Abstract:
The invention concerns a method for mounting a sprung joint for the frame of spectacles, comprising a step which consists in placing a spring pin in a first component and a step which consists in articulating the first component to a second component through a pivot pin enabling a bow of the frame, integral with one of the components, to pivot relative to a surface of the frame integral with the other component. The invention is characterised in that it consists in: opening the first component by elastic deformation, inserting the spring pin into the first component, and closing the later around the pin so as to retain it by elastic pinching against the spring compression. Preferably, the first component is forcefully opened with the pin. The method enables to simplify mounting a spring joint wherein the pin is permanently retained in the first component even if the pivot pin is lost.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
         [0001]    This application is a Continuation application of PCT/IB01/00614 filed Apr. 12, 2001, which claimed priority of European Application No. 00.420074.7 filed Apr. 14, 2000, entitled “Method for Fitting a Resilient Hinge of a Spectacle Frame and Resilient Hinge Designed for Implementation of this Method” all of which are included in their entirety by reference made hereto.  
         BACKGROUND OF THE INVENTION  
         [0002]    2. Field of the Invention  
           [0003]    The invention relates to a method for fitting a resilient hinge of a spectacle frame and to a resilient hinge which is designed for implementation of such a method.  
           [0004]    More particularly, the invention relates to a method for fitting a resilient hinge of a spectacle frame, comprising a step for putting a spring thruster into place in a first component and a step for articulating the first component on a second component via a rotational shaft. The fitting is such that an arm of the frame, which is integral with one of the components, is pivoted relative to a surface of the frame which is integral with the other component by displacing the thruster in translation in the first component against the compression of the spring.  
           [0005]    2. Description of the Related Art  
           [0006]    In this well-known type of fitting, the thruster is thrust against the compression of the spring in order to articulate the two components with the rotational shaft. The removal or loss of the rotational shaft releases the thruster, which escapes from the first component by means of the relaxation of the spring. There is therefore a risk of losing the thruster and the spring, since it is understood that these parts have small dimensions.  
           [0007]    In order to eliminate this disadvantage, document FR 2 519 434 published on Jul. 8, 1983 describes a method for fitting a resilient hinge for a spectacle frame wherein, after the step of putting the thruster into place, a the thruster in the first component against the compression of the spring. This pin is withdrawn after the step of articulation of the components by means of the rotational shaft. In other words, this arrangement is designed to retain the thruster temporarily during fitting or removal of the resilient hinge. In the event of loss of the rotational shaft during use of the frame, the thruster escapes from the first component by means of the relaxation of the compression spring.  
           [0008]    Document FR 2 334 808 published on Jul. 8, 1977 describes a method for fitting a resilient hinge for an optical frame, wherein the thruster and the spring are introduced into a case and the case is fitted in hot conditions into a first component of the frame before the latter is articulated on a second component via a rotational shaft. The step by means of which the case is rendered integral with the first component is necessary in order to close the case and thus to prevent the thruster permanently from escaping in the event of withdrawal or loss of the rotational shaft. In addition, a separate case of the first component complicates the design of the resilient hinge itself.  
           [0009]    Document US 5 515 575 published on May 14,1996 describes another method for fitting a resilient hinge of a spectacle frame, which makes it possible to retain the thruster permanently in one of the components of the hinge. According to this document, the thruster is put into place by being made to slide into an aperture in the component, against the compression of the spring. During this step, it is necessary to introduce lugs of the thruster in corresponding grooves in the aperture in the component. Then the thruster is subjected to rotation of 90° for example, in order to offset the lugs relative to the grooves, such that the thruster is retained permanently in the component. Putting the thruster into place in the thruster. A thruster which is provided with lugs and a component which has an aperture provided with corresponding grooves in this case also complicate the design of the resilient hinge itself.  
         BRIEF SUMMARY OF THE INVENTION  
         [0010]    One of the objects of the invention is to provide simplification in comparison with the known methods for fitting a resilient hinge of a spectacle frame, one of the components of which comprises a spring thruster. More particularly the invention relates to simplification of the step of putting the thruster into place in the component, taking into account the requirement to retain the thruster permanently in the component. The invention also relates to a method which provides simplification during removal of the resilient hinge. The invention further relates to a method for fitting a resilient hinge which provides simplification of the design of the hinge itself, in particular relative to the thruster and the component in which it is put into place.  
           [0011]    For this purpose, the invention relates to a method for fitting a resilient hinge of a spectacle frame, comprising a step for putting a spring thruster into place in a first component and a step for articulating the first component on a second component via a rotational shaft, such that an arm of the frame, which is integral with one of the components, pivots relative to a surface of the frame which is integral with the other component by displacing the thruster in the first component against the compression of the spring, characterised in that the first component is opened by resilient deformation, the spring thruster is introduced into the first component, and the latter is closed around the thruster such as to retain the latter by resilient gripping against the compression of the spring.  
