FIELD OF THE INVENTION

The present invention concerns a hinge for spectacles, in particular a so-called flexible hinge. < BACKGROUND ART

As is known, hinges for spectacles are composed of a series of components and mechanisms which enable the two lateral temples to be mounted in an articulated way on the front frame of the pair of spectacles.

Spectacle hinges come in wide variety of different shapes, depending on both their function and the aesthetic appearance which they are to give the spectacles. Some of the most widely used hinges nowadays are the so-called flexible hinges.

Flexible hinges normally consist of a box-like housing body, mounted on each temple, within which a slider or carriage is slidable, being provided with a projecting part with an eyelet designed to be coupled, by means of an articulation pivot, with a female fork provided on the end piece or front frame of the spectacles. The sliding movement of the carriage in the boxlike housing is opposed by an elastic component, normally in the form of one or more helical springs, which provide the so-called flexible movement.

Examples of conventional flexible hinges are described in EP1175638 and FR2662516, in the name of the same applicant. In these hinges, the helical spring is fitted to a cylindrical pin of the carriage. The pin, on the one hand, supports the helical spring in the correct working position and, on the other hand, serves to restrain the distal end of the helical spring (or the end nearest to the bottom of the box-like housing) . The other end of the spring, or the proximal end, is, on the other hand, restrained by a retaining clip which holds it to the fixed, boxlike housing. In this way, the sliding movement of the carriage causes compression of the spring which therefore provides the desired elastic reaction. The retaining clip of the spring is normally in the form of a catch body or of an elastic fork, which is designed to bend only when it is moved in a longitudinal direction of insertion of the carriage into its housing. In this way, the carriage with the spring and the clip can be freely inserted into the box-like housing (flexion of the elastic fork takes place in the direction of insertion) , but they can no longer be completely withdrawn in the opposite direction (the fork digs into seats inside the housing and blocks itself with respect to the housing and abuts against the spring, producing the desired elastic deformation thereof) .

Since the portion of the carriage on which the spring is mounted cannot be produced with precise tolerances, another guide portion is provided, in order to guide the carriage into the housing correctly. Typically, the portion of the carriage between the eyelet and the retaining clip is machined with good tolerances and acts as a guide along the internal, lateral walls of the housing.

Understandably, this conventional configuration imposes a minimum length on the carriage, below which one cannot go. Typically, the pin with spring portion, plus the clip assembly portion, plus the guide and eyelet portions add up to a length of not less than 10 mm.

Furthermore, these hinges pose some problems relating to the thinness of the pin which supports the spring (which must sustain the entire traction load on the sliding element), and manufacturing difficulties.

According to the prior art, hinges have already been proposed in which the helical spring is not fitted onto a elongated pin, but is rather contained between the two lateral portions of a U-shaped body of the slide component. Examples of such hinges are described in FR2741459 and EP615149.

These hinges however, still use retaining clips which take up a certain amount of space in a longitudinal direction and which dig in near the mouth of the housing. Therefore, in addition to the fact that they still take up a lot of room, they stress the area of the mouth of the housing, which is in fact the most delicate part of the hinge. Where, on the other hand, it was provided not to have autonomous retention components, as in US20030147045 and FR2206513, it is necessary to provide complex assembly systems.

EP0822438 also shows another elastic hinge solution in which the helical spring is contained inside the body of the hinge.

SUMMARY OF THE INVENTION

The object of the present invention is therefore to solve the aforesaid problems, by providing a shorter, stronger, flexible hinge with few components, which can be easily and perma- nently interlinked.

Λ further object is to provide a flexible hinge in which the retaining clip of the spring, despite blocking the outermost (proximal) end of the spring, can act within the housing in a position which is far away from the mouth, or deep within the housing.

Such objects are achieved by means of a device as described in its essential features in the attached claims.

