Enclosed spring bridge mechanism for clip-on sunglasses

Abstract: The clip-on sunglass assembly mounts on eyeglasses and has mirror image frame parts (10, 12). Each includes a lens retaining frame portion (14, 16) with a set of protruding "L" shaped eyeglass engaging prongs (26-32) and a bridge element (34, 36). A mechanism (38) is provided for connecting the bridge elements (34, 36) for movement between a proximate position, where the frame parts are relatively close to each other, and a remote position, where the frame parts are relatively far from each other. The connecting mechanism (38) includes at least one coil spring (50) situated within a cylindrical enclosure (40). The frame parts (10, 12) are normally biased toward each other by the spring (50) such that the prongs (26-32) securely engage the eyeglass frame. In one preferred embodiment, the enclosure (40) has an open end (42) which receives the bridge element (34) of one frame part (10). The spring (50) is operably situated between the enlarged end (46) of the bridge element and the interior wall (41) of the enclosure (40), adjacent the open end (42). In another preferred embodiment, separate springs and enclosures are provided for each bridge element. Each bridge element is fixed to the wall of the adjacent enclosure. A connecting bridge element extends between the enclosures. Within each enclosure, a spring is situated between the enlarged end of the connecting element and the enclosure wall.

Description: The present invention relates to a clip-on sunglass assembly and more particularly to a spring bridge mechanism for a clip-on sunglass assembly which permits the assembly to be easily and securely mounted on eyeglasses. A clip-on sunglass assembly consists of a metal or plastic frame which carries a pair of light attenuating plastic or glass lenses. A mechanism is provided to permit the assembly to be removably mounted on eyeglasses. In order to be commercially acceptable, the clip-on sunglass assembly must be light in weight, reasonably rugged and relatively inexpensive. It must also be easy to mount on and remove from the eyeglasses. Further, it must mount without damaging the eyeglasses, particularly the lenses. one common type of mounting mechanism is a clamp which is attached to the bridge of the sunglass assembly. It includes pairs of opposing prongs which are spring loaded toward each other so as to retain the lenses of the eyeglasses between the prongs. Examples of this clamp-type mechanism are disclosed in U.S. Patent No. 3,575,497 issued April 20, 1971 to Leblanc, U.S. Patent No. 5,164,749 issued November 17, 1992 to Shelton and U.S. Design Patent No. Des 350,359 issued September 6, 1994 to Friedman. However, clamp-type mechanisms have their disadvantages. The prongs must clamp tightly to the lenses, potentially scratching the lenses. The mechanism may obstruct the view partially. Moreover, this type of mechanism has several inter-engaging parts which must be fabricated precisely and assembled, making it relatively expensive and not always unreliable. In order to overcome these drawbacks, a spring bridge mechanism was developed for mounting a clip-on sunglasses assembly which does not contact or clamp the lenses of the eyeglasses and therefore cannot scratch them. The-mechanism utilizes one or more sets of exposed spring loaded prongs. The prongs are movably or flexibly mounted on the sunglass frame assembly such that they can be moved against a spring force, for insertion between spaced portions of the eyeglasses frame.: The spring force causes the prongs to frictionally engage the eyeglass frame. Because the prongs only touch the frame, the lenses of the eyeglasses are not clamped or otherwise engaged. U.S. Patent No. 5,953,096 entitled "Universal Center Bridge Mounting Mechanism for Clip-On Sunglasses" was issued to Dean M. Friedman for that mechanism. Another type of clip-on sunglass frame assembly, such as is described in Lockwood U.S. Patent No. 2,926,563, consists of mirror image frame parts, each of which carries a lens. The frame parts are connected together by a bridge mechanism which includes a metal coil spring. The mechanism permits the frame parts to move away from each other as the spring is compressed. Each frame part, at its outer extremity, is provided with a set (typically two or three) eyeglass frame engaging prongs. When the frame parts are moved away from each other, against the force of the spring, the eyeglass frame can be inserted between the prong sets. Releasing the frame parts permits the spring to move frame parts toward each other, such that the eyeglass frame is securely retained between the prong sets. One problem inherent in this type of spring bridge mechanism is that. the coil spring is exposed. Aside from being unsightly, this is undesirable because bits of solid debris and other particulate foreign matter can enter between the