           [0012]    According to this method the component closes as a resilient gripper around the thruster such as to keep the latter abutted against the compression of the spring. It will be appreciated that the first component can be closed by resilient gripping around the thruster when the latter is introduced sufficiently far into the first component. After the introduction of the thruster into the component it is not necessary to impose additional rotation of the thruster relative to the component in order to prevent the thruster from escaping from the latter. The design of the thruster is therefore simpler, since it is not necessary to provide means for retention on the thruster itself. In addition, the thruster is retained permanently by the component in which it is put into place, without making it necessary to fit the thruster into a case and to close the latter by securing it to the component.  
           [0013]    According to an advantageous embodiment of the invention, the first component is forced open by the thruster until this component closes by means of resilient gripping around the thruster. This embodiment simplifies further the fitting of the resilient hinge by making the thruster act as a resilient deformation tool for the first component.  
           [0014]    Other advantages of the invention will become apparent from reading the description of two embodiments illustrated by the drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIGS. 1A to  1 C illustrate a resilient hinge of a spectacle frame according to the invention, respectively when an arm of the frame is in the closed position, in a position of normal opening, and in a position of opening beyond the position of normal opening.  
         [0016]    [0016]FIGS. 2A to  2 D illustrate a step of a method according to the invention which makes it possible to put a spring thruster into place in one of the two components of the resilient hinge.  
         [0017]    [0017]FIGS. 3A to  3 C illustrate different forms of the component and of the thruster of a resilient hinge which is designed to be fitted according to the method for fitting illustrated by FIGS. 2A to  2 D.  
         [0018]    [0018]FIGS. 4A to  4 D illustrate a step of a method according to the invention which makes it possible to articulate a first component on a second component by means of a rotational shaft.  
         [0019]    [0019]FIGS. 5A and 5B illustrate on two different cross-sectional planes the one of the components of the resilient hinge represented in FIGS. 1A to  1 C which receives a spring thruster. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    A resilient hinge for a spectacle frame comprises, FIGS. 1A to  1 C, a first  5  and a second  9  component which are articulated by a rotational shaft  13 . A spring  3  thruster  1  is disposed in the first component  5  such that an arm  11  of the frame which is integral with one  9  of the two components pivots relative to an opposite tenon  7  which is integral with the other component  5  in displacing the thruster  1  in translation in the first component  5  against the compression of the spring  3 .  
         [0021]    In a well-known manner the second component  9  has a knuckle  8  in the form of a cam in order for the compression of the spring to be subjected to a maximum level when the arm pivots from a position of closure illustrated in FIG. 1A to a position of normal opening illustrated in FIG. 1B. Thus, the thruster tends to return the arm to the positions respectively of closure and normal opening when the pivoting is respectively before and after the pivoting which corresponds to the maximal compression of the spring. As illustrated in FIG. 1C, the form of a cam of the knuckle  8  of the second component  9  also makes it possible for the thruster to return the arm to the positron of normal opening when it is actuated by being pivoted beyond this position.  
         [0022]    A method for fitting the hinge previously described comprises a step for putting the spring  3  thruster  1  into place in the first component  5  and a step for articulating the first component  5  on the second component  9  via a rotational shaft  13 .  
         [0023]    According to the invention, the first component  5  is opened by means of resilient deformation, the spring  3  thruster  1  is introduced into the first component  5 , and the latter  5  is closed around the thruster  1  such as to retain it by resilient gripping against the compression of the spring  3 .  
         [0024]    In the embodiment of the invention illustrated in FIGS. 2A to  2 D, the first component  5  is forced open by the thruster  1  until this component  5  closes by means of resilient gripping around the thruster. More particularly, in FIG. 2A, the spring  3  is disposed in a receptacle  15  of the first component  5  and the thruster  1  is disposed supported on two knuckles  17  of the first component  5 . The receptacle  15  opens onto the space which separates the two knuckles  17 , which project relative to the receptacle  15 . A force F, in FIG. 2B, is applied to the thruster  1  in order to part the two knuckles  17  and the receptacle  15 , in other words to open the first component  5  by resilient deformation. Then, in FIG. 2C, the thruster is introduced into the receptacle  15  until the latter closes onto the thruster  1  by resilient gripping and therefore, in figure  2 D, the receptacle retains the thruster in the first component  5  against the compression of the spring  3 .  
         [0025]    As can be seen in FIG. 2D, the thruster  1  is permanently retained in the first component  5  of the hinge, even when the two components  5  and  9  are not articulated by the rotational shaft  13 . In the event of removal or loss of the first component  5 . In addition, the thruster  1  can be removed easily by opening the first component  5  slightly by means of resilient deformation.  
         [0026]    In a resilient hinge of a spectacle frame which is designed to be fitted according to the method of the invention, the receptacle  15  of the first component  5  is deformed resiliently when the thruster  1  is introduced into this receptacle  15 , which, as can be seen in FIG. 2A or  3 A, has one or two kinks  19  which form a retention stop for the thruster  1  against the compression of the spring  3  when the first component  5  and the receptacle  15  close resiliently around the thruster  1 .  
