Patent Publication Number: US-9422756-B2

Title: Concealable hinge for the controlled rotatable movement of a door, in particular a reinforced door

Description:
FIELD OF INVENTION 
     The present invention is generally applicable to the technical field of the closing or damping/control hinges, and particularly relates to a hinge for the controlled rotatable movement of a door, in particular but not exclusively a reinforced door. 
     BACKGROUND OF THE INVENTION 
     As known, the closing or damping hinges generally comprise a movable element, usually fixed to a door, a shutter or the like, which movable element is pivoted on a fixed element, usually fixed to a support frame, or to a wall and/or the floor. 
     More particularly, in the case of concealed hinges for reinforced doors or the like, the fixed element of the hinge is inserted into a support structure that includes a rear tubular counterframe anchored to a wall or like support and a front frame anchored to the counterframe. 
     On the other hand, the movable element generally includes a connecting plate to be fixed to the door intended to come out from the tubular support structure in the open position and to retract completely within the tubular support structure in the closed position. 
     Generally, such hinges are purely mechanical, and not allow any kind of adjustment of the opening angle of the door or anyway no control of the movement of the door. 
     Examples of such known hinges are shown in the documents U.S. Pat. No. 5,075,928 and WO2010049860. 
     The absence of control makes such hinges extremely dangerous, since due to the great weight of the reinforced door there is the danger of unhinging of the door or the inflection of the tubular support structure to which the hinge is anchored. 
     Similarly, due to the great weight of the door, the hinge tends to lose the initial position and/or to misalign. 
     Moreover, the adjustment of the position of the door is difficult and complicated. Furtherly, to do this operation at least two operators are needed. 
     Another recognized drawback of these hinges is in the high frictions between fixed and movable element, which leads to frequent wear and breakage, with consequent need for continuing maintenance. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to overcome at least partly the above mentioned drawbacks, by providing a hinge having high performances, simple construction and low cost. 
     Another object of the invention is to provide a hinge which allows controlling the movement of the door upon its opening and/or its closing. 
     Another object of the invention is to provide a strong and reliable hinge. 
     Another object of the invention is to provide a hinge having extremely small dimensions. 
     Another object of the invention is to provide a hinge suitable for supporting very heavy doors and shutters. 
     Another object of the invention is to provide a hinge that has a minimum number of constituent parts. 
     Another object of the invention is to provide a hinge suitable to maintain the exact closing position during time. 
     Another object of the invention is to provide a hinge that is safe. 
     Another object of the invention is to provide a hinge that is easy to install. 
     Another object of the invention is to provide a hinge that simplifies the operations of maintenance and/or replacement thereof. 
     Another object of the invention is to provide a hinge which allows a simple adjustment of the door to which it is connected. 
     These objects, as well as other which will appear clearer hereafter, are fulfilled by a hinge having one or more of the features herein disclosed, claimed and/or shown. 
     Advantageous embodiments of the invention are defined in accordance with the dependent claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of the invention will appear more evident upon reading the detailed description of some preferred, non-exclusive embodiments of a hinge  1 , which is described as non-limiting examples with the help of the annexed drawings, in which: 
         FIG. 1  is an exploded view of an embodiment of the hinge  1 ; 
         FIGS. 2 a  and 2 b    are perspective views of the embodiment of the hinge  1  of  FIG. 1  respectively in the closed and open position; 
         FIGS. 3 a  and 3 b    are respectively perspective and upper views of the embodiment of the hinge  1  of  FIG. 1  in which the movable element  20  is mounted on a door D and the fixed element  10  is mounted on a frame F, the door D being in the closed position; 
         FIGS. 3 c  and 3 d    are respectively perspective and upper views of the embodiment of the hinge  1  of  FIG. 1  in which the movable element  20  is mounted on a door D and the fixed element  10  is mounted on a frame F, the door D being in the open position; 
         FIG. 4  is a schematic view of the assembly pivot  40  cam  51  interface element  62  elastic counteracting element  61  to be used in the embodiment of the hinge  1  of  FIG. 1 ; 
         FIGS. 5 and 6  are respectively side views of a first embodiment of the interface element  62  and the pivot  40  to be used in the embodiment of the hinge  1  of  FIG. 1 ; 