In particular, according to a first aspect, a flexible hinge for spectacles is provided of the type comprising a female component and a male component which are reciprocally articulated, the latter having at least one housing with a slide cavity and a carriage, which is slidable in said housing, being in a U-shape and provided with two terminal heads with eyelets defining a hinge axis, also being provided with an elastic ele- ment, which is held between a U-shaped carriage base portion and retention means, which can be coupled to said slide cavity, and which is capable of producing an elastic reaction which opposes withdrawal of said carriage from the housing, in which said retention means consist of a cage-like clip inserted between two arms of said U-shaped carriage, the clip having a base portion, located between said arms of the carriage and abutting onto said elastic element, from which two pairs of tines project, extending in the direction of said elastic element, the terminal ends of said tines being provided with hooks to be engaged in corresponding retention recesses in said slide cavity.

According to another aspect, at least one pair of tines of said clip is arranged adjacent to the edges or to lowerings of the edges of said arms. Preferably both pairs of tines are ar- ranged adjacent to the upper and lower longitudinal edges of the arms of said U-shaped carriage.

According to another preferred aspect, the tines are provided with a projection intended to engage with a corresponding step on the edge of said arms, which establishes a stop means of the clip in relation to the carriage.

Again, preferably, at least one projecting tooth is provided from the edge of the base portion of the U-shaped carriage, which can be inserted between a pair of said tines, in order to prevent them from getting too close to each other.

According to a further aspect of the invention, at least the hook-shaped extremity of said tines, when the U-shaped carriage is mounted stably in said slide cavity, abuts onto the two opposite sides of said tooth, so that the clip establishes as a transversely-rigid component between the two lateral arms of said U-shaped carriage.

According to an aspect, said hooks protrude from the lateral profile of said arms of the U-shaped carriage.

Furthermore, said clip has a pair of tabs projecting from said base portion, apt to engage, slidingly, with corresponding slots in said arms of the U-shaped carriage.

According to another aspect, said carriage has capture means in which said hooks of the tines may be held in a condition disengaged from said retention recesses in the slide cavity. Preferably, the capture means are in the form of a notch in a tooth, the carriage housing further comprising wedge-shaped projections designed to drive said hooks into said notch, following a movement of the clip in the direction of the base portion of the U-shaped carriage.

Advantageously, the two pairs of tines of said cage-like clip project according to the longitudinal axis of said elastic element in the form of a spring, on either side of the same spring.

According to another aspect of the invention, a method of assembly of a hinge as described above is provided, in which a group is first assembled, consisting of said U-shaped carriage onto which said clip and said elastic component are installed, said group is then inserted into said slide cavity, until said U-shaped carriage is brought to its internal end-of-stroke, and wherein it is further provided to drive said cage-like clip towards the interior, compressing said elastic element and bringing said hooks to engage said retention recesses in the slide cavity.

According to a preferred aspect, the driving action of said clip towards the interior is carried out by using a pin tool, inserted between the two arms of the U-shaped carriage in such a way as to exert pressure on said base portion of the clip.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the device ac- cording to the invention shall be more apparent from the following detailed description, which is given by way of example and illustrated in the attached drawings in which:

Fig. 1 is an exploded, perspective view from above, of a first embodiment of the male hinge component according to the invention;

Fig. 2 is a perspective view from below of the component in Fig. 1, assembled;

Fig. 3 is an elevation, lateral view of a male hinge component, disassembled, according to a second embodiment of the in- vention;

Fig. 4 is a top plan view of the component in Fig. 3;

Fig. 5 is a perspective view of the component in Fig. 3; Fig. € is a similar view to that in Fig. 5, with the car- riage assembled in the housing;

Fig. 7 is an elevation lateral view of the male hinge component in Fig. 6, complete with the female fork;

Fig. 8 is a top plan view of the hinge in Fig. 7;

Fig. 9 is a perspective view of the hinge in Fig. 7;

Fig. 10 is an exploded, perspective view of a third embodiment of the male hinge component; and

Figs. 11-13 are schematic, perspective views which illustrate the stages of assembly of a preferred embodiment of the invention, in which Fig. 12A represents an enlargement of a de- tail.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the course of the present specification, just one of the two components of which a spectacle hinge is made up will be basically considered. In particular, reference will be made to the component which is conventionally described as "male", i.e. the component which includes a carriage which is slidable into a relative housing and which has a terminal part with an eyelet, into which the articulation pivot of the hinge engages. Typically, this component is found on the spectacle temple, whereas the opposite component (usually referred to as the female component of the hinge) is an integral part of the front frame or end piece of the spectacles.

