Abstract:
An interchangeable scope lens covers system comprises a pair of lens covers each comprising a lens cover sleeve that is generally shaped like a hollow cylinder having a generally decreasing diameter from a proximal end to a distal end. Near the distal end, a generally annular lens is removably secured by a lens cap. The lenses are therefore easily removed and interchanged as desired by the user to configure the system to respond to changing shooting conditions. Between the pair of lens covers is attached a plurality of elastic cords or similar materials that hold the lens covers tightly against both ends of a scope tube in order to provide a press fit that keeps moisture, debris, etc. from entering the space between the lens covers and the scope lenses. The press fit forms a seal or barrier between the lens covers and the scope.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/397,824 entitled “Interchangeable Firearm Scope Lens Covers” and filed on Jun. 17, 2010. 
    
    
     TECHNICAL FIELD 
     The invention relates generally to telescopic sights for firearms and more particularly, but not by way of limitation, to interchangeable scope lens covers. 
     BACKGROUND 
     There are many different types of sighting/aiming devices for firearms. Traditional devices include open sights, peep sights, etc. In relatively recent times, telescopic sights have gained in popularity and are a common means for sighting/aiming firearms, including rifles, pistols, shotguns, blackpowder weapons, air rifles, crossbows, etc. As some scopes do not magnify the sight picture and otherwise have somewhat departed in form and function from the standard telescopic sights, the term “scope” is used to encompass all such related devices. Scopes often comprise a single tube of aluminum or other material containing therein a plurality of lenses that gather and/or magnify incoming light. They are designed for light to enter the objective end of the scope and be transmitted to the ocular end or eyepiece and then on to a user&#39;s eye. Commonly, scopes employ one or more reticles, often referred to as crosshairs, to aid the user in aligning the scope with the target in the sight picture provided to the user when he or she looks into the eyepiece. Since scopes are usually attached to firearms in a fixed manner, by aligning the scope with the target, the user is automatically aligning the firearm as well. Some scopes incorporate electronics such as lights, lighted-reticles, and/or laser range-finding devices. 
     Regardless of the internal components of a scope, both ends of a scope&#39;s tube (the objective end and the ocular end) are sealed with relatively delicate lenses. As such lenses are generally made from glass or other delicate materials, it is desirable to protect them from damage. Furthermore, moisture (fog, rain, snow, etc.) can reduce the effectiveness and usability of scopes if said moisture is allowed to impact and/or collect upon the surfaces of lenses. 
     Therefore, what is needed is a means for protecting the external surfaces of the external lenses in a rifle scope. A number of lens-protection devices have been developed in the art. Many known devices use opaque scope covers that have to be removed before the scope can be employed. Such devices may cause difficulties if, for example, in a hunting situation, the scope must be quickly employed before the target no longer presents a good shot. In such cases, taking the time to manually remove an opaque scope cover can cause the user to miss a shot opportunity. In response to these difficulties, some devices have been developed that utilize generally transparent covers that allow a user to sight through a scope without removing the lens covers. Although an improvement, such systems have other limitations, including that they are fixed-lens protective devices and when such devices become scratched, worn, clouded, etc., the covers no longer provide a clear sight picture and thus again necessitate removal of the covers prior to utilizing the scope. In an attempt to solve this problem, other known devices use quick-release or flip-up lens covers which still require that the user have time to activate such mechanisms before the scope can be properly employed. 
     An additional problem with known lens covers is that they employ a permanent or fixed lens cover that is not quickly and easily customized or interchanged. For example, such devices may employ a shaded lens cover for use on bright, sunny days. However, if the device is employed in low-light conditions (such as near dawn or dusk), the shaded lens cover reduces the light transmission through the scope resulting in the user not being able to properly see a target. Similarly, some devices employ amber lens covers that can be useful in certain shooting circumstances but are a detriment in others. 
     Yet another problem inherent in known lens covers is that they are designed to either loosely fit a small range of scope sizes or more tightly fit a single scope size. An obvious problem with the former type of devices is that they can allow rain, fog, snow, debris, dust and moisture to enter the space between the lens covers and the lenses, thus defeating the purpose of the lens covers. The latter type of devices may do a better job of keeping out such offending substances, but they can only be employed on scopes of a single size, thus requiring a user to purchase a large number of such devices in various sizes in order to properly protect all the differently sized scopes that a particular user may own. 
     Thus, what is needed is an interchangeable scope lens cover system that allows a user to quickly and easily change out old, scratched lens covers for new, un-blemished covers while simultaneously allowing a user to select from multiple types of lens covers including, but not limited to: clear, shaded, colored, polarized, amber, smoke, glass, polycarbonate, anti-glare, UV-blocker, etc. (or a combination thereof). Further, the lens cover system should also be designed to provide a press fit on a number of differently sized scopes in order to maximize the scope lens cover system&#39;s interoperability with various scopes while maintaining a high level of scope lens protection. 
