Abstract:
A hinge for glasses includes a hinge part securely attached to a central part, a housing firmly connected to a glasses leg, and a spring-core device received in the housing. The spring-core device includes a core shaft with a securing means, a slide block and a coiled spring disposed around the core shaft, and a single-tooth core body rotatably connected to the hinge part. The single-tooth core body is firmly connected to the core shaft, and the slide block is positioned in the housing. The coiled spring is respectively resisted against the securing means and the slide block. When the glasses leg rotates outwards to a slight angle at a wearing position, the single-tooth core body is pulled outwards to thereby cause the slide block to position in the housing and cause the coiled spring to be compressed.

Description:
CROSS REFERENCE TO RELATED PATENT APPLICATION 
       [0001]    This application claims the priority of the Chinese patent application No. 200710074160.0 with filing date of Apr. 26, 2007, which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to a hinge for glasses, especially a spring hinge for glasses. 
         [0004]    2. Description of the Related Art 
         [0005]    Spring hinges are preferably to be used more and more frequently in order to increase the wearing comfort of glasses. For example, Chinese issued patent CN96192848.4, Spring hinge for glasses and its manufacturing method, shows a spring hinge with simple structure and low cost, especially a spring hinge for glasses which has a intermediate piece and two side pieces of glasses hinged with it. The spring hinge contains a spring housing corresponding with the side pieces of glasses and a coactive intermediate hinge piece, on which the intermediate piece is fixed. The spring housing has a longitudinally extended groove with a continuous through in wall. The spring housing can be pressed in the groove of a locking ring, which is supported by the groove and used as a lock, and thus the locking ring is fixed in the groove to secure against axial displacement. The spring hinge is characterized in that the spring housing is made by means of metal-powder compression casting. Its disadvantage is that the housing uses a concave locking ring, which degrades the glasses&#39; appearance. 
         [0006]    In addition, another Chinese patent CN02217242.4, Close-type spring hinge for glasses, shows a spring hinge including a bird-head-like hinge part, a core unit, screws, a core, a hinge and a spring. There is a circlip within the hinge and outside the core. Its disadvantage is the housing is hard to manufacture. 
         [0007]    What is needed, therefore, is a spring hinge for glasses which is readily assembled for manufacturers and reliably used for users. 
       SUMMARY OF THE INVENTION 
       [0008]    A hinge for glasses includes a hinge part securely attached to a central part, a housing firmly connected to a glasses leg, and a spring-core device received in the housing. The spring-core device includes a core shaft with a securing means, a slide block and a coiled spring disposed around the core shaft, and a single-tooth core body rotatably connected to the hinge part. The single-tooth core body is firmly connected to the core shaft, and the slide block is positioned in the housing. The coiled spring is respectively resisted against the securing means and the slide block. When the glasses leg rotates outwards to a slight angle at a wearing position, the single-tooth core body is pulled outwards to thereby cause the slide block to position in the housing and cause the coiled spring to be compressed. 
         [0009]    Other advantages and novel features will become more apparent from the following detailed description of embodiments when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Many aspects of the present hinge for glasses can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present hinge for glasses. 
           [0011]      FIG. 1  is a longitudinal sectional view of the hinge for glasses in accordance with a first embodiment of the present invention; 
           [0012]      FIG. 2  is an exploded, perspective view of a main part of the hinge for glasses in accordance with the first embodiment of the present invention; 
           [0013]      FIG. 3  is a partial longitudinal sectional view of a single-tooth core body of the hinge for glasses in  FIG. 2 ; 
           [0014]      FIG. 4  is a longitudinal sectional view of a slide block of the hinge for glasses in  FIG. 2 ; 
           [0015]      FIG. 5  is a schematic assembly view of the single-tooth core body, the slide block, a coiled spring, and a core shaft in accordance with the first embodiment of the present invention; 
           [0016]      FIG. 6  is another schematic assembly view of the single-tooth core body, the slide block, the coiled spring, and the core shaft in accordance with the first embodiment of the present invention; 
           [0017]      FIG. 7  is an isometric, perspective view of the hinge for glasses in accordance with the first embodiment of the present invention; 
           [0018]      FIG. 8  is a longitudinal sectional view of the hinge for glasses in accordance with a second embodiment of the present invention; 
           [0019]      FIG. 9  is a longitudinal sectional view of the hinge for glasses in accordance with a third embodiment of the present invention; and 
           [0020]      FIG. 10  is a longitudinal sectional view of the hinge for glasses in accordance with a fourth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Referring to  FIGS. 1 and 7 , a hinge for glasses in accordance with a first embodiment of the present invention includes a bird-head-like hinge part  1 , a housing  7  connected with a glasses leg  8 , a spring-core device, and a screw  2 . The spring-core device mentioned above includes a core shaft  4  with a securing means on one end, a coiled spring  6  and a slide block  5  enclosing the core shaft  4 , and a single-tooth core body  3  firmly connected with the core shaft  4 . The bird-head-like hinge part  1  may be securely connected to a central part  9  or integrally molded with the central part  9 . The central part  9  is firmly connected to a glasses frame  90  (as shown in  FIG. 7 ) by electric welding or other securing means. The housing  7  is a half one, and an inner side of the housing  7  and the glasses leg  8  cooperatively form a cavity  71  in which the spring-core device is arranged, and a groove  72  is defined in the cavity  71 . Furthermore, the slide block  5  can be only moved in the groove  72  after the slide block  5  is assembled. 