This convention will be used below for greater clarity, but it is understood that the inventive principles expressed here can also apply to a component which is an integral part of the front frame of the spectacles or a component which is referred to as "female" in its specific application field.

Fig. 1 illustrates a box-like housing 1, with an internal sliding seat la for a carriage 2. The box-like housing is de- signed to be fixed stably to one of the reciprocally-mobile components of the frame of a pair of spectacles, for example to a temple. Carriage 2 extends for a certain length and has a slide portion 2a, which is placed in housing 1 (once the hinge has been assembled) and an external end portion 2b, which is designed to remain outside small box 1, and which is provided with a pivoting head with an eyelet.

In particular, carriage 2 is in a U shape, both terminal ends of which have heads with eyelets 21a and 21b, provided with holes the axes of which are aligned. The U-shaped slide portion is so arranged that the two lateral arms 22a and 22b are parallel and with a finished surface such as to constitute a guide along corresponding internal wall surfaces in cavity la of housing 1. The two external lateral surfaces of the two lateral arms 22a and 22b therefore act as a guide in the transverse direction of the width of the hinge, i.e. in the direction in which the articulation pivot runs (only illustrated in the variant in Figs. 7-9) passing into the eyelets in heads 21a and 21b.

Furthermore, the two parallel arms 22a and 22b have upper and lower edges which are manufactured in such a way as to maintain adequate parallelism: these edges are designed to slide, precisely, in corresponding guide surfaces made at least on the ceiling of internal cavity la of housing 1 and possibly also on the base of said cavity la. These opposing edges, in pairs on each lateral arm 22a and 22b, therefore act as a guide to the carriage, mainly in the direction of the height of the hinge, i.e. perpendicularly to the pivoting axis.

The U-shaped carriage can be obtained by cold forging or punching of a sheet of suitable metal material, for example nickel silver, Monel or stainless steel. For that reason, the carriage is inherently robust and can be mass produced quickly and inexpensively.

Between the two arms 22a and 22b of the carriage, a helical spring 3 is located, laid along the longitudinal axis of car- riage 2. The reciprocal distance between the two arms 22a and 22b is therefore a function of the diameter of the spring, considering that it is advantageous to keep this distance as small as possible, in order for it to be as compact as possible, whilst keeping said spring as robust as possible. The length of the two arms 22a and 22b is the minimum indispensable in order to provide spring 3 with an internal housing space. According to the invention, in fact, the internal (or distal) end of spring 3 abuts onto the terminal (curved) end of U-shaped car- riage 2, whilst the outermost end of spring 3 is designed to abut onto a clip component 4, close to the working area of external heads 21a and 21b.

Clip 4 is advantageously in the form of a cage, so that it embraces at least spring 3 longitudinally, and, at the same time, acts as a stop component to it. In particular, clip 4 is composed of a small base portion 4a, at the corners of which four tines 4b project, intended to be arranged along the longitudinal (or sliding) axis of carriage 2.

The small base portion 4a is of a size such as to be accom- modated between the two arms of the U-shaped carriage, so that it abuts onto the external (or proximal) end of spring 3.

Tines 4b extend towards the curved portion of the base of the carriage, for at least half the length of the guide portion 2a of carriage 2, ending in retention hooks 4b' . Along the length of tines 4b stop protrusions 4b' ' are also devised, which are designed to form the internal end-of-stroke of the carriage on the clip.

Because they depart from small base portion 4a, tines 4b also extend internally to the two arms of the U-shaped carriage, with retention hooks 4b' which, however, project slightly laterally, outwards (therefore superimposing themselves on the thickness of the two arms 22a and 22b and projecting outside from the lateral profile of carriage 2 ) .

