Abstract:
Eyewear is configured to use pairs of polarized lenses, with one pair held stationary within an eyeglass frame, and the remaining pair disposed adjacent with the fixed pair and permitted to rotate under the control of the wearer. A novel mechanism is included within the eyewear for the wearer to use in rotating the movable lenses with respect to the fixed lenses. In particular, a flexible member is included to surround a majority of each rotatable lens, with the flexible member riding within a channel formed in the frame. A lever, or other type of hand control fixture, is attached to the flexible member. The wearer may than move the lever back and forth, which imparts a linear motion to the flexible member. The linear motion of the flexible member is translated into a rotational movement of the attached lenses, thus creating a wearer-adjustable tint.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application Ser. No. 62/029,385, filed Jul. 25, 2014 and herein incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to tinted eyewear (such as sunglasses) and, more particularly, to eyewear having a tint that is easily adjustable by the wearer as necessary, for convenience and/or comfort. 
     BACKGROUND OF THE INVENTION 
     There are many instances where it would be convenient to adjust the tint (i.e., the “darkness”) of eyewear. When driving, for example, the amount of sun glare may change on a moment&#39;s notice, particularly when changing directions. The ability for a wearer to adjust the tint of his/her sunglasses would be useful. Various other types of eyewear—traditional eye glasses, goggles, safety glasses, and the like—could benefit from this ability of allowing the wearer to adjust the tint quality. 
     For years, there have been sunglasses that have “self-adjusted” their degree of tint as a function of the ambient light conditions. That is, the glasses would “lighten” when an individual would go indoors, and would then darken when going back outside. While useful in many situations, various versions of these self-darkening lenses have been only moderately successful. At times, the material used to form the lenses does not allow for a sufficient lightening effect to be obtained. Moreover, it generally takes a few minutes for the lenses to change their tint. When driving, this slow reaction time is unacceptable. Additionally, the wearer cannot control the amount of tint, or the circumstances under which the lenses will become darker or lighter; that is, the wearer is at the mercy of the photochromic properties of the lens material and cannot provide any type of adjustment him/herself. 
     There are various arrangements in the prior art directed to providing adjustment of eyewear tint that address the concerns associated with using lenses that automatically (via a chemical process) change tint. One exemplary adjusting arrangement is disclosed in U.S. Pat. No. 5,320,552, issued to P. Baran et al. on May 11, 1993. The Baran et al. configuration, described as a pair of “variable density sunglasses”, uses two separate elements of polarized material to form each lens. The two separate elements are positioned in an overlapping arrangement, defined as an “inner” polarized element and an “outer” polarized element. The inner polarized elements for each lens are permanently attached to the frame. The outer polarized elements are positioned in a channel in the frame and held in a “rotatable” configuration such that the outer polarized elements are capable of rotating with respect to the inner polarized elements, where the angular separation between the polarization orientations of the pair of elements will dictate the degree of tint that is achieved. 
     In the Baran et al. arrangement, the rotation of the outer polarized elements is controlled by the manipulation of a gear wheel by the wearer. The outer elements are formed to include gear teeth around their periphery, where these teeth will mesh with the gear wheel when the various piece parts are combined. While somewhat of an improvement, the need to include teeth around the periphery of the lens elements is a time-consuming (and thus expensive) proposition. Moreover, the manipulation of the gear wheel itself may be difficult, and its position on the nose piece of the frame may be unacceptable and unnecessarily limit the types of frames within which these adjustable tint lenses may be used. 
     Thus, a need remains in the art for eyewear that may include an adjustable tint, where the adjustment is provided simply and easily by the wearer, without the need to incorporate difficult components and piece parts into the structure of the frame. 
     SUMMARY OF THE INVENTION 
     The needs remaining in the prior art are addressed by the present invention, which relates to adjustable tint eyewear and, more particularly, to eyewear having a tint that is easily adjustable by the wearer as necessary, for convenience and/or comfort. 
