 are connected to the connecting means 4, for example by a rigid pin 8.

In the embodiment shown in the drawings, there are two constraining means 7 positioned one above and the other below the connecting means 4.

The constraining means 7, pivoted on the connecting means 4, by means of the pin 8, comprises a first end 7a at which the second slot 1007 is made.

The constraining means 7 comprise a second end 7b comprising a contact roller 11 shaped to match at least one cavity 10 made on the second support 3 and a second guide 190 also made on the second support 3.

The second guide 190 is designed to remain in contact with the contact roller 11 when the second support 3 rotates relative to the second axis of rotation 102.

The pin 8 defines a third axis of rotation 103, between the constraining means 7 and the connecting means 4.

By means of the geometrical interference between the cavity 10, and the respective contact 11, the constraining means 7 keep the second support 3 integral with the connecting means 4, when the locking element 9 is located in the first portion 12 of the guide 14, that is, during the step of rotation of the unit: connecting means 4, second support 3 and constraining means 7, relative to the first axis 101.

The movement of the locking element 9 along the guide 14, and in particular the passage from the first portion 12 to the second portion 13, allows a relative movement between the constraining means 7 and the second support 3.

This relative movement, advantageously a relative rotation, allows release of the constraining means 7 from the second support 3 and allows, therefore, the rotation of the second support 3 relative to the second axis of rotation 102 and the locking of the rotation of the connecting means 4 with respect to the first axis of rotation 101.

The first slot 1004, of the connecting means 4, and the second slot 1007, of the constraining means 7, have dimensions, shape and orientation, advantageously with an oval cross-section with curved longitudinal axes, such that the locking element 9 inserted inside them is positioned with the relative axis of symmetry 2005 at the intersection point X of the first trajectory 3004 with the second trajectory 3007.

This occurs in all the possible relative positions that the first slot 1004 and the second slot 1007 adopt during the relative movement of the first support 2 relative to the second support 3.

Advantageously, the second trajectory 3007 has a length greater than the length of the first trajectory 3004.

This configuration allows a substantial reduction in the movement of the constraining means and a consequent multiplication of the thrust force which, with the opening/closing of the sash it is possible to transmit to the constraining means 7, which in turn controls the locking element 9.

This increase in force makes it possible to obtain greater control and greater overall precision in the movement of the sash relative to the frame during both the opening and closing operation. Advantageously, moreover, the second slot 1007 also has a length greater than the length of the first slot 1004. Advantageously, the slots 1004 and 1007 may have a shape and orientation such that the irreversibility of relative movement between the locking element 9 and the constraining means 7 occurs, that is, the constraining means 7 can move the locking means 9 but the reactions of the latter cannot move the constraining means 7.

This is achieved thanks to the angle of friction between the slots 1004 and 1007 and the locking element 9 inserted inside them.

As shown for example in Figure 4a, the locking element 9 advantageously comprises a plurality of coaxial cylindrical portions 91, 92 and having different diameters from each other.

This configuration makes it possible to obtain a high level of smoothness given by the portion with a larger diameter without having to make the slots 1004, 1007 too large in size, with the advantage of the compactness of the assembly.

Under equal conditions of smoothness of the element 9 on the slots 1004, 1007, the fact that the locking element 9 comprises a plurality of coaxial cylindrical portions 91, 92 makes it possible to optimise the mechanical strength of the hinge 1 as a whole.

Moreover, the first slot 1004 has a shape and orientation such as to determine a rotation of the connecting means 4 relative to the first axis of rotation 101 when the locking means 9 travel along the first trajectory 3004. Thanks to this feature, the movement of the connecting means 4 is continuous and fluid also during the delicate step of changing the axes of rotation 101, 102; a step which occurs in approximately 15 degrees (passing from the configuration shown in Figure 2c and that shown in Figure 2d).

The locking element 9 may be made in a single piece, if the cylindrical portions 91, 92 can be made by turning, or, advantageously, it may be made with separate portions which are free to rotate relative to each other, with respect to the relative axis of symmetry 2005.

In the case of separate pieces, there is the advantage that there is no sliding between the cylindrical portions 91, 92 and the respective contact elements\guides since they can rotate relative to them at their own speeds. Advantageously, between the coaxial cylindrical portions 91, 92 of the locking element 9 there are elastic elements or springs 500 designed to maintain the optimum contact between the locking element 9 and the portions 12, 13 of the guide 14.

In addition, the locking element 9, and hence the relative cylindrical portions 91, 92, advantageously have a circular cross section.

As shown in Figure 3, the first guide 14 comprises at least one contact means 100 shaped to match the locking element 9.

