Abstract:
A hinge structure for interconnecting the temples of glasses or spectacles to the frame thereof is disclosed. The hinge structure is made of resilient polymeric material such as elastomeric material. The hinge structure also defines a generally smooth inner surface and a generally corrugated or bellows-shaped outer surface. The elastically compressible alternating ridges and furrows of the corrugation bias the temples of the glasses toward each other, thereby securing the temples to the head of the wearer. Still, at least one of the furrows is further provided with an enlarged groove at the bottom thereof to reduce the tension of the temples on the head of the wearer.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    There are no cross-related applications. 
       FIELD OF THE INVENTION 
       [0002]    The present invention generally relates to glasses and spectacles and relates more particularly to hinge structures for glasses and spectacles. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is known to provide flexible resilient hinges to link or connect the temples of glasses or spectacles to the front frame thereof. These flexible resilient hinges allow a hinged attachment of the temples to the frame, thus allowing the temples to be pivoted between an inward stored, or folded, position in which the temples extend generally parallel to and along the frame, and an operative, or unfolded, position in which the temples extend generally perpendicularly to and away from the frame to engage the wearer&#39;s head above his ears. 
         [0004]    Flexible resilient hinges have the advantage of further allowing the temples to be pivoted outwardly away from the frame beyond their operative position without damaging the hinges. This is useful in cases where the temples are accidentally moved beyond their operative position, to prevent the hinges, the temples and/or the frame from being damaged. 
         [0005]    However, though flexible resilient hinges have some advantages over typical mechanical hinges, flexible resilient hinges also have some shortcomings. For instance, in order for the glasses to firmly engage head of the wearer, typical flexible resilient hinges are configured to bias the temples toward each other and thus toward the head of the wearer when the temples are in operative position. However, the bias, of biasing force, caused by the flexible resilient hinges can generate uncomfortable pressure points on the head of the wearer, the more so when the glasses are worn over an extended period of time. 
         [0006]    Hence, despite ongoing developments in the field of glasses and flexible resilient hinges therefor, there is still a need for a new and improved flexible resilient hinge which at least mitigates some of the shortcomings of prior art flexible resilient hinges. 
       SUMMARY OF THE INVENTION 
       [0007]    The principles of the present invention are generally embodied in a flexible and resilient elastomeric hinge for used with glasses, the hinge having an inner surface and a generally corrugated outer surface having alternating ridges and furrows, the bottom end of at least one of the furrows having an enlarged groove for relieving or reducing the tension or pressure generated by the temples on the head of the wearer. 
         [0008]    Hinges in accordance with the principles of the present invention will still bias the temples toward each other and thus toward the head of the wearer, thereby maintaining the glasses in place when worn while making the glasses generally more comfortable to wear, at least with respect to the engagement between the temples and the head of the wearer. 
         [0009]    A hinge in accordance with the principles of the present invention generally comprises a main hinge portion, a first protrusion extending at a first extremity of the hinge portion and configured to engage the frame of the glasses, and a second protrusion extending at a second extremity of the hinge portion and configured to engage one of the temples of the glasses. 
         [0010]    The inner surface of the hinge portion, i.e. the surface facing the wearer when the glasses are worn, is generally smooth, while the outer surface, i.e. the surface facing away from the head of the wearer when the glasses are worn, is generally corrugated, or bellows-shaped, as indicated above. 
         [0011]    The corrugated outer surface comprises alternating ridges and furrows. In accordance with the principles of the present invention, at least one of the furrows comprises, in its bottom, an enlarged groove. In a further preferred embodiment, this groove has preferably a curvature radius larger than the bottom portion of the other furrow. 
         [0012]    The enlarged groove generally reduces the biasing force of the hinges and thus the tension or pressure generated by the temples on the head of the wearer. 
         [0013]    The first and second protrusions are generally configured to be sliding inserted into complementary openings in the frame and temples of the glasses. 
         [0014]    In accordance with an improvement, the first and second protrusions are generally T-shaped (i.e. having a T-shaped cross-section) and the upper ends of the T-shaped protrusions are generally round or curved in configuration. By being curved, the upper ends of the protrusions can be more easily inserted into the machined openings of the frame and temples. 
         [0015]    In accordance with another improvement, the rigidity of the elastomeric material from which the hinge is made is so chosen such that thinner hinges are made of more rigid material than thicker hinges. In other words, the thinner the hinge, the more rigid the elastomeric material from which it is made. 
         [0016]    This increased rigidity of the thinner hinge compensates for the fact that a thinner hinge comprises less material to provide the same biasing force as a thicker hinge. 