coils to jam the mechanism or distort the spring. Liquid, such as rain or sweat, can enter the mechanism resulting in rusting or deterioration of the parts. Further, the skin, hair and eyebrows of the user are not protected from the exposed spring and can be pinched by the spring. Another problem involved with having lens carrying frame parts which are moveable relative to each other relates to the linear alignment of the lenses. Since the lenses are polarized, it is important that proper linear alignment of the lenses be maintained. This requires the bridge mechanism to include a means for maintaining proper linear alignment between the lenses. Embodiments of this invention which overcome these problems are disclosed. In these embodiments the coil spring of the bridge mechanism is enclosed within a slender cylindrical enclosure. The enclosure isolates the spring from the skin and air of the wearer and prevents debris and liquids from reaching the spring. U.S. patent 5,801,804 discloses a clip-on sunglass assembly for mounting on eyeglasses. The assembly is of the kind comprising: first and second frame parts each comprising a lens retaining portion; a bridge structure extending between the frame parts and including first and second bridging elements extending from the first and second frame parts respectively, a connector portion acting between said first and second bridging elements and having a cylindrical enclosure in which a part is slidably received to allow movement of the frame parts between a proximate position and a remote position, and a spring in the enclosure acting to bias the first and second frame parts to one of the positions. In patent 5,801,804 the spring acts to bias the frame parts toward the remote position. Each lens carries a notch 33, 38 at its outer edge which engages a respective temple piece of the eyeglasses. The sunglass assembly is mounted inwardly of the temple pieces and rearwardly of. the frame of the eyeglasses in order to be disposed between the temple pieces and to engage them by being biased to the remote or expanded position. U.S. patent 5,477,281 discloses a clip-on sunglass assembly that is mountable forwardly of the eyeglasses. It is provided with adjustable means carried by the frame parts for mounting the sunglass assembly to the eyeglasses. The assembly is of the kind set forth above but lacks the spring for biasing the frame parts to one of the positions. There is no bias in the bridge mechanism. The lenses of the sunglass assembly are biased to a proximate position by a separate mechanism in which a tension spring is directly secured to and between the sunglass lenses. The spring is located within a telescopic tube. According to one aspect of the present invention a sunglass assembly of the kind set forth above is characterised in that: each frame part has at least one prong for engaging an eyeglass to mount the sunglass assembly forward of the eyeglasses, and the spring of the bridge structure acts between the bridging elements to bias the frame parts toward the proximate position for engaging the prongs with the eyeglasses. Preferably each frame part has two spaced prongs, i.e. a set of prongs, whereby the eyeglasses frame can be inserted between the sets of prongs and the spring force acts to move the frame parts together to engage the eyeglasses between the prongs. In one embodiment of the invention the enclosure of the connector portion is carried by one bridging element and the part slidably received in it is an end portion of the other bridging element. In another embodiment the bridge structure comprises a further connective portion comprising a further cylindrical enclosure in which a further part is slidably received and a further spring in the further enclosure acting to bias the frame parts to the proximate position. The two connector portions are connected to the first and second bridging elements respectively. A further bridging element connects between the connector portions. In the embodiment to be described the enclosures are carried by the first and second bridging elements respectively and the respective parts slidably received therein are respective end portions of the further bridging element. According to another aspect of the invention there is provided a clip-on sunglass assembly which is as set out in Claim 12. An embodiment in accordance with this aspect of the invention is describe below with reference to Fig. 5 to 8. There are preferred features of the connector portion(s) which are generally applicable in the embodiments to be described and which are generally applicable to the aspects of the invention set forth above as set forth in dependent claims. Such features will now be outlined in general terms referring to a connector portion connected to and between bridge elements extending from respective frame parts. The enclosure of the connector portion serves the additional