Title:
Illuminated Sight for use with Firearms and other instruments
Kind Code:
A1


Abstract:
A front sight assembly includes a self powered substantially permanent light source such as tritium source carried within a bore defined in a housing, where the housing preferably defines a structure symmetrically aligned along a central plane, where the bore carrying the light source has a central axis that lies within or parallel to the housing's central plane. The sight assembly housing terminates proximally in a proximal surface that faces the user when mounted on a firearm or other instrument. The sight assembly housing's proximal surface further includes a region surrounding or defining a periphery around the light source which is coated with, laminated with or altered to define a region of photo-luminescence that is substantially concentric with the center of the visible portion of light source.



Inventors:
Callihan, Rick (Atlanta, GA, US)
Application Number:
12/564498
Publication Date:
04/15/2010
Filing Date:
09/22/2009
Primary Class:
International Classes:
F41G1/00; F41G1/02; F41G1/32
View Patent Images:
Related US Applications:
20070101631Modular cheek rest and storage assemblyMay, 2007Bentley
20070089598Automatic personal weapon with electronic management and caseless ammunitionsApril, 2007Courty
20060168868GunstockAugust, 2006Phillips
20090000175ADJUSTABLE FIREARM SUPPORTS AND ASSOCIATED METHODS OF USE AND MANUFACTUREJanuary, 2009Potterfield et al.
20060123687Aiming sightJune, 2006Howe et al.
20080016746Fellow Law Officers Encounter Warning System (FLOEWS)January, 2008Mathis
20060272193Device for coupling a grenade launcher with an automatic rifleDecember, 2006Zedrosser
20100043271SCOPE MOUNTING SYSTEMFebruary, 2010Williams et al.
20090282718Adapter Device for Coupling an Auxiliary Stock to a HandgunNovember, 2009Bartley
20090229161Moon Clip ServerSeptember, 2009Austin
20040200111Magazine clip exterior housing systemOctober, 2004Horn



Foreign References:
EP04663091992-01-15
Primary Examiner:
LEE, BENJAMIN P
Attorney, Agent or Firm:
EVERSHEDS SUTHERLAND (US) LLP (ATLANTA, GA, US)
Claims:
What is claimed is:

1. A sight assembly, comprising: a first self powered substantially permanent light source carried within a bore defined in a housing; wherein said sight housing preferably defines an elongate substantially planar segment symmetrically aligned along a central plane, wherein said sight assembly terminates proximally in a proximal surface that will face the user; and wherein said sight assembly housing's proximal surface further includes a region surrounding or defining a periphery around said light source which is altered to define a region of photo-luminescence that is substantially concentric with the center of the visible portion of said light source.

2. The sight assembly of claim 1, wherein said first self powered substantially permanent light source comprises a tritium vial carried within the bore defined in said housing.

3. The sight assembly of claim 2, wherein said bore carrying said tritium vial has a central axis within or parallel to said housing's central plane.

4. The sight assembly of claim 1, wherein said sight assembly's proximal surface that will face the user when the sight assembly is mounted on a firearm near the muzzle.

5. The sight assembly of claim 1, wherein said region surrounding or defining a periphery around said light source which is coated with a substance to define said region of photo-luminescence that is substantially concentric with the center of the visible portion of said light source.

6. The sight assembly of claim 1, wherein said region surrounding or defining a periphery around said light source which is laminated with a substance to define said region of photo-luminescence that is substantially concentric with the center of the visible portion of said light source.

7. The sight assembly of claim 1, wherein the region surrounding or defining a periphery around said light source is defined within a counterbore, thereby providing a protective proximally projecting encircling wall around the photo-luminescent region and light source.

8. The sight assembly of claim 7, wherein, when using a pistol or other firearm equipped with the sight assembly of the present invention, the user looks down the central axis of the counterbore, so that the protection is provided without any adverse impact upon the visibility of the photo-luminescent region or light source.

