The present invention relates to a hinge. More particularly it relates to a hinge for door leaves, doors or windows, in particular formed from a panel of glass, wood or the like (see e.g. document US-A-3657766).

Such hinges currently present a connection element positioned on a pin inserted into a support structure or directly into the floor, and connected to the panel to be supported.

The panel to be supported is usually a glass element, hence very heavy, with which a generally pneumatic external device is usually associated to return the panel or door leaf to its closed position.

An object of the present invention is to provide a hinge presenting an integrated system able to return the door leaf or door to its closed position after being moved from said position, for opening.

This and other objects are attained by a hinge formed in accordance with the technical teachings of the accompanying claims.

Further characteristics and advantages of the invention will be more apparent with reference to the accompanying description of one embodiment of the hinge of the present invention provided by way of non-limiting example, in which:

• Figure 1 is a view taken on the section line 1-1 of Figure 4,
• Figure 2 is a partial front view of a detail of a pin of the hinge shown in Figure 1,
• Figure 3 is a section through the pin of Figure 2, taken on the line 3-3, and
• Figure 4 is a plan view of the hinge of the present invention.

With reference to said figures, these show a hinge for door leaves, doors or the like, which is indicated overall by the reference numeral 1.

The hinge 1 comprises a support element 2 which can have any shape. In particular, this element is of circular shape and is arranged to be partially embedded in the floor and fixed to it. The support 2 presents an axial hole 3 with axis A, housing a pin 5 mounted in bearings 4A, 4B. In particular, the upper bearing 4a is a thrust ball bearing, while the lower bearing is a conventional ball bearing.

Integral with the pin 5 there is a cylindrical portion having a circular cross-section of radius greater than that of the pin 5 and projecting from the top of the support element 2. The portion 6 presents an upperly open diametrical cavity 7 intended to house a portion of a glass door leaf. In one of the shoulders 8 defined by said cavity 7, two holes are provided housing two setscrews which, when tightened against the panel, maintain it in position within the cavity 7.

The pin 5 presents a portion the form of which defines a cam 11. This cam presents a first surface of radius coinciding with that of the pin 5, and a second curved surface 13 of radius of curvature greater than that of the first surface. The two surfaces are connected together at two cusp points 15 and 16. At the centre of the second surface a recess 14 is provided, the use of which is clarified hereinafter.

The support element comprises a guide hole 20, which faces the cam 11 when the pin is inserted into the hole 3; this guide hole 20 acts as a housing for a sphere 21. The sphere 21 presents a diameter slightly less than that of the guide hole 20, being hence slidable within it.

The sphere 21 is loaded by a presser 22, on which there rests the end of a spring 30 housed in a second hole 23 substantially coaxial with the guide hole 20. The other end of the spring is connected to an end element 24 presenting an inclined plane 25 on that surface thereof opposite that on which the spring rests.

The support element 2 also presents a further threaded axial hole 26 in which a threaded stop element 27 engages. The stop element presents two cylindrical portions 27A, 27B of different radius, connected by an inclined surface 27C. The surface 27A is threaded and engages in the hole 26, while the surface 27B is freely inserted and is slidable within a further hole 28, coaxial to the hole 26.

When the stop 27 is in position, the profile or inclined plane 27 of the stop element and the inclined plane 25 of the end element 24 are in contact, a greater or lesser extent of screwing of the stop 24 into the hole 26 causing greater or lesser compression of the spring 30, to load the sphere 21 resting on the cam 11 with different force. This adjustment facility is very useful in adapting the hinge to the different weight of the glass or other material panels which it has to support.

The operation of the invention is apparent to the expert of the art from the aforegoing description and is as follows.

When in its rest position the sphere 21 is housed within the recess 14 of the cam 11. In this position, the door leaf inserted into the recess 7 is closed. An opening movement of the door leaf causes the pin to rotate about the axis A. Consequently the sphere leaves the recess 14 and enables the door to be opened. However the profile of the cam 11, and in particular the sliding of the sphere 21 along the second surface 13 of the cam 11, causes compression of the spring 30. The compression of the spring is minimal when the sphere rests on a region of the second surface close to the recess 14 and increase as the sphere approaches the points 13 or 15; it is a maximum at these points and along the entire first surface 12.

Consequently, when the pressure on the door leaf ceases, if the sphere lies on the second surface 13 the pressure of the spring 30 returns the pin 5 to its rest position (i.e. housed in the recess 14), so causing the pin 5 to rotate and close the door or leaf. If instead the sphere rests on the first surface 12, the spring 30 does not operate, hence leaving the door in the position in which it lies.

The extent of the first surface can be varied to set the angle of intervention for automatic closure, and the curvature of the second surface can be varied to obtain a different closure response. In the same manner the spring can be of different length and cross-section, and can also be replaced by another elastic element, such as a pneumatic cylinder.

In an alternative embodiment, the ball bearings 4A and 4B can be eliminated and the pin be inserted directly into the support 2, or the ball bearings can be replaced by plain bearings.