         [0017]    Other and further aspects and advantages of the present invention will be obvious upon an understanding of the illustrative embodiments about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice. The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The above and other objects, features and advantages of the invention will become more readily apparent from the following description, reference being made to the accompanying drawings in which: 
           [0019]      FIG. 1  is a perspective view of a pair of glasses comprising hinge structures in accordance with the principles of the present invention. 
           [0020]      FIG. 2  is a perspective view of one of the hinge structures of  FIG. 1 , alone. 
           [0021]      FIG. 3  is a top perspective view of the hinge of  FIG. 2 . 
           [0022]      FIG. 4  is a top cross-sectional view of the hinge of  FIG. 2 . 
           [0023]      FIG. 5  is a top view of a pair of glasses in an unfolded position. 
           [0024]      FIG. 6  is a close-up view of one of the hinge shown in  FIG. 5 . 
           [0025]      FIG. 7  is a top view of a pair of glasses where the temples are pivoted beyond their operative position. 
           [0026]      FIG. 8  is a close-up view of one of the hinge shown in  FIG. 7 . 
           [0027]      FIG. 9  is a close-up view of one of the hinge in a resting or folded position. 
           [0028]      FIG. 10  is another close-up view of one of the hinge in a resting or folded position. 
           [0029]      FIG. 11  is another close-up view of one of the hinge in a resting or folded position. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0030]    A novel hinge structure for glasses will be described hereinafter. Although the invention is described in terms of specific illustrative embodiments, it is to be understood that the embodiments described herein are by way of example only and that the scope of the invention is not intended to be limited thereby. 
         [0031]    Referring first to  FIG. 1 , a pair of glasses  10  having two hinge structures  100  in accordance with the principles of the present invention is depicted. The glasses  10  are typical in that they comprise a front frame  200  configured to hold a pair of lens  210  and  220 , and two temples  310  and  320  respectively connected to the sides of the frame  200  via the hinge structures  100 . 
         [0032]    As both hinge structures  100  are mirror image of each other, only one will be described hereinafter. 
         [0033]    The hinge structure  100  is made of flexible and resilient elastomeric material such as thermoplastic elastomers (TPE), sometimes referred to as thermoplastic rubbers. In a preferred embodiment, the hinge  100  is made from the product sold as MEGOL®. MEGOL® family of TPE compounds is based on SEBS (Styrene-Ethylene-Butadiene-Styrene). It is characterised by excellent elastomeric properties, good UV and ozone resistance, easy colourability, a wide range of service temperatures, and is available in hardnesses from 10° Shore A to 60° Shore D. They are particularly suitable for co-moulding applications to PP and PE. By varying the proportions of the co-moulding product (for example PP and PE) the characteristics of the hinge are modified (ex: to modify the hardness). The resiliency of the elastomeric material generally provides the bias or biasing force necessary to secure the temples  310  and  320  of the glasses  10  to the head of the wearer. 
         [0034]    Referring now to  FIG. 2-4 , the hinge structure  100  generally comprises a central or main hinge portion  120  and two end protrusions  140  and  160  extending respectively at the first extremity  121  and at the second extremity  123  of the hinge portion  120 . 
         [0035]    As best shown in  FIG. 4 , the protrusions  140  and  160  generally define a T-shaped cross-section. 
         [0036]    The hinge portion  120  comprises an inner surface  122  and an outer surface  124 . The inner surface  122  generally faces toward the head of the wearer while the outer surface  124  generally faces away from the head of the wearer when the glasses  10  are worn. 
         [0037]    In the present embodiment, the inner surface  122  is relatively smooth while the outer surface  124  is substantially corrugated or bellows-shaped. In that sense, the outer surface  124  typically displays a series of alternating ridges  126  and furrows  128 . 
         [0038]    In the present embodiment, there are four ridges  126   a,    126   b,    126   c  and  126   d,  and three furrows  128   a,    128   b  and  128   c.  However, the number of ridges  126  and furrows  128  could vary depending, for instance, on the size (e.g. length, thickness, etc.) of the hinge structure  100 , and/or on the properties of the material of the hinge structure  100  or simply to modify the look of the glasses. A hinge structure in accordance with the principles of the present invention is not limited to four ridges and three furrows. 
         [0039]    In addition, the exact shape and configuration of each of the ridges  126  need not be identical. 
         [0040]    As further shown in  FIG. 4 , in the present embodiment, the opening angle  130   b  of the central furrow  128   b  is wider than the opening angle  130   a  and  130   c  of the other two furrows  128   a  and  128   c.  The larger distance between the two sides of the central furrow provides higher movement amplitude and a higher flexibility. In addition, and importantly, the central furrow  128   b  is provided, in its bottom  132   b,  with an enlarged groove  134 . 