9. A sight assembly, comprising: a sight body with a proximal surface and an upper surface, said body including an elongate substantially longitudinal notch defined in said upper surface and symmetrically aligned along a central axis, wherein said sight body's proximal surface is defined around said notch's proximal end so said proximal surface faces the user whereby the user can sight along said notch; a first self powered substantially permanent light source carried within a first bore defined in the housing; a second self powered substantially permanent light source carried within a second bore defined in the housing; wherein said sight assembly housing's proximal surface further includes a first region surrounding or defining a periphery around said first light source which is altered to define a region of photo-luminescence that is substantially concentric with the center of the visible portion of said first light source; and wherein said sight assembly housing's proximal surface further includes a second region surrounding or defining a periphery around said second light source which is altered to define a region of photo-luminescence that is substantially concentric with the center of the visible portion of said second light source.

10. The sight assembly of claim 9, wherein said first and second self powered substantially permanent light sources each comprises a tritium vial carried within said bores defined in said housing.

11. The sight assembly of claim 10, wherein said first bore carrying said first tritium vial has a central axis parallel to said housing's central axis.

12. The sight assembly of claim 9, wherein said sight assembly's proximal surface that will face the user when the sight assembly is mounted proximally on a firearm.

13. The sight assembly of claim 9, wherein said first region surrounding or defining a periphery around said first light source which is coated with a substance to define said first region of photo-luminescence that is substantially concentric with the center of the visible portion of said first light source.

14. The sight assembly of claim 9, wherein said first region surrounding or defining a periphery around said first light source which is laminated with a substance to define said first region of photo-luminescence that is substantially concentric with the center of the visible portion of said first light source.

15. The sight assembly of claim 9, wherein the first region surrounding or defining a periphery around said first light source is defined within a first counterbore, thereby providing a protective proximally projecting encircling wall around the first photo-luminescent region and first light source.

16. The sight assembly of claim 15, wherein, when using a pistol or other firearm equipped with the sight assembly of the present invention, the user looks down the central axis of the sight body and through the notch, so that the protection is provided without any adverse impact upon the visibility of the first photo-luminescent region or first light source.

17. A sight assembly, comprising: a housing adapted to be mounted to an instrument or firearm; a first self powered substantially permanent light source which generates light in a first selected color, wherein said light source is carried within a bore defined in the housing; wherein said sight assembly terminates proximally in a proximal surface that will face the user when grasping the instrument or firearm; wherein said sight assembly housing's proximal surface further includes a region surrounding or defining a periphery around said light source which is altered to define a region of photo-luminescence that is substantially concentric with the center of the visible portion of said light source; and wherein said region of photo-luminescence defines a region which emits light in a second color.

18. The sight assembly of claim 17, wherein said first selected color is selected from the colors green, yellow and orange.

19. The sight assembly of claim 17, wherein said region of photo-luminescence emits light in a second color which is selected from the colors white, orange and green.

20. The sight assembly of claim 17, wherein the region surrounding or defining a periphery around said light source is defined within a counterbore, thereby providing a protective proximally projecting encircling wall around the photo-luminescent region and light source.

Description:

PRIORITY CLAIMS AND REFERENCE TO RELATED APPLICATIONS

This application claims priority to related and commonly owned U.S. provisional patent application No. 61/136,776, filed Oct. 2, 2008, the entire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to sights and, more particularly, to sights adapted for use in low-light environments on firearms and other instruments.

2. Discussion of the Prior Art

For purposes of nomenclature and as an example of one type of firearm, FIG. 1 illustrates a Glock model 17 pistol. When using or shooting a pistol, the user grasps grip frame and aims by aligning a notch or aperture included as part of a rear sight with the distal front sight, thereby pointing the pistol's muzzle at a target. The front sight is usually an upwardly projecting protuberance mounted at or near the muzzle or distal end of the pistol's barrel or slide. An important part of sight alignment is first visually acquiring the front sight and then bringing the front sight into alignment with (a) the target and (b) the rear sight's notch or aperture. In many competition, tactical or combat situations, the time expended by the shooter in performing this sight alignment process is critical. Shooting in low light situations makes front sight acquisition and sight alignment more of a challenge.

In the industry of weapon sights there is a need for a sight that can be used in various environments, regardless of lighting conditions in the user's (or shooter's) environment.