         FIGS. 7 a  and 7 b    are side views of a second embodiment of the pivot  40  to be used in the embodiment of the hinge  1  of  FIG. 1 ; 
         FIG. 7 c    is a side view of a second embodiment of the interface element  62  to be used in the embodiment of the hinge  1  of  FIG. 1 ; 
         FIGS. 8 a , 8 b  and 8 c    are respective top view and views sectioned along a plane VIIIb-VIIIb and along a plane VIIc-VIIc of the embodiment of the hinge  1  of  FIG. 1 , the hinge being in the closed position; 
         FIG. 9  is an enlarged view of some details of  FIG. 8 b   , with in  FIG. 9 a    an exploded view of such details; 
         FIG. 10  is an enlarged view of further details of  FIG. 8 b   , with in  FIG. 10 a    an exploded view of such details; 
         FIG. 11  is an exploded perspective view of a further embodiment of the hinge  1 , in which the box-shaped hinge body  11  is integral with the backplate  102 ; 
         FIG. 12  is a perspective view of the hinge body  11  of the embodiment of the hinge  1  of  FIG. 11 ; 
         FIGS. 13 a  and 13 b    are respectively perspective and sectional partly cut views of some details of a further embodiment of the cam means  50  and the follower means  60 ; 
         FIGS. 14 to 19  are sectional views of the cam means  50  and follower means  60  of  FIGS. 13 a  and 13 b    in various operational steps, in which for each step the relative position of the cam means  50 , the pushing member  68 ′ and the elastic counteracting element  61  is enlargedly shown. 
     
    
    
     DETAILED DESCRIPTION OF SOME PREFERRED EMBODIMENTS 
     With reference to the above figures, the hinge according to the invention, generally indicated  1 , is particularly useful for the rotatable possibly controlled movement during opening and/or closing of a closing element D, such as a reinforced door, which may be anchored to a stationary support structure, such as a wall, a floor or a ceiling. 
     Suitably, the hinge  1  may be concealedly inserted in a tubular support structure, which may be formed in a per se known manner by a rear counterframe CF, which can be anchored to the wall W or like support, and by a front frame F anchored to the counterframe CF. 
     In particular, the hinge  1  can be configured as a concealed “Anuba” hinge anchored to the frame F by the plate P 2 . 
     Advantageously, the hinge  1  is concealedly insertable in the support structure formed by the tubular rear counterframe CF and the front frame F. 
     Conveniently, the hinge  1  may include a fixed element  10  to be fixed to the stationary support W, for example by the frame F or the counterframe CF, on which a movable element  20  is pivoted to rotate about a longitudinal axis X, which may be substantially vertical, between an open position and a closed position. 
     In particular, the hinge  1  may include, respectively may consist of, a lower fixed half-hinge  10  and a movable upper half-hinge  20  rotatably coupled each other to rotate between the open and closed positions about the axis X. 
     Advantageously, the lower fixed half-hinge  10  may include a box-shaped hinge body  11  anchored to the stationary support W, while the movable upper half-hinge  20  may include means  21  for fixing to the door D. 
     Suitably, the hinge body  11  may be concealedly insertable within the support structure formed by the tubular rear counterframe CF and the front frame F, while the connecting means  21  may be defined by a connecting plate susceptible to extend from the tubular support structure in the open position of the door D, as shown for example in  FIGS. 3 c  and 3 d   , and to retract within the same tubular support structure in the closed position of the door D, as shown for example in  FIGS. 3 a    and  3   b.    
     In particular, the connecting plate  21  of the hinge  1  may be rotatably connected to the body  11  by means of the hinge pivot  40 , which will be better described later. 
     Advantageously, the box-shaped hinge body  11  may include a passing-through seat  12  defining the axis X within which is inserted with minimal clearance the pivot  40 , which may be unitary connected to the connecting plate  21 . 
     In this way, the pivot  40  is unitary movable with the door D between the open and closed positions. Thanks to this feature, the hinge  1  is able to support even very heavy doors D without misalignments or changing of the behaviour. 
     Suitably, at the ends of the passing-through seat  12  of the box-shaped body  11  respective anti-friction elements  13  may be placed, such as bearings. This allows the movable element  20  to rotate about the axis X with minimum friction, so that the hinge  1  is able to support even very heavy doors D. 
     The hinge body  11  may internally include a working chamber  14  defining a second axis Y which is substantially perpendicular to the first axis X defined by the passing-through seat  12  for the pivot  40 . 
     Suitably, the pivot  40  may include cam means  50  rotating around the axis X, while the working chamber  14  may include follower means  60  interacting with the former to slidably move along the axis Y between a first and a second end-stroke position, corresponding for example to the open and closed door D position. 
