Background of the Invention Generally, auxiliary eyeglass frames, such as sunglass frames, are attached with clips to primary frames, such as frames for prescription eyewear. Such clips are often highly visible, and detract from the cosmetic appearance of the eyeglasses. Such "clip-ons" also may affect the field of vision of the wearer, and may scratch the lenses of the eyeglasses to which they are clipped.

This invention relates generally to eyewear systems having primary and auxiliary eyeglass frames that can be removably interconnected to provide a dual-frame configuration. Specifically, this invention relates to a primary frame having a permanent magnet located at each end of the frame, and an auxiliary frame having a pair of magnets at positions corresponding to the positions of the primary frame magnets, so that the auxiliary frame can be removably connected to the primary frame by the attractive force of the magnets. The auxiliary frame may hold any of a number of lens types, such as sunglass lenses, magnifying lenses, reading lenses, or decoratively colored lenses. Sadler, in U.S. Patent No. 5,416,537, describes a pair of auxiliary lenses that can be magnetically attached to a pair of eyeglasses. Notwithstanding the eyeglass system disclosed in Sadler, however, there remains a need for a high quality and aesthetically pleasing eyeglass system which permits removable magnetic retention between the eyeglasses and the secondary frames.

Summary of the Invention It is therefore an object of the present invention to provide a magnetic eyewear system comprising primary and auxiliary eyeglass frames that are magnetically interconnectable.

It is another object of the present invention to provide a magnetic eyewear system comprising magnetically interconnectable primary and auxiliary eyeglass frames that are precisely manufactured to ensure that, when the frames are interconnected, the magnets on the auxiliary frame align precisely with the corresponding magnets on the primary frame, such that the attractive magnetic force between the frames is maximized.

It is a further object of the present invention to provide a magnetic eyewear system comprising magnetically interconnectable primary and auxiliary eyeglass frames, each frame having a pair of magnets with sufficient strength to maintain the magnetic bond between the frames while a wearer engages in normal everyday activities and light sports, but of sufficiently small size to ensure that the magnets do not detract from the cosmetic appearance of either of the frames.

Another object of the present invention is to provide a magnetic eyewear system comprising magnetically interconnectable primary and auxiliary eyeglass frames, wherein the auxiliary frame has a specially-configured hinge in its bridge that allows the auxiliary frame to be folded in half and stored in a small area, but that does not detract from the cosmetic appearance of the auxiliary frame and that provides means to ensure that the auxiliary frames will not inadvertently fold while in use, resulting in detachment of the auxiliary frame from the primary frame.

A further object of the present invention is to provide a magnetic eyewear system comprising magnetically interconnectable primary and auxiliary eyeglass frames configured so that, when the two frames are magnetically interconnected, there is a gap between the two frames, to allow for a variety of lens thicknesses and to minimize the possibility of one lens scratching another Yet another object of the present invention is to provide a method of manufacturing a magnetic βyβwβar system that results in a high-quality product at a low cost.

In a preferred embodiment of the present invention, these and other objects are attained by means of a magnetic eyewear system comprising a primary eyeglass frame having a high-powered magnet at each and and an auxiliβry eyeglass frame hβving a central hinge and a pair of high-powered magnets at positions corresponding to the positions of the primary frame magnets, such that the auxiliary frame can be removably connected to the primary frame by the attractive force of the respective frames' magnets. The auxiliary frame can be used to hold any of a number of lens types, such es sunglass lenses, magnifying lenses, reading lenses, or decoratively colored lenses

Brief Description of the Prawmps These and other features of the invention will now be described with reference to drawings of a preferred embodiment which are intended to illustrate and not to limit the invention and in which:

Figure 1 is a perspective view of a magnetic eyewear system In accordance with en embodiment of the present invention, showing magnetically interconnactablo primary and auxiliary eyeglass frames in an attached configuration;

Figure 2 is a side aievational view of thα magnetic eyewear system of Figure 1, showing the frames in an attached configuration;