Some prior art sights have included employed a photo-luminescent material, much like on a typical “permanent” illumination watch face. These photo-luminescent materials are most often seen as “permanent” illumination for the hands of wristwatches intended for diving, nighttime, or “tactical” use. They are also favored by the military for critical applications where illumination of the glow-in-the-dark sort is desired but a powered light source may not be available. Some uses of this sort are analog dials in aircraft, in compasses, and sights for weapons. Tritium light sources were invented in the 1960s as a reliable self-powered light source for NATO. Prior art self-powered light sources used radium paint, which posed health risks. Gaseous tritium, a radioactive isotope of hydrogen, has also been used in self-powered lighting applications, such as emergency exit signs. More recently, many applications using radioactive materials have been replaced with photo luminescent materials.

In a self powered lighting structure such as a gaseous tritium light source, the tritium undergoes beta decay, releasing electrons which cause the phosphor layer to fluoresce. During manufacture, a length of borosilicate glass tube which has had the inside surface coated with a phosphor-containing compound is filled with the radioactive tritium. The tube is then fused with a CO2 laser at the desired length. Borosilicate is preferred because it is a type of glass noted for its strength and resistance to breakage. In the tube, the tritium gives off a steady stream of electrons due to beta decay. These particles excite the phosphor, causing it to emit a low, steady glow. One could use any beta particle-emitting substance, but in practice tritium is preferred because it is not very hazardous. Various preparations of the phosphorus compound can be used to produce different colors of light. Some of the colors that have been manufactured in addition to the common phosphorus green are red, blue, yellow, purple, and orange. The types of coatings used in watches give off a small amount of light—not enough to be seen in daylight, but enough to be visible in the dark from a distance of several meters.

Front sights containing vials of Tritium are well known for use on firearms at night or in low light. Tritium vials are known as self lighting and are made using glass tubes with a phosphor layer in them and tritium (a hydrogen isotope) gas inside the tube. Such a tube is known as a “gaseous tritium light source” (GTLS) or a Tritium vial. Tritium (self luminous) sights are ideal in low-light settings, but the tritium sight's glow is not visible during daylight (and most lighted indoor) environments. The average such GTLS has a useful life of 10-20 years. As the tritium component of the lighting is expensive, manufacturers try to use as little as possible. Being an unstable isotope with a half-life of about 12.36 years, tritium loses half its brightness in that period. The more tritium that is initially placed in the tube, the brighter it is to begin with and the longer its useful life. For example, tritium devices usually come in three brightness levels guaranteed for 10, 15, or 20 year useful life expectancies. The difference between the devices is how much tritium the manufacturer installs.

Sights using a fiber optic rod to transfer collected light to a surface facing the user are ideal for outdoor use, but require a constant source of ambient light (e.g., sunlight for outdoors or adequate artificial light for indoors) and are not effective without abundant ambient light to make the fiber optic surface ‘glow’.

Brightly painted sights, although visible with in an area with adequate lighting, are not effective in low light situations.

There is a need, therefore, for an effective, convenient and unobtrusive sight system and method for providing an illuminated sight picture.

OBJECTS AND SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to overcome the above mentioned difficulties by providing an effective, convenient and unobtrusive sight system and method for providing an illuminated sight picture.

In accordance with the present invention, a sight is provided that is highly effective for use at indoor shooting ranges, where lighting is usually too dim for using fiber optic sights yet not dark enough to effectively use tritium. The sight of the present invention is also suitable for use on outdoor shooting ranges and for all other environments where lighting conditions vary.

The sight of the present invention incorporates self-luminous (tritium) type sight lamps (where the tritium lamp is encased in a sight housing) and a visible end of the tritium lamp is surrounded with a surface coated with non-radioactive photo-luminescent material.

The tritium lamp feature of the sight provides a constant ‘glow’, visible in low light environments while the brightly colored photo-luminescent material remains highly visible in daylight and, after storing energy from a secondary source, highly visible in low-light environments.

The photo-luminescent material surrounding the tritium lamp can be seen by the user whether it is ‘charged’ or not charged, and the user can decide whether to charge the surrounding photo-luminescent material based on the lighting in the environment.

The photo-luminescent material provides a bright, highly visible ‘glow’ that remains highly visible to the user for an extended period after receiving a ‘charge’ from a secondary light source. The user can deliberately ‘charge’ the photo-luminescent material with a common handheld flashlight or any other artificial light source (light bulb, table lamp, indoor lighting, chemical light stick, etc). This ‘charge’ creates a bright, highly visible surface on the sight, making the sight very noticeable and allowing the user to quickly acquire the sight and focus on the sight for improved performance.