         [0041]    As it can be seen in  FIGS. 5 and 6 , when the temples are approximately perpendicular to the frame  200 , the groove  134  is compressed and the central furrow  128   b  is not completely compressed, i.e. the surfaces forming the furrow  128   b  are not in contact. Consequently, the temples can still be opened further as shown in  FIGS. 7 and 8 , in this position, the surfaces forming the furrow  128   b  are closer. 
         [0042]    As best illustrated in  FIG. 4 , the surface  135  of the groove  134  is deeper then the apex  131   b  of the opening angle  130   b  of the central furrow  128   b.    
         [0043]    In the present embodiment, the groove  134  has a generally semi-circular or circular cross-section as best shown in  FIG. 4 . However, in other embodiments, the shape of the groove  134  could be different. It is however preferable to have a generally round-shaped groove  134  to prevent premature cracking of the hinge structure  100 . Tests have been made with hinges having the same shape as the present hinge but without a groove at the bottom portion of the wider furrow. Results show that hinges without a groove at the bottom portion of the central furrow are prone to cracking at the bottom portion of the wider furrow or where the protrusions are connected to the hinge. 
         [0044]    As illustrated in  FIGS. 2-4 , the hinge structure  100  generally assumes a curved configuration when at rest. Consequently, when the glasses  10  are not worn, the temples  310  and  320  adopt automatically a folded or semi-folded configuration. 
         [0045]    When the temples  310  and  320  are unfolded in their operative position, i.e. substantially perpendicular to the frame  200 , the hinge portions  120  of the hinge structures  100  are straightened. When the hinge portion  120  is in a straight position, the outer surface  124  becomes in compression. As the hinge portion  120  tries to return to its resting position, the hinge structure  100  biases the temple  310  or  320  toward the head of the wearer. 
         [0046]    However, as indicated above, the force applied by the temples  310  and  320  on the head is such that it prevents or decreases uncomfortable pressure points. 
         [0047]    In accordance with the principles of the present invention, the groove  134  acts as a stress relief for the hinge portion  120 . Indeed, the groove  134  allows the hinge portion  120  to be straightened or opened more easily as it reduces the level of compression of the outer surface  124 , more particularly where the groove is located and where the protrusions are connected to the hinge. Consequently, the groove  134  reduces the biasing force of the hinge structure  100 . By reducing the biasing force, the temples  310  and  320  engage the head of the wearer with less force, making the glasses  10  generally more comfortable to wear, at least relative to the temples&#39; engagement with the head of the wearer 
         [0048]    As shown in the figures, even though, in the present embodiment, the enlarged groove  134  is located at the bottom  132   b  of the central furrow  128   b,  the enlarged groove  134  could possibly be located at the bottom  132  of another furrow  128 . 
         [0049]    In addition, in a variant of the present embodiment, the hinge portion  120  could comprise more than one enlarged groove  134 . 
         [0050]    Referring particularly to  FIG. 4 , the skilled addressee will note that in the present embodiment, the hinge structure  100  is substantially symmetrical with respect to the axis  105 . Though not necessary, this symmetry is preferable as it provides for a more aesthetically pleasing and more balanced hinge structure  100 . 
         [0051]    In the present embodiment of the hinge structure  100 , the rigidity of the elastomeric material from which the structure  100  is made is selected according to the thickness  107  of the hinge portion  120  or according to a particular design characteristic. 
         [0052]    In a further preferred embodiment, for a thinner version of the hinge structure  100 , the rigidity will be greater than for a thicker version. This relation between the rigidity and the thickness of the hinge structure is to compensate for the difference in the amount of material. 
         [0053]    Indeed, a thicker hinge portion  120  does not need to be as rigid as a thinner hinge portion  120  to generate the same amount of biasing force. 
         [0054]    Referring now particularly to  FIG. 2 , the skilled addressee will notice that the upper portions  142  and  162  of the protrusions  140  and  160  are round or curved. 
         [0055]    The curvature of the upper portions  142  and  162  of the protrusions  140  and  160  allows the protrusions  140  and  160  to be more easily inserted into the complementary openings in the frame  200  and the temple  310 / 320 . 
         [0056]    It is to be understood that when the openings in the frame  200  and in the temples  310  and  320  are machined after the molding thereof, some machining debris or asperities can remain stuck at the bottom of the openings and it is difficult and/or expensive to produce an opening that matches very closely the shape of the upper portions  142  and  162 . 
         [0057]    By having round or curved upper portion  142  and  162 , the protrusions  140  and  160  of the present embodiment can be more easily inserted into the openings even if some machining debris remain in the openings. 
         [0058]    While illustrative and presently preferred embodiments of the invention have been described in detail hereinabove, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.