         [0027]    Preferably, as can be seen in FIG. 3B, the thruster  1  has a chamfer  21  in order to facilitate opening of the first component  5  by resilient deformation. A chamfer  18  is also formed on each knuckle  17  of the first component  5  in order to facilitate opening of the latter by resilient deformation during introduction of the thruster  1 .  
         [0028]    A corresponding shape can also be provided between the kinks  19  of the first component  5  and the chamfer  21  of the thruster  1 , as can be seen in FIG. 3C. This arrangement facilitates creation of the receptacle  15 .  
         [0029]    On completion of the step of putting the thruster  1  into place in the first component  5 , the thruster  1  is thrust against the compression of the spring  3  by means of the second component  9  in order to align the bores in the knuckles  17  and  8  of the two components and to insert the rotational shaft  13  which permits articulation of the two components.  
         [0030]    Preferably, the bore in the knuckles  17  of the first component  5  is spaced from the kink(s)  19  of the receptacle  15 , such as to limit axial offsetting of the bore in the knuckle  8  of the second component  9  and therefore to limit the compression of the spring  3  when the bores are aligned. This limitation is such that it makes it possible to articulate the two components  5  and  9  by means of a screw  13 , without needing to force the thruster  1  back in advance by means of the second component  9 . When the two components  5  and  9  are articulated by the screw  13 , the thruster  1  is pre-stressed by the spring  3  and exerts contact pressure permanently on the knuckle  8  of the second component  9 .  
         [0031]    [0031]FIGS. 4A to  4 D illustrate the step of articulation of the two components  5  and  9 . FIG. 4A illustrates more particularly slight offsetting between the bores in the knuckles  17  of the first component  5  and in the knuckle  8  of the second component  9 , whereas the latter does not exert any pressure on the thruster  1  against the spring  3 . FIGS. 4B and 4C illustrate the alignment of the bores by means of a point  23  and the insertion of an articulation screw  13 . FIG. 4D illustrates full insertion and screwing of the screw  13  into one of the knuckles  17  of the first component  5 .  
         [0032]    The articulation screw  13  can be replaced by a shaft which is provided with a head at one end and a chamfer at the opposite end in order to align the bores in the knuckles of the two components without using an additional point. The end opposite the head is then deformed by a riveting technique. This end can also be welded to the first component of the hinge.  
         [0033]    According to another embodiment of the invention, the first component  5  has a receptacle  15  which receives a longitudinal part  10  of the thruster  1  whilst being offset relative to the rotational shaft  13  and open  29  in order to receive a transverse part  12  of the thruster  1  which is pressed against the second component  9  by the compression of the spring  3 .  
         [0034]    As can be seen clearly in FIGS. 5A and 5B, the axial direction S of the receptacle  15  is offset by a distance D relative to the axial direction of the bore T in two knuckles  17  of the first component  5  which receives the rotational shaft  13 . The offsetting D makes it possible to thread the bore in the first component along all, or less than all if required, of the thickness H of the knuckles  17 , without needing to compensate for a loss of thickness of thread caused by machining of the receptacle  15 . This therefore contributes towards reducing the total width L of the first component parallel to the rotational shaft  13 .  
         [0035]    As can be seen in FIGS. 1A to  1 C and  5 A, the receptacle  15  of the first component  5  is preferably closed on one side E and receives the transverse part  12  of the thruster  1  only via an aperture  29  in the opposite side I, the thruster then having the shape of an “L”.  
         [0036]    The lateral closure of the first component  15  is obtained by means of a wall  27  of the receptacle  15  which guides the longitudinal part  10  of the thruster  1  and is extended in the continuity of the knuckle  8  of the second component  9  when the arm is in the position of normal opening, as illustrated by FIG. 1B. If the guiding wall  27  is disposed on the side E of the first component which corresponds to the outer side of the frame, i.e. the side which is seen by a third party when the frame is worn by a user, the thruster  1  can no longer be seen from this outer side when the arm is in the position of normal opening. This therefore adds to the general aesthetic attraction of the spectacle frame.  
         [0037]    The thruster in the shape of an “L” is obtained from a section in the form of a lock which is machined around the longitudinal part  10 , whilst offsetting the axis of turning relative to the axis of the section. The thruster can be bored in order to receive the spring and thus reduce the proportion of the receptacle of the first component in the longitudinal direction S.  
         [0038]    It is advantageous to assemble the spring and the thruster such as to form a mechanism in a single piece. A stepped bore can be provided in the thruster, the diameter of the bore being smaller than the diameter of the spring along a short length. In the case of a full thruster, a stud is produced, the diameter of which is larger than the diameter of the core of the spring.  
         [0039]    It should be noted that the receptacle  15  of the first component can be open on both sides E and I in order to receive a thruster  1 , the longitudinal  10  and transverse  12  parts of which form a T.  
         [0040]    It should also be noted that in the embodiments  1 A to  1 C, the first component  5  comprises a rear stop  25  to limit the compression of the spring  3  during pivoting of the arm  11  relative to the opposite tenon  7  of the frame.