Abstract:
Swimming goggles that are shaped by approximately profiling the goggles to the swimmer&#39;s head resulting in the goggles having a minimal tendency to be pulled off or pulled ajar from the swimmer&#39;s head by hydrodynamic forces while exhibiting minimal hydrodynamic drag. Optical arrays molded into the lenses of the goggles permit normal vision both underwater and above the water.

Description:
[0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/276,470, having the filing date of Sep. 12, 2009. 
     
    
     TECHNICAL FIELD 
       [0002]    Swimming goggles that exhibit a hydrodynamically streamlined profile and provide for normal vision both underwater and above water. 
       BACKGROUND OF THE INVENTION 
       [0003]    The present invention relates generally to swimming goggles for covering and protecting the eyes of a swimmer while enhancing the swimmer&#39;s vision. In particular this invention relates to swimming goggles that geometrically approximate a hydrodynamically streamlined profile with respect to the swimmer&#39;s head while simultaneously permitting normal vision when the swimmer&#39;s eyes are either above or below the water surface. More particularly, the invention relates to lens structures for swimming and diving goggles. 
         [0004]    Swimming goggles, especially those for competitive swimmers, should provide several functions and exhibit several characteristics. Firstly, the goggles should protect the swimmer&#39;s eyes from the irritations of the water. In swimming pools these irritations are caused from chemical disinfectants such as chlorine, bromine, or ozone. Additional irritations are caused from incompatible pH levels, ionic concentrations, and chemical buffers in the pool water. Secondly, goggles should provide for normal vision both underwater and above water. Thirdly, the goggles should perform these functions without requiring the swimmer to alter his or her diving entry into the pool for fear of the goggles being displaced from the swimmer&#39;s head by hydrodynamic forces and moments. Fourthly, the goggles preferably exhibit no more hydrodynamic drag than if the swimmer were swimming without goggles. Prior art goggles have failed to satisfy all of these functions and characteristics. 
         [0005]    Swimming goggles have been made to match a section of a hydrodynamically streamlined contour to the face. (For example, see  FIG. 1 .) Shaping goggles this way permits a swimmer to dive into the pool, turn and push off from walls, and swim with minimal concern that the goggles might be pulled off or pulled ajar due to hydrodynamic forces and moments. Additionally, the hydrodynamic drag of such goggles is less than that for coplanar lens swimming goggles, an advantage for competitive swimmers. The deficiency of these types of prior art goggles is that underwater binocular-like viewing is not normal. Incoming parallel optical rays diverge as they refract through the hydrodynamically streamlined lenses. (For example, see  FIG. 2 .) This requires that the swimmer&#39;s eyes point in convergent directions to attain binocular focus while viewing underwater; the swimmer must adjust his or her eyes in a cross-eyed orientation to attain binocular vision. It is difficult to rapidly toggle back and forth from a cross-eyed orientation for underwater binocular viewing to a straight-ahead orientation for above water binocular viewing. Double images are observed when viewing underwater with both eyes looking straight ahead. Using these prior art goggles may cause headache, vertigo, or induce nausea. 
         [0006]    Two characteristics are required for providing normal vision when wearing swimming goggles. Firstly, if two optical rays are parallel as they enter the lenses of the goggles with one ray on a trajectory to enter the left pupil and the other ray on a trajectory to enter the right pupil, then they shall also be approximately parallel after both rays pass through the lenses of the goggles. Secondly, that objects focus approximately on the retina when viewing through the lenses of the goggles in a manner similar to the human eye when viewing in air without goggles. 
         [0007]    Keeping optical rays parallel as they pass through the left and right lenses of goggles has been accomplished in the prior art in several ways. One technique disclosed by Bengtson et al., U.S. Pat. No. 4,051,557, utilizes coplanar sections of plastic or glass as part of the right and left lenses. Widenor, U.S. Pat. No. 3,027,562, discloses a flat section of plastic in front of the eyes which then curves in the peripheral region of viewing outside of binocular vision. Another technique, disclosed by Hagan, U.S. Pat. No. 3,672,750, uses a section of a sphere as the outer surface of each uniform thickness lens with the radius of curvature centered within each eye. Here, any axis through the center of the pupil is always normal to the lens surface regardless of the angle of the eye. Flory, U.S. Pat. No. 5,313,671, discloses use of a section of a cylinder instead of a sphere. These techniques preclude matching the contour of the face with a goggle that is minimally intrusive into the free stream of water such as shown in  FIG. 1 . 
