Abstract:
A pair of safety sunglass, particularly for use when arc welding, includes auto darkening lenses having suitable characteristics for providing high intensity light protection during welding procedures. The sunglasses have a tight fitting frame conforming to an individual&#39;s face curvature. When an arc is struck, or another high intensity light source is present, the lenses instantly and automatically darken to protect the individual&#39;s eyes from damage. Each lens includes a plurality of layers for prohibiting the high intensity direct light rays from passing therethrough. A feature and benefit of such eyewear is that welding operations may be performed in confined spaces where a conventional welding face shield can not fit. When the welding is completed, the eyeglasses would quickly return to their sun tinted state allowing them to be used as a conventional pair of sunglasses.

Description:
RELATED APPLICATIONS 
     The present invention was first described in Disclosure Document No. 590,456 filed on Nov. 22, 2005. 
     FIELD OF THE INVENTION 
     This invention relates to welding sunglasses and, more particularly, to welding sunglass form-fitted for use in space-confined areas. The sunglasses include means for automatically darkening the lenses when a predetermined quantity of high intensity direct light rays are detected by a photoelectric sensor such that a user can be safely shielded from undesirable welding arcs and light respectively. 
     BACKGROUND OF THE INVENTION 
     Arc welding is a process that is used in a multitude of industries and hobbies. Due to the nature of the arc, vast amounts of ultraviolet (UV) radiation are released which poses a severe danger to one&#39;s eyesight. To help combat this radiation, welding masks which use a very high level of tinted glass, are flipped down over the user&#39;s eyes right before the arc is struck. While the arc is moving, adequate illumination is provided to illuminate the work pieces. While such a method does work, it is sometimes cumbersome to use. Also, there are times when someone may be welding in a confined space, which may not allow the welding helmet to be used. To help in these situations, some people resort to using sunglasses. This however does not provided adequate protection, as the lenses are not dark enough. Even if lenses of an adequate tint were used, there is no way to flip them down at the last instance as the arc is struck. Accordingly, a need exists for a means by adequate eye protection for arc welding can be provided without the shortcomings and disadvantages as listed above. The development of the present invention fulfills this need. 
     Several attempts have been made in the past to develop a welding helmet employing a photochromic lens that automatically changes color based upon detected ambient light. U.S. Pat. No. 6,401,244 in the name of Kramer, et al discloses a welding helmet comprising: a face portion defined by a wall about the perimeter of the face portion, extending toward the interior of the welding helmet; a flange extending from the interior end of the wall; a sloped outer portion about the exterior perimeter of the face portion; and at least one opening in the flange adjacent a first portion of the wall, the at least one opening having a protrusion therein protruding parallel to the flange. The welding helmet may also comprise a plurality of channels in a second portion of the wall. The welding helmet may also include a face plate for covering the face portion of the welding helmet comprising a bezel and an interior groove about the perimeter of the bezel. Unfortunately, this prior art example does not provide a means for detecting high intensity direct light rays wherein a tint level of the lenses are automatically adjusted to protect user eyes. 
     U.S. Pat. No. 6,185,739 in the name of Verkic, et al discloses a light shielding helmet system that includes a helmet shell configured for placement on the head of a user and at least two interchangeable lens holders having different lens-holding configurations. Each lens holder holds one or more lens plates and each can be releasably mounted on the helmet shell. The lens holders can be of different styles (e.g., flip up or fixed front) and/or hold lens plates of different sizes. Unfortunately, this prior art example also does not provide a means of for detecting high intensity direct light rays wherein a tint level of the lenses are automatically adjusted to protect user eyes. 
     U.S. Pat. No. 5,959,705 in the name of Fergason describes a switch activating system for an automatically darkening lens system and an automatically darkening lens system including such a switch activating system, includes a cover plate through at least part of which a scene may be viewed, a support, a pair of switch electrodes, one switch electrode positioned in relatively fixed relation with said support, the other switch electrode being positioned for movement with respect to said one switch electrode selectively to make electrical connection therewith in response to deflecting of said cover plate. The automatically darkening lens assembly also includes a controllable light shutter for controlling transmission of light for viewing therethrough, and a circuit for operating said light shutter and affecting operating characteristics thereof. A method for operating an auto-darkening welding lens including an operating circuit includes selecting an operational characteristic of the welding lens by setting a characteristic of the circuit, said setting comprising deflecting a mechanical member of the welding lens to operate a switch. Unfortunately, this example is complicated to use and includes a variety of circuits which may become damaged or inoperable over extended usage, thus rendering the invention cumbersome for its intended purpose. 
     U.S. Pat. No. 4,868,930 in the name of Blackstone discloses protective eye wear useful as sunglasses, safety glasses, or the like. The product includes a unitary plastic lens piece or shield having a uniform thickness. The side edges of the lens piece are folded rearwardly to form side shields. A brow member is attached to the top edge of the lens piece and extends along the entire length of the lens piece and is perpendicular to the lens piece. Temple members can be attached to the ends of the lens piece or shield. The eye wear product can be made from plastic sheets. Unfortunately, this example is not suitable for use as protective eyewear during welding operations and the like because of its size. 
