HINGE FOR ARMOUR-CLAD DOORS OR THE LIKE

Abstract: The hinge, in particular for armour-clad doors or the like, substantially comprises a male element (2) and a female element (3) respectively formed by a cylindrical pivot (5) provided with a top plane (8), and a cylindrical bore (13) provided with a bottom plane (14). The top plane of the pivot and the bottom plane of the bore interact during the operativity of the hinge with the interposition of low-­ friction-coefficient elements, such as, e.g., balls (10) or bushings (24). The bottom plane of the bore can be adjusted and blocked in the desired position along the revolution axis of the hinges by means of screw/counterscrew means.

Description: The present invention relates to a hinge, in particular for armour-clad doors, according to the preamble of claim 1. The hinges particularyly intended for armour-clad doors, or the like, show a particularly strong structure, in order to be able to resist to the stresses they undergo whenever the heavy door they support is opened or closed. Hinges are known which comprise a female element integral with the door, and a male element integral with the doorpost, provided with a pivot on which a rolling thrust bearing is slid, with said bearing resulting thus compressed between the female element and the male element Owing to reasons of functionality of the hinge, the overall dimensions of the bearing must mandatorily be limited within narrow limits, in that said bearing must be housed inside the small toroidal room existing between the outer surface of the pivot on which it is slid, and the external surface of the hinge, which coincides with both the outer surface of the male element, and the outer surface of the female element which, when assembled with each other, compose the same hinge. As a consequence, the diameter of the rolling bodies of the bearing, usually balls, is very small, so that said rolling bodies generate high specific pressures on the relevant races, with the result that such races wear out very early, requiring the whole bearing to be frequently replaced. Such a situation becomes more serious when, due to reasons foreign to the hinge, displacements occur, which are due to phenomena of settling, or the like, of the doorpost/door assembly, with the result that the weight of the door comes to be nearly totally supported by one only of the hinges. In order to prevent the hinge from early wearing out due to phenomena of settling or the like, an improved type of such a hinge is provided with means of adjustment of the position of the pivot along the axis of the same hinge. In such an "adjustable hinge", the desired position of the pivot is obtained by revolving the same pivot inside a relevant screwthreaded seat destined to be fastened to the doorpost. The rotation of the pivot when the hinge is mounted in its operative position is carried out by acting on a first, hexagonal end of an idle spindle, coaxial with the same pivot, and provided with a second end having a blade shape, which engages a slot provided in the pivot. When the adjustment is ended, blocking means, constituted by a blocking grub screw, constrain the pivot, so as to prevent it from rotating around the axis of the hinge when the door is opened and closed. The adjustable hinge, contrarily to the non-adjustable hinge, is capable of obviating the early wear of the bearing due to the overloads applied to said bearing due to settlings of the doorposts, but it is not anyway capable of obviating the wear deriving from missed lubrication and to the penetration of foreign bodies inside the bearing. Such forms of wear, indeed much more noxious, are due to the fact that the bearing is difficult to lubricate, and is particularly exposed to impurities, because it is housed in a peripheral area of the same hinge. In fact, such hinges cannot be profitably used outdoor, or in corrosive and/or dusty environments. In case of gripping, the bearing acts as a coupling interposed between the female element of the hinge and the ring-shaped surface associated with the pivot of the male element, applying to this latter such a high twisting torque, as to easily exceed the strength of the pivot blocking means, in particular the above mentioned grub screw, which gets broken during the rotation of the hinge. When one continues to operate the door under such conditions, the position of the pivot, no longer constrained along the axis of the hinge, progressively changes, till to prevent the door from being correctly closed when the hinge results by that time damaged to an irreparable extent. From GB-A-380 549 there is known a type of hinge in which the friction undergoing means are housed inside the female element. In one embodiment the hinge is provided with a ball placed at the end of the pivot and resting against the bottom surface of the bore the female element is provided with. In such a hinge, the ball can be: constructed with a rather high diameter, because said diameter is no longer dictated by problems relating to overall dimensions; sheltered, because it is housed on the bottom of the bore of the female element. Also such hinges have resulted to be not free from drawbacks due to the excessive wear the top surfaces of the pivot, the bottom surface of the female element, and the same ball are subjected to. Such an excessive wear is due to the fact that the revolution axis of the ball coincides with the revolution axis of the hinge, and therefore during the actions of door opening and/or closure, the ball revolves on itself, with its own surface sliding against the surfaces it spaces apart from each other, generating sliding friction, which is particularly destructive for the surfaces. According to another embodiment disclosed in GB-A-380 549, a ball thrust bearing is interposed between the bottom of the bore of the female element and the end of the pin of the male element. Said bottom is formed by a plug engaging a lower bearing plate and the pin is provided with an axial extension engaging an upper bearing plate, so that the bearing plates are each made stable with one of the relatively rotating parts to allow correct operation of the bearing. Also in this case, however, the overall dimensions of the bearing must mandatorily be held within narrow limits and the rolling bodies (balls) of the bearing have necessarily to be very small because they must be housed between the bearing plates and within the periphery thereof. As a consequence, the rolling bodies generate high specific pressures on the relevant races with the effect of rapidly wearing them out. The purpose of the present invention consists in providing a hinge capable of obviating the above drawbacks, namely a hinge wherein the elements under relative motion stressed by the load are: of a relatively large diameter, so as to validly counteract the stresses due to the weight of the door, even if increased due to phenomena of settling of the doorposts; submitted to rolling friction, and not to sliding friction. Such a purpose is achieved by means of a hinge, in particular for armour-clad doors, having the features claimed in claim 1. Preferred embodiments of the invention then being defined in dependent Claims 2 to 5. Characteristics and advantages of the present invention are set forth in detail in the following disclosure of two exemplifying forms of practical embodiment, depicted in the hereto attached drawings wherein: Figure 1 shows a partially sectional front view of a hinge according to the present invention; Figure 2 shows a sectional view along path II-II of figure 1; Figure 3 shows a sectional view along path III-III of figure 1; Figure 4 shows a view of a hinge of the invention, equipped with adjusting means. The advantages achieved by means of the present invention essentially consist in that such a hinge is capable of supporting, as compared to hinges having the same overall dimensions, higher loads, with a lower wear over time, with no need for periodic overhauls. Such advantages are still more evident when the hinge is requested to operate outdoor, and/or in a corrosive environment, towards which it results practically insensible. Referring to the above figures, and, in particular to Figures 1 through 3, the hinge 1 generally comprises a male element 2 and a female element 3. The male element 2 is formed by a cylindrical base 4, and a pivot 5, also cylindrical, and constituting one single body with the same base, with which it joins defining a ring-shaped plane 6. The cylindrical base 4 is provided with a flange 7 which constitutes a means for fastening to a door (not shown in the figures). The pivot 5 ends with a top end cross surface 8 provided with a first ring-shaped area 16, wherein an annular race 9 is shaped, which rotatably receives a plurality of rolling elements, e.g., balls 10, running along said race 9 with low values of friction coefficient. The female element 3 is provided as well with a cylindrical base 11 provided with a flange 12, identical to the flange the cylindrical base 4 of the male element 2 is provided with, and destined to be fastened to the doorpost (not shown in the figures). Said female element 3 is provided with a cylindrical bore 13 coaxial with the pivot 5 and ending with a bottom end cross surface 14, also provided with a ring-shaped area 17 wherein an annular race 15 is shaped, which is identical to and coaxial faces the race 9, and is destined as well to rotatably receive the balls 10 which thus roll between the surfaces 8 and 14 and within the lateral surface of the bore 13. In order to secure a sufficient and constant lubrication of the balls, the hinge must be installed in such a way that the female element directs upwards its concavity, so as to also act as a sump for the lubricant of the hinge. The hinge is completed by a tight-sealing gasket 22 placed between the edge 23 of the bore 13, and the ring-shaped plane 6 of the pivot 5, which simultaneously prevents the lubricant from escaping, and foreign bodies from entering the hinge. Such a hinge can operate in an optimum way and for long time also under dusty and/or corrosive atmospheres. The races 9 and 15 may be hardened by means of case-hardening. In an improved form of practical embodiment, (see fig.4), the hinge 1 is endowed with the possibility of stably adjusting the position of the ring-shaped area 14 along the revolution axis A-A of the same hinge, by screw means. Such screw means comprise a threading 18, coaxial with axis A-A and provided inside the cylindrical base 11 of the female element 3, which is engaged by a screw 19 totally contained inside the same base 11, and provided, at a first end thereof, with an axial cavity 20 of polygonal cross section. In the second end of said screw, i.e. in the front surface thereof facing the plane 8 of the pivot 5, a portion of the race 15 is provided, on which the balls 10 run. Inside the threading 18, in series to the screw 19 a locking screw 21 is housed, whose structure is at all similar to that of the screw 19, and which acts on the screw 19 so as to block it inside the base 11. By screwing down or unscrewing the screw 19, the position of the race 15 can be adjusted along the axis A-A, thus enabling the hinge to compensate for possible settlings of the doorpost or of the door on which it is installed, making it possible to equally subdivide the loads on each hinge of the same door.