Hooks 4b are also preferably arranged in such a way as to arrange themselves in pairs above and below (transversely to the hinge axis) the two arms of the U-shaped carriage. For that purpose, in order to avoid interference with the carriage guide, the upper and lower edges of arms 22a and 22b have, at the rear, (i.e. the part nearest to the curved base portion), lowerings 22a' and 22b' which are designed to receive the most projecting part of tines 4b (see Fig. 2). In the curved base portion of U- shaped carriage 2, lowering [s] 22a' and 22b' are not provided on the two opposite edges of arms 22a and 22b, in such a way as to leave a step or tooth 23 (both above and below, as visible from a comparison between Figs. 1 and 2), which rises up from the edge of carriage 2, the use of which is explained below.

Assembly of this male hinge component involves arranging spring 3 between the arms of U-shaped carriage 2 and then in- serting, from the front, the cage-shaped retention clip 4. For this operation, tines 4b need to be slightly deformed, bringing them towards each other, in such a way as to bring projecting retention hooks 4b' closer together and enable them to be inserted between the two terminal heads 21a and 21b. Alterna- tively, or in combination, heads 21a and 21b can be distanced from each other, causing arms 22a and 22b to bend and drawing them apart. One then deeply inserts the cage clip along the longitudinal axis of the carriage, until small base portion 4a abuts onto the outer end of spring 3. By pressing slightly fur- ther the clip and bringing gently the spring 3 into compression, the stop protuberances 4b'' are made to overcome step S of lowerings 22a' and 22b'. Protuberances 4b'' can then elastically snap outwards and abut onto said small step. In this way, a compact and self-contained assembly is obtained, consisting of the carriage, spring and clip, which can then be inserted frontally into cavity la of box-like housing 1.

Cavity la, as appreciable in Fig. 2, has two parallel, internal guide walls, which have a relative distance equivalent to the width of carriage 2, therefore such as to accommodate the sliding of carriage 2 precisely. Along the two lateral walls there are recesses or notches lb, which are designed to permit hooking of retention cage 4, as indicated below.

When inserting the carriage+spring+clip assembly into seat la, the four hooks 4b' need, once again, to be pressed inwards (which, by projecting from the lateral perimeter of carriage 2, would otherwise abut against the mouth of cavity la), overcoming the elastic reaction of tines 4b. Carriage 2 is made to slide precisely on the lateral and ceiling walls (not visible) of housing 1, until it ends up in its fully inserted position. In correspondence with this position, retention hooks 4b' can snap outwards, inserting themselves into corresponding recesses lb on the internal walls of housing 1. Recesses lb are shaped in such a way that hooks 4b' securely engage with them, thereby prevent- ing clip 4 from coming out of the mouth of housing 1 again, should extraction traction be exerted.

During flexible operation of the hinge, on the articulation pivot (not represented) inserted into eyelets 21a and 21b, traction is exerted which tends to withdraw carriage 2 from housing 1. Since clip 4 is blocked on the internal walls of housing 1, the spring is progressively compressed between the curved base portion of carriage 2 and base portion 4a, providing the desired elastic reaction.

If the carriage is subjected to high extraction traction, a displacement is caused which is such that tooth 23 end up between the two tines of the pair of tines 4b (Fig. 2), thereby opposing them. By doing so, the possibility of the tines being elastically deformed inwards is completely ruled out, thereby avoiding the possibility of hooks 4b' coming out of the respec- tive recesses lb.

Figs. 3-6 illustrates a second embodiment of the invention, wherein the parts which make up the assembly to be inserted into housing 1 are the same as in the previous embodiment. In this case, clip 40, which is also obtainable by cold forging or punching of a metal sheet, presents a different configuration.

First of all, compared with the previous embodiment, clip 40 has two guide tabs 41a and 41b , which depart laterally from small base portion 40a, between the two pairs of upper and lower tines. These two tabs 41a and 41b are designed to be inserted into corresponding grooves or slots 210, cut longitudinally into the two arms 202a and 202b of carriage 200. The sliding coupling of tabs 41a and 41b in grooves 210 improves the guidance of carriage 200 in relation to its housing (with which clip 40 is integral after assembly) .