     In accordance with the present invention, eyewear is configured to use pairs of polarized lenses, with one pair (oriented to exhibit the same polarization direction) held stationary within the frame, and the remaining pair disposed adjacent with the fixed pair and permitted to rotate under the control of the wearer. Thus, the inventive eyeglasses utilize pairs of polarized elements in the same manner as Baran et al. However, in accordance with the present invention a novel mechanism is provided for the wearer to use in rotating the movable lenses with respect to the fixed lenses. This novel mechanism eliminates the need for modifications to the lenses themselves, as required in Baran et al. to provide movement. The novel mechanism allows for the hand control element to be positioned at virtually any location on the eyewear frame, allowing for the inventive adjustable tint eyewear to be used with any desired frame configuration. 
     In particular, the novel mechanism of the present invention consists of a single flexible member that is disposed to surround a peripheral portion of both of the movable, polarized lenses. The flexible member includes a U-shaped inner channel for holding these peripheral regions of the rotatable lenses secured in place. The flexible member itself is positioned to ride within a channel formed in the eyewear frame, and includes a hand control element (located in a position preferred by a wearer). By moving the hand control element, the wearer causes the flexible member to move back and forth, changing the orientation of the rotatable lenses with respect to the fixed lenses. Thus, an individual can quickly and easily move the hand control element back and forth until the desired degree of tint is obtained. Obviously, the wearer can easily re-adjust the tint level as needed by moving the hand control element. The hand control element may take the form of a small lever, a textured surface area along the flexible member, or any other suitable type of mechanism that is integral with the flexible member and is easily manipulated by the wearer to provide the desired amount of tint. 
     In one embodiment, the flexible member rides within a channel formed in a horizontal frame member component of conventional eyewear frames. In frame styles that do not include such a horizontal frame member, the flexible member can be disposed to surround the pair of rotatable polarized lenses in a type of “figure 8” pattern across the nose piece. Other configurations for supporting the positioning of the flexible member around the rotatable lenses may be used and are considered to fall within the spirit and scope of the present invention. In any case, the utilization of a single flexible member to provide the simultaneous rotation of both movable lenses, in accordance with the present invention, ensures that the same amount of darkening or lightening is provided for each eye. 
     An exemplary embodiment of the present invention takes the form of Eyewear exhibiting wearer-adjustable tint, comprising the following components: (1) a first pair of polarized lenses (oriented in a same polarization direction) fixed within an eyewear frame; (2) a second pair polarized lenses (also oriented in the same polarization direction), disposed adjacent to the first pair of polarized lenses in a one-to-one relationship and configured to be rotatable while the first pair of polarized lenses remains fixed; (3) a flexible member disposed to surround a portion of a periphery of each lens forming the second pair of lenses; and (4) a hand control element coupled to the flexible member for providing a linear movement of the flexible member, which generates a rotational movement of the second pair of polarized lenses so as to adjust the polarization orientation of the second pair of polarized lenses with the first pair of polarized lenses and adjust the tint of the eyewear as a function of the movement of the hand control element. 
     Other and further aspects of the present invention will become apparent during the course of the following discussion and by reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring now to the drawings, where like numerals represent like parts in several views: 
         FIG. 1  is an exploded view of the various components forming the adjustable tint eyewear of the present invention; 
         FIG. 2  is a cut-away view of a portion of the adjustable tint eyewear, showing the U-shaped channel within the flexible member and the position of a rotatable lens within this U-shaped channel; 
         FIG. 3  is a cut-away view of another portion of the adjustable tint eyewear, showing a keying arrangement that may be used to properly position (and align) the rotatable lenses with respect to the flexible member; 
         FIG. 4  is a cut-away side view of a portion of the horizontal frame member, illustrating the positioning of the flexible member within a slot formed in the frame; 
         FIG. 5  is a top view of the illustration of  FIG. 4 ; 
         FIG. 6  is an isometric view of a front frame element, particularly illustrating the location of the slot used to control the range of motion of the flexible member; 
         FIG. 7  is a rear view of the inventive adjustable tint eyewear as shown in  FIG. 1 ; 