     SUMMARY 
     One embodiment of the present invention is a device comprising a pair of lens covers each comprising a lens cover sleeve that is generally shaped like a hollow cylinder having a generally decreasing diameter from a proximal end to a distal end. Near the distal end, a generally annular lens is removably secured by a lens cap. The lenses are therefore easily removed and interchanged as desired by the user to configure the system to respond to changing shooting conditions. Between the pair of lens covers is attached a plurality of elastic cords or similar materials that hold the lens covers tightly against both ends of a scope tube in order to provide a press fit that keeps moisture, debris, etc. from entering the space between the lens covers and the scope lenses. The press fit forms a seal or barrier between the lens covers and the scope. Furthermore, as there are known a number of scopes that utilize tubes having an objective end (and/or an ocular end) that is not generally annular in shape, other embodiments of the present invention include lens covers that are shaped to match. Examples of such shapes include, but are not limited to: an ellipse, a circle with its top and bottom curves replaced with relatively straight horizontal line portions, a circle with an indent on its bottom curve to allow the scope&#39;s objective to be placed very close to a rifle barrel, etc. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The aforementioned and other features and objects of the present invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following descriptions of a preferred embodiment and other embodiments taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  illustrates a perspective view of an exemplary embodiment of an interchangeable scope lens covers system; 
         FIG. 2  illustrates an elevation view of an exemplary embodiment of an interchangeable scope lens covers system in place on a rifle scope; 
         FIG. 3  illustrates an elevation exploded view of an exemplary embodiment of a lens cover; 
         FIG. 4  illustrates an elevation cross-sectional view of an exemplary embodiment of a lens cover; and 
         FIG. 5  illustrates a close-up of an elevation cross-sectional view of an exemplary embodiment of a lens cover. 
     
    
    
     DETAILED DESCRIPTION 
     In the following discussion, numerous specific details are set forth to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without such specific details. 
     Referring now to the drawings,  FIG. 1  illustrates a perspective view of an exemplary embodiment of an interchangeable scope lens covers system  100 . The system comprises a pair of scope lens covers  110  and  120  attached to each other via a plurality of elastic cords  150  and  160 . In the embodiment shown in  FIG. 1 , two elastic cords  150  and  160  are depicted; in other embodiments, the plurality of elastic cords  150  and  160  can comprise one, two, three, four, or more elastic cords  150  and  160 . In yet other embodiments, the elastic cords  150  and  160  are not actually made from elastic cording material; “elastic cords” is to be interpreted to include cords, bands, strips, strings, etc. that are made of rubber, stretch cord, or any other suitable material that provides a stretchy, elastic means of holding the scope lens covers  110  and  120  to the ocular and objective ends of a scope. 
     As depicted in  FIG. 1 , the first scope lens cover  110  has a first lens cap  112 , a first lens  114 , and a first lens cover sleeve  116 . The first lens cap  112  attaches to an upper portion of the first lens cover sleeve  116  and holds the first lens  114  therebetween. Although not shown in  FIG. 1 , the first scope lens cover  110  utilizes a threaded lens attachment means: the first lens cap  112  and an upper portion of the first lens cover sleeve  116  are threaded so that the first lens cap  112  can be secured snugly to the first lens cover sleeve  116 . In other embodiments, other attachment means are contemplated, including, but not limited to: a snap-over ring, one or more magnets, removable/reusable adhesive, etc. 
     As depicted in  FIG. 1 , the second scope lens cover  120  has a second lens cap  122 , a second lens  124 , and a second lens cover sleeve  126 . The second lens cap  122  attaches to an upper portion of the second lens cover sleeve  126  and holds the second lens  124  therebetween. Although not shown in  FIG. 1 , the second scope lens cover  120  utilizes a threaded lens attachment means: the second lens cap  122  and the second lens cover sleeve  126  are threaded so that the second lens cap  122  can be secured snugly to the second lens cover sleeve  126 . In other embodiments, other attachment means are contemplated, including, but not limited to: a snap-over ring, one or more magnets, removable/reusable adhesive, etc. 
     The ease of changing lenses  114  and  124  should be apparent: a user simply detaches the lens caps  112  and  122  from the lens cover sleeves  116  and  126 , respectively, and replaces the lenses  114  and  124  with other lenses. This allows a user to quickly and easily change out old, scratched lens covers for new, un-blemished covers by only changing the lenses  114  and  124  themselves rather than having to replace the entire scope lens covers. Simultaneously, the system allows a user to select from multiple types of lenses including, but not limited to: clear, shaded, colored, polarized, amber, smoke, glass, polycarbonate, anti-glare, UV-blocker, etc. (or a combination thereof). Thus, the same interchangeable scope lens covers system can be used regardless of changing lighting/weather conditions. 