Furthermore, hooks 40b' of the tines of clip 40 are configured in such a way that they do not project from the lateral profile of carriage 200. The upper and lower edges of the two arms 202a and 202b do not have distinguishable lowerings in this case, but at least the hooked ends of clip 40 are intended to lie above and below said edges (Fig. 3).

Since hooks do not project outside from the lateral profile of carriage 2, in order to achieve the desired hooking of clip 40 to the housing 100, the engagement seat of hooks 40b' is made in as a small step on the ceiling and basal wall of the housing. In order to obtain such a step, the ceiling wall of housing 100 has a longitudinal groove, delimited by guide edges 101a, and a stepped widening 101b, obtained, for example, by milling (therefore with slight conicity, as appreciable in Figs. 3 and 4).

The width of the longitudinal groove is such as to allow the two upper tines 40b of clip 40 to pass through it, but not their hooked ends 40b' . In this way, in order to insert the carriage+spring+clip assembly into housing 100, the two upper tines 40b need to be elastically deformed, one towards the other, in such a way that hooks 40b' are brought closer together and inserted into the longitudinal groove. Once the assembly has been completely inserted into the housing, the two hooks 40b' can elastically snap outwards, having overcome the small step between guide edges 101a and widening 101b, in such a way as to hold clip 40 in position, in relation to housing 100.

In the lower part of the housing, the same configuration can be devised, in which case the base of housing 100 must present a closing wall. Alternatively, as can be seen in Fig. 3, on the bottom a similar configuration to that of the first embodiment can be devised, i.e. one with lowerings 202a' and 202b' on the two lower edges of the arms of carriage 200.

In the embodiment illustrated in Figs. 3-6, there is no arrangement for a snap engagement of tines 40 on arms 202a and 202b of carriage 200. However, assembling of the car- riage+spring+clip is also achieved by means of tabs 41a and 41b. In order for them to be inserted into the respective grooves 210, it is in fact necessary to stretch apart the two arms 202a and 202b of the carriage elastically. Once the clip, carriage and spring have been assembled, the tabs can no longer exit and abut onto the terminal edge of grooves 210, thanks to preloading of the spring, which is constrained between the curved base of carriage 200 and small base portion 40a of the clip. Under these conditions, active coupling is advantageously maintained between the three components that go to make up the assembly.

An alternative, preferred configuration, which is applicable to both of these embodiments, provides that the position of the hooks in relation to the carriage to be set quite far back, in pre-assembly mode. Basically, the length of the tines is such that, with the carriage completely inserted into its slide cavity, the hooks fall into a position which does not allow them to snap outwards in the respective seats of the housing. In order to engage the hooks in the respective seats, one needs to act on small base portion 4a or 40a, by pushing further the cage-like clip 4 or 40 within the slide cavity, until the hooks manage to snap outwards and engage with the respective seats of the housing. This assembly procedure, which is obtainable for example by using a pin tool designed to press against small base portion 4a or 40a, has the advantage of bringing the elastic spring into compression, even when the hinge is at rest. Excellent and stable assembly of the hinge is thereby achieved, without having to allow for restricted tolerances when sizing the cavity and clip.

This solution may also be regarded as advantageous for im- proving resistance to the flexion acting on the carriage. In fact, with the hooks laterally abutting onto tooth 230 (as visible in Fig. 8), said clip 40 represents a component which is basically rigid tranversely and which is interposed between the two lateral arms of the U-shaped carriage. During lateral stress, therefore, the carriage offers greater rigidity, which certainly favours good operation of the hinge.

In Figs. 7-9, the male hinge component is shown coupled to a respective female component 300. The latter is in the form of a fork and has two parallel slits 301, into which the two heads with eyelets of carriage 200 are inserted precisely, but with enough play to permit rotation. The rotational coupling is guaranteed by threaded pivot 302, inserted transversely to the arms of the carriage, along the two coaxial holes of the heads of carriage 200.

