Abstract:
A hinge for doors or windows, comprising a hinge-pin ( 26 ) defining an axis of rotation ( 28 ), a first hinge element ( 22 ) and a second hinge element ( 24 ), which are articulated to one another about said axis ( 28 ) via said pin ( 26 ), the hinge including a reinforcement kit comprising an extension element ( 32 ) that can be applied by shape fit to an end of the pin ( 26 ), and a third hinge element ( 30 ) connectable to the first hinge element ( 22 ) in a pre-set position and having a hole ( 82 ) that can be engaged by said extension element ( 32 ) of the pin ( 26 ).

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a hinge for doors or windows, in particular for doors or windows with aluminium frames. 
     Hinges for doors or windows normally comprise a first, fixed, hinge element and a second, mobile, hinge element, articulated to one another by means of a pin. The hinges formed only by a first hinge element and the second hinge element are referred to as two-leaf hinges. In this type of hinge, the pin has a section that projects in cantilever fashion from the fixed hinge element and is thus subjected to bending stress. Hinges of this type have a relatively low loading limit, for example in the region of 100 kg. 
     In the case where the hinge has to ensure a resistance to a higher load, hinges with three leaves are normally used, comprising a bottom fixed hinge element, a central mobile hinge element, and a top fixed hinge element. Hinges of this type have a higher loading limit than two-leaf hinges, for example in the region of 150 kg. However, the difference in cost between hinges with three leaves and hinges with two leaves is quite considerable. With the solutions of current production, in the case where the hinge has to ensure a resistance to a load intermediate between the load of a hinge with two leaves and that of a hinge with three leaves, for example 110 kg, it is necessary to use three-leaf hinges. 
     The object of the present invention is to provide a hinge of the two-leaf type provided with a reinforcement kit that enables raising of the loading limit of the two-leaf hinge up to an intermediate level between that of normal two-leaf hinges and three-leaf hinges, for example in the region of 130 kg. 
     SUMMARY OF THE INVENTION 
     According to the present invention, the above object is achieved by a hinge comprising a reinforcement kit comprising an extension element configured as an element detached from the pin that can be applied by shape fit to said second end of the pin, said extension element projecting beyond the top front end of the second hinge element, and a third hinge element configured as element separate from the first and from second hinge elements and connectable to the first hinge element in a pre-set position, the third hinge element having a hole that can be engaged by said extension element of the pin. 
     The hinge according to the present invention is configured as a normal two-leaf hinge and has a reinforcement kit that transforms the hinge into a three-leaf hinge. The cost of the hinge with reinforcement kit is lower than that of a three-leaf hinge of a conventional type. A particularly important advantage of the hinge according to the present invention is that the reinforcement kit can be applied at any moment, also with the door or window already set in place. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The characteristics and advantages of the hinge according to the present invention will emerge clearly from the ensuing detailed description, which is provided purely by way of non-limiting example, with reference to the attached drawings, in which: 
         FIG. 1  is an exploded perspective view of a hinge according to the present invention partially mounted on the frame of a door or window; 
         FIG. 2  is a cross section of the first hinge element according to the line II-II of  FIG. 1 ; 
         FIGS. 3 and 4  are perspective views of the hinge-pin indicated by the arrow III in  FIG. 1 ; 
         FIG. 5  is a cross section according to the line V-V of  FIG. 4 ; 
         FIGS. 6-13  are perspective views illustrating the sequence of assembly of the hinge according to the present invention; and 
         FIG. 14  is a cross section according to the line XIV-XIV of  FIG. 13 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to  FIG. 1 , designated by  10  is a part of a fixed frame of a door or window, including a vertical upright  12  and a horizontal cross member  14 . The uprights and cross members forming the frame  10  are made up of sectional elements of aluminium of a conventional type, provided with longitudinal slots  16 ,  18  facing the inside of the opening of the door or window. 
     In  FIG. 1 , a hinge according to the present invention is designated as a whole by  20 . The hinge  20  comprises a first hinge element  22  and a second hinge element  24 , articulated to one another by means of a hinge-pin  26  defining an axis of articulation  28 . The hinge  20  according to the present invention moreover comprises a reinforcement kit including a third hinge element  30  and an extension element  32 , which can be applied to one end of the pin  26 . 