Claims: Hinge, in particular for armour-clad doors, comprising a male element (2) and a female element (3) having respectively a cylindrical pivot (5) ending with a top end cross surface (8) and a coaxial cylindrical bore (13) ending with a bottom end cross surface (14), said cylindrical pivot (5) revolving inside said cylindrical bore (13) about a revolution axis (A-A) which constitutes the revolution axis of the hinge (1), the bottom of the bore (13) rotatably supporting the pivot (5) by interposition of rolling means (10), characterised in that in the end cross surfaces (8,14) of the pivot (5) and the bore (13) there are shaped two facing coaxial annular races (9,15) rotatably engaging a plurality of rolling elements (10) therebetween and within the lateral surface of said bore (13). Hinge according to claim 1, characterized in that at least a portion of the annular race (15) defined in said bottom end cross surface (14) is provided in the front surface of an element (screw 19) adjustable along the revolution axis (A-A) of the hinge (1). Hinge according to claim 2, characterized in that said adjustable element comprises a screw (19) screwable in said female element (3) and lockable by a locking screw (21). Hinge according to claim 3, characterized in that said screw (19) and locking screw (21) each have an axial cavity (20) of polygonal cross section for operation of said screw (19) and locking screw (21). Hinge according to claim 1, characterized in that the annular races (9,15) are hardened by means of case-hardening.

Inventors: MAGGI, MARIO
Applicants: MAGGI S.P.A.
Application year: 1988
Main classification: E05D11
IPC codes: E05D11