DESCRIPTION IMPROVED SHAFT PARTICULARLY FOR SPECTACLE FRAMES. AND RELATIVE ELASTICIZING DEVICE Technical Field This invention has as object an improved shaft, particularly for frames of spectacles, and relative elasticizing device. The innovation finds particular if not exclusive application in the sector of spectacles. Background Art At the present, state of the art there are a multitude of frames for spectacles. A good part of these, have devices which are made in proximity of the hinge, to allow the elasticized engagement to the part of frame that comprises the eye-piece joined by the intermediate bridge. Such function, obtained on both sides of the spectacles, has the advantage on one side to confer a greater wear-ability, in that the less pressure the shaft puts on the temples, the easier they are for the vast public to tolerate and on the other they would result more suitable for the different shapes of faces. The firms of the sector therefore, for some time have oriented themselves in such a way, with the main purpose to find innovative and often better solutions, both in terms of functioning and in size, in respect to the pre-existing ones. For example, a traditional elasticized shaft, that has found a wide consent in the consumer public, is constituted from the application of European patent n.79400087.7, in which is described an elastic hinge for frame of spectacles, essentially made of a box, associated on the side of the shaft, which contains a coaxial tie rod means to said box, and in which the end portion of the tie rod is
threaded, on which a bush is screwed that ensures the positioning of a spring, whilst on the other side it is in stop inside a seat obtained in said box. Another system, based conceptually on the solution provided from the preceding patent, may be constituted by the utility model n.181221, having as object an improved hinge for the articulation to a spectacle frame of an elastically opening shaft, in which a square support sunken into the frame is provided, on which a support pivots, this also being square constituent shoulder for the compression of a spring. The Italian patent n. 1 147 198, has as object an earpiece for spectacles with elastic hinging, in which the extremity of the ear- piece involves a small block, holed axially in which a connection end of the hinge is inserted. Proceeding with a reduced diameter, carries inserted a cornered sheet that engages within the holing, while rearward to this a tension helical spring blocked at the extremities of the element with a threaded locknut is provided. In this case an elastic opening of the ear-piece is allowed according to a determined angle through the elastic give of the connecting hinge. The noticeable drawbacks, in general common to the solutions cited, are composed essentially from the excessive complexity of the devices used. In fact, although performing their tasks excellently, they determine many problems in the manufacturing phase, on one side regarding the realization of the innumerable precision components, on the other in their assembly, in conclusion engraving in considerable measures on times and costs. The main purpose of present firms of the sector, has therefore been to reach the elasticizing devices realization of the shaft, that, although being more contained
in size, offers a much sought-after functionality aiming at the same time to reduce the components, making the assembly easier and reducing costs. In the sight of recent devices, in line with the principles described above and that they are proposed more or less effectively on the market, a solution is present in which the articulation is all one with the containing sliding body of an elasticizing spring of the shaft. In more detail said body, has a square cross section, in which material has been removed longitudinally right through, until obtaining thin contraposed sheets that define the guide seat, realizing the containing walls of a spring. On one side, the spring is in stop on said seat, while on the other it is anchored to a tooth which protrudes in respect to the profile defined by the sliding body. Also part of the device in examination is a half-hull, opened on one side to be then joined to a shaft, and on the inside of which the sliding body, complete of spring, is inserted, turning the tooth on the longitudinal surface in which a stop reference is obtained. Being in a condition of traction, the articulation obliges the body to slide on the inside of the half-hull maintaining the tooth constantly in grip along the base of said half-hull, until compressing the spring, to then in this way elastically recall the same articulation. In the state of the art, other improved devices of elastic give are known, that more or less descend from the solutions described previously, and in which for example difficulty of working inside the box is noticeable, requiring a certain precision. In more detail, very common is the fact to ensure to said preassembled box on the extremities of the shaft, the elastic give group, essentially made up from an articulation on which a coaxial tie rod is screwed to a spring,
held from the opposite side by a convenient bush. Consequently, at least two drawbacks can be found, on one side, the necessity to resort to a discreet sizing, that influences on the heaviness of the structure, not excluding the aesthetics, on the other side, the use of screw means involves considerable assembly times, and consequently incises on the high costs. For certain shafts, lets say the ones of value, the system is still valid, proof of this is the wide use, but for other shafts, as for example those directed to the majority of the public, the device is no longer convenient, having to adapt to the decidedly more contained costs of the frame. Lately the research of the operators of the sector, is therefore concentrated in the interests of alternating devices, destined to be promoted in large quantities and able to mainly avoid the use of the screw passing the box for the engagement of the elastic give group. An example may be given by the elasticizing device and shaft so obtained, particularly for spectacle frames, as in Patent Application n. TN94A000080. In practice, it comprises one complex articulation, hinged to a female hinge provided on side of the frame, and partially received in a small box joined to the shaft, free to slide for the articulation; being that the giving device of the articulation is constituted by a screw engaged on the base and is coaxial to a spring which provides an extremity in stop of a washer that stops in connection with a shoulder inside the small box; and in which said small box, is essentially parallelepiped developed on three sides allowing to make the welding of the fourth opened side directly in contact of the shaft ensuring simultaneously both the small box and the shaft giving device, said shaft providing a seat, made longitudinally, for the partial housing of the device.
