Abstract:
A spring hinge for eyewear with assembly locking elements that snap-in to place. The locking elements are in the form of a bent spring pin that is insertable in a compressed form and which, once inserted, expands to engage a stepped recess, locking it in place. The bent spring pin is formed from a single T-shaped blank allowing economical manufacturing and assembly, resulting in a secure, compact spring hinge.

Description:
This application constitutes a Continuation-In-Part of U.S. patent application Ser. No. 08/909,618 Aug. 12, 1997, now abandoned which is a Continuation-In-Part of U.S. patent application Ser. No. 08/098,121 Jul. 27, 1993, now U.S. Pat. No. 5,657,107 and discloses further modifications and improvements. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a spring hinge for eyewear, that enables to open the temples of eyeglasses beyond the regular position of use and that is intended for use with the temples of eyeglasses with the characteristics set forth in the introductory clause of claim 1. 
     2. Description of the Related Art 
     From patent EP 90 107 388 are known spring hinges for eyewear that allow the opening of the temples beyond the regular position of use and that are intended for use with the temples of eyeglasses. Such a hinge spring is provided with a locking element having a U-shaped cross section, presenting a projection on the first of its legs on its free end toward the outside, in which the locking element is lodged in a sliding element and in a first recess of same in such a manner, that its two legs point away from the axis of the hinge. The locking element abuts in a spring-loaded manner the shoulder of a second recess with its projection, thus constituting a stop for a spring plunger. 
     Furthermore, from GB-2 248 121 A is known a spring hinge for eyewear, in which a cylindrical locking element is provided with a circular shoulder, wherein the locking element is diametrically divided by a slot. The shoulder engages in a recess provided in the temple of the glasses. 
     A disadvantage of such a design of the spring hinge is that the locking effect by the locking element can be obtained only by a spring tension acting upon the locking element, since the locking element is spread by the spring itself or by a spring plunger. A further disadvantage is that a spring guide pin must preload the required spring to ensure that the locking effect is attained. This, in turn, has the disadvantage that the assembly is relatively costly and difficult. 
     The present invention has the task to further develop the known hinge, so that an interlocking of the locking element with the frame is automatically attained. 
     In accordance with the invention, this task is solved by the object of claim 1. Further advantageous embodiments are objects of the subclaims. 
     SUMMARY OF THE INVENTION 
     The spring hinge according to the invention is characterized by the fact that the locking element presents at least one snap-in pin bent in direction of the wall of the recess. Because of the bent, spring snap-in pin occurs an automatic locking of the snap-in pin in the stepped recess. Therefore, no additional preloading is required, which reduces the assembly costs. 
     In the case of a locking element designed in one piece, the snap-in pin or the snap-in pins can be produced at the same time as the locking element is prepared and/or manufactured. Therefore, the manufacture of the snap-in pin together with the locking element does not require any additional components that must be connected to the locking element. 
     In the case of a locking element that presents a top from which extend the snap-in pins, and in which a sliding element is installed in a slidable manner between the snap-in pins, on one hand, such locking element ensures the locking and, on the other hand, the locking element itself guides the sliding element. 
     Therefore, the locking element has two operational functions. This design of the locking element minimizes the number of elements making up the spring hinge. 
     If the locking element is designed in such a manner that it presents a recess into which the snap-in pin can be lowered, the dimensions of the locking element or of the recess in the temple of the glasses, respectively, are reduced, since the snap-in pin is lowered into the recess at the time of its assembly, and it snaps into the second recess after having reached it from the recess in the locking element. 
     The snap-in pin or snap-in pins, respectively, can be produced from a lamina, that is a stamped metal part. This design has the advantage that the locking element can be manufactured in a simple manner, which makes it cost-effective. The snap-in pins are then bent away from the lamina. The bending angle is less than 90°. 
     In order to prevent the danger of breaking, it is advantageous if the locking element is made out of a T-shaped blank, whereby the top of the T-shaped blank is bent partly cylindrically. This has the advantage that, e.g., in the case of spring hinges with a recess in which is installed a spring guide pin, the spring guide pin extends along the cylindrical part of the locking element, which would obviate the need of manufacturing an opening for the spring guide pin. 
