DESCRIPTION

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.

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.

Background art

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 of is described in Italian patent application 102016000007254 entitled: concealed hinge equipped with two axes of rotation operating in sequence, in the name of the same Applicant. The above-mentioned patent application describes a hinge which by 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.

This solution of the concealed hinge is an excellent solution in order to allow opening of a door relative to its frame by 180°, however it has several drawbacks.

More specifically, the mechanism which controls the sequence of rotation relative to the two axes comprises rigid elements which, when the door is completely open relative to the frame, protrude from the hinge, extending towards the gap passage of the door or of the window.

It is clear that the presence of a mechanical element projecting towards the gap of the door or window represents a physical obstacle and even a danger and an unsightly aspect.

This drawback is more evident with the increase in size of the hinge.

Another example of a concealed hinge having two axes of rotation operating in sequence is described in patent JP 200721 1577 in which the sequence of change of the axis of rotation occurs through constraining elements pivoted on the connecting elements between the two axes in which the locking/unlocking parts are made as one piece.

A major drawback of this solution is represented by the snap-type operation of the hinge, due to the fact that the exchange of the axis of rotation is not gradual but is instantaneous, which makes difficult, if not impossible, the synchronism between the two or more hinges mounted on the same door.

Similar drawbacks are also found in the operation of a further prior art type of hinge as disclosed with patent DE202005000064 U.

Also according to the invention, the constraining elements are in one piece with the parts which make the sequence for locking the axes.

A further prior art example of a concealed hinge with two axes of rotation operating in sequence is disclosed with patent ITBO2010031 1 A in which the sequence of change of the axis of rotation is controlled by a locking element with a rhomboid shape fixed rigidly to the constraining element pivoted to the midpoint of the connecting element.

As well as having the problems mentioned above relative to the other patents, this solution is not adaptable for all types of doors since the fluidity of its operation is strictly linked to the equilibrium of the forces acting on the hinge.

Aim of the invention

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

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 this invention is to improve the reliability and the precision of the sequence of change of the axes of rotation of the concealed hinge forming a hinge in which the locking means are separated by the constraining means, are controlled in the movement by the connecting units between the supports and the exchange of the axes of rotation is more fluid and progressive thanks to the relative movement between locking elements and constraining elements.

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 this 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 this invention passes from the completely closed condition on the frame (Figure 2a) to the fully open condition to 180° (Figure 2d) and

- Figure 3 shows a further embodiment of a concealed hinge according to this invention.

Detailed description of preferred embodiments of the invention

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 this 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.

More specifically, 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 concealed hinge 1 also comprises a locking element 9 which is movable in a respective guide 14 and controlled in the movement by the connecting means 4.

In the embodiment shown 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 double groove and the locking element 9 being controlled in movement by the connecting means 4. More specifically, the two grooves 14 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 rigid connection elements 18 thereby defining a practically box-shaped body with the side surfaces open.

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

Advantageously, the first portion 12 has curvilinear extension and the second portions 13 extends substantially radially relative to the first axis of rotation 101 .

The locking element 9 may therefore run, controlled in terms of movement by the connecting means 4, both in the curvilinear portion 12 and in the substantially radial portion 13.

Advantageously, as shown in Figure 3, the locking element 9 comprises at the relative ends (that is, in the portions designed for the sliding in the guide 14) respective bushes 21 .

The presence of the bushes makes it possible to reduce the sliding friction with the side walls of the guide 14 and, therefore, prevent sudden movements as well as any wear of the locking element 9.

Preferably, the above-mentioned bushes 21 are made of steel.

The hinge 1 also comprises at least one constraining means 7 for locking the second support 3 relative to the connecting means 4.

The at least one constraining means 7 is connected to the connecting means 4, for example by a rigid pin.

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, pivoting on the connecting means 4, by means of the pin 8, comprise a first end 7a shaped, for a first portion 19, substantially in the form of a "U" and designed to prevent the rotation of the constraining means 7 relative to the connecting element 4 when the locking element 9 is in the curvilinear portion 12 of the guide 14.

Moreover, the first portion 19 is designed to remain in contact with the locking element 9 during the rotations for opening of the door on which the hinge 1 is mounted and, more specifically, when the locking element 9 is in the curvilinear portion 12 of the guide 14.

The constraining means 7 comprises a second portion 15 shaped in such a way as to allow the rotation of the constraining means 7 with respect to the connecting means 4 when the locking element 9 is in the substantially radial stretch 13 of the guide 14.

Advantageously, the second portion 15 comprises a protrusion designed to remain in contact with the locking element 9, when the latter is in the radial portion 13 of the guide 14.

The protrusion 15 also allows limitation of the reciprocal rotation between the constraining means 7 and the connecting means 4.

The constraining means 7 can move relative to the locking element 9 using the amplitude of the first portion 19 as far as the protrusion 15.

The constraining means 7 comprises a second end 7b comprising at least one cavity 10 shaped to match at least one respective contact 1 1 integral with the second support 3.

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, which in the drawing are two, and the respective contacts 1 1 , the constraining means 7 keep the second support 3 integral with the connecting means 4, when the locking element 9 is located in the curvilinear portion 12 of the guide 14, that is, during the step of rotation of the unit: second support 3, constraining means 7 and connecting means 4, relative to the first axis

101 . Advantageously, the first end 7a of the constraining means 7 comprises a protrusion 15 designed to remain in contact with the locking element 9, when the latter is in the substantially radial portion 13 of the guide 14. The movement of the locking element 9 along the guide 14, and in particular the passage from the first curvilinear portion 12 to the second substantially radial 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 allow, therefore, the rotation of the second support 3 relative to the second axis of rotation 102.