     With reference to  FIGS. 1 and 2 , the first hinge element  22  is formed by a monolithic body of metal material having a fixing portion  34  and an articulation portion  36 . The fixing portion  34  is configured for being fixed to the longitudinal groove  16  of the upright  12  by means of a pair of screws  38 . The way in which the first hinge element  22  is fixed to the upright  12  is conventional in the sector of accessories for doors and windows made of aluminium and does not call for an in-depth description. 
     With reference to  FIGS. 1 ,  2  and  6 , the articulation portion  36  of the first hinge element  22  has a bottom front end  40  and a top front end  42 . The articulation portion  36  has a through articulation seat  44 , which extends between the front ends  40 ,  42 . With reference in particular to  FIG. 2 , the articulation seat  44  has three longitudinal grooves  46  that project outwards with respect to a circular profile. The articulation portion  36  moreover comprises a groove with undercut cross section  48  having a longitudinal axis parallel to the longitudinal axis of the articulation seat  44 . The groove with undercut cross section  48  is open on a face  50  of the articulation portion  36 , which, in use, rests on a plane face of the upright  12 . 
     With reference to  FIG. 1 , the second hinge element  24  comprises a fixing portion  52  and an articulation portion  54 . The fixing portion  52  is configured for fixing to an L-shaped arm  56 . The arm  56  serves to connect the second hinge element  24  to the openable leaf (not illustrated of the door or window. The second hinge element  24  is fixed to a scissor-like arm in the case of a door or window with wing-like and swivel-like opening. In the case of a door or window that can only be opened in a wing-like way, the second hinge element  24  is fixed by means of the arm  56  to the frame of the openable leaf. The articulation portion  54  of the second hinge element  24  has a bottom front end  58 , a top front end  60 , and a through articulation seat  62  that extends between the front ends  58 ,  60 . 
     With reference to  FIGS. 3-5 , the hinge-pin  26  has a cylindrical body with circular cross section having at a first end a widened head  64 . At the opposite end, the pin  26  has a blind hole  66  sharing the axis  28 . The pin  26  is provided on its external surface with an annular groove  68 . Preferably, the pin  26  has a constant external diameter, with the exception of the stretches in which the groove  68  and the head  64  are formed. 
     Once again with reference to  FIGS. 3-5 , the extension element  32  is configured as an element detached from the pin  26  and comprises a first cylindrical portion  70  and a second cylindrical portion  72 , which are coaxial with respect to one another and are separated by a radial collar  74 . The first cylindrical portion  70  has a smaller diameter than the second cylindrical portion  72 , and the collar  74  projects in a radial direction beyond the external surface of the second cylindrical portion  72 . The first cylindrical portion  70  is sized so as to establish a shape fit with the blind hole  66  formed at the end of the pin  26 . The collar  74  preferably has an external diameter substantially equal to the external diameter of the pin  26 . In the condition where the first cylindrical portion  70  of the extension element  32  is fitted in the hole  66 , the collar  74  rests on the front end of the pin  26  where the hole  66  gives out. As may be noted in  FIGS. 4 and 5 , when the extension element  32  is fitted to the pin  26 , the second cylindrical portion  72  forms an extension of the pin  26  coaxial to the axis  28 . 
     With reference to  FIG. 1 , the third hinge element  30  is configured as element separate from the first hinge element  22  and the second hinge element  24  and comprises a monolithic body of metal material comprising a head  76 , a spacing portion  78 , and a coupling portion  80 . The coupling portion  80  is shaped to be inserted by shape fit into the groove with undercut cross section  48  of the first hinge element  22 . The spacing portion  78  has a height in the direction of the axis of articulation  28  slightly greater than the height of the articulation portion  54  of the second hinge element  24 . The head  76  has a hole  82  intended to receive the second cylindrical portion  72  of the extension element  32 . The head  76  of the third hinge element  30  is moreover provided with a fixing hole designed to receive a screw  84 . 