     The two legs of the T-shaped blank are advantageously designed at a angle to each other. After the blank is bent, a locking element with a slot for a guide pin. The slot is of such dimensions, that the locking element rests with play on the guide pin. The bent locking element presents a tilted plane opposite the longitudinal axis of the spring hinge, so that, because of the effect of a spring resistance, the snap-in pin engages into the recess. 
     Prior art spring hinged eye glasses or spectacles have the disadvantage that the spring is fully compressed when the bows are spread apart substantially beyond their normal position. This extended out-turning of the bows can result in damage of the spring or other parts of the spring hinge. 
     The prior art structures use stops which limit the outward movement of the bow beyond a normal position. Such structure is shown in U.S. Pat. No. 4,991,258 and in German Utility Model G11417. For example, in the German Utility Model there is disclosed an external stop for preventing excessive outward movement of the bow. The difficulty with this construction utilizing an external stop is that a manufacturer is not able to guarantee the proper function, since the function mostly depends on the work of the frame manufacturer who links the middle part or frame and the bow by the spring hinge. 
     In U.S. Pat. No. 4,991,258 the spring hinge disclosed uses an internal stop. However, this solution is complicated and requires a number of additional parts. It lacks simplicity. 
     It is an object of the improvement here to provide a spring hinge having a stop which is easily fabricated and which enables the manufacturer to guarantee the function of the stop. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     The figures describe the further advantages and characteristics of the spring hinge according to the invention and wherein: 
     FIG. 1 shows a longitudinal view of an operable spring hinge; 
     FIG. 2 shows a top view of the spring hinge according to FIG. 1 with a portion broken away; 
     FIG. 3 shows a longitudinal view of a second embodiment of a spring hinge; 
     FIG. 4 shows a top view of the spring hinge according to FIG. 3 with a portion broken away; 
     FIG. 5 shows a longitudinal view of a third embodiment of an operable spring hinge; 
     FIG. 6 shows the top view of the spring hinge according to FIG. 5; 
     FIG. 7 shows a single-piece locking element with a snap-in pin; 
     FIG. 8 shows a two-piece locking element with a snap-in pin; 
     FIG. 9 shows a second embodiment of a two-piece locking element with a snap-in pin; 
     FIG. 10 shows a locking element with a snap-in pin; 
     FIG. 11 shows a locking element with two snap-in pins; 
     FIG. 12 shows a first embodiment of the blank for a locking element; 
     FIG. 13 shows the blank for the snap-in pin according to FIGS. 8 and 9; 
     FIG. 14 shows another embodiment of the blank for a locking element; 
     FIG. 15 shows a front view of a locking element according to FIG. 14; 
     FIG. 16 shows a lateral view from the left of a locking element according to FIG. 14; 
     FIG. 17 shows a top view of a spring hinge with a locking element according to FIG. 15; 
     FIG. 18 shows a front view section of the spring hinge according to FIG. 17; 
     FIG. 19 shows the view from the left of the spring hinge according to FIG. 18; 
     FIG. 20 shows a front view of another embodiment of a locking element; 
     FIG. 21 shows a lateral view from the left of a locking element according to FIG. 20; 
     FIGS. 22 and 23 show a partial bow, in cross-section; 
     FIG. 24 shows a portion of a bow; 
     FIG. 25 is an end view of the bow shown in FIG. 24; 
     FIG. 26 is a side view of the bow of FIG. 24, taken along section line A—A; 
     FIG. 27 is a side view of a locking element; 
     FIG. 28 is a rear view of the locking element of FIG. 27; 
     FIG. 29 is a bottom view of the locking element of FIG. 27; 
     FIG. 30 is a perspective view of the locking element of FIG. 27; 
     FIG. 31 is a top view in partial cross-section of a bow incorporating the locking element of FIG. 27; 
     FIG. 32 is a top view in a partial cross-section of the bow of FIG. 31, in a bent position. 