         [0008]    Swimming goggles of the prior art may also add optical corrections similar to those found in corrective prescription glasses to reduce the effects of visual deficiencies such as myopia, hypermetropia, and astigmatism. For coplanar lenses these corrections are often added to each of the inner lens surfaces with the outer surface of each lens remaining flat. Most commonly offered are simple spherical corrections in whole or half diopter steps. 
         [0009]    Reducing the tendency of normal vision goggles from being pulled off or ajar has been addressed by the prior art in several ways. Drew, U.S. Pat. No. 4,279,039, discloses attaching coplanar lens goggles directly to the swim cap. Van Atta et al., U.S. Pat. No. 7,475,435, discloses reducing coplanar lens size. Fukasaw, U.S. Pat. No. 6,996,857, discloses adding fillets to the protruding sections of coplanar lens goggles. 
         [0010]    Prior art refinements enhancing normal vision include blackening whole sections of the viewing field as disclosed by Yokota, U.S. Pat. No. 7,165,837. Wick, U.S. Pat. No. 2,008,530, discloses allowing water to directly contact the eyes while using hollow lenses to effect normal vision underwater. 
       SUMMARY OF THE INVENTION 
       [0011]    The present invention relates to swimming goggles having lenses with outer surfaces which geometrically approximate a portion of a hydrodynamically streamlined profile while simultaneously providing for normal vision both above and below the water. 
         [0012]    The present invention comprises swimming goggles with an optical array formed into both the inner and outer surfaces of the lenses of the goggles. The outer optical arrays have two functions. Firstly, the outer surfaces of the outer optical arrays geometrically approximate a portion of a hydrodynamically streamlined profile. Secondly, outer arrays optically approximate the outer surface of an optically appropriate lens section such as coplanar lenses. The inner array optically approximates the inner surface of an optically appropriate lens section without geometrically conflicting with human anatomy. 
         [0013]    Goggles of this invention are less prone to being pulled off or pulled ajar from a swimmer&#39;s head by hydrodynamic forces or moments, particularly during a diving entry into the water. They also exhibit reduced hydrodynamic drag compared to other goggles that provide for normal vision. This is true both for the unsteady and for the steady hydrodynamic environments. 
         [0014]    These and other benefits of this invention will become apparent from the following description by reference to the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a perspective view of prior art goggles. 
           [0016]      FIG. 2  is a top sectioned view of the prior art goggles of  FIG. 1 ; 
           [0017]      FIG. 3  is another perspective view of prior art goggles; 
           [0018]      FIG. 4  is a sectioned view of prior art goggles wherein each lens is a spherical or cylindrical section with a center of radius within the eye; 
           [0019]      FIG. 5  is a perspective view of an embodiment of goggles of the present invention; 
           [0020]      FIG. 6  is a top sectioned view of the goggles of  FIG. 5 ; 
           [0021]      FIG. 7  is another sectioned view of the goggles of  FIG. 5 ; 
           [0022]      FIG. 8  is a sectioned side view showing another embodiment of the hydrodynamically streamlined goggles of the present invention; 
           [0023]      FIG. 9  is a sectioned view of another embodiment of the hydrodynamically streamlined goggles of the invention; 
           [0024]      FIG. 10  is a perspective view of goggles of the invention having an alternative optical array pattern; 
           [0025]      FIG. 11  is a sectioned view of another embodiment of the goggles of the invention; 
           [0026]      FIG. 12  is a sectioned side view showing outer contour lines through this section of the goggle lenses of the instant invention; and 
           [0027]      FIG. 13  is a sectioned view of another embodiment of the lenses for the goggles of the invention that do not have air adjacent to the wearer&#39;s eyes while underwater. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]      FIGS. 1-4  show prior art goggles and which are discussed in the Background of the Invention. The present invention relates to lenses which are used in swimming and diving goggles which essentially hold the lenses in position with respect to the eyes and face of the wearer. It is within the purview of the present invention to be used in connection with any means which hold lenses in position. 