         FIG. 8  illustrates one specific positioning of the flexible component, used to rotate the inner lenses and provide a first specific degree of tint; 
         FIG. 9  illustrates another specific positioning of the flexible component, in this case where the inner lenses are further rotated such that the polarizations of the pairs of lenses are essentially parallel, thus providing a minimal degree of tint; 
         FIG. 10  is a cut-away diagrammatic view of another embodiment of the present invention, in this case where the flexible member is disposed in a “figure-8” pattern to surround the lenses in a manner where the rotatable lenses simultaneously rotate with respect to the fixed lenses; 
         FIG. 11  is a cut-away view of yet another embodiment of the present invention, in this case positioning the flexible member in a different configuration within the same eyeglass frame as shown in  FIG. 10 ; 
         FIG. 12  is a cut-away view of a portion of the inventive eyewear, in this case illustrating the spacing that is maintained between the fixed lenses and the rotatable lenses; 
         FIG. 13  illustrates an alternative embodiment of the present invention, in this case utilizing a textured surface area along the flexible member as the hand control element; 
         FIG. 14  shows the configuration of  FIG. 13  as positioned within an exemplary eyewear frame; 
         FIG. 15  is another view of the configuration of  FIG. 13 , in this view showing the internal stop features formed within the frame to prevent over-rotation of the lenses; and 
         FIG. 16  illustrates yet another embodiment of the present invention, in this case utilizing a small thumbwheel that works in conjunction with a serrated surface area on the flexible member to provide movement of the flexible member and control of the degree of tint obtained for the eyewear. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is an exploded view of the components that create adjustable tint eyewear in accordance with the present invention. In particular,  FIG. 1  shows a pair of polarized lenses  10 ,  12  (hereinafter referred to as “fixed lenses”) that are permanently attached to a front frame element  26 . For the sake of discussion, lenses  10  and  12  are illustrated as oriented such that their polarization state (which is controlled to be the same) is in the vertical direction (indicated by the double-ended arrows in the drawing). In a preferred embodiment of the present invention, lenses  10  and  12  are formed to include a keying structure in the form of a tab  13 , shown as tabs  13 - 1  and  13 - 2 . With reference to  FIG. 1 , it is clear that tabs  13 - 1  and  13 - 2  fit in place in associated openings  15 - 1  and  15 - 2  formed in front frame element  26 . By virtue of using these tabs, the prior vertical alignment of the polarization orientation of lenses  10  and  12  is ensured. However, it is to be understood that there may be other keying configurations used to provide the necessary orientation of lenses  10 ,  12  within front frame element  26 . 
     Also shown in  FIG. 1  is a pair of rotatable polarized lenses  14  and  16 , hereinafter referred to as “rotatable lenses”. In the particular embodiment as shown in  FIG. 1 , rotatable lenses  14 ,  16  are disposed behind fixed lenses  10 ,  12  (with respect to front frame element  26 ), with polarized rotatable lens  14  disposed behind (and aligned with) polarized fixed lens  10 , and polarized rotatable lens  16  disposed behind (and aligned with) polarized fixed lens  12 . In this particular embodiment, lenses  14  and  16  are shown as oriented such that their lines of polarization are horizontal (again, both lenses are oriented in the same direction), as indicated by the double-ended arrows in the drawing. In this situation with orthogonal (i.e., perpendicular) polarization states between the fixed lenses and rotatable lenses, maximum darkening (tinting) is achieved. 
     It is to be understood that the principles of the present invention equally apply to a configuration where the rotatable lenses are positioned in front of the fixed lenses (i.e., the rotatable lenses positioned between the fixed lenses and the front frame element). As long as a rotatable lens is positioned adjacent to (and properly oriented with) a fixed lens, the principles of wearer-adjustable tint in accordance with the present invention apply. 
     Also shown in  FIG. 1  is a flexible member  20 , which is disposed to surround the outer periphery of at least a portion of each polarized rotatable lens  14  and  16 . Flexible member  20  may comprise any suitable pliable material that is relatively thin, so as to easily surround the thickness of common lens structures (e.g., a monofilament fiber such as nylon, rubber, elastic, etc.). Flexible member  20  is configured to include an inner channel  21 , as best shown in the cut-away view of  FIG. 2  (showing a portion of flexible member  20  surrounding rotatable lens  16 ). By virtue of using this inner channel  21  to secure the positioning of lenses  14 , 16 , the peripheral regions of each rotatable lens  14 ,  16  is held snugly in place within flexible member  20 . 