    
    
     DETAILED DESCRIPTION 
     FIGS. 1 to  6  show a spring hinge for eyewear, that enables to open the temples beyond their regular position of use, and that is intended to be used with a temple [of eyeglasses]  1 . The temple  1  presents at its front end, closer to a center part of a frame for eyeglasses (not shown) when assembled, a first longitudinal recess  2  in which is located a second recess with a stepped rim at its end closer to the center part when assembled. 
     The spring hinge consists of a hinge center piece  4  that is provided to be fastened to the center part of a frame for eyewear, and of a temple hinge  5  that can be connected with the hinge center piece  4  swiveling around a hinge axis  6 . 
     The temple hinge  5  presents a sliding element  7 , that engages into the recess  2 . The sliding element  7  is connected with a spring guide pin  8 . This spring guide pin  8  presents a stop  9  at its end facing the sliding element  7 . The spring guide pin  8  passes through a spring  10 . A locking element  11  is provided between the sliding element  7  and the spring  10 . The locking element is provided with a through-hole  12 , through which extends the spring guide pin. 
     FIGS. 1 and 2 show a first embodiment of a locking element. FIG. 11 shows the locking element by itself. 
     The locking element is of cylindrical shape. However, this is not absolutely necessary. It is possible to use also other geometries. The cross sectional geometry of the locking element  11  is preferably adapted to the cross sectional geometry of the recess  2  or vice-versa. 
     As it can be seen from FIG. 11, the cylindrical locking element  11  presents a top  13  provided with an axial bore hole  12 . The guide pin  8  passes through the bore hole  12 . The front plane  14  serves as limit stop for the spring  10 . 
     The cylindrical locking element presents a recess  15 , into which engages, at least partially, the sliding element  7 . The recess  15 , of essentially rectangular cross section, of which the geometry is adapted to the sliding element  7 , forms two outwardly bent snap-in pins  16  that extend in axial direction from the head. These snap-in pins are spring mounted. 
     The spring hinge is assembled in such a manner that the locking element  11  is placed on the temple hinge  5  with its sliding element  7 . Subsequently, the spring guide pin  8  with the spring  10  and the stop  9  is connected to the sliding element  7 . This connection can be obtained, e.g., by means of a screw connection, for which a taphole can provide in the sliding element, while the spring guide pin  8  presents an outside thread. The temple hinge  5  with its sliding element  7  and the spring guide pin can also be designed in one piece. The thus produced component is subsequently pushed into the spring saddle  1  until the snap-in pins  16  audibly engage into the recess  3 . 
     The sliding element  7 , that is provided inside the locking element  11 , can slide a determined distance out of the first recess  2  against the spring resistance of the spring  10 . Hereby it is advantageous, that the sliding element  7  be moved over the total distance in the sliding element  11 , over which the sliding element  7  can slide out, since the sliding element  7  shortens the bending point of the snap-in pin  16 , whereby an improved reliability is obtained. 
     FIG. 2 illustrates the recess  3  in the recess  2  only in the area of the snap-in pins  16 . This is not necessary. The recess  3  can be channeled around recess  2 . A continuous recess is preferable if the locking element  11  with its snap-in pins  16  can be installed in the temple of the eyewear regardless of its position. This would be the case, e.g., if the sliding element  11  had a circular cross section. 
     In the below description of the FIGS. 3 to  6  are used the same numbers for the same components. 
     The spring hinge, as illustrated in FIGS. 3 and 4, differs from the spring hinge according to FIGS. 1 and 2 in the design of the locking element  11  and of the recess  3 . 
     The recess  3  is provided only in a certain area of the recess  2 . 
     FIG. 9 shows a separate illustration of the locking element according to FIG.  3 . 
     The locking element  11  is made up of two parts. It consists of a first part  11   a  and of a second part  11   b.  The part  11   a  is of cylindrical shape and presents a bore hole  12  for the insertion of the spring guide pin  8 . In part  11   a  is provided a recess  15  extending in an axial direction, in which is guided the sliding element  7  in its assembled condition. The top  13  of the part  11   a  presents a recess  17  extending in an axial direction. The dimensions of the recess  17  essentially correspond to the width and the thickness of the snap-in pin  16 . The recess  17  extends in an axial direction. 