Fig. 10 represents a third embodiment, entirely similar to the one just described. In this case, the length of the pair of longitudinal slots 210', in which tabs 41a are designed to run, is extended for a short distance, equal to the stroke permitted for the carriage. The tabs are designed to act as an end-of- stroke, against the innermost extremity of the slots, even in the direction of withdrawal of the carriage from housing 100.

Note, moreover, that the heads with eyelets of the two arms of the carriage extend rearwards of the carriage. Part of each head is designed to be received and partially guided in corre- sponding slots 102 made on the mouth part of housing 100. Between the pair of slots 102 a tab 103 is therefore defined which, by inserting itself between the two heads of the carriage, acts both as a guide in a longitudinal direction and as a constrain against unwanted torsion of carriage 200 with respect to housing 100.

Finally, Figs. 11-13 illustrate a fourth embodiment which exploits the features of the hinge according to the invention to further advantage.

In this case, each of the teeth 23' - which are designed to prevent the tines from moving too close together during normal use of the hinge - has a central groove 23a, which is preferably flared (Fig. 12A) . Correspondingly, on the walls of housing 100, in the terminal part, opposed inclined walls 104 are provided, which are shaped to act as a guide for hooks 40b' of clip 40. In particular, inclined walls 104 are arranged to act as a wedge to drive the hooks towards each other as the clip 40 moves towards the interior of housing 100.

With this configuration, it is possible to extract the car- riage+spring+clip assembly from the housing without any destructive intervention. As is visible in the sequence of figures, the extraction is done by inserting an extractor tool in the form of a pin S between the two heads of the carriage. The pin S is pressed against small base portion 40a, driving it in the direc- tion of the basal extremity of housing 100. In this movement towards the basal extremity of the housing, the hooks are obliged to close one on the other by the inclined walls 104, disengaging themselves from the retention notches of housing 100 and engaging in central groove 23a (Fig. 12A) of the carriage (which, however, remains still in relation to housing 100). From this state (Fig. 12), maintaining a thrust on pin S such as to overcame the elastic reaction of the spring (which has been further compressed) , the hooks are kept closed and disengaged from the walls of the housing, because trapped in groove 23a. After which, acting with extraction traction on carriage 200 (Fig. 13), it is possible to separate the carriage+spring+clip assembly from its housing.

As can be clearly understood from the above description, the hinge device according to the invention enables the objects explained in the preamble to be well achieved.

The original conformation of the carriage and its clip enable a compact assembly to be created, with the elastic reaction spring, an assembly which can then easily be assembled in the housing of the hinge. According to the preferred embodiments, the carriage+spring+clip assembly can be assembled, regardless of the presence of the housing, and then handled and distributed to the purchaser independently, as well.

The cage-like clip, which "embraces" the spring in a longi- tudinal direction, occupying a length which is related to the bulk of the spring, does not need to allow for additional longitudinal space, thereby enabling reduction of the overall length of the carriage with respect to the prior art. The entire length of the arms of the U-shaped carriage is usable as a guide sur- face (both laterally and on the upper and lower edges), in cooperation with the slide cavity of the housing, so that it is not necessary to allow for further carriage guide portions, which would increase its length.

Also, since the hooks of the tines act on the base of the slide cavity, the stresses relating to traction on the carriage are discharged in the most robust area of the housing and the one where unwanted flexion and torsion can best be avoided. Furthermore, the presence of four tines provides a section resistant to traction which is much better than the one available with the hinge support pin of conventional carriages.

Finally, the provision of means designed to capture the hook means and keep them closed enables the carriage to be extracted from the housing without any destructive intervention, which makes it easy to carry out maintenance or replace the hinge components.

It is in any case understood that the invention is not confined to the particular configurations illustrated above, which only constitute non-limitative examples of the scope of the invention. Numerous variants are possible, all within the reach of skilled in the art, without departing from the scope of the invention itself , as defined in the attached claims .