Figure 3 is an exploded perspective view of the magnetic eyewear system of Figure 1, showing the frames in a detached configuration;

Figure 4 is a rear elβvational view of the auxiliary eyeglass frame of Figure 1, showing tha auxiliary frame in an unfolded configuration; Figure 5 is a front elavational view of the auxiliary eyeglass frame of Figure 1, showing the auxiliary frame

In an unfolded configuration;

Figure 5a is an enlargement of the hinge area of Figure 6;

Figura 6 is a top plan view of the auxiliary eyeglass frame of Figure 1, showing the frame in a folded configuration; Figure 7 is a top plan view of the auxiliary eyeglass frame of Figure 1, showing the auxiliary frame in en unfolded configuration;

Figure 8 is a bottom plan view of the auxiliary eyeglass frame of Figure 1, showing the auxiliary frame in an unfolded configuration;

Figure 9 Is an exploded frontal perspective view of the hinge area of the auxiliary eyeglass frame of Figure

RECTIFIED SHEET (RULE 91) ISA/EP

Detailed Description of the Preferred Embodiment

Figures 1-2 illustrate a preferred embodiment of a magnetic eyewear system 1 in accordance with an embodiment of the present invention. The eyewear system 1 comprises a primary eyeglass frame 2 to which is magnetically attached an auxiliary eyeglass frame 3. The primary frame 2 holds a pair of primary lenses 4, and the auxiliary frame holds a pair of auxiliary lenses 5. The primary frame 2 is provided with a pair of rearwardly extending earstems 6. Each earstem 6 is pivotably connected to the eyeglass frame 2 such as by a hinge 7.

The lenses 4 and 5 in accordance with the present invention can be formed in any of a variety of configurations, while still obtaining the benefits of the present invention. In the illustrated embodiment, each lens 4 and 5 is generally oval in configuration, having a lens height of approximately 1 1/2 inches and a lens width in the horizontal plane of approximately 1 7/8 inches. Lens heights in excess of 1 1/2 inches, including lens heights up to about 2 inches or more may also be utilized. Lens heights of less than about 1 1/2 inches may also be utilized; however, the provision of a lens height of much less than about 1 1/4 inches or 1 inch may not provide sufficient eye protection as will be understood to those of skill in the art. Similarly, the tens width in the horizontal plane can be varied such as between about 1 inch to about 2 1/2 inches or more, depending upon stylistic considerations and the level of eye protection desired for a particular model.

In general, the preferred dimensions recited above reflect a compromise believed by the present inventor to optimize eye protection within the context of fashion eyewear, while at the same time minimizing the weight of the eyeglass and lenses. Minimizing weight, among other advantages, increases the relative ratio of magnet strength to weight, thereby improving retention of the auxiliary eyeglass frames as will be discussed. The lenses 4 and 5 may be formed from any of a variety of lens materials, such as glass, polycarbonate, and other optically suitable lens materials known in the art. Preferably, the lenses 4 and 5 comprise a material that is lightweight and possesses excellent optical qualities, such as acrylic or the material known in the eyewear industry as CR39.

With reference to Figure 2, when the primary frame 2 and the auxiliary frame 3 are in a magnetically interconnected position, there is preferably a gap 8 between the two frames. This gap 8 is provided to allow the use of prescription lenses of a variety of thicknesses to be mounted into the primary frame 2 without preventing attachment of auxiliary frame 3 to primary frame 2. The gap 8 also prevents the lenses mounted within the primary and auxiliary frames from inadvertently rubbing together during use of the eyewear system 1 and causing the lenses to scratch. The auxiliary frame 3 is preferably complementary in shape to the primary eyeglass frame 2, so that the light filtering properties of the auxiliary lenses 5 in a sunglass embodiment fully cover the optical zone of the primary lenses 4. In the illustrated embodiment, the auxiliary frame 3 is substantially identical in exterior configuration to the primary eyeglass frame 2, and the corresponding auxiliary lenses 5 are similarly substantially identical in configuration to the primary lenses 4 in the primary rame 2. Figure 3 shows the eyeglass system 1 in a detached position wherein the auxiliary frame 3 is separated from the primary frame 2. The primary frame 2 may comprise annular rings that completely surround the lenses 4. Alternatively, the primary frame 2 may surround only a portion