More in detail, according to a possible embodiment, the locking element 9 comprises a ball 94 positioned at least at one of its ends and shaped to match the contact means 100 of the guide 14, for example in the form of a cavity. This solution makes it possible to obtain intermediate and stable positions between the fully open condition and the fully closed condition. Advantageously, moreover, the hinge 1 comprises further elastic means 500, designed to maintain in the correct position the connecting means 4, the constraining means 7, the locking element 9 and the contact roller 11.

Once the second support 3 is no longer connected to the constraining means 7, the second support 3 may continue its rotation relative to the second axis of rotation 102 and reach a total opening of approximately 180° relative to the first support 2.

It should be noted that the passage from the first portion 12 to the second portion 13 of the guide 14 also causes the locking of rotation of the connecting element 4 relative to the first support 2.

Advantageously, moreover, the hinge 1 comprises adjustment means which are able to adjust in the three spatial directions the sash relative to the frame of the door on which the hinge 1 according to the invention is installed.

These adjustment means comprise one or more selected between thrust screws, eccentric pins, or inclined planes suitably integrated between the various components of the hinge 1.

During operation, starting from the condition of Figure 2a that is, in the condition in which the door is closed relative to the frame:

- the first support 2 is fixed to the frame,

- the second support 3, integral with the constraining means 7, may be rotated relative to the first axis of rotation 101,

- the locking element 9 slides in the first portion 12 of the guide 14 Therefore, the second support 3, the constraining means 7, the locking element 9 and the connecting means 4 rotate in an integral fashion until reaching the position shown in Figure 2b, that is, the opening to approximately 70°-90°.

Subsequently, a further rotation transmitted to the second support 3 (to which, in this example described, a door is connected):

- moving the locking element 9 in the second portion 13 of the guides 14,

- the movement of the locking element 9 allows the constraining means 7 to release from the second supporting 3,

- the second support 3 does not have obstacles for starting its rotation relative to the second axis of rotation 102, as shown in Figure 2d.

Simultaneously with the start of the rotation of the second support 3 relative to the second axis of rotation 102, the connecting element 4 is locked in rotation with respect to the first support 2, that is, relative to the first axis of rotation 101.

In the reverse operation, that is, during the process for closing the door relative to the frame, the following steps will occur:

- the second support 3 rotates relative to the second axis of rotation 102 until reaching approximately 90°/70° of opening, and the locking element 9 is in the second portion 13 of the guide 14,

- with a further rotation of the second support 3 the engaging of the cavity 10 of the constraining means 7 occurs on the respective contact rollers 11 of the second support 3 (that is, again making the second support 3 integral with the constraining means 7),

- the constraining means 7 rotate relative to the third axis 103 making the locking element 9 slide in the first portion 12 of the guide 14.

The closing operation concludes with the complete sliding of the locking element 9 in the first portion 12 of the guide 14 and the respective integral rotation of the second support 3, connecting element 4 and constraining means 7 relative to the first axis of rotation 101 with the simultaneous locking of the rotation relative to the second axis of rotation 102.

The invention overcomes the drawbacks of the prior art and brings major advantages.

A first important advantage consists in the fact that by means of a concealed hinge 1 according to the invention it is possible to obtain the rotation up to more than 180° of a sash relative to the frame thanks to the fact that the hinge 1 operates on two axes of rotation 101, 102 in sequence, that is to say, one after the other, exploiting the advantages that this system offers, in a fluid, secure, reliable and silent manner thanks to the control of the position of the locking element 9 which is always managed by the reciprocal position of the slots 1004 and 1007 in which the locking element 9 is inserted. A further important advantage consists in the fact that thanks to the relative movement and the interaction of the locking element 9 with the slots 1004 and 1007 the constraining means 7 indirectly control the locking element 9 making it possible to multiply the thrust and the control which the constraining means 7 exert on the locking element 9.

Thanks to the shape and orientation of the slots 1004 and 1007 this occurs during the entire operating cycle, that is to say, both during the opening and closing operation.

A further advantage consists in the fact that by suitably making the slots 1004 and 1007 it is possible to obtain the irreversible movement of the locking element 9 relative to the constraining means 7, that is to say, the constraining means 7 can move the locking element 9 but the reactions of the locking element 9 cannot move the constraining means 7.

This allows, amongst other things, the production of the constraining means 7 with more compact dimensions, with the advantage of the overall dimensions and therefore the applicability of the invention to hinges designed for doors and windows made with structural elements such as, for example, profiles or extruded sections made of aluminium, steel, plastic or wood having reduced cross- sections with advantages in terms of appearance, functionality and economy.