     In order to provide the proper initial orientation of lenses  14 , 16  with respect to lenses  10 ,  12 , a preferred embodiment of the present invention includes a keying structure within flexible member  20 , and a like keying structure within each rotatable lens  14 ,  16  so that lenses  14 ,  16  are locked into a desired initial position.  FIG. 3  illustrates a portion of flexible member including a keying structure  23  within channel  21 . Lens  14  is shown as including a notch  14 - n  at a predetermined location. Thus, when positioning flexible member  20  around lens  14 , notch  14 - n  mates with keying structure  23  such that lens  14  is properly positioned with respect to flexible member  20 . A similar keying structure is used to properly align and position lens  16  within flexible member  20 . Thus, when combined with fixed lenses  10 ,  12 , the orientation of the polarization for lenses  14 , 16  is known and defined with respect to the polarization orientation of the fixed lenses. 
     Referring back now to the structure of  FIG. 1 , the hand control element that is used by the wearer to rotate lenses  14 ,  16  with respect to fixed lenses  10 ,  12  is shown as taking the form of a lever control  30 . In accordance with this specific embodiment of the present invention, lever control  30  is attached to flexible member  20 , where as described in detail below, the wearer moves lever control  30  back and forth to rotate attached lenses  14 ,  16  and thus control the amount of tinting that is created. 
     In the embodiment as shown in  FIG. 1 , flexible member  20  is disposed to fit in a frame channel  22  formed within frame element  26 , which in this view includes a horizontal frame member  24 . In cases where fixed lenses  10 ,  12  are disposed in front of rotatable lenses  14 ,  16 , frame channel  22  is located behind fixed lenses  10 ,  12 . Conversely, in configurations where rotatable lenses  14 ,  16  are positioned in front of fixed lenses  10 ,  12 , frame channel  22  will be formed in front of fixed lenses  10 ,  12 . Once all components are in place, lever control  30  extends outward through a longitudinal opening (slot)  32  formed in horizontal frame member  24 .  FIG. 4  is a cut-away view illustrating the relative placement of flexible member  20 , frame channel  22 , lever control  30 , slot  32  and horizontal frame member  24 . Also shown in this view is a portion of a rear frame element  38  that is positioned between rotatable lenses  14 ,  16  and mates with front frame element  26  to form the complete eyewear assembly.  FIG. 5  is a top view of a portion of horizontal frame member  24 , showing the position of lever control  30  within slot  32 . 
     In operation of this particular embodiment, the wearer moves lever control  30  along slot  32  (indicated by the double-ended arrows in  FIG. 5 ) to perform the tint adjustment of the eyewear. Advantageously, the length of slot  32  is used to control the range of motion of lever control  30 , functioning as a “stop” so that over-rotation of rotatable lenses  14 ,  16  does not occur.  FIG. 6  is an isometric view of front frame element  26 , horizontal frame member  24  and slot  32 . As shown, slot  32  includes opposing end terminations  32 - 1  and  32 - 2  that function as the stops to prevent further movement of lever  30 . It is to be understood that the precise location of lever control  30  and slot  32  are design details and do not impact the performance the adjustable tinting feature of the inventive eyewear. 
       FIG. 7  is a rear view of the inventive adjustable eyewear as shown in  FIG. 1 , with fixed lenses  10 ,  12  permanently attached to eyewear frame  26 , and flexible member  20  disposed within channel  22  of frame  26 . By virtue of the attachment of polarized lenses  14 ,  16  to flexible member  20 , these lenses rotate as flexible member  20  is moved under the wearer&#39;s control. Evident in this view is the disposition of flexible member  20  with respect to lenses  14  and  16 . As discussed above, it is important that polarized lenses  14 ,  16  are able to rotate through a full 90° arc with respect to fixed lenses  10 ,  12 , in order to adjust between full tint and minimal tint. To this end, slot  32  is formed to have a length L of πr/2, where “r” is the radius of the lenses. With this relationship between the slot length and the lens radius, the full 90° rotation of lenses  14 , 16  is provided. In the view as shown in  FIG. 7 , the pairs of lenses are disposed perpendicular to each other (indicated by the 90° orientation shown in the side drawing), thus providing the maximum degree of tint. 