The photo-luminescent material can also be ‘charged’ or activated by natural lighting such as sunlight. The photo-luminescent material on the sight needs to be recharged, unlike the tritium light source, once the photo-luminescent material no longer produces the desired brightness for the user (time will vary from minutes to hours, depending upon the user's preference, the strength (the amount of energy stored in the photo-luminescent material) of the previous ‘charge’, and the specific photo-luminescent material formula used (the photo-luminescent material is available in an unlimited number of colors and glow times and, for example, green photo-luminescent material may be designed for 20-minute glow or for 8-hour glow, depending upon the application).

In a preferred embodiment, the photo-luminescent material is applied to the sight base after the sight base has been machined to create a surrounding counter-bore (having a square, triangular, circular or rounded shape) to a selected depth in the range of, preferably, 0.020″ to 0.060″. The photo-luminescent material is placed in this surrounding counter-bore area. In the center of the surrounding counter-bore area is a deeper central concentric hole or bore, which drilled to a depth which will receive most or all of entire length of a substantially cylindrical vial containing the self-luminous tritium light source.

The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of a specific embodiment thereof, particularly when taken in conjunction with the accompanying drawings, wherein like reference numerals in the various figures are utilized to designate like components.

DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a firearm, and more particularly a pistol, in accordance with the prior art.

FIG. 2a illustrates a proximal end view, in elevation for a first embodiment of the front sight having a round counterbore to define the chamfered phosphorescent surface surrounding the Tritium illumination source, in accordance with the present invention.

FIG. 2b illustrates a top view, in elevation of the front sight of FIG. 2a with its round counterbore to define the chamfered phosphorescent surface surrounding the Tritium illumination source, in accordance with the present invention.

FIG. 2c illustrates a right side view in elevation of the front sight of FIGS. 2a and 2b, in accordance with the present invention.

FIG. 2d illustrates a bottom view of the front sight of FIGS. 2a-2c, in accordance with the present invention.

FIG. 3a illustrates a proximal end view, in elevation for a second embodiment of the front sight having a square counterbore to define the chamfered phosphorescent surface surrounding the Tritium illumination source, in accordance with the present invention.

FIG. 3b illustrates a top view, in elevation of the front sight of FIG. 3a with its square counterbore to define the chamfered phosphorescent surface surrounding the Tritium illumination source, in accordance with the present invention.

FIG. 3c illustrates a right side view in elevation of the front sight of FIGS. 3a and 3b, in accordance with the present invention.

FIG. 3d illustrates a bottom view of the front sight of FIGS. 3a-3c, in accordance with the present invention.

FIG. 4 illustrates a proximal end view, in perspective for a first embodiment of a rear sight having a tapered body and first and second round counterbores configured define first and second chamfered phosphorescent surfaces surrounding the left and right Tritium illumination sources, in accordance with the present invention.

FIG. 5 illustrates a proximal end view, in perspective for a two-piece sight kit containing a front sight such as the one illustrated in FIGS. 2a-2d, and a second embodiment of a rear sight having a polygonal body and first and second round counterbores configured define first and second chamfered phosphorescent surfaces surrounding the left and right Tritium illumination sources, in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, and for purposes of nomenclature, a pistol 10 is shown in profile. Pistol 10 is a Glock model 17, but is exemplary of pistols, generally. As noted above, when using or shooting pistol 10, the user grasps grip frame 40 and aims by aligning a notch or aperture included as part of the proximal rear sight 30 with the distal front sight 20, thereby pointing muzzle 50 at the desired target. Front sight 20, as shown, is usually an upwardly projecting protuberance (e.g., blade or post) mounted at or near the muzzle or distal end of the pistol's barrel or slide. An important part of sight alignment is first visually acquiring the front sight and then bringing the front sight into alignment with (a) the target and (b) the rear sight's notch or aperture. In many competition, tactical or combat situations, the time expended by the shooter in performing this sight alignment process is critical. Shooting in low light situations makes front sight acquisition and sight alignment more of a challenge.

Turning now to FIGS. 2a-5, in accordance with the present invention, a first embodiment front sight is illustrated in FIGS. 2a-2d; front sight assembly 100 includes a source of illumination such as self-luminous tritium vial 102 encased in a sight housing 104 and the visible (or proximal) end of the tritium lamp 106 is surrounded with an annular surface 110 coated with non-radioactive photo-luminescent material, preferably within a counterbore such as circular counterbore 112, defined in the front sight assembly's proximal surface.