     None of the prior art particularly describes a pair of tight fitting glasses with auto darkening lenses for use during welding operations. Accordingly, there is a need for a protective ocular shield for use in confined spaces when performing welding operations. The use of the present invention provides personal protective equipment for a user&#39;s eyes in a manner which still allows welding in a tight confined space. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing disadvantages inherent in the prior art, it has been observed that there is a need a welding helmet employing a photochromic lens that automatically changes color based upon detected ambient light. 
     The apparatus includes a curvilinear frame partially fitted around a head of a user such that eyes of the user are covered. A pair of coextensively shaped lenses is directly attached to the frame, without the use of intervening elements, and disposed at a front area of the frame. Each of such lenses conveniently includes a plurality of laminated and contiguously abutted layers covering an entire surface area of each of the lenses respectively. 
     The apparatus further includes a mechanism for automatically darkening a tint of the lenses when high intensity direct light rays are detected above a predetermined threshold level during the welding operations. Such an automatic darkening mechanism includes a photoelectric light sensor centrally located on the frame and forwardly facing away from the frame, which is essential such that the high intensity direct light rays traveling towards the lenses also advantageously strike the photoelectric light sensor and are effectively detected by the photoelectric light sensor. A battery compartment is monolithically formed within the frame and positioned rearward of the lenses. Such a battery compartment is provided with an associated cover removably engaged therewith. 
     The automatic darkening mechanism further includes a power supply source removably nested within the battery compartment, and a power switch located forward of the battery compartment. Such a power switch is electrically mated to the power supply source and is advantageously adaptable between three distinct positions effectively defined as an off position, an on-inactive position and an on-active position respectively. The lenses are partially tinted, which is critical for allowing the user to view surrounding objects under normal ambient light conditions when the switch is toggled to the off position as well as the on-inactive position. The lenses are fully tinted, which is crucial for advantageously restricting a maximum quantity of the high intensity direct light rays when the switch is adapted to the on-active position. 
     The automatic darkening mechanism further includes a driver circuit electrically coupled to the switch and the photoelectric light sensor respectively. Such a photoelectric light sensor effectively generates and transmits an input signal to the driver circuit based upon a quantity of the high intensity light rays detected during welding operations. Such a driver circuit effectively generates and transmits output signals to the first and second liquid crystal apertures respectively, which is critical for regulating passage of the high intensity direct light arrays through the lenses during the on and off positions respectively. 
     The frame includes first and second ear support members, and a bridge member medially positioned between the first and second ear support members and monolithically formed therewith. Such a bridge member is registered perpendicular to the first and second ear support members. Such first and second ear support members are oppositely disposed on left and right sides of the frame. The first and second ear support members are aligned parallel to each other, which is vital for maintaining a static spatial relationship therebetween during operating and non-operating conditions. 
     Each of the lenses includes a plurality of discrete layers assembled in a laminated format. Such discrete layers include a first and outer most layer defining a replaceable protective plate which is detachable from remaining ones of the discrete layers after extended use, a second layer including an ultraviolet light and infrared light filter directly coupled to the first layer, without the use of intervening elements, which is essential for continuously blocking harmful ultraviolet and infrared light rays while the switch is toggled to the on and off positions respectively, a third layer defining a first polarizing lens, which is critical for restricting high intensity direct light rays which are polarized in a predetermined orientation, and a fourth layer defining a first liquid crystal aperture, which is crucial for filtering out the polarized high intensity direct light rays that pass through the first polarizing lens. 
     Each of the lenses further includes a fifth layer defining a second polarizing lens directly coupled to the fourth layer, without he use of intervening elements, a sixth layer defining a second liquid crystal aperture cooperating with the fifth layer and directly coupled thereto, without the use of intervening elements, a seventh layer defining a third polarizing lens, which is vital for providing an additional filter stage and thereby blocking all of the high intensity light rays generated during welding operations, an eighth layer directly coupled to the seventh layer, without the use of intervening elements, and defining an intermediate protective layer, which is essential for sealing and protecting the first, second, third, fourth, fifth, sixth and seventh layers from undesirable foreign debris, and an inner most located ninth layer removably attached to the eight layer for defining a replaceable protective film. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
         FIG. 1  is an isometric view of the sport type protective welding glasses for confined space utilization  10  shown in an utilized state on a user  15 , according to the preferred embodiment of the present invention; 
         FIG. 2  is a detailed isometric view of the sport type protective welding glasses for confined space utilization  10 ; 
         FIG. 3  is an exploded cross sectional view of the auto darkening lens  30  as used with the sport type protective welding glasses for confined space utilization  10 ; and, 
         FIG. 4  is an electrical schematic diagram depicting the major components of the sport type protective welding glasses for confined space utilization  10 . 
     