     In accordance with the present invention, a wearer easily adjusts the amount of tinting by moving lever control  30  along slot  32 . Since lever control  30  is attached to flexible member  20 , the movement of lever control  30  will result in flexible member  20  moving as well. The movement of flexible member  20  functions to rotate lenses  14  and  16 —always by the same amount and in the same direction—and thus adjusts the polarization orientation of rotatable lenses  14 ,  16  with respect to fixed lenses  10 ,  12 . In the initial position shown in  FIG. 7 , the polarization of rotatable lenses  14 ,  16  is oriented at 90° with the polarization of fixed lenses  10 ,  12 . This position provides for maximum tint, as indicated by the side drawing shown perpendicular polarization lines and a relatively dark tint. 
       FIGS. 8 and 9  illustrate the possible adjustments in tinting that is achieved by using lever control  30  to move flexible member  20  and rotate lenses  14 ,  16 . In the configuration as shown in  FIG. 8 , lever control  30  has moved to the midpoint of slot  32  (i.e., a shift of length πr/4). This movement causes a like movement of flexible member  20 , rotating polarized lenses  14 ,  16  through an angle of about 45°, as shown. In this case, lever control  30  has been moved to the left (as shown by the arrow), so that lenses  14 ,  16  rotate counterclockwise. The side drawing in  FIG. 8  shows that the polarization of lenses  14 ,  16  has now rotated with respect to the fixed ‘vertical’ polarization lines of lenses  10 ,  12 . In this state, the tint has now somewhat lightened. 
       FIG. 9  illustrates the adjustable eyewear of the present invention in the configuration where lever  30  has been moved to the opposing end (stop  32 - 1 ) of slot  32 . This movement results in an additional rotation of 45° for lenses  14 ,  16  and results in an arrangement where the polarization orientation of the lenses is parallel. When the polarized lenses are oriented in this position, minimal blocking of sun rays is obtained, thus the lightest amount of tinting (if any) is created. The side drawing in  FIG. 9  depicts the lenses in this state. 
     As mentioned above, it is possible to use a “figure-8” type of placement of flexible member  20  around rotatable lenses  14 ,  16 . This type of placement is particularly useful for frames that do not include a horizontal frame member.  FIG. 10  illustrates an alternative embodiment of the present invention where flexible member  20  is disposed in such a figure-8 type of pattern around lenses  14 ,  16 . As with the configurations discussed above, flexible member  20  is positioned to surround a portion of the outer periphery of lens  14 . In this figure-8 configuration, however, flexible member  20  is disposed to then surround a portion of the inner periphery of lens  16 . The “figure-8” threading of flexible member  20  may be disposed in the opposite direction, with flexible member  20  surrounding a portion of the outer periphery of lens  16  and a portion of the inner periphery of lens  14 . 
     Regardless of the direction used to dispose flexible member  20  in a figure-8 configuration, a lever control  30 A is disposed along the side of the frame as shown in  FIG. 10  and attached to flexible member  20  in the same manner as above. Thus, an “up” and “down” movement of lever control  30 A with a slot  32 A formed in the eyewear frame and used to move flexible member  20  and rotate polarized lenses  14 ,  16 .  FIG. 11  illustrates an alternative placement of flexible member  20  within the same frame design as shown in  FIG. 10 . In this configuration, a lever control  30 B is located in an upper area of the eyewear, with associated slot  32 B extending across the nose piece of front frame element  26 . It is clear that various other placements of flexible member  20  with respect to rotatable lenses  14 ,  16  are possible. All are considered to fall within the scope of the present invention. 
     Advantageously, flexible member  20  provides and maintains a slight separation s between the fixed lenses  10 ,  12  and rotatable lenses  14 ,  16 . This slight separation, or gap, prevents scratches from occurring as lenses  14 ,  16  rotate with respect to fixed lenses  10 ,  12 .  FIG. 12  is a cut-away view of two alternative configurations of the elements, in each case depicting the spacing s created by holding rotatable lens  16  within the U-shaped channel  21  of flexible member  20 . 