of each lens 4. In the illustrated embodiment, the primary frame comprises a pair of orbitals 21 that surround only slightly more than an upper one half of each lens 4. The lenses 4 preferably seat within channels (not illustrated) within the primary frame 2, and may be retained therein such as by polymeric bands which surround the exposed edges of the lenses 4 and connect at each end to the frame 2. In this embodiment, each of the lenses 4 is provided with a radially inwardly directed recess surrounding the peripheral edge of the lens to receive the polymeric band. This arrangement is known in the eyewear industry as the "Nylor" frame style.

The primary frame 2 further comprises a bridge 22 interconnecting the orbitals 21. The bridge 22 can be integrally formed with the orbitals 21, or can be formed separately and secured thereto. In a preferred embodiment, the bridge 22 is separately formed from the orbitals 21, and is secured thereto such as by welding or other metal bonding techniques.

The primary frame 2 further comprises connectors 23 that are mounted at opposing ends of the primary frame 2. The connectors 23 preferably extend from the hinges 7 to the orbitals 21. in the illustrated embodiment, the connectors 23 comprise rearwardly extending segments 24 and medially extending segments 25 for connecting to the orbitals 21. Mounted within the connectors 23 are first and second permanent magnets 26 and 27. Preferably, the magnets 26 and 27 are covered with a sealing material (not shown), such as epoxy resin, to minimize the risk of rusting. A variety of alternate configurations for the arrangement among the hinges 7, the connectors 23, and the magnets 26 and 27 can also be devised in view of the disclosure herein by those of ordinary skill in the art.

The primary frame 2 can be constructed from any of a variety of materials which exhibit sufficient dimensional stability in the intended use environment. For example, the primary frame 2 may be formed from any of a variety of plastic materials, or metals. In a preferred embodiment, the primary f ame 2 is formed from a durable metal such as monel, using a metal casting technique commonly used in the eyewear manufacturing industry. Preferably, the earstems 6, orbitals 21, the bridge 22, and the connectors 23 are all formed from similar materials. However, dissimilar materials may also be used for the various components of the primary frame 2, provided that joints of sufficient integrity can be formed between the components.

Nosepads 28 may be connected to the bridge 22, or to the edge of the frame 2 on the medial side of each lens 4. Nosepads 28 can be constructed in any of a variety of ways which are known in the art, and may be secured to the frame 2 in a metal frame embodiment such as by welding, brazing, attachment using a "rimlock" mechanism, or by other techniques known in the art. With further reference to Figure 3, the auxiliary frame 3 may comprise annular rings for surrounding the auxiliary lenses 5. Alternatively, the auxiliary frame 3 may surround only a portion of each auxiliary lens 5. In the illustrated embodiment, the auxiliary frame 3 comprises a pair of orbitals 31 that surround only slightly more than an upper one half of each lens 5. The lenses 5 preferably seat within channels (not illustrated) within the auxiliary frame 3, and may be retained therein such as by polymeric bands which surround the exposed edges of the lenses 5 and connect at each end to the frame 3. In this embodiment, each of the lenses 5 is provided with a radially inwardly directed recess surrounding the peripheral edge of the lens to receive the polymeric band.

The auxiliary frame 3 further comprises a bridge 32 interconnecting the orbitals 31. The bridge can be integrally formed with the orbitals 31, or can be formed separately and secured thereto. In a preferred embodiment, the bridge 32 comprises a series of elements formed separately from the orbitals 31, and subsequently secured thereto such as by soldering, brazing or welding. The preferred bridge comprises a hinge 34, as described in further detail below.