     The plurality of elastic cords  150  and  160  are attached to the first lens cover  110  and the second lens cover  120  and serve to keep the lens covers  110  and  120  from becoming separated and lost. Furthermore, because of the tension created by stretching the elastic cords  150  and  160  when placing the lens covers  110  and  120  in place on a scope, the lens covers  110  and  120  are tightly secured against the ocular and objective ends of a scope while in use. 
     As illustrated in the embodiment shown in  FIG. 1 , one means of attaching the elastic cords  150  and  160  to the lens covers  110  and  120  is through the use of cord attachment ears  151  and  163 . Each cord  150  and  160  attaches to a pair of ears  151 / 153  and  161 / 163 . Although ears  153  and  161  are not explicitly shown in  FIG. 1 , placement, shape, etc. can be inferred from those ears  151  and  163  which are illustrated. The ears  151  and  163  are tab-shaped protrusions near the lower portions of the lens cover sleeves  116  and  126  which have holes  152  and  164  therein through which the cords  150  and  160  can be passed and then knotted  156  and  167 . This method of attaching the cords  150  and  160  to the lens cover sleeves  116  and  126  allows the user to unknot and re-knot the cords  150  and  160  to adjust the system for scopes having tubes of different lengths. 
     The interchangeable scope lens covers system is attached to a scope by placing the lens covers  110  and  120  over the ocular end and the objective end, respectively, of the scope (see  FIG. 2 ). The tension provided by stretching the elastic cords  150  and  160  to allow the covers  110  and  120  to fit over the ends of the scope causes the covers to have a press fit against the ends of the scope. The press fit forms a seal or barrier between the lens covers  110  and  120  and the scope (since there are two lens covers  110  and  120  a first barrier and a second barrier are formed). Furthermore, as there are known a number of scopes that utilize tubes having an objective end (and/or an ocular end) that is not generally annular in shape, other embodiments of the present invention include lens covers that are shaped to match such scopes. Examples of such shapes include, but are not limited to: an ellipse, a circle with its top and bottom curves replaced with relatively straight horizontal line portions, a circle with an indent on its bottom curve to allow the scope&#39;s objective to be placed very close to a rifle barrel and partially surrounding the rifle barrel, etc. Of course, when the lens covers  110  and  120  are not generally round in shape then other attachment means for removably attaching the lens caps  112  and  122  to the lens cover sleeves  116  and  126  besides the use of threading must be employed. 
     Each of the two lens caps  112  and  122  shown in the embodiment in  FIG. 1  has a series of grippers  118  and  128 . The first lens cap  112  has a first series of grippers  118  located on a first outer diameter and the second lens cap  122  has a second series of grippers  128  located on a second outer diameter. These provide a means for a user to easily grasp the lens caps  112  and  122  so they can be removed from the lens cover sleeves  116  and  126 . In other embodiments, other type of grippers are contemplated including using rubber or some other suitable non-slippery material in the construction of the lens caps  112  and  122 . 
       FIG. 2  illustrates an elevation view of an exemplary embodiment of an interchangeable scope lens covers system  200  in place on a rifle scope  290 . The scope  290  has an ocular end  292  and an objective end  294 . Although the diameter of the objective end  294  is usually larger than that of the ocular end  292 , it is not a requirement. In the embodiment shown in  FIG. 2 , the first lens cover  210  fits over the ocular end  292  of the scope  290  and the second lens cover  220  fits over the objective end  294 . In other embodiments, the lens covers  210  and  220  can be swapped. 
     The first lens cap  212  and second lens cap  222  are illustrated in  FIG. 2  as are the first lens cover sleeve  216  and the second lens cover sleeve  226 . Although the first cord attachment ear  251  and the second cord attachment ear  253  are shown, the other cord attachment ears ( 161 / 163 ) are not. Also illustrated in  FIG. 2  are the first knot  256  and the second knot  257 ; the third knot (which would be numbered  266 , if present) and the fourth knot (which would be numbered  267 , if present) are not illustrated. It should be apparent that if the lens covers system  200  is to be redeployed on a scope  290  that has a shorter tube length than the one in  FIG. 2 , one or both of the knots  256  and  257  can be undone and then more of the first elastic cord  250  can be pulled through the first and/or second ears  251  and  253  and the knots  256  and  257  can be retied. This effectively shortens the length of cord  250  between the first and second lens covers  210  and  220  and provides a tighter fit on the existing scope  290  or allows for shorter scope tubes to be used. In other embodiments, the length of the elastic cord  250  is longer than that illustrated in  FIG. 2  to allow the system  200  to be used for longer scope tubes. 