The drawback of this solution, consists in the fact that like others, the group of elastic give must be engaged to the shaft contextually to the fixing of the box on the same. Such technique, therefore is not suitable for those cases, in which the assembly of the group of elastic give is provided in a subsequent phase to the anchorage of the box on the respective shaft. Scope of this invention is also that to avoid the above- mentioned drawbacks. This and other aims, are reached with this innovation according to the characteristics as in included claims, solving the arising problems by means of an improved shaft, particularly for spectacles frames, and relative elasticizing device of the types made from a complex articulation introduced on the inside of a box associated to said shaft and hinged to the reference face, said articulation comprising essentially; a tie rod, coaxial to a helical spring of compression held on one side by an enlargement obtained in connection with one end of said tie rod, on the other insisting in proximity of the articulation engaged on the opposite end of the same tie rod, and in which between the articulation and the spring a stop is interposed, said stop being made of a harpoon that wedges in a hollow obtained on the internal surface of the containing box. In this way, through the notable creative contribution which effect realizes an immediate technical progress, various advantages are achieved. Firstly a discreet relation between functionality-price is obtained, making the use of the elastic giving device possible in the interests of a large number of spectacles, consequently widening the base of the possible user subjects. A second advantage, consists in the fact of making possible a substantial simplification of the productive
process of the finished shaft, as the operators are called to carry out a simple introduction of the articulation group within the box of the rod, without the assistance of special tools but above all without resorting to the engagement of the classic screw. Such operation in conclusion, is substantially speeded up, making the increase of the productive capacity of this type of shaft possible, not excluded a certain control of costs. Finally, it must be remembered that it is also possible to greatly reduce the encumbrances obtaining a very compact device, as well as lightening the shaft even more. These and other advantages appear from the subsequent specific embodiments with the help of the enclosed drawing the details of which are not to be considered limitative but only illustrative. Figure 1. represents a whole view of the articulation dissociated from the shaft of the types with welded box. Figure 2. represents a sectional view of the insertion of the articulation in the corresponding box of a shaft. Figure 3. represents a whole view of the articulation engaged on the reference shaft and to hinge to the face of a spectacles frame. Figure 4. represents a view also in section of the assembly of the shaft to the respective face, highlighting the function of the elastic hinge. Figure 5., represents a view of the internal side of the box to be associated to the reference shaft. Figures 6. and 7., respectively represent sectional views, on a cross and longitudinal surface, of the box as in preceding figure, taken respectively along axis A- A and B-B. Figure 8. represents a head view of the same box as in figure 5.
Finally, figures 9. and 10., represent views of a metallic stop, respectively from the front and from above. Also making reference to the figures, it is disclosed that at least one shaft (A), particularly for spectacles, is elastically pliable to allow, if worn, the divarication of the same beyond the usual axis opening, generally at right angles, in respect to the frame. In more detail, each shaft (A) of a pair of spectacles is made up of one preassembled complex articulation, received inside of box (1) associated to the actual shaft (2), of support of the spectacles frame. In particular, the complex articulation, is made up of a male hinge having a rounded and flattened head (3), provided centrally of a hole (3') for the fulcrum, by means of a through screw, to the face (4) on the side of the ocular of the spectacles. The body (3") of the male hinge or better still of the articulation (3), provides the execution of a hole (5) that develops longitudinally, in which one part is threaded. The purpose of the receptacle (5), is that to allow the engagement of the extremity of a tie rod (6), whose opposite end is structured analogously to receive a screw (7) essentially of a truncated cone shape, or rather said end being provided with a widening (7) essentially truncated cone shaped, eventually with two flat grip surfaces (not illustrated) that realize the engagement key of the screw-tie rod (6). In the space that elapses, between said screw (7) and the live (3") of the articulation (3), a helical spring of compression (8) is made operative, coaxially to which is received the tie rod (6). Therefore we will have, on one side an end (8') of the spring (8) disposes in stop on the screw (7), on the other insisting on a stop (9), interposed between the end (8") of the spring (8) and the live (3") of the articulation. The stop (9), in this case, is made up of a kind of washer,
obtained by a metal sheet, that may be of harmonic steel, provided with a hole in a central position to coaxially house the tie rod (6), and of a protrusive part (9'), in practice a blade, bent between 45 and 90° to form the harpoon. The ensemble; articulation (3), screw-tie rod (6, 7), spring (8) as well as the stop (9), are introduced once assembled, inside a box (1), already engaged in connection of an end of the shaft (2) in order to mill (v. Fig. 2). A particularity of said box (1) is constituted by the fact of providing, on the internal surface (1'), a hollow (1"), essentially of a circular shape with flat base. Function of the hollow (1"), is that to house the harpoon (9') of the ensemble of the articulation, in such a way that the last one being bent in the opposite sense to the introduction, contrasted with the tendency to be removed, and simultaneously offering stop surface for compression of the spring (8) during the dynamic phase (figure 4.). In this case, to favour the introduction of the articulation (3) inside the box (1), the realization of a housing on the surface near the live (3") is provided, in such a way that the harpoon (9') on hitting disposes the same plane to the perimetrical surface of that part of body (3) introduced on the internal the box (1). The functioning of the elasticizing device of the shaft (A), in wearing the spectacles frame, is ensured by the force exercised from the spring (8), which is compressed, if a pull is made on the longitudinal axis of the screw (6-7), condition that happens on the divarication of the shaft beyond the axis that insists perpendicularly in respect to the frame. Consequently, the shaft (A) hinged to a correspondent face (2), gives elastically, pulling the articulation (3) and simultaneously compressing the spring (8), held by a stop (9) that
opposes wedging itself in the seat (1") made on the bottom of the box (1). Obviously the recall of the same spring (8), allows the spectacles, on one side to be correctly and easily worn, on the other when no more used, until closing the shaft.