A second embodiment is illustrated in FIGS. 3a-3d, wherein front sight assembly 200 includes a source of illumination such as self-luminous tritium vial 102 encased in a sight housing 204 and the visible or proximal end of the tritium lamp 106 is surrounded with a square-shaped surface 210 coated with non-radioactive photo-luminescent material, preferably within a counterbore such as square counterbore 212, defined in the front sight assembly's proximal surface.

The tritium lamp feature of sight assembly 100 or 200 will provide a constant, substantially perpetual self powered ‘glow’, that is visible in low light environments while the surrounding brightly colored photo-luminescent material-covered surface (110 or 210) will be highly visible in daylight and, after storing energy from a secondary source, highly visible in low-light environments.

The photo-luminescent material surrounding the tritium can be seen to the user whether it is ‘charged’ or not charged, based on the lighting in the environment. The photo-luminescent material provides a bright (highly visible to the user) ‘glow’ after receiving a ‘charge’ from a secondary light source. The secondary light source can be provided by the user or can be an ambient source, such as bright sunlight. The user can deliberately ‘charge’ the photo-luminescent material with a common handheld flashlight or any other artificial light source (light bulb, table lamp, indoor lighting, chemical light stick, etc). This ‘charge’ creates a bright, highly visible surface on the sight (on the peripheral surface 106, 206), making the sight very noticeable and allowing the user to quickly acquire the sight and focus on the sight for improved performance.

As noted above, the photo-luminescent material can also be ‘charged’ or activated by natural lighting such as sunlight. The photo-luminescent material on the sight needs to be recharged, unlike the tritium light source, once the photo-luminescent material no longer produces the desired brightness for the user (time will vary from minutes to hours, depending upon the user's preference, the strength (the amount of energy stored in the photo-luminescent material) of the previous ‘charge’, and the specific photo-luminescent material formula used. The photo-luminescent material is available in a virtually unlimited number of colors and glow times. A green photo-luminescent material may be designed for 20-minute glow or for 8-hour glow, depending upon the application.

In accordance with the present invention, rear sight assemblies can also be improved.

FIG. 4 illustrates a proximal end view, in perspective for a first embodiment of a rear sight 300 having a tapered body defining a longitudinal sighting notch 320. First and second round counterbores are configured define first and second chamfered phosphorescent surfaces surrounding the left and right Tritium illumination sources 302A and 302B. Rear sight assembly 300 includes first and second sources of illumination 302A, 302B which can be identical to self-luminous tritium vial 102,and each is encased in a tapered or contoured sight housing 304 and the visible (or proximal) end of the first and second tritium lamps are each surrounded with an annular surface 310a, 310b, and each annular surface area is coated with non-radioactive photo-luminescent material, preferably within a counterbore such as a circular counterbore, defined in the rear sight assembly's proximal surface, as seen mounted on pistol 10. The left illumination source 302A is positioned on the proximal surface in the sight body 304, to the left of sight notch 320 and, when seen from the proximal end, above the bottom surface of sight notch 320. Right illumination source 302B is positioned on the proximal surface in the sight body 304, to the right of sight notch 320 and above the bottom surface of sight notch 320, to be substantially level or even with the left illumination source 302A.

Another configuration for a rear sight is illustrated in FIG. 5, which shows a proximal end view, in perspective, for a second embodiment of rear sight 400 having a polygonal body defining a longitudinal sighting notch 420. First and second round counterbores are configured define first and second chamfered phosphorescent surfaces surrounding the left and right Tritium illumination sources 402A and 402B. Rear sight assembly 400 includes first and second sources of illumination 402A, 402B which can be identical to self-luminous tritium vial 102,and each is encased in sight housing 404 and the visible (or proximal) end of the first and second tritium lamps are each surrounded with an annular surface 410a, 410b, and each annular surface area is coated with non-radioactive photo-luminescent material, preferably within a counterbore such as a circular counterbore, defined in the rear sight assembly's proximal surface The left illumination source 402A is positioned on the proximal surface in the sight body 404, to the left of sight notch 420 and, when seen from the proximal end, above the bottom surface of sight notch 420. Right illumination source 402B is positioned on the proximal surface in the sight body 404, to the right of sight notch 420 and above the bottom surface of sight notch 420, to be substantially level or even with the left illumination source 402A.