purpose of co-operating with the bridge elements of the frame parts to keep the frame parts in proper alignment. This is achieved by one or more slots in the enclosure which cooperate with protrusions on the bridge elements to maintain the frame parts in alignment. The enclosure interior wall also provides an end surface for the spring to abut. The enclosure enhances the appearance of the assembly by hiding the unsightly spring and the bridge element ends. Preferably, the enclosure is made of the same material and finish as the bridge elements and frame, resulting in a mechanism which is much less conspicuous than an exposed spring, and in which the spring is fully enclosed. The clip-on sunglass assembly has an attractive appearance. An open end of the enclosure or each enclosure section through the slidable part is received may be tapered. The spring abuts the tapered end. The invention and its practice will now be described with reference to embodiments thereof illustrated in the accompanying drawings, in which: Figure 1 is a front plan view of a first preferred embodiment of the assembly of the present invention showing the frame parts in the proximate position in solid and in the remote position in phantom; Figure 2 is a top plan view of the embodiment of the invention shown in Figure 1 mounted on eyeglasses; Figure 3 is an enlarged cross-sectional view taken along line 3-3 of Figure 2; Figure 4 is an enlarged cross-sectional view taken long line 4-4 of Figure 3; Figure 5 is a front plan view of a second preferred embodiment of the assembly of the present invention showing the frame parts in the proximate position in solid and in the remote position in phantom; Figure 6 is a top plan view of the embodiment of the invention shown in Figure 5; Figure 7 is an enlarged cross-sectional view taken along line 7-7 of Figure 6; Figure 8 is an enlarged cross-sectional view taken along line 8-8 of Figure 7; Figure 9 is a front plan view of a third preferred embodiment of the present invention showing the frame parts in the proximate position in solid and in the remote position in phantom; Figure 10 is a top plan view of the embodiment of Figure 9; and Figure 11 is an enlarged cross-sectional view taken along line 11-11 of Figure 10. As seen in the drawings, theclip-on assembly includes first and second frame parts, 10 and 12, which are substantially mirror images of each other. Each frame part 10, 12 includes a lens retaining portion 14, 16 respectively formed of a metal or plastic frame 18, 20 respectively at least partially surrounding a light attenuating lens 22, 24 respectively. Each frame 18, 20 carries a set (two or more) spaced, eyeglass engaging "L" shaped prongs 26, 28 and 30, 32, respectively, adapted to secure the assembly to eyeglasses 33. The prongs are preferably plastic or rubber coated. Each frame part 18, 20 has a bridge element 34, 36, respectively, which is joined to and extends from the top of the frame part. Bridge elements 34, 36 are connected by a spring mechanism, generally designated 38. Mechanism 38 includes a cylindrical enclosure 40 a tapered end parts 42, 44, respectively. As best seen in Figure 3, bridge element 34 extends through an opening in end part 42 and into the interior of enclosure 40. The end of bridge element 34 carries a protrusion 46. Protrusion 46 extends in a direction generally perpendicular to the axis of the bridge element and is slidably received within a slot 48 along the bottom of enclosure 40, as seen in Figure 4. Protrusion 46 and slot 48 cooperate to maintain proper alignment between the frame parts. A coil spring 50 is situated around. bridge element 34, operably interposed between protrusion 46 and the interior surface wall 41 of tapered end part 42. In this embodiment, bridge element 36 is fixed to tapered end piece 44 of enclosure 40. The second preferred embodiment of the invention is illustrated in Figures 4 through 8. The major difference between the first preferred embodiment and the second preferred embodiment is that the second embodiment employs two smaller coil springs 53 and 54 instead of one large spring. Here, the portion of bridge element 34 received within enclosure 40 is smaller and the end part 44 of the enclosure is open such that a portion of bridge element 36 may be received within the interior of enclosure 40. See Figure 7. The end of bridge element 36 carries oppositely extending protrusions 52 which extend in a direction generally perpendicular to the axis of the bridge element. Protrusions 52 are received within slots 48 and 49 in enclosure 40. See Figure 8. Second coil spring 54 is situated around bridge element 36 and operably interposed between oppositely extending protrusions 56 on the end of element 36 and the interior surface wall 45 of enclosure end part 44'. Protrusions 56 cooperate with and are slideably received within slots 48 and 49, respectively, in the