The auxiliary frame 3 further comprises end pieces 33 that are mounted at opposing lateral ends of the auxiliary frame 3. Mounted within the end pieces 33 are third and fourth permanent magnets 36 and 37. Preferably, magnets 36 and 37 are covered with a sealing material (not shown), such as epoxy resin, to minimize the risk of rusting. More than two magnets can be provided in each of the primary frame 2 and auxiliary frame 3 as desired for alternate embodiments of the invention. For example, three pairs of corresponding magnets or four pairs or more can readily be used. In addition, non-round magnets such as narrow, elongated strip magnets, rectangular, triangular, oval or magnets of other shapes can also be used.

With reference to Figure 4, which shows a rear elevational view of auxiliary frame 3, it can be seen that magnets 36 and 37 extend from front to back all the way through the end pieces 33 so that surfaces of the magnets 36 and 37 are exposed on a rear surface of the auxiliary frame 3. With reference to figure 5, it can further be seen that the magnets 26 and 27 of primary frame 2 extend to a front surface of the primary frame 2. When the primary frame 2 and the auxiliary frame 3 are in the interconnected position shown in Figure 1, the magnets 36 and 37 on the auxiliary frame 3 are magnetically attracted to the corresponding exposed portions of the magnets 26 and 27 on the primary frame 2.

The auxiliary frame 3 can be constructed from any of a variety of materials which exhibit sufficient dimensional stability in the intended use environment. For example, the auxiliary frame 3 may be formed from any of a variety of plastic materials, or metals. In a preferred embodiment, the auxiliary frame 3 is formed from a durable metal such as moπel, using a metal casting technique commonly used in the eyewear manufacturing industry. Preferably, the orbitals 31, the bridge 32, and the end pieces 33 are all formed from similar materials. However, dissimilar materials may also be used for the various components of the auxiliary frame 3, provided that joints of sufficient integrity can be formed between the components.

The primary frame 2 and the auxiliary frame 3 are preferably manufactured with a greater level of precision than is typically practiced in the eyewear manufacturing industry, because a difference in width of as little as 1-2 mm between the magnet centers on the primary frame 2 and the magnet centers on the auxiliary frame 3 could reduce the attractive force between the frames 2 and 3 sufficiently to cause inadvertent detachment of the auxiliary frame 3 from the primary frame 2.

Thus, the distance between the primary frame magnets 26 and 27 preferably differs by less than about 2 mm, more preferably less than about 1 mm, and optimally less than about 0.5mm from the corresponding distance between the auxiliary frame magnets 36 and 37. In order to further optimize performance of the present invention, the primary and auxiliary frames 2 and 3 are preferably constructed to minimize variation in the distance between

magnet centers. The distance between magnets 36 and 37 in the preferred embodiment is variable in the sense that the orbitals 31 are pivotably attached to each other by way of hinge 34. However, once the auxiliary frame 3 is opened for attachment to the primary frame 2, the axial distance between the centers of the magnets 36 and 37 is substantially invariable. The axial distance between the centers of magnets 36 and 37 generally cannot be varied by more than about 2 mm, preferably no more than about 1 mm and most preferably no more than about 0.5 mm when the auxiliary frames are in use.

The foregoing optimal tolerance is achieved by the combination of relatively rigid construction materials with the design of the present invention. For example, secondary frames 3 hingeably open for use to about a 180° configuration, such that both orbitals 31 lie roughly on a single plane. When mounted on the primary frame 2, except for the corresponding magnets, which preferably contact each other, the primary frame 2 and secondary frame 3 together with their respective lenses are roughly equidistant from each other throughout the horizontal plane.