     The follower means  60  may include an elastic counteracting element susceptible to elastically oppose the pushing force imparted by the cam means. As non-limiting example, the elastic counteracting element may include, respectively may consist of, a spring, a nitrogen cylinder or a portion of polymeric material. 
     In a preferred but not exclusive embodiment of the hinge  1 , the elastic counteracting element may consist of an elastomer body  61 , which may be plate-shaped, disk-shaped or cylindrical-shaped. 
     Advantageously, the elastomer body  61  may be made of a polyurethane elastomer of the compact type, for example Vulkollan®. Suitably, the elastomer may have a Shore A hardness of 50 ShA to 95 ShA, preferably of 70 ShA to 90 ShA. More preferably, the elastomer body  61  may have a Shore A hardness of 80 ShA. 
     The use of the elastomer in place of the classic spring allows for a very high braking force, in a very small space. In fact, the stroke of the elastomer body  61  along the axis Y may be of some millimeters, for example 2-4 mm. 
     Moreover, the elastomer body  61  allows achievement of a braking effect of great efficiency in a purely mechanical hinge without the use of oil or like hydraulic damping means, for example during the opening. 
     In fact, upon the opening of the door D the elastic counteracting element  61  passes from the first to the second end-stroke position and remains in this position until the closing of the door by a user, so that the hinge  1  is a control hinge braked during opening. 
     Moreover, the follower means  60  may advantageously include an interface element  62  having a first end  63 ′ which interacts with the elastic counteracting element  61  and a second end  63 ″ interacts with the cam means  50 . 
     Advantageously, the interface element  62  may have a substantially “C”-shape with a central elongated portion  64  defining a third longitudinal axis Z substantially parallel to the axis X and perpendicular to the axis Y and a pair of end transverse appendices  65 ′,  65 ″ substantially perpendicular to the axis X and parallel to the axis Y. 
     Both the elongated central portion  64  and the end transverse appendices  65 ′,  65 ″ may include respective operating surfaces  66 ,  67 ′,  67 ″ placed at the front end  63 ″, the function of which is better explained later. 
     Moreover, the pivot  40  may suitably include the cam means  50 , so that the latter rotate unitary with the former around the axis X. Advantageously, the cam means  50  may include one or more cam elements susceptible to interact with the follower means  60 . 
     More particularly, in the pivot  40  of  FIGS. 4 and 6  the cam means  50  may include a single cam element, while in the pivot  40  of  FIGS. 7 a  and 7 b    the cam means  50  may include two cam elements. 
     For example, the single cam element may be defined by a plate-shaped body  51  insertable transversely in a removable manner within a seat  42  of the pivot  40  so that a portion of the former extends from the latter. This configuration simplifies the assembly of the hinge  1 . 
     On the other hand, the plate-shaped body  51  may be integrated into the pivot  40  in an unremovable manner. 
     Suitably, the plate-shaped body  51  may have a front peripheral edge  53  susceptible to interact with the interface element  62 , for example in correspondence of the operating surface  66 . To this end, the front peripheral edge  53  may be appropriately rounded. 
     In this way, the interface element  62  progressively compresses the elastomer body  61  upon the opening of the door D. The elastomer body  61  may further be susceptible to remain in the configuration elastically deformed until the closing of the door D by a user. In other words, the hinge  1  is elastically braking upon opening. 
     Suitably the hinge  1  may be configured so that the cam element  51  interacts with the operating surface  66  after an angular rotation of the door D, for example 45°. Following interaction with the interface element  62 , the cam element  51  compresses the elastomer body  61 , so that the hinge is mechanically braked upon opening during the subsequent angular rotation, for example the next 45°. In other words, the first angular rotation is free, that is not braked, while the subsequent angular rotation is braked by the braking action of the elastomer body  61 . 
     In one preferred but not exclusive embodiment, two cam elements may be provided, in particular a pair of first cam elements  52 ′,  52 ″ susceptible to interact with the operating surfaces  67 ′,  67 ″ of the interface element  62  and a second cam element consisting of the plate-shaped element  51  which is susceptible to interact with the operating surface  66 . 
     The first cam elements  52 ′,  52 ″ may be defined by a pair of substantially flat faces formed on the outer surface  44  of the pivot  40 , in longitudinally staggered positions so as to be operatively in contact with the operating planar surfaces  67 ′,  67 ″ of the interface element  62 . 