    
    
     DESCRIPTIVE KEY 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 10 
                 sport-type protective welding glasses 
               
               
                   
                 for confined space utilization 
               
               
                 15 
                 user 
               
               
                 20 
                 frame system 
               
               
                 25 
                 extraneous light rays 
               
               
                 30 
                 auto darkening lens 
               
               
                 35 
                 photoelectric light sensor 
               
               
                 37 
                 direct light rays 
               
               
                 40 
                 battery compartment cover 
               
               
                 45 
                 side ear piece 
               
               
                 50 
                 batteries 
               
               
                 55 
                 battery compartment 
               
               
                 60 
                 power switch 
               
               
                 65 
                 logo areas 
               
               
                 70 
                 first ear support member 
               
               
                 75 
                 frame bridge piece 
               
               
                 80 
                 second ear side support member 
               
               
                 85 
                 outer replaceable protective plate 
               
               
                 90 
                 ultraviolet and infrared filter 
               
               
                 95 
                 first polarizing lens 
               
               
                 100 
                 first liquid crystal aperture 
               
               
                 105 
                 second polarizing lens 
               
               
                 110 
                 second liquid crystal aperture 
               
               
                 115 
                 third polarizing lens 
               
               
                 120 
                 intermediate protective cover 
               
               
                 125 
                 inner replaceable protective plate 
               
               
                 130 
                 display driver circuit 
               
               
                   
               
             
          
         
       
     