same manner as protrusions 52. The protrusions and slots cooperate to maintain proper alignment between the frame parts. Both of these embodiments function in the-same manner. The spring mechanism 38 permits the user to grasp frame parts 10, 12 and to move them to a remote position, phantom in Figures 1 and 5, against the action of the springs, such that prongs 26, 28 and 30, 32 fit around the eyeglass frame. When released, the spring action of mechanism 38 causes the frame parts to move toward each other, so as to retain the eyeglass frame between the prongs, as seen in Figures 2 and 6. The prongs may be plastic or rubber coated so as not to scratch the eyeglass frames. The third preferred embodiment, illustrated in Figures 9, 10 and 11, utilizes two separate cylindrical enclosures 38a and 38b, the end walls 40a and 40b of which are fixed respectively to shortened bridge elements 34' and 36'. Enclosures 38a and 38b are connected by a connecting element 60 having ends 62, 64 with protrusions 70, 72, respectively. Two springs, 66, 68 are provided. Spring 66 is situated within enclosure 38a, operatively interposed between the open end 40a and protrusion 70 on end 62 of connecting element 60. Similarly, spring 68 is situated within enclosure 38b, operatively interposed between the open end 40b and the protrusion 72 on end 64 of connecting element 60. This embodiment operates essentially the same way as the previous embodiment. Each enclosure has an elongated slot axial 48a, 48b, along which the protrusion 70, 72 on the end of connecting element 60 move so as to maintain proper alignment of the parts. As the frame parts are moved to the remote position, springs 66, 68 are compressed. The springs thus urge the frame parts toward the proximate position, so as to engage the eyeglasses between prongs 26, 28, 31 and 32. It will now be appreciated that there has been described an enclosed spring bridge mechanism for mounting a sunglass assembly on eyeglasses without contacting or damaging the eyeglass lenses. Opposing frame parts with sets of prongs are moved apart to permit insertion of the eyeglass frame therebetween and then released to permit the spring force to move the parts together to retain the frame. The bridge mechanism includes one or more cylindrical enclosures within which the springs are situated.

Claims: A clip-on sunglass assembly for mounting on eyeglasses comprising: first (10) and second (12) frame parts each comprising a lens retaining portion (14: 16); a bridge structure (34: 36: 38, 34': 38a, 60, 38b, 36') extending between the frame parts (10: 12) and including first (34, 34') and second (36, 36') bridging elements extending from the first (10) and second (12) frame parts respectively, a connector portion (38, 38a) acting between said first (34, 34') and second (36, 36') bridging elements and having a cylindrical enclosure (40, 38b) in which a part (34, 34') is slidably received to allow movement of the frame parts (10: 12) between a proximate position and a remote position, and a spring (50) in the enclosure acting to bias the first (10) and second (12) frame parts to one of the positions, characterised in that each frame part (10: 12) has at least one prong (26: 31) for engaging an eyeglass to mount the sunglass assembly forward of the eyeglasses, and the spring (50) acts between the first and second bridging elements to bias the frame parts toward the proximate position for engaging the prongs with the eyeglasses. A clip-on sunglass assembly as claimed in Claim 1 in which the enclosure (38, 40) is carried by one bridging element (36) and said part slidably received in it is an end portion of the other bridging element (34). A clip on sunglass assembly as claimed in Claim 1 in which said bridge structure (34': 38a: 60: 38b: 36') comprises a further connector portion (38b) comprising a further cylindrical enclosure (38b) in which a further part is slidably received and a further spring in the further enclosure acting to bias the frame parts to the proximate position, the connector portions (38a, 38b) being connected to said first (34'a) and second (36') bridging elements respectively and a further bridging element (60) which connects between the connector portions (38a, 38b). A clip-on sunglass assembly as claimed in Claim 3 in which the enclosures (38a, 38b) are carried by the first (34') and second (36') bridging elements respectively and the respective parts slidably received therein are respective end portions of the further bridging element (60). A clip-on sunglass assembly as claimed in Claim 2 in which the spring (50) acts between first and second end parts carried by the enclosure (40) and the other bridging element (34) respectively. A clip-on sunglass assembly as claimed in Claim 5 in which the other bridging element (34) passes through the first end part (42) and said spring (50) and terminates in the second end