     The recess  17  serves for the positioning of the part  11   b  and also to facilitate the assembly, since during the assembly of the spring hinge, the inside surface of the recess  2  slides on the snap-in pin  16 , thus pressing the snap-in pin  16  into the recess  17 . After the snap-in pin  16  reaches the recess  3 , it snaps from recess  17  into the recess  3 . 
     FIG. 13 illustrates a blank for the part  11   b.  The blank is T-shaped. The top of the T-shaped blank is bent round. The front surface  14  of part  11   b  serves as support for spring  10 . 
     A shoulder can be provided at the top  13  of the part  11   a,  of which the outside diameter corresponds to the inside diameter of part  11   b.  The part  11   b  can then be slipped over part  11   a,  so that the locking element becomes a one-piece component. 
     The spring hinge, as illustrated in FIGS. 5 and 6, differs from the presentation of the spring hinge in FIGS. 3 and 4 in the placing of part  11   b  on part  11   a  of the locking element  11 . 
     FIG.8 shows the presentation of the locking element  11 . 
     The locking element  11  is made up of two parts and consists of a part  11   a  and a part  11   b  The part  11   b  according to FIG. 8 corresponds to part  11   b  in FIG.  9 . 
     Part  11   a  is cylindrical and presents a bore hole  12  for the insertion of the spring guide pin  8 . The cylindrical part  11   a  presents a recess  15  extending in an axial direction for the insertion of sliding element  7 . 
     The lateral surface of part  11   a  is provided with a recess  17 , of which the dimensions with respect to length, width and depth essentially correspond to the dimensions of the snap-in pin  16 . 
     As it can be seen from FIG. 8, the periphery of recess  17  is offset approximately 90° with respect to recess  15 . This, however, is not necessary. It is decisive that the snap-in pin  16  is installed in such a manner that the recess  15  does not partly overlap it. Such arrangement is of particular advantage if, as it can be seen from FIG. 5, the transversal extension of sliding element  7  is so large that there is insufficient space to install the snap-in pin  16 . 
     FIGS. 7 and 8 illustrate two other embodiments of the locking element  11 . 
     FIG. 7 shows a one-piece cylindrically shaped locking element  11 . The locking element  11  is provided with a recess  15  for the insertion of a sliding element  7 . Partly overlapping the recess  15  is provided a snap-in pin  16 , that extends from the head  13  to the open end of the recess  15 . The snap-in pin  16  is outwardly bent. The locking element  11  is provided with a bore hole  12  for the insertion of a spring guide pin  8 , as well as a front surface  14  to support a spring  10 . 
     FIG. 10 illustrates a locking element  11  with a snap-in pin  16 . From the head  13  extend parallel running flaps  18 , that are tip-stretched at the head  13 . 
     FIG. 10 shows another embodiment of a locking element  11 . The locking element is a turned/milled piece. 
     FIG. 12 illustrates a blank, that could be a stamped metal piece. The blank presents a lamina  19  with an opening  20  through which can pass the spring guide pin  8  after it is assembled. At the periphery of the lamina  19  is provided at least one flap extending in a radial direction which, after bending, serves as a snap-in pin. According to FIGS. 8 or  9 , the lamina  19  can be placed, for example, at part  11   a,  replacing part  11   b.    
     FIG. 13 shows a blank for part  11   b.    
     It is understood that it is not necessary that the illustrated locking elements be cylindrical. The outside geometry of the locking elements  11  can be adapted to the geometry of the recess  2 . 
     Also the recess  15 , that is provided as guide for the sliding element  7 , can present different geometries. Decisive herein is that the recess  15  is provided as guide for the sliding element  7 . 
     FIG. 14 shows a second embodiment of a blank for a locking element component  11   b.  The blank for the locking element component  11   b  according to FIG. 14 differs from the blank for the locking element component  11   b  according to FIG. 13 in that the two legs  21   a,    21   b  of the T-shaped blank are designed so as to form an angle a to each other. 