     Conveniently, the cam means  50  and the follower means  60  may be configured so that the substantially flat faces  52 ′,  52 ″ and the operative surfaces  67 ′,  67 ″ are substantially parallel and in mutual contact when the door D is in the closed position, as shown for example in  FIGS. 11 a  to 11 d   , and are substantially perpendicular and spaced apart each other when the door D is in the open position, as shown for example in  FIGS. 13 a    to  13   d.    
     The plate-shaped element  51  may further define a plane π substantially perpendicular to the substantially planar faces  52 ′,  52 ″. 
     In this way, it is possible to achieve a full control on the door D upon the opening, throughout all the angular rotation thereof. 
     In fact, for a first portion of angular rotation the substantially flat faces  52 ′,  52 ″ and the operative surfaces  67 ′,  67 ″ interact with each other to partially compress the elastomeric body  61 , thus urging it from the rest or starting stroke position to an intermediate compressed position. Further, for the next portion of the angular rotation of the door D the plate-shaped element  51  and the operating surface  66  of the interface element  62  interact each other so as to further compress the elastomeric body  61 , thus compressing it from the intermediate compressed position to the totally compressed or end stroke position. 
     This allows to progressively compress the elastic element, so as to obtain a braking effect for the entire angular rotation of the door D. 
     In another preferred but not exclusive embodiment, shown for example in the  FIGS. 13 a    to  19 , the interface element  62  may be configured as a pushing member  68 ′ and include a protrusion  300 , having a generally hemispherical shape. On the other hand, the cam means  50  may include a plurality of seats  310 ,  320 ,  330  each corresponding to a supper position of the door. 
     More in particular, the seats  310 ,  320 ,  330  are able to receive the protrusion  300  to supper the door in the supper positions. 
     Suitably, the seat  310  may correspond to the closed door position, while the seats  320 ,  330  may correspond to the open door positions. Advantageously, the latter may be mutually opposite with respect to the closed door position. 
     In a preferred but not exclusive embodiment, the seat  310  corresponding to the closed door position may have a generally “V”-shape with two consecutive planes  311 ,  312  angled each other with predetermined angle. 
     In this way, as particularly shown in  FIG. 15 , the sliding of the hemispherical protrusion  300  on the planes  311 ,  312  upon the rotation of the door is simplified, so as to ensure the automatic closing of the door starting from a predetermined angle, for example 20°. 
     At the same time, the user can rotate the door from the closed door position in both opening directions. 
     To maximize this effect, the angle between the planes  311 ,  312  may be at least 90°, preferably at least 110°. In a preferred but not exclusive embodiment, the angle between the planes  311 ,  312  may be 120°. 
     Moreover, each of the seats  320 ,  330  corresponding to the open door positions may advantageously have two consecutive portions  321 ,  322 ;  331 ,  332  having different shape. 
     The first portions  322 ;  332  may be generally flat, while the second portions  321 ;  331  may be countershaped with respect to the shape of the protrusion  300 , and in particular may be hemispherical. 
     In this way, the first flat portions  322 ;  332  may promote the sliding of the projection  310  thereon to convey it towards the second portions  321 ;  331 , suitable to supper the door. 
     In this way, as particularly shown in  FIG. 16 , the automatic opening of the door starting from a predetermined angle, for example 70°, is ensured. 
     As particularly shown in  FIG. 17 , the first flat portions  322 ;  332  act as pilot members for the second hemispherical portions  321 ;  331 , so that the insertion of the protrusion  300  in the latter takes place without noise. 
     Advantageously, the first flat portions  322 ;  332  may be substantially perpendicular to the planes  312 ,  311 . 
     Moreover, thanks to the above configuration the door may be rotated from the supper position only in one direction. In other words, the rotation in the other direction is prevented. 
     Indeed, as particularly shown in  FIG. 19 , if a user attempts to further rotate the door, the momentum caused by the elastic counteracting element  61  opposes this force, which momentum urges the one against the other the protrusion  300  and the second portions  321 ;  331 . 
     Suitably, the elastic counteracting element  61  may be configured so as to allow a further slight rotation of the door after the supper position in the door open position. To this end, the elastic counteracting element  61  after this minimum rotation can reach the position of maximum compression. 
     This absorbs the shock undergone by the door upon the reaching of the supper position. This configuration is particularly advantageous in the case of glass door, which in the case of abrupt shock could be damaged or broken. 