FIG. 5 also illustrates a two-piece sight kit 500 containing a front sight 100 such as the one illustrated in FIGS. 2a-2d, and a rear sight 404, in accordance with the present invention. When purchased or installed together, the front sight 100 and rear sight 404 can be configured to have identical illumination sources having identically sized surrounding counterbore areas 110, 410A and 410B.

In the illustrated embodiments, the photo-luminescent material is applied to the sight base after the sight base has been machined to create a surrounding counter-bore (having a square or rectangular (e.g., 206), triangular, circular (e.g., 106) or rounded shape) to a selected depth in the range of, preferably, 0.020″ to 0.060″. The photo-luminescent material is placed in this surrounding counter-bore area (e.g., 106). In the center of the surrounding counter-bore area is a deeper central concentric hole or bore, which drilled to a depth which will receive the most or all of entire length of a substantially cylindrical vial containing the self-luminous tritium light source 102.

In an alternative embodiment, the deeper central concentric hole or bore is drilled to a depth which will receive not quite all of the entire length of substantially cylindrical vial containing the self-luminous tritium light source 102, and instead, the light source 102 is installed with a proximal crystal or sapphire jewel-lens, so the proximal end actually projects out of the central bore by 20 to 60 thousandths of an inch, but is flush with the added photo-luminescent material in the annular region of the counter bore, so that a portion of the light emitted by light source 102 shines laterally and directly into or onto the surrounding photo-luminescent material in the annular region.

Alternative Embodiments

Preferably, the sight assembly's tritium insert 102 includes the tritium light source vial (a cylindrical glass ampoule containing gaseous tritium and phosphor), a sleeve (made of metal or plastic) surrounding the tritium ampoule, and a protective end-mounted lens (e.g., a sapphire jewel or lens) on the proximal end (the end visible by the user) of the ampoule. This configuration of Tritium filled glass lamp is offered by the Trijicon® Company, for example. In the center of the annular surrounding counter-bore area is a deeper central concentric hole or bore, which is drilled to a depth to receive the tritium ampoule, but not the added sapphire lens (if present). During manufacture, the photo-luminescent material (before curing or drying, e.g., when in a gel or paint-like state) is applied into the annular counter-bore in such a way that fills in around and surrounds the sides of the end mounted sapphire lens, creating a flush surface including the lens and the photo-luminescent material and that portion of the sight housing beyond the annular counter-bore. The end-mounted lens may be sapphire, plastic or may be applied as a clear adhesive. Alternatively, there may be no lens on the proximal end of insert 102.

In the illustrated and exemplary embodiments, the photo-luminescent material is a paint-like coating including a photo-luminescent pigment or phosphor; an example of a suitable photo-luminescent pigment is one currently sold under the brand name Super-LumiNova® by LumiNova AG Switzerland, under license from Nemoto & Co. Ltd. of Japan, patent holder of these new compositions and RC TRITEC Ltd. The “photo-luminescent” or “afterglow” pigments or phosphor, are a non-radioactive and non-toxic alternative for illuminating markings on time-piece dials and hands, making them visible in the dark. Selected grades of new chemical pigment compositions have up to 100 times better brightness than previous zinc sulphide materials. These pigments or phosphors operate like a light battery. After sufficient activation by sunlight or artificial light, they glow in the dark for many hours. Larger markings are visible for the whole night. This activation and subsequent light emission process can be repeated again and again, and the material does not suffer any ageing. Super-LumiNova® pigments are available in ISO 3157 or ISO/DIS 17514 standard colors and many other shades. Before use they are mixed with suitable (e.g., RC TRITEC™) binders, which can be characterized as working like a varnish. Here, the luminous pigments are supplied as dry powders and must be mixed before use with transparent binders. The pigment and binder mixture is applied and then cured in the air or in a curing oven. Zinc is used to make an orange photo-luminescent material, and photo-luminescent materials in other colors can also readily be made.