     With reference to  FIGS. 1 and 6 , the hinge  20  according to the present invention moreover comprises a washer  86  that is applied on the top front end  42  of the first hinge element  22 . The washer  86  comprises an annular portion  88  and three integral arms  90 ,  92 ,  94 , which extend in an axial direction from the annular portion  88 . The washer  86  is described in a more detailed way in a simultaneous patent application filed in the name of the present applicant. 
     The sequence of assembly of the hinge according to the present invention will now be described with reference to  FIGS. 6-13 . 
     With reference to  FIG. 6 , in a first step the first hinge element  22  is fixed to the upright  12  by means of screws  38  according to modalities in themselves conventional. Then, the washer  86  is inserted into the seat  44 , on the side of the top front end  42 . The arms  90 ,  92 ,  94  of the washer  86  are inserted in the grooves  46  of the seat  44 .  FIG. 7  shows the washer  86  inserted in the seat  44 . Then, as illustrated in  FIG. 8 , the third hinge element  30  is fitted to the first hinge element  22 , as illustrated in  FIGS. 8 and 9 . The coupling portion  80  of the third hinge element  30  is inserted in the groove with undercut cross section  48  of the first hinge element  22 . The third hinge element  30  is located in the correct position when the spacing portion  78  comes to bear upon the top front end of the first hinge element  22  ( FIG. 9 ). In this condition, the third hinge element is fixed to the upright  12  by means of the screw  84 , as illustrated in  FIG. 9 . 
     Next, as illustrated in  FIG. 10 , the second hinge element  24  is inserted in the direction indicated by the arrow in  FIG. 10  in the space comprised between the head  76  of the third hinge element  30  and the top front end  42  of the second hinge element  22 . The second hinge element  24  is positioned with the articulation seat  62  aligned to the articulation seat  36  and to the hole  82  of the third hinge element  30 , as illustrated in  FIG. 11 . 
     In the meantime, the extension element  32  is applied to the end of the pin  26 , and the pin assumes the configuration illustrated in  FIG. 10 . The pin  26 , with the corresponding extension element  22 , is then inserted into the articulation seats, aligned with respect to one another, of the first and second hinge elements, in the direction indicated by the arrow in  FIG. 11 . The cross section of  FIG. 12  shows the hinge after complete insertion of the pin. It may be noted that the second cylindrical portion  72  of the extension element  32  engages the hole  82  of the third hinge element. It may moreover be noted that the annular portion  88  of the washer  86  is comprised between the top front end of the first hinge element  22  and the bottom front end of the second hinge element  24 . 
     The assembly is completed, as illustrated in  FIGS. 13 and 14 , by screwing a grubscrew  96  in a transverse threaded hole  98  of the second hinge element  20 . The threaded hole  98  is situated in a position corresponding to the annular groove  68  of the pin  26 . Consequently, the internal end of the grubscrew  96  engages the annular groove  68  of the pin  26  as illustrated in  FIG. 14 . 
     The procedure of assembly described previously refers to the complete hinge  20  of the reinforcement kit  30 ,  32 . The hinge  20  can also be mounted without the reinforcement kit  30 ,  32 . In this case, the hinge  20  becomes a conventional two-leaf hinge. The top end of the pin  26  without the extension element, is substantially flush with the top front end  60  of the second hinge element  24 . 
     The use of the reinforcement kit  30 ,  32  enables conversion of the two-leaf hinge into a three-Leaf hinge, with consequent increase of the maximum load that the hinge can withstand. In fact, with the reinforcement element  30  and the extension element  32 , the pin  26  is subjected to shearing stress instead of bending stress, and its strength increases. For example, the two-leaf hinge without the reinforcement kit can have a maximum load-bearing capacity of 100 kg, whereas the hinge with the reinforcement kit can have a maximum load-bearing capacity in the region of 130 kg. The reinforcement kit  30 ,  32  consequently enables increase in the load of the hinge in a simple and inexpensive way. The reinforcement kit  30 ,  32  can be mounted at any moment, also with the door or window already in place. In fact, it is sufficient to slide out the pin  26  of the two-leaf hinge and proceed with the sequence of assembly described previously.