     The embodiment of the cam means  50  and the follower means  60  shown in  FIGS. 13 a    to  19  and described above is particularly advantageous with the above described elastic counteracting element  61  made of elastomer. 
     In fact, in the latter a minimum stroke corresponds to a very high strength. 
     Therefore, suitably precompressing the elastic counteracting element  61  in the working chamber  14  the strength of the hinge  1  is maximized. 
     Also, the elastic counteracting element  61  made of elastomer maximizes the effect of stopping the rotation, as described above. 
     In one preferred but not exclusive embodiment, it is possible to adjust the opening angle of the door D. 
     For the purpose, an adjusting screw  80  may be provided transversely inserted in the hinge body  11  with a first operating end  81  accessible by a user to adjust the penetration of the former  80  through the corresponding wall of the latter  11  and an opposite end  82  susceptible to come into contact with the plate-shaped element  51 . 
     By appropriately acting on the operating end  81  of the screw  80  the opening angle of the door can be adjusted in a simple and rapid manner, so as to avoid any impact of the door D against the stationary support W. 
     The hinge  1  is extremely effective and performing, and is also greatly simple to assemble. 
     For example, the hinge body  11  may have, in addition to the passing-through seat  12  for containing the pivot  40 , a passing-through opening  16  to make accessible the working chamber  14  from the outside. 
     In particular, the passing-through opening  16  may be susceptible to allow the insertion within the working chamber  14  of both the follower means  60  and the cam means  50 , in particular of the plate-shaped element  51 . 
     The passing-through opening  16  defines an axis Y′ perpendicular to both the axis Y and the axis X. 
     In practice, both the cam means  50  and the follower means  60  may be removably inserted in the working chamber  14  by sliding along the axis Y′. 
     This is particularly advantageous if it is necessary to change the elastic element  61 , for example to insert a softer or harder one in order to vary the braking action of the hinge  1 , or to change the plate-shaped element  51 , for example to insert one of different configuration to vary the braking action of the hinge  1 . 
     In fact, in order to mount the cam means  50  and the follower means  60 , it is simply needed to insert within the working chamber  14  through the passing-through opening  16  the elastic counteracting element  61  and the interface element  62 , subsequently to insert the pivot  40  into the seat  12  and then rotate the latter to move the seat  42  thereof in correspondence of the same passing-through opening  16 , so as to allow the insertion of the plate-shaped element  51 . The dismounting thereof may occur in the reverse order. 
     The hinge  1 , in addition to the above mentioned features and advantages, is particularly advantageous because it is possible to adjust the position of the door D in the three dimensions, that is both in height and in a plane substantially parallel to the floor as shown for example in  FIG. 3   c.    
     In fact, the connecting plate  21  may include a first portion  25 ′ susceptible to receive the pivot  40  and a second portion  25 ″ susceptible to receive the mounting bracket  30  and to allow the adjustment along the directions d, d′, as shown in  FIG. 2   b.    
     Suitably, the mounting bracket  30  may have a first plate portion  31  operatively fixable to the first portion  25 ′ of the mounting body  24  monolithically coupled with a second plate portion  32 , connectable in turn to the door D by means of suitable screws insertable into the holes  33 . 
     The operational connection between the first portion  25 ′ of the mounting body  24  and the first plate portion  31  of the mounting bracket  30  may be made by means of suitable screws  34  inserted through the holes  26  of the mounting body  24  and the openings  35  of the mounting bracket  30  and lockable in suitable locking elements  36 . 
     By suitably operating on the screws  34  it is possible to move the mounting bracket  30 , and then the door D, along the direction d′. In fact, by appropriately unscrewing the screws  34  it is possible to move the mounting bracket  30  for a stroke equal to the length L of the openings  35  in which the screws  34  are inserted. 
     The movement along the vertical direction d is ensured by the screws  37 ′,  37 ″ inserted through the second portion  25 ″ of the connecting plate  21 , the first plate portion  31  of the mounting bracket  30  lying therebetween. As mentioned above, the latter is secured to the former by using the screws  34 . 
     The screws  37 ′,  37 ″ can be operated by unscrewing the screws  34 , that allow the movement of the mounting bracket  30  with a stroke equal to the height H of the openings  35  in which the screws  34  are inserted. 
     To enable movement of the hinge  1  along the direction d″, the hinge body  11  may be movably mounted on an anchor plate  100 , which may be anchored to the tubular support structure F, CF by using the screws  101 . 