The unique hinge construction, discussed infra, inhibits flexing of the central portion of the auxiliary frame 3 towards the primary frame 2 such as when the wearer presses against the bridge region to reposition the glasses higher on the weaver's nose. The bridge portion may be widened front to back or a spacer (not illustrated) may also be provided in the bridge region to limit rearward movement of the center of the auxiliary frame 3 with respect to the primary frame 2 to further ensure that rearward pressure on the auxiliary frame 3 will not move them closer to the primary frame 2. This is in contrast to the flexible and rearwardly concave sunglass shield disclosed in U.S. patent no. 5,416,537 to Sadler, which appears susceptible to sufficient flattening upon application of rearward pressure in the bridge region to increase the distance between the magnets on opposite ends of the sunglass shield. Preferably, the magnets 26, 27, 36 and 37 are all of similar construction, being cylindrical in shape and having diameters of approximately 3 mm, and depths of approximately 2.5 mm. The magnets 26, 27, 36 and 37 preferably comprise a rare earth metal such as Neodium (Nd), Ferrous (Fe), or Boron (B). Permanent magnets made from rare earth metals can have approximately twice the strength of similarly-sized cobalt-based magnets and approximately ten times the strength of similarly-sized ferrite magnets. The magnets 26, 27, 36 and 37 in the preferred embodiment each have a strength in excess of about 1500 gauss, preferably at least about 2,500 gauss, and more preferably of approximately 3,500 gauss or more, which is much higher than the strength of conventional permanent magnets of the same dimensions.

The relatively small size of the magnets 26, 27, 36 and 37 allows the magnets to be barely visible to a casual observer, yet the great strength of the magnets ensures that the auxiliary frame 3 will remain magnetically attached to the primary frame 2 even when the wearer of the eyewear system 1 engages in everyday activities involving abrupt head movements, such as jogging or other light sports, or driving an automobile over rough roads. However, the strength of the magnets is not so strong as to interfere with electrical devices that may be located on or within the wearer's body, such as a pacemaker or a "walkman" type headset.

With reference to Figures 4-6, magnets 36 and 37 are preferably aligned so that, when the auxiliary frame 3 is in the unfolded configuration as shown in Figure 4, the magnets 36 and 37 have relatively opposite polarity, e.g. if the positive pole of the magnet 36 located near the wearer's right temple is facing forward, then the positive

pole of tha magnet 37 located near the wearer's left temple Is facing rearward. Thus, when the auxiliary frame 3 Is in a folded configuration as shown in Figure 8, the magnets 36 and 37 are attracted together to magnetically retain the auxiliary frame 3 in a folded position.

With reference to Figures 4-9, the bridge 32 of auxiliary frame 3 comprises a hinga 34, allowing the auxiliary frame 3 to be folded into a smaller configuration for storage. The hinge 34 comprises a pair of hinge members 40 each connected to respective right and left lens frame segments. Each hinge member 40 is provided with a forked portion 41 forming a slot 42 end a pair of tines 43. See Figure 9. A pin hole 44 extends through each pair of tines 43. A linkage 45, preferably of a generally flat and trepezoidal shape, has a pin hole 46 at either end. Whan the hinge 34 Is assembled, each and of the linkage 45 is inserted within a corresponding slot 42 of the hinge members 40, and a fixture pin 47 Is passed through tha pin hole 44 through each pair of tinas and the pinhoies 46 at either end of the lin age 45.

As assembled, the hinge 34 is configured to limit tha relative angular movement of the two orbitals 31 to between a folded configuration, wherein tha angle between the orbitals 31 is approximately 0° (i.e. the lenses are essentially parallel) and wherein the rear surfaces of the orbitals 31 are directly adjacent, and an unfolded configuration, wherein tha angle between the lens retalning-membβrs 31 is approximately 180° (i.β. the lenses are essentially coplanar). With reference to Figure B, it can be saan that when tha auxiliary frame 3 is in the unfolded configuration, no portion of any of the components of the hinge 34 extends horizontally beyond either the front or the rear surface of the bridge 32, resulting in a "seamless" configuration that is both aesthetically pleasing and, unlike conventional hinges (such as the earstem hinge 7), there are no protrusions to distract the wearer's vision. With reference to Figures 5a, 6, and 9, hinge members 40 have radiused corners 48 and linkage 45 hβs symmetrical first and second inclined stop surfaces 49, Radiused corners 48 and inclined stop surfaces 49 ensure that orbitals 31 can ba rotated freely relative to each other about the hinge 34 throughout the entire 180° range of the hlnga 34, without obstructions between the hinge members 40 or between the linkage 45 end hinge members 40. Each of tha first and second Inclined stop surfaces 49 cooperates with a complementary angled wall 50 between tha tines 43 of each hlnga member 40 to prevent the orbitals 31 from rotating beyond the 180° unfolded position. This feature of the hinge prevents the bridge portion 32 of the auxiliary frame 3 from inadvertantly folding inwards while the auxiliary frames 3 ara in use, which could result In auxiliary frame 3 being detached accidentally from primary frame 2. Providing a 180" stopping point also makes it easier for a wearer to unfold the auxiliary frame 3 precisely to its operational position. Preferably, there is sufficient friction al contact between the hinge members 40 and the linkage 45 so et to prevent the bridge portion 32 of the auxiliary frame 3 from inadvertently folding outwards while tha auxiliary frame 3 is in use, which could result in the auxiliary frame 3 becoming accidentally detached from the primary frame 2.