For purposes of nomenclature, the term “photo-luminescent material” is construed to include all coatings applied in a manner similar to paint as well as solid lamina or film-like structures adapted to conform to the surface of the sight surrounding the tritium vial's bore. Those having skill in these arts will understand that “photo-luminescent material” is, as noted above, a generically descriptive term for light sources that emit light continuously without an external power source, most frequently used on wristwatches (i.e. “night” watches) and certain emergency and tactical equipment, and those materials are also appropriate for use in the peripheral photoluminescent region (e.g., 110). Other photoluminescent lamina, coatings or layers are also appropriate; for example, a coating including the features of US published patent application 20070200074, filed in 2007, has sand-grain-sized tritium containers or glass or polymer “microspheres” that can be applied in self-powered lighting paint or incorporated into a film layer, where the plurality of individual containment microspheres minimizes the likelihood of escaping radioactive gas in the event of any physical damage to an assembly having the microspheres.

In accordance with the present invention, a sight assembly includes a self powered substantially permanent light source such as tritium source 102 carried within a bore defined in a front sight blade or housing (104 or 204), where the sight housing preferably defines an elongate substantially planar segment symmetrically aligned along a central plane, where the bore carrying tritium source 102 has a central axis that lies within or parallel to the housing's central plane. Sight assembly blade or housing (104 or 204) terminates proximally in a proximal surface that will face the user when the sight assembly is mounted on a firearm (e.g. 10) near the muzzle (e.g., 50). Sight assembly housing's proximal surface further includes a region surrounding or defining a periphery around light source 102 which is coated with, laminated with or altered to define a region of photo-luminescence that is substantially concentric with the center of the visible portion of light source 102.

In the illustrated, preferred embodiments, the region surrounding or defining a periphery around light source 102 is defined within a counterbore, thereby providing a protective proximally projecting encircling wall around the photo-luminescent region and light source 102. When using a pistol or other firearm equipped with the sight assembly of the present invention, the user looks down the central axis of the counterbore (e.g., 112 or 212), so that the protection is provided without any adverse impact upon the visibility of the photo-luminescent region or light source 102.

In use, a gunsmith or user can remove the plain front sight 50 from the distal end of pistol 10 and replace it with the front sight assembly of the present invention (e.g., 100 or 200).

Similarly, a gunsmith or user can remove the plain front sight 30 from the proximal end of pistol 10 and replace it with one of the rear sight assemblies of the present invention (e.g., 300 or 400), and of course, a gunsmith or user can remove both the plain front sight 50 and the plain rear sight 30 from pistol 10 and replace them both, once having obtained a pair of sight assemblies (100, 400) in a kit 500, thereby obtaining a pistol adapted for use in a wider variety of ambient lighting conditions.

Rear sights (e.g., 300 or 400) are readily configured using the illumination structure and method of the present invention in the following heights: 0.256″, 0.271″, 0.287″, 0.311″, 0.393″ (6.5 mm, 6.9 mm, 7.3 mm, 7.9 mm, and 10.0 mm). Similarly, front sights (e.g., 100 or 200) are readily configured in plain or serrated housings using the illumination structure and method of the present invention in the following heights: 0.165″ (standard factory height), 0.180″, 0.200″, 0.220″, 0.240″, 0.260″, 0.280″, 0.300″, 0.315″, 0.330″, 0.350″. Users typically know their current sight heights. The standard height of a Glock® plastic front sight is 165″ (measuring only the sight blade) and the Glock® parts suppliers offer a variety of rear sights, indicated with a series of dashes; Glock refers to these heights as +0 (6.5 mm), +1 (6.9 mm), and this knowledge is used when comparing observed shooting performance (e.g., shooting low at desired range) to the optimal performance for a given user.

Broadly speaking, a sight assembly in accordance with the present invention, comprises a housing (e.g., 100) adapted to be mounted to an instrument or firearm;

a first self powered substantially permanent light source 102 which generates light in a first selected color (e.g., green, yellow or orange) carried within a bore defined in the housing. The sight assembly terminates proximally in a proximal surface that will face the user when grasping the instrument or firearm and housing's proximal surface further includes a region 112 surrounding or defining a periphery around light source 102 which is altered to define a region of photo-luminescence that is substantially concentric with the center of the visible portion of light source 102 which emits light in a second color (e.g., white, orange or green).

Having described preferred embodiments of a new and improved method, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the teachings set forth herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the scope of the present invention as set forth in the claims.