         [0029]    Referring to  FIG. 5 ,  FIG. 6 , and  FIG. 7 , swimming goggles  10  are shown having lens frames  11 ,  12 , lenses  13 ,  14 , nose bridge  15 , head strap  16 , and eye seals  17 . The lenses are shown having an exterior surface and incorporating optical arrays as part of both the inner surfaces  20 ,  21  and the outer surfaces  18 ,  19  of the exterior surfaces of the lenses  13 ,  14 , respectively. Each optical array of goggles  10  consists of refractive surfaces alternating with and congruous with return surfaces. The inner optical array for the right lens  14  consists of refractive surfaces  600  that are generally flat and parallel with each other and are approximately parallel to the inner refractive surfaces  605  of the inner optical array of the left lens  13 . The outer refractive surfaces  610  on the right lens  14  are generally flat and also parallel with each other and are approximately parallel to the outer refractive surfaces  615  on the left lens  13 . The inner refractive surfaces  600 ,  605  are not necessarily parallel to the flat outer refractive surfaces  610 ,  615 . For example, as shown in lens  30  in  FIG. 8 , outer refractive surfaces  31  are parallel to each other but not to inner refractive surfaces  32 . The left and right lenses also need not be mirror images of each other. The number of inner refractive surfaces further does not need to be the same as the number of outer refractive surfaces of the lens. 
         [0030]    Light rays, for example  640  and  650 , observed by the swimmer both underwater and above water pass through the refractive surfaces  610  and  600 , respectively. Light rays that are parallel with each other as they enter the lenses are also parallel with each other after passing through the lenses. This is true both underwater and above the water. This is true both for light rays coming from straight ahead such as  640  and  650 , and for light rays coming from the side, as depicted by  770  and  780  in  FIG. 7 . The light rays  770  and  780  are shown with underwater refraction angles. The direction cosines of optical rays may change as they pass through the lenses of the goggles. However, the change in the direction cosines will be the same for an optical ray that will be entering the right eye as for an optical ray that will be entering the left eye if these two rays are parallel to each other before they enter the lenses. Parallel optical rays remain parallel after passing through the lenses of these goggles. 
         [0031]    The latter description is true when the parallel optical rays are either both underwater or both above water. 
         [0032]    Referring again to  FIGS. 5-7 , the size of the outer refractive surfaces  610  and the size of the outer return surfaces  630  may be reduced while the number of such surfaces is increased to ensure that the maximum distance between any point on the outer surface and a specified profile  660  is arbitrarily small. Any profile, for example profile  660 , may be approximated to any degree of accuracy using only flat and parallel refractive surfaces  615  connected by alternating return surfaces  625 . 
         [0033]    Referring to  FIG. 9 , an embodiment of the swimming goggles is shown and which uses refractive surfaces and return surfaces to mimic the optical properties of the goggles described in  FIG. 4 . These are similar in concept to the goggle embodiment of  FIGS. 5-7 , except the embodiment of  FIG. 9  approximates the optical properties of spherical or cylindrical lenses and the refractive surfaces of  FIG. 9  are not flat or parallel with other. 
         [0034]    The optical arrays as described in the instant invention with respect to the goggle embodiments of  FIGS. 5-10  exhibit several characteristics. Each optical array has at least two refractive surfaces. The refraction angle of a light ray passing through a refractive surface may be zero degrees such as when a light ray is normal to the refractive surface. Refractive surfaces are smooth or piecewise smooth, but not necessarily flat. Refractive surfaces are regions of the goggles through which visual images are observed. Adjacent refractive surfaces are connected by return surfaces. The refractive surfaces of these optical arrays differ from two transparent sections of goggles which are adjacent to each other in the prior art in two ways. Firstly, adjacent refractive surfaces are connected by a return surface. Secondly, the outward normals of adjacent refractive surfaces differ by less than 15 degrees, and preferably by less than 5 degrees. For refractive surfaces that are not flat the difference of outward normals between adjacent refractive surfaces is the minimum or minimum limit of differences between outward normals on the adjacent refractive surfaces. 