         [0022]      FIG. 2  shows an exploded, perspective view of a main part of the hinge for glasses in accordance with the first embodiment of the present invention. Referring to  FIGS. 2 ,  3  and  4 , the bird-head-like hinge part  1  is formed to have a pair of opposite, spaced protruding blocks  12 . Each protruding block  12  defines a screw hole  120  therein for extension of the screw  2  therethrough. The single-tooth core body  3  has an upper portion  31  and a lower portion  36 , as shown in  FIG. 3 . The upper portion  31 , whose top is semicircular and oblate, is thinner than the lower portion  36  of the single-tooth core body  3 . The upper portion  31  defines a lateral throughhole  32  for the screw  2  to connect the single-tooth core body  3  and the bird-head-like hinge part  1  (double-tooth). The lower portion  36  is a thicker flat cubic, and a bottom of the lower portion  36  is an incline  33 , on which there is a blind hole  34  for connecting the core shaft  4 , along the axial direction of the single-tooth core body  3 . As illustrated in  FIG.4 , a longitudinal section of the slide block  5  is a quadrilateral. An upper end face  53  of the slide block  5  is an incline and there is a through hole  51  in the slide block  5  along the axial direction for extension of the core shaft  4  therethrough. A corner of the upper end of the slide block  5  is designed as a sharp corner  52 , and a diagonal corner of the lower end is also a sharp corner  54 . A fore-end of the core shaft  4  can be inserted in the blind hole  34  to thereby firmly connect the single-tooth core body  3  with the core shaft  4 . If the fore-end of the core shaft  4  in the spring-core device is threaded, correspondingly, the blind hole  34  of the single-tooth core body  3  is also threaded. A rear-end of the core shaft  4  can prevent the coiled spring  6  from moving when the coiled spring  6  is disposed on the core shaft  4 . 
         [0023]    Referring to  FIGS. 5 and 6 , in assembly, the coiled spring  6  is first displaced around the core shaft  4 , and then slide block  5  is also disposed around the core shaft  4 . Further, the fore-end of the core shaft  4  is inserted into the blind hole  34  of the single-tooth core body  3  along the axial direction to thereby firmly connect the single-tooth core body  3  with the core shaft  4 . At the beginning, the slide block  5  moves upwards and laterally along the incline  33  of the single-tooth core body  3  to protrude outwards the single-tooth core body  3 . Apply lateral force P on the slide block  5 , it can go back to align the side face of the single-tooth core body  3 . Meanwhile, the coiled spring  6  is compressed. With reference to  FIG. 1 , when mounting the spring-core device into the housing  7 , first slightly press the slide block  5  to make its side face align to the side face of the single-tooth core body  3 . When the spring-core device is well accommodated in the cavity  71  of the housing  7 , the slide block  5  automatically moves upwards and laterally along the incline  33  into the groove  72  due to the coiled spring  6 . Thus, the spring-core device is forevermore accommodated in the housing  7  except that the housing  7  is broken. Finally, the bird-head-like hinge part  1  and the single-tooth core body  3  are connected by the screw  2 . 
         [0024]    With reference to  FIG. 7 , when the glasses leg  8  is rotated to a slight angle along the arrow direction at a wearing position and the central part  9  keep immovable, the single-tooth core body  3  and the core shaft  4  can be moved in the cavity  71 . Then the sharp corner  52  of the slide block  5  is fixed in the groove  72  and the lower sharp corner  54  abuts against the inwall of the glasses leg  8 , so the whole spring-core device is movably locked in the housing  7 . The slide block  5  is immobilized at this time, however, the single-tooth core body  3  and the core shaft  4  can be moved in the housing  7  along the axial direction. Meanwhile, the coiled spring  6  is compressed. At the moment, when a user wears the glasses, the glasses leg  8  can slightly press on the head of the user due to recovery of elasticity of the coiled spring  6  so that the glasses is prevented from easily falling off. As such, when the central part  9  is rotated along the reverse arrow direction and the glasses leg  8  keeps immovable, the single-tooth core body  3  and the core shaft  4  can be moved in the cavity  71 . Then the sharp corner  52  of the slide block  5  is fixed in the groove  72  and the lower sharp corner  54  abuts against the inwall of the glasses leg  8 , so the whole spring-core device is locked in the housing  7 . The slide block  5  is immobilized at this time, however, the single-tooth core body  3  and the core shaft  4  can be moved in the cavity  71  along the axial direction. Meanwhile, the coiled spring  6  is compressed. At the moment, when a user wears the glasses, the glasses leg  8  can slightly press on the head of the user due to recovery of elasticity of the coiled spring  6  so that the glasses is prevented from easily falling off. 