     After bending the blank, one obtains a locking element component  11   b  as shown in FIGS. 15 and 16. After bending, the locking element component  11   b  presents a through-hole  23  through which passes a guide pin  22  in its assembled condition. The through-hole  23  must be dimensioned in such a manner that the locking element component  11   b  can rest with play on the guide pin  22 . The bent locking element component  11   b  presents a tilted plane  25  with respect to the longitudinal axis of a spring hinge, so that due to the effect of a spring resistance the snap-in pin  16  can engage in a recess  3 . In that, the spring effect pushes out the part of the locking element. 
     The locking element according to FIGS. 20 and 21 differs from the locking element according to FIG. 14 in that the locking element is made out of a tube. The manufacturing process is through a metal cutting. The locking element presents two essentially parallel planes  26 ,  27  facing each other. The planes are tilted at an angle β with respect to the axis of the hollow section, so that because of the spring resistance action the snap-in pin  16  can engage in a recess  3 . 
     FIG. 17 illustrates an assembled spring hinge with a locking element component  11   b  according to FIG.  14 . 
     The spring hinge is provided with an oblong guide housing  26  that is mounted on a temple [of eyeglasses]  1 . The housing  26  is provided with an oblong recess  2  in which is located a second recess  3  with a stepped rim and, when assembled, closer to the end of the center part. Into the recess  2  engages a sliding element  7  that is connected with a spring guide pin  8 . The spring guide pin  8  is provided at the end facing the sliding element  7  a stop  9 . The spring guide pin  8  passes through the spring  10 . Between the sliding element  7  and the spring  10  is mounted the locking element component  11   b.  the locking element component  11   b  is provided with a snap-in pin  16 , that engages into the second recess  3 . 
     In the presentation according to FIG. 17, the snap-in pin  16  of the locking element component  11   b  engages into the recess  3 . This is attained by the spring action of spring  10 , insofar as the latter lifts the locking element component  11   b.  One end of the spring  10  abuts the locking element component. 
     The sliding element  7  is provided with a recess  27  in which is engaged the snap-in pin  16  while the spring is not under tension. 
     FIGS. 22 and 23 show a spring hinge in a first position and in a second position, respectively. 
     The spring hinge comprises a sliding element  101 , a locking element  103  and a housing  105 . 
     The locking element  103  is provided with a snap-in element  107  which snaps into a recess  109  of the housing  105 . The locking element  103  supports one end of a spring  111 . The other end of the spring  111  is supported by holding means  113  fixed on a spring guide pin  115  of the sliding element  101 . In a preferred embodiment, the function of the holding means  113  is achieved by the pin  115  itself, which will be flattened or pinched in order to support the spring  111 . 
     As shown in FIGS. 24,  25 , and  26 , the sliding element  101  is provided with a recess or groove  117  which has at least one shoulder  119 . 
     As shown in FIG. 27, or in the perspective view of FIG. 30, the locking element  103  is provided with an arm  121 , which arm is extended in a longitudinal direction of the spring hinge and which arm is fixed to the locking element with an end adjacent to the opening of the housing  105 . The free end  123  of the arm  121  lies on the opposite side of the opening of the housing  105 . 
     The free end  123  of the arm  121  is bent inwardly as shown in FIG.  30 . 
     The stop means of the spring hinge consists of the recess  117  with the shoulder  119  of the sliding element  101  and the arm  121  with a free end  123 . As shown in FIG. 23, the movement of the sliding element  101  against the force of the spring  111  is limited by the shoulder  119  and the recess  117 , which strikes the free end  123  of the arm  121  which is bent inwardly into the recess  117 . 
     In FIGS. 31 and 32, there is shown another embodiment of the present invention, wherein the spring hinge also comprises a sliding element  101  and a locking element  103  which is locked into the housing  105  by a locking pin or tongue  107 . 
     The sliding element  101  is provided with a groove or recess  117  having a shoulder  119 . This shoulder  119  cooperates with a shoulder  123  provided on the upper side of the locking element  103 . 
     The movement of the sliding element  101  in the direction of the arrow P is limited by the shoulder  119  which strikes the shoulder  123 , as shown in FIG.  32 . 
     The stop means can also comprise a tongue provided on the sliding element and the recess provided in the housing, whereby the movement of the sliding element is stopped by the tongue which snaps into the recess and strikes the shoulder of the recess.