     To this end, a backplate  102  may be provided, which may be coupled to the hinge body  11  by means of screws  103  to define an interspace  104  therebetween, in which interspace the anchor plate  100  is housed. The interspace  104  may include two side abutment surfaces  105 ′,  105 ″. 
     In the alternative embodiment shown in  FIGS. 11 and 12 , the backplate  102  may be integrated into the hinge body  11 , i.e. the two parts can be made in a single piece. This allows to provide a more economic hinge  1 . 
     The screws  101  are engageable in the anchor plate  100  by passing through the slots  106  of the backplate  102 . 
     By appropriately acting on the screws  101  it is possible to move the assembly of the hinge body  11  and the backplate  102 , and then the door D, along the direction d″. In fact, by suitably unscrewing the screws  101 , it is possible to move the assembly between the hinge body  11  and the backplate  102 , and hence the hinge  1 , for a stroke equal to the length L′ of the slots  106  in which the screws  101  are inserted and/or the distance between the side abutment surfaces  105 ′,  105 ″ of the interspace  104 . 
     The hinge  1  may further be designed to minimize friction between the fixed half-hinge  10  and the movable half-hinge  20 . 
     For this purpose, the upper end  110 ′ of the seat  12  may include a respective upper annular housing  111 ′ suitable to receive a respective upper antifriction element  13 ′, such as a bearing. 
     As particularly shown in  FIGS. 17 d  and 17 e   , the pivot  40  may include a upper radial expansion  112 ′, for example a flange, with an upper operating surface  113 ′ susceptible to come in contact with the connecting plate  21  and a lower operating surface  113 ″ susceptible to remain faced to the upper annular housing  111 ′. 
     Advantageously, the upper annular housing  111 ′ and the upper antifriction element  13 ′ may be mutually configured so that the lower operating surface  113 ″ of the upper radial expansion  112 ′ is susceptible to abut against the upper antifriction element  13 ′. In this way, the pivot  40  can rotate onto the upper antifriction element  13 ′ by remaining mutually spaced from the hinge body  11 . 
     To this end, the inner diameter D 1  of the upper annular housing  111 ′ may be substantially equal to the outer diameter D 2  of the upper antifriction element  13 ′, while the height h 2  of the latter may be slightly greater than the height h 1  of the former, for example a few tenths of a millimeter. 
     Furtherly, the lower end  110 ″ of the seat  12  suitably includes a lower annular housing  111 ″ susceptible to receive a respective lower antifriction element  13 ″. 
     The lower end  41  of the pivot  40  may include a blind axial hole  114  susceptible to receive a locking screw  115 . A pressure element  112 ″ may further be provided, for example a washer, susceptible to be interposed between the locking screw  115  and the lower antifriction element  13 ″ to define a lower radial expansion. Advantageously, the latter may include an upper operative surface  116  susceptible to remain faced to the lower annular housing  111 ″. 
     The latter, the lower antifriction element  13 ″ and the pivot  40  may be mutually configured so that the upper operative surface  116  of the pressure element  112 ″ is susceptible to abut against the pivot  40  and to remain spaced apart from the lower antifriction element  13 ″. 
     In this way, the possible reaction force due to the rotation of the pivot  40  at its lower end  41  is loaded on the lower antifriction element  13 ″. 
     This prevents the slipping of the pivot  40  from the seat  12  and/or the misalignment of the same pivot  40 . 
     To minimize friction between the lower fixed half-hinge  10  and the upper half-hinge  20 , the inner diameter D 3  of the lower annular housing  111 ″ may be substantially equal to the outer diameter D 4  of the lower antifriction element  13 ″, while the outer diameter D 5  of the pressure element  112 ″ may be slightly less than the inner diameter D 3  of the lower annular housing  111 ″. 
     Moreover, the height h 3  of the latter may suitably be substantially equal to the sum of the height h 4  of the lower antifriction element  13 ″ and the height h 5  of the pressure element  112 ″. 
     Advantageously, the upper and lower antifriction elements  13 ′,  13 ″ may consist of bearings of the axial-radial type, in order to suitably load thereon both the axial and the radial stresses due to the weight of the door D and/or their reactions forces. 
     From the above description, it is apparent that the hinge  1  fulfils the intended objects. 
     The hinge  1  is susceptible to many changes and variants. All particulars may be replaced by other technically equivalent elements, and the materials may be different according to the needs, without exceeding the scope of the invention defined by the appended claims.