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within  FIGS. 1 through 4 . However, the invention is not limited to the described embodiment, and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. 
     Referring to  FIG. 1 , an isometric view of the sport-type protective welding glasses for confined space utilization  10  shown in a utilized state on a user  15 , according to the preferred embodiment of the present invention is disclosed. The user  15  wears the sport type protective welding glasses for confined space utilization  10  on his or her face such that it covers the eye area. A frame system  20  comprises the overall outer housing of the sport-type protective welding glasses for confined space utilization  10  and provides several essential functions. First, it provides an overall look that is aesthetically pleasing and provides an active, sport look that is generally appealing to all types of user  15 . Such attractiveness is envisioned to generally encourage use. Secondly, the frame system  20  provides a fit that is generally close to the eye area of the user  15 . The frame system  20  is designed to be curvilinear to effectively fit around the head of the user  15  such that the eyes of the user  15  are covered. 
     A series of extraneous light rays  25  are generally unable to access the eye area of the user  15 , thus providing increased eye and light protection for the user  15 . Finally, the close fitting nature of the frame system  20  reduces the possibility that the frame system  20  will become caught or snagged on nearby objects when the user  15  is welding in close or confined quarters. An auto darkening lens  30  is provided within the front area of the frame system  20 , as would be customarily expected. Said auto darkening lens  30  allows the user to view outward. The auto darkening lens  30  uses known technology currently used in full face welding helmets. The auto darkening lens  30  will be described in greater detail herein below. A photoelectric light sensor  35  is centrally located on the frame system  20  as part of the auto darkening feature of the auto darkening lens  30 . The forward facing nature of the photoelectric light sensor  35  ensures that direct light rays  37  that will strike the auto darkening lens  30  will also strike the photoelectric light sensor  35  thus enabling operation as will be described in greater detail herein below. 
     Referring now to  FIG. 2 , a detailed isometric view of the sport-type protective welding glasses for confined space utilization  10  is depicted. A battery compartment cover  40  is shown in a removed state from a side ear piece  45 . A series of batteries  50  which power the sport type protective welding glasses for confined space utilization  10  are visible in a battery compartment  55 . The batteries  50  are envisioned to be of the small watch type variety to allow for use in the lightweight configuration of the frame system  20  such as, but not limited to, lithium button cells, silver oxide, manganese alkaline button cells, or other batteries. 
     A power switch  60  is located immediately forward of the battery compartment  55  to allow for ease of activation in a one handed operation. In it&#39;s OFF position, the auto darkening lenses  30  are of a slightly tinted nature that allows viewing under normal ambient light conditions. In its ON but inactive position, the auto darkening lens  30  are of the same slightly tinted nature that allows for viewing through the auto darkening lens  30  under normal ambient light conditions. In its ON and active position, the auto darkening lens  30  are severely tinted so as to restrict the transference of the direct light rays  37  through the auto darkening lens  30 . Such darkening is associated with protection against high intensity light generally associated with welding protection. Those skilled in the art will realize that the protection against high intensity light is only afforded to the eye area of the user  15  (as shown in  FIG. 1 ), and other areas of the face are left unprotected. 
     However, it should be noted that use of the sport type protective welding glasses for confined space utilization  10  is intended for those areas which are confined and unable to accommodate a full face shield as would typically be worn. It should be generally agreed that the protection against direct light rays  37  of a high intensity nature as provided by the sport type protective welding glasses for confined space utilization  10  would be more appropriate than no protection at all. 
     A series of logo areas  65  are located about the frame system  20  as shown. Said logo areas  65  can be used for the display of a variety of aesthetically pleasing motifs and/or other images such as, but not limited to, cartoon characters, sport logos, flames, and/or other motif designs. Other themes for the logo areas  65  envisioned include, but are not limited to, country flags, state flags, animals, characters, and/or the addition of inscriptions such as the user&#39;s name, special dates, quotes, and/or other terms and expressions instead of or in combination with the motifs. 
     The frame system  20  comprises a first ear support member  70  attaching to one side of a frame bridge piece  75 , extending in a perpendicular manner as expected with conventional eyewear. In addition, a second ear side support member  80  attaches to the opposite side of the frame bridge piece  75  in a perpendicular manner to the frame bridge piece  75  and parallel to the first ear support member  70 . Due to internal electrical components as described above and to be described herein below, the first ear support member  70  and the second ear side support member  80  are not capable of retracting inwardly with respect the to the frame bridge piece  75 , a feature typically found in common eyeglasses and sunglasses. 