part. A clip-on sunglass assembly as claimed in Claim 5 or 6 in which the enclosure (40) has a slot (48) and the second end part has a protrusion (46) slidably received in the slot (48) to allow movement of the frame parts (10: 12) between the proximate and remote positions. A clip-on sunglass assembly as claimed in Claim 3 or 4 in which each spring (50) acts between respective first (42) and second (64) end parts carried by the respective enclosure (38a: 38b) and the part slidably received therein. A clip-on sunglass assembly as claimed in Claim 8 in which the respective part slidably received in each enclosure (38a, 38b) passes through the respective first end part (42) carried by the enclosure and the spring (50) therein and terminates in the second end part (64). A clip-on sunglass assembly as claimed in Claim 8 or 9 in which each enclosure (38a: 38b) has a slot (48b) and the second end part (64) of the part slidably received in the enclosure has a protrusion (72) slidably received in the slot to allow movement of the frame parts (10,: 12) between the proximate and remote positions. A clip-on sunglass assembly as claimed in Claim 1, 2 or 3 in which the or each enclosure, as the case may be, has a slot (48, 48') and the or each part slidably received therein has a protrusion (46, 72) slidably received in the slot (48, 48'). A clip-on sunglass assembly as claimed in any preceding claim in which each frame part (10: 12) has two spaced prongs (26, 28: 31, 32) for engaging an edge of an eyeglass. A clip-on sunglass assembly for mounting on eyeglasses, comprising: first (10) and second (12) frame parts each comprising a lens retaining portion (14: 16); first (34) and second (36) bridging elements extending from said first (10) and second (12) frame parts; and a connector portion (38) acting between the bridging elements (34: 36) and comprising a cylindrical enclosure (40) and a part slidably received therein to allow movement of the frame parts (10: 12) between a proximate position and a remote position, and a spring (53) in the cylindrical enclosure acting between the enclosure (40) and said part slidably received therein to bias the first (10) and second (12) frame parts to one of the positions, characterised in that : the cylindrical enclosure (40) comprises first and second sections in which a first and second part respectively is slidably received, said first and second parts being carried by said first (34) and second (36) bridging elements respectively, and a first (53) and a second (54) spring is received within said first and second enclosure sections respectively to act between the respective enclosure section and the respective part slidably received therein to bias the first (10) and second (12) frame parts to the proximate position; and each frame part (10: 12) has at least one prong (26: 31) for engaging an eyeglass to mount the sunglass assembly forward of the eyeglasses. A clip-on sunglass assembly as claimed in Claim 13 in which each frame part (10: 12) has two spaced prongs (26, 28: 31, 32) for engaging an edge of an eyeglass. A clip-on sunglass assembly as claimed in Claim 13 or 14 in which the first spring (53) acts between first (42) and second end parts carried by the first enclosure section and the first part slidably received therein respectively and the second spring (54) acts between the third (44') and fourth end parts carried by the second enclosure section and the second part slidably received therein respectively. A clip-on sunglass assembly as claimed in Claim 15 in which the first part slidably received in the first enclosure section passes through the first end part (42) and the first spring (53) and terminates in the second end part, and the second part slidably received in the second enclosure section passes through the third end part (44') and the second spring (54) and terminates in the fourth end part. A clip-on sunglass assembly as claimed in Claim 15 or 16 in which each of the first and second enclosure sections has a slot (48: 49) and each of the second and fourth end parts has a respective protrusion (52: 56) slidably received in the respective slot (48: 49) of the first and second enclosure sections to allow movement of the first and second frame parts (10: 12) between the proximate and remote positions. A clip-on sunglass assembly as claimed in Claim 13 or 14 in which each enclosure section has a slot (48: 49) and the respective part slidably received therein has a respective protrusion (52: 56) slidably received in the slot (48: 49). A clip-on sunglass assembly as claimed in any one of Claims 12 to 16 in which said first and second slidably received parts are end portions of said first (34) and second (36) bridging elements respectively.

Inventors: FRIEDMAN DEAN M, FRIEDMAN, DEAN M.
Applicants: FRIEDMAN DEAN M, FRIEDMAN, DEAN M.
Application year: 2001
Main classification: G02C9
IPC codes: G02C5, G02C9