The distance between tha apertures 46 on linkage 45 Is preferably sufficient that the right and left lenses of the auxiliary frame 3 can be folded back generally in parallel with each other as seen in Figure 5 so that magnets 3B and 37 contact each other but the right and left lenses 5 do not. In a preferred embodiment, the linkage 45

RECTIFIED SHEET (RULE 91)

has a length of about 8.7 mm on its long side 52 and a length of about 7.0 mm on its shorter longitudinal side 54. The distance between the centers of apertures 46 is about 5 mm.

The basic components of metal framed eyewear constructed in accordance with the present invention can be manufactured and assembled in any of a variety of manners, using conventional metal forming techniques. Certain post assembly steps may also be desired, such as polishing and brushing steps and potentially coating steps such as to minimize oxidation for certain types of metals. An aesthetic texturing or colored finish may also be applied as will be understood to those of skill in the art.

The magnetic eyewear system 1 shown in Figure 1 is preferably constructed using a preferred embodiment of the present inventive process. The method comprises a step of casting the connectors 23 and end pieces 33 from a heated metal such as monel in such a way that an aperture (not shown) is defined through each of the connectors 23 and end pieces 33 for receiving magnets 26, 27, 36 and 37. Since the dimensional size of casted parts often varies slightly among the parts as a result of the heat treatment process, the method comprises, where necessary to achieve uniformity in the size of the holes, the step of milling the inside walls of the holes through connectors 23 and end pieces 33. It may also be desirable to trim the length of medial segments 25 to obtain the desired spacing between the magnets 26 and 27.

Other components such as the linkage 45, the hinge members 40, the pins 47, the orbitals 21 and 31, and the earste s 6 can be manufactured in any of a variety of conventional ways known in the art. Metal embodiments of the invention can be cut, stamped, milled, bent from appropriately dimensioned wire stock, or the like, as will be understood to those of skill in the art. The method further comprises the steps of securing the magnets 26, 27, 36 and 37 within each of the four holes defined within the connectors 23 and end pieces 33. Gluing is preferred over other methods that could be used to attach the magnets, such as soldering, driving, screwing, or fixing with pins. Soldering could deteriorate the magnetic power of the magnets due to the extreme heat involved, and the high impact involved in driving could cause the magnets to break. Screwing and pin-fixing would involve time-consuming and expensive adaptation of both the magnets and the metal parts into which the magnets are to be placed. Gluing, on the other hand, does not involve extreme heat, high impact, or expensive workmanship, and therefore is superior to these alternative methods.

Preferably, construction of the primary and auxiliary frames 2 and 3 further comprises the step of coating the magnets 26, 27, 36 and 37 with a sealant such as epoxy resin to prevent rusting. Other methods well known in the eyewear industry may also be used in the manufacture and assembly of the dual-lens eyewear system 1. Although this invention has been described in terms of a certain preferred embodiment, other embodiments apparent to those of ordinary skill in the art are also within the scope of this invention. Accordingly, the scope of the invention is not intended to be limited by the foregoing description, but should be defined by the claims which follow.