     Referring next to  FIG. 3 , an exploded cross sectional view of the auto darkening lens  30  as used with the sport type protective welding glasses for confined space utilization  10  is shown. The auto darkening lens  30  consists of nine (9) discrete layers assembled in a laminated format. The most outward of these is an outer replaceable protective plate  85  which can be replaced should it become scratched, pitted or otherwise unsuitable for use. 
     The next is an ultraviolet and infrared filter  90 , which continually blocks harmful radiation, whether the auto darkening lens  30  is ON, OFF, activated or deactivated. Next in progression is a first polarizing lens  95  that restricts direct light rays  37  (as shown in  FIG. 1 ) by only allowing said rays to pass, which are aligned or polarized in a predetermined orientation. Following the first polarizing lens  95  is a first liquid crystal aperture  100  which functions as a shutter to filter out direct light rays  37  (as shown in  FIG. 1 ) that are let through by the first polarizing lens  95 . Said first liquid crystal aperture  100  is similar in nature to those found on LCD displays, such as on watches, cameras, and the like. 
     Next in sequence is a second polarizing lens  105  which works in conjunction with a second liquid crystal aperture  110  and a third polarizing lens  115  to provide additional filter stages and effectively block all direct light rays  37  (as seen in  FIG. 1 ) that are of a high intensity nature such as provided by a welding arc. Following said layers, an intermediate protective cover  120  is provided which effectively seals and protects the laminated layers aforementioned described. Finally, a inner replaceable protective plate  125  is provided, which similarly to the outer replaceable protective plate  85 , can be replaced by the user  15  (as shown in  FIG. 1 ) should it become scratched, permanently soiled or otherwise unusable. 
     Referring finally to  FIG. 4 , an electrical schematic diagram depicting the major components of the sport-type protective welding glasses for confined space utilization  10  is disclosed. Power from the batteries  50  is routed through the power switch  60  that serves as the only single user control of the sport type protective welding glasses for confined space utilization  10 . The resultant power is routed to a display driver circuit  130 . Such driver circuits are well known by those skilled in the art. The photoelectric light sensor  35  serves to provide an input signal to the display driver circuit  130  that allows it to function in the manner aforementioned described. An output is generated to drive the first liquid crystal aperture  100  and the second liquid crystal aperture  110  to their desired state whether inactive or active. It should be noted that should the direct light rays  37  (as shown in  FIG. 1 ) be blocked in way from reaching the photoelectric light sensor  35  that said photoelectric light sensor  35  will not function. Such unwanted blockages may occur from hats, hair, nearby objects and the like which may be present in confined spaces. 
     It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. After purchase of the sport type protective welding glasses for confined space utilization  10 , the user would place the batteries  50  into the battery compartment  55  and replace the battery compartment cover  40 . At this point the sport-type protective welding glasses for confined space utilization  10  is ready for operation. 
     At the beginning of an operation in a confined space which may expose the user  15  to direct light rays  37  of a high intensity nature, the user  15  would activate the sport-type protective welding glasses for confined space utilization  10  by placing the power switch  60  in its ON position, and place the sport-type protective welding glasses for confined space utilization  10  upon their face in the same manner as conventional eyewear. When the arc or other high intensity light source is generated, the direct light rays  37  will strike the photoelectric light sensor  35  and cause the display driver circuit  130  to drive or activate the first liquid crystal aperture  100  and the second liquid crystal aperture  110  to their active state in a manner of milliseconds. 
     In such a state, the eyes of the user  15  are protected from intense UV radiation and subsequent damage. At the completion of said operation, the direct light rays  37  will direct the display driver circuit  130  to drive the first liquid crystal aperture  100  and the second liquid crystal aperture  110  back to their passive or inactive state. In such a state or an OFF state as directed by the power switch  60 , the user  15  may wear the sport-type protective welding glasses for confined space utilization  10  as a conventional pair of tinted eyewear or sunglasses. At the completion of use, the user  15  would place the power switch  60  in its OFF position and store the sport type protective welding glasses for confined space utilization  10  away until needed again. 
     The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention and method of use to the precise forms disclosed. Obviously many modifications and variations are possible in light of the above teaching. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application, and to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions or substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but is intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.