       FIG. 3  illustrates an elevation exploded view of an exemplary embodiment of a lens cover  310 . A first lens cap  312  is shown in a non-attached position above a first lens  314 . The first lens  314  fits down inside the upper portion of the first lens cover sleeve  316 . As can be seen in  FIG. 3 , the first lens cover sleeve  316  is shaped as a cylinder but with a decreasing diameter from its proximal end to its distal end. The proximal end is also called the first lower portion  317  and is where the cord attachment ear  351  is generally located. The distal end is also called the first upper portion  311  and is generally where the first lens cap  312  is attached. 
     The decreasing diameter of the lens cover sleeve  316  is an extremely useful feature as it allows the lens cover  310  to be used on scopes of various sizes while still providing a tight press fit seal between the lens cover  310  and the scope. For example, if the internal diameter of the lens cover sleeve  316  decreases from two inches to one and a half inches then the lens cover  310  can be used on scopes with an outside diameter of either the ocular or objective end of the scope ranging from one and a half to two inches. Scopes will snugly fit against the interior sidewall of the lens cover  310  wherever their outside diameter matches the inside diameter of the lens cover  310 . 
     As illustrated in the embodiment depicted in  FIG. 3 , the first upper portion  311  of the lens cover sleeve  316  is threaded for mating with the first lens cap  312  which is internally threaded (not shown in  FIG. 3 , see  FIG. 5 ). As discussed above, in other embodiments, other attachment means besides threading is contemplated to snugly attach the first lens cap  312  to the first lens cover sleeve  316 . Although not depicted in  FIG. 3 , in one embodiment, the second lens cover is generally shaped and sized to resemble the first lens cover  310 ; but as most scopes have a larger objective end versus their ocular end, the second lens cover will similarly need to have a larger internal average sidewall diameter than the first lens cover. 
       FIG. 4  illustrates an elevation cross-sectional view of an exemplary embodiment of a first lens cover  410 . This view is the same as in  FIG. 3  except that a cross section has been taken through the approximate center of the first lens cover  410 . The shape of the side wall of the first lens cover sleeve  416  can be seen and the generally decreasing nature of its diameter from its lower portion  417  to its upper portion  411  is obvious. As depicted in  FIG. 4 , both the internal and external diameters of the first lens cover sleeve  416  are illustrated as generally decreasing in diameter; however, in other embodiments, the external dimensions of the first lens cover sleeve  416  could be such that its diameter is either constant or increasing from its lower portion  417  to its upper portion  411 . Furthermore, the shape of the external sidewalls of the lens covers can vary in other embodiments. Although not depicted in  FIG. 4 , in one embodiment, the second lens cover is generally shaped and sized to resemble the first lens cover  410 . 
       FIG. 4  also clearly illustrates how the first lens  414  is sandwiched between the first lens cap  412  and the first lens cover sleeve  416  and thereby firmly and securely held in position. For detail on the interactions between the first lens cap  412 , the first lens  414  and the first lens cover sleeve  416 , a highlighted area  5  provides a zoomed in view in  FIG. 5 . 
     Turning now to  FIG. 5 , it illustrates a zoomed-in close-up view of a portion of the elevation cross-sectional view of an exemplary embodiment of a lens cover  510  from  FIG. 4 . The upper portion  511  of the first lens cover sleeve  516  is shown and the threading thereon can be clearly seen. This threading engages the internal threading on the first lens cap  512  as seen in  FIG. 5 . The threading is configured such that by turning the first lens cap  512  about its central vertical axis while preventing the first lens cover sleeve  516  from rotating along its central vertical axis, the first lens cap  512  can be detached from the first lens cover sleeve  516 . Similarly, by turning the first lens cap  512  in the other direction, its threads will engage those on the first lens cover sleeve  516  and the two will tighten together. 
     The location of the first lens  514  relative to the positions of the first lens cap  512  and the first lens cover sleeve  516  can be clearly seen in  FIG. 5 . As the first lens cap  512  is screwed onto the first lens cover sleeve  516 , the first lens  514  is sandwiched between the cap  512  and the sleeve  516  and firmly secured in place. The gaps shown between the various components in  FIG. 5  are accentuated for ease of interpretation of the drawing figure. 
     The above specification, examples and data provide a description of the structure and use of exemplary embodiments of the described articles of manufacture and methods. It will further be understood from the foregoing description that various modifications and changes may be made in the embodiments of the present invention without departing from its true spirit. This description is intended for purposes of illustration only and should not be construed in a limiting sense. The scope of this invention should be limited only by the language of the following claims.