Thanks to the fact that the constraining means 7 can move relative to the locking element 9 using the amplitude of the first portion 19 up to the protrusion 15, there is an exchange of the axes of rotation which is fluid and progressive and capable of absorbing the various reactions to which the two or more hinges mounted on a same door are subjected, eliminating the synchronism differences and sudden movements.

In detail, with reference to Figure 2b, it may be noted that, when the locking element 9 is in the curvilinear portion 12, the end 7a of the constraining means is with the relative portion 19 shaped in the form of a "U" in contact with the locking element 9 and the cavity 10, positioned at the end 7b of the constraining means 7, are in contact with the respective contacts 1 1 of the second support 3.

With reference to Figure 2c it may be noted that the passage of the locking element 9 in the substantially radial portion 13 of the guide 14 allows a reciprocal rotation of the constraining means 7 with respect to the second support 3 and the movement of the constraining means 7 from the locking element 9 using the amplitude of the first portion 19.

This reciprocal rotation is permitted since the constraining means 7 has the third axis of rotation 103 different from the second axis of rotation 102 of the second support 3. Since the trajectories of the two different rotations (second support 3 on the second axis 102 and constraining means 7 on the third axis 103) are different the cavity 10 is disengaged from the respective contacts 1 1 .

Advantageously, the hinge 1 may comprise an elastic means 20, for example, a spring, for maintaining the locking element 9 in the substantially radial portion 13.

More specifically, the elastic means 20 performs the function of keeping the locking element 9 in the radial portion 13 whilst waiting that the U- shaped portion 19 of the constraining means 7, during closing of the door, that is to say, the reverse operation relative to that described, impacts against it, overcoming the reaction force of the elastic means 20, and repositioning the locking element 9 in the curvilinear portion 12 of the guide 14.

Advantageously, moreover, the hinge 1 may comprise a further elastic means, not shown in the drawings, interposed between the connecting means 4 and the constraining means 7 to keep the constraining means 7 in the correct position when it is separated from the second support 3. Other elastic elements, also not shown in the drawings, can be used in the hinge 1 according to this invention in order to keep in the correct position the various movable components (connecting means 4, constraining means 7, locking element 9, second support 3).

As shown in Figure 3, advantageously the guide 14 is made in such a way as to have an variable amplitude.

More in detail, the guide 14 may be made by a ridge 23 made directly on the support 2 and by a movable wall 24, pivoted advantageously on the support 2 to allow the rotation relative to the ridge 23.

In order to dampen the speed of variability of the amplitude of the guide 14, in particular due to the passage of the locking element 9 from the radial portion 13 to the curvilinear portion 12 of the guide 14, the hinge 1 comprises an elastic means 22 operating in compression and connected with one end to the support 2 and with the distal end to the movable wall 24.

The elastic means 22 makes it possible to keep in certain contact the movable wall 24 with the locking element 9 (or the respective bushes 21 , if present).

The effect of the elastic element 22 is to dampen the passage of the locking element 9 between the radial portion 13 and the curvilinear portion 12 of the guide 14, avoiding any sudden movements.

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.

The disengagement of the constraining means 7 with respect to the second support 3 also ensures that the constraining means 7 do not protrude relative to the gap for passage of the door, indicated schematically in Figure 2d with the letter L.

Advantageously, the constraining means 7 remaining in contact with the locking element 9 prevent any movement caused by the resultant of the external forces acting on it.

It should be noted how the passage from the curvilinear portion 12 to the substantially radial portion 13 of the guides 14 also causes the locking of the rotation of the connecting element 4 relative to the first support 2.

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, controlled in terms of movement by the connecting means 4, runs in the curvilinear portion 12 of the guide 14,

- the constraining means 7 is in contact with its first end 7a, in particular with the U-shaped portion 19, with the locking element 9.

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):

- moves the locking element 9 in the substantially radial 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 substantially radial portion 13 of the guide 14, kept in position advantageously by the action of the constraining means 7,

- the constraining means 7 is with its protrusion 1 5 in contact with the locking element 9,

- 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 elements

1 1 of the second support 3 (that is, again making the second support 3 integral with the constraining means 7),

- the constraining means 7 rotates relative to the third axis 103, at the end of this rotation the end 7a of the constraining means 7 comes into contact with the locking element 9 moving it in the curvilinear portion 12 of the guide 14. The closing operation concludes with the complete sliding of the locking element 9 in the curvilinear 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 blocking of the rotation relative to the second axis of rotation 102.

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

A first important advantage consists in the fact that by means of a concealed hinge 1 according to this invention it is possible to obtain an opening of a door of approximately 180° relative to the frame without any component of the concealed hinge 1 extending significantly towards the gap of passage L of the door.

A further advantage consists in the fact that by means of a concealed hinge 1 according to this invention it is possible to obtain an opening on two axes of rotation 101 , 102 in sequence which is a fluid, safe and reliable, controlling the position of the locking element during the entire operating cycle thanks to the fact that the constraining element 7 can move relative to the locking element 9 using the amplitude of the first portion 19 up to the protrusion 15.