         [0025]    Referring to  FIG. 8 , a hinge for glasses in accordance with a second embodiment of the present invention is similar to the hinge for glasses in accordance with the first embodiment of the present invention. The hinge for glasses includes a bird-head-like hinge part  1  (not shown in  FIG. 8 ), a housing  7   a  connected with a glasses leg  8   a,  a spring-core device, and a screw  2 . The spring-core device includes a core shaft  4  with a securing means on one end, a coiled spring  6  and a slide block  5  enclosing the core shaft  4 , and a single-tooth core body  3   a  firmly connected with the core shaft  4 . The screw  2 , the core shaft  4 , the slide block  5 , and the coiled spring  6  in the second embodiment are the same to the corresponding members in the first embodiment, so their labels are not changed. The housing  7   a  is an entire one, and defines a cavity  71   a  in which the spring-core device is arranged. A through hole  72   a  is defined in the back wall of the housing  7   a.  The through hole  72   a  of the housing  7   a  and the glasses leg  8   a  cooperatively forms a groove. Furthermore, the slide block  5  can be only moved in the groove after the slide block  5  is assembled. The movement of the hinge for glasses in the second embodiment is substantially same to the hinge for glasses in the first embodiment. 
         [0026]    Referring to  FIG. 9 , a hinge for glasses in accordance with a third embodiment of the present invention is similar to the hinge for glasses in accordance with the second embodiment of the present invention. The hinge for glasses includes a bird-head-like hinge part  1  (not shown in  FIG. 9 ), a housing  7   b  connected with a glasses leg  8   b,  a spring-core device, and a screw  2 . The spring-core device includes a core shaft  4  with a securing means on one end, a coiled spring  6  and a slide block  5  enclosing the core shaft  4 , and a single-tooth core body  3   b  firmly connected with the core shaft  4 . The screw  2 , the core shaft  4 , the slide block  5 , and the coiled spring  6  in the third embodiment are the same to the corresponding members in the first embodiment, so their labels keep unchanged. The housing  7   b  is a half one, and the housing  7   b  and the glasses leg  8   b  cooperatively form a cavity  71   b  in which the spring-core device is arranged, and a groove  72   b  is defined in the cavity  71   b  for the slide block  5  to move or wedge in. Furthermore, the slide block  5  can be only moved in the groove  72   b  after the slide block  5  is assembled because a projection  81   b  of the glasses leg  8   b  prevent the a sharp corner  52  of the slide block  5  from moving outwards. The movement of the hinge for glasses in the third embodiment is substantially same to the hinge for glasses in the second embodiment. 
         [0027]    Referring to  FIG. 10 , a hinge for glasses in accordance with a fourth embodiment of the present invention is similar to the hinge for glasses in accordance with the third embodiment of the present invention. The hinge for glasses includes a bird-head-like hinge part  1  (not shown in  FIG. 10 ), a housing  7   c  connected with a glasses leg  8   c,  a spring-core device, and a screw  2 . The spring-core device includes a core shaft  4  with a securing means on one end, a coiled spring  6  and a slide block  5  enclosing the core shaft  4 , and a single-tooth core body  3   c  firmly connected with the core shaft  4 . The screw  2 , the core shaft  4 , the slide block  5 , and the coiled spring  6  in the third embodiment are the same to the corresponding members in the first embodiment, so their labels keep unchanged. The housing  7   c  is a half one, and the housing  7   c  and the glasses leg  8   c  cooperatively form a cavity  71   c  in which the spring-core device is arranged, and a groove is defined in the cavity  71   b  for the slide block  5  to move or wedge in. Furthermore, the slide block  5  can be only moved in the groove after the slide block  5  is assembled, because a slot  81   c,  defined in the glasses leg  8   c  prevent the a sharp corner  52  of the slide block  5  from moving outwards. The movement of the hinge for glasses in the third embodiment is substantially same to the hinge for glasses in the second embodiment. 
         [0028]    It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the present invention.