         [0035]    Referring to  FIG. 12 ,  1210  is a contour line through a hydrodynamically streamlined profile  1220  is a contour line through another useful profile. This profile represented by contour line  1220  will increase drag, but will also increase the inward hydrodynamical force applied to the lenses. This helps keep the goggles in the correct position particularly during a diving entry. The profile illustrated by contour line  1220  does not present corners that stick out into the free stream such as those exhibited by the 4,051,557 goggles, for example, as shown in prior art goggles of  FIG. 3 . 
         [0036]    Pressure profile devices such as spoilers, airfoils, hydrofoils, flaps, and slats can be appended to the goggle profile to help provide retention of the goggles to the head. 
         [0037]    For ease of plastic injection molding these goggles may be configured to provide for an approximately uniformly thick lens section. 
         [0038]    The refractive surfaces  600 ,  610  may vary in shape. The outer refractive surfaces  43 ,  44  may have hexagonal shapes as shown in  FIG. 10 . 
         [0039]    Optically blackening, opaquing or dulling one or more of the return surfaces  620 ,  630 ,  625 , and  635  may generate less glare for the swimmer. Blackening or dulling the return surfaces does not restrict the region of view. It only reduces the glare within the region of view. 
         [0040]    Referring to  FIG. 11 , an embodiment of lenses is shown which exhibits smooth outer surfaces  1100  and  1110  while exhibiting parallel ray performance for some underwater light rays directed towards the pupils of the eyes. The outer surfaces of these goggles may be configured as a hydrodynamically streamlined profile. However, above water light rays do not remain parallel after passing through this section of the lenses. A set of goggles using this technique may incorporate a bifocal configuration permitting normal vision below the surface of the water through the lens sections just described and normal vision through different lens sections when viewing above the water. The inner surface lens sections that exhibit parallel ray performance for some underwater optical rays directed towards the pupils may consist of an optical array instead of a single smooth optical surface  1120  and  1130 . The refractive surfaces of these inner optical arrays may consist of surfaces that are not parallel with each other and are not flat. 
         [0041]    Referring to  FIG. 13 , another embodiment of goggles is shown having lenses  45 ,  46  and which does not seal air between the lenses of the goggles and the eye. Rather, water is allowed to directly contact the eye when swimming with the eyes underwater. These goggles are intended especially for competition where good visibility coupled with robust tolerance from goggles being pulled ajar during a diving entry into the water are most important. Eye protection from pool water during competition is a lesser concern than during workouts. At least a portion of these lenses are configured to focus underwater images onto the retina of the eye permitting normal vision under water. 
         [0042]    The techniques disclosed in the instant invention are most useful for the region of binocular vision. For peripheral vision outside of the binocular region simple curved sections of clear material that match the desired outer profile may be acceptable. 
         [0043]    Lenses of the present invention may be fabricated from clear or tinted plastic or from clear or tinted glass. Examples of suitable plastics include polycarbonate and acrylic. Eye seals or eye cups may be fabricated from an elastomer or elastomeric foam that minimizes leakage of water into the area adjacent to the eyes. Four materials commonly used for this purpose are chloroprene foam rubber, EPDM, silicone rubber, and plasticized PVC. 
         [0044]    Fabrication and sealing techniques known to those skilled in the art may be used to fabricate a complete set of goggles including a bridge connecting the left and right lenses together and an elastomeric head strap for holding the goggles to the head. Commonly used materials for bridges are polyethylene, polypropylene, polybutylene, acrylic, polycarbonate, polyurethane, plasticized PVC, or elastomers such as silicone rubber, natural rubber, chloroprene rubber, or EPDM. Head straps are commonly constructed from elastomers such as natural rubber including natural latex rubber, chloroprene rubber, EPDM, silicone rubber, or thermoplastic polymers such as polyurethane or plasticized PVC. 
         [0045]    As many changes are possible to the swimming goggle and lens embodiments of this invention, utilizing the teachings thereof, the description above and the accompanying drawings should be interpreted in the illustrative and not in the limited sense.