     As mentioned above, there are a variety of other types of hand control elements that may be used by the wearer to move the flexible element (and thus rotate lenses  14 ,  16  with respect to fixed lenses  10 ,  12 ).  FIG. 13  illustrates a flexible member  70 , also formed in accordance with the present invention, where flexible member  70  is shown as including a textured surface portion  72  that is used by the wearer to move flexible member  70  back and forth and adjust the amount of tint. The view of  FIG. 13  shows rotatable lenses  14 ,  16  as surrounded by flexible member  70 . As with the embodiments described above, flexible member  70  includes a channel (not shown) within which the outer peripheries (or the combination of inner and outer peripheries for the figure-8 disposition of the flexible member) of lenses  14 ,  16  are held. A keying arrangement (such as a keying structure and notch) is used as before to properly align lenses  14 ,  16  within flexible member  70 . 
       FIG. 14  illustrates an exemplary eyewear frame  80  with the combination of flexible member  70  and lenses  14 ,  16  in place. It is to be understood that fixed lenses  10 ,  12  are also positioned (and properly oriented) with respect to rotatable lenses  14 ,  16 . Evident in this view is the positioning of textured surface  72 , as extending through a slot  82  formed in a horizontal frame member  84  of eyewear frame  80  (see cut-away view along line A-A). In accordance with the present invention, a wearer may simply adjust the amount of tint by touching textured surface  72 , and moving this portion of flexible member  70  back and forth within slot  82 . The linear movement of flexible member  70  causes the rotational movement of lenses  14 ,  16  and adjusts the polarization between the pairs of lenses accordingly, thereby allowing the wearer to control the amount of tint by himself. 
       FIG. 15  is another view of the embodiment of  FIGS. 13 and 14 , in this view showing the internal “stop” mechanisms controlling the movement of the flexible member. As mentioned above, these stops are hidden within the eyewear frame (as opposed to being an exposed slot, as described above). The eyewear frame in this case can be configured in somewhat of a clamshell form that encloses the flexible member while allowing for the hand control element to remain accessible for the wearer. As shown, textured surface  72  is formed to extend somewhat above the lower profile of the remainder of flexible member  70 , where this extension of surface area  72  is used to limit the amount of lateral movement possible with flexible member  70 . 
     As shown, eyewear frame  200  is formed to include embedded stops  210  and  212  for preventing the end terminations of textured area  72  (shown as ends  72 - 1  and  72 - 2 ) from over-rotating lenses  14 ,  16 . The cut-away side view of a central area of the eyewear frame, taken along line A-A shows flexible member  70  located within a channel  205  formed within the eyewear between a back eyewear frame piece  200  and a front eyewear frame piece  220  (thus forming a “clamshell” type of enclosure for capturing and retaining flexible member  70  within the frame structure. As shown, textured surface area  72  extends above front frame piece  205 , allowing for the user to adjust the tint by rotating the lenses. Another cut-away view, taken along line B-B shows how flexible member  70  remains hidden within the combination of frame pieces  200  and  220  in all areas of the eyewear that are not contacted by the wearer. 
       FIG. 16  shows yet another type of hand control element. In particular, a flexible member  300  is positioned to surround (and be aligned with) rotatable polarized lenses  14 , 16  in the manner discussed above. In this particular embodiment, flexible member  300  is formed to include at least one surface area where a set of teeth  310  is formed across the outer surface. This set of teeth  310  is used to mesh with teeth  320  of a thumbwheel  330 , as shown. In order to adjust the tint of the eyeglasses, the wearer simply rotates thumbwheel  330  to cause movement of flexible member  300  and rotation of lenses  14 ,  16 . In the exemplary embodiment shown in  FIG. 16 , a pair of such controls is included, one located near an upper side of each lens  14  and  16 . Obviously, the thumbwheel mechanism can be located at any point along the frame where it is most appropriate. 
     Various other features of the frame and hand control elements, as well as positioning of the flexible member, may be modified as a function of a particular frame design and are considered to fall within the scope of the present invention. While the provisioning of adjustable tint in this manner obvious requires the use of circular inner lenses (in order to provide proper rotation), the outer lenses may exhibit an suitable geometry, as long as the outer lenses are polarized and can be fixed in place to provide adjustable tint in conjunction with the rotatable inner lenses. Moreover, various ornamental features may be added to the frame structure to change the physical appearance of the lenses.