US20130000172A1

US20130000172A1 - Splatter indicator sight for firearms

Info

Publication number: US20130000172A1
Application number: US13/554,021
Authority: US
Inventors: Timothy D.F. Ford
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-01-11
Filing date: 2012-07-20
Publication date: 2013-01-03
Also published as: CA2649279C; CA2649279A1; US20090217565A1

Abstract

Method of providing a gun sight for a firearm having an accuracy comprising predetermining as a function of the accuracy a region surrounding a point of aim within which a projectile issued from the firearm will strike with a known probability, aiming the firearm at the intended target, and outlining the region about the point of aim with a laser and method for supporting a decision to fire a projectile from a firearm having an accuracy and pointed towards an intended target and an unintended target comprising precalculating as a function of the accuracy a region surrounding a point of aim within which a projectile issued from the firearm will strike with a known probability, aiming the firearm at the intended target, delineating the region about the point of aim with a laser, and not firing when at least a portion of the unintended target is within the region.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent application Ser. No. 12/352,355, now pending, filed on Jan. 11, 2009, which itself claims benefit of U.S. provisional application Ser. No. 61/020,515, filed on Jan. 11, 2008. All documents above are incorporated herein in their entirety by reference.

FIELD OF THE INVENTION

The present invention relates to a splatter indicator sight for firearms. More specifically, the present invention is concerned with an indicator device for processing data regarding variables affecting the bullet trajectory and creating a visual map of all of the probable hit zones after the user has aimed the firearm at the target, thereby allowing the user to evaluate the risk of hitting the wrong target before shooting.

BACKGROUND OF THE INVENTION

Firearms, such as handguns (single-shot pistols, revolvers, and semi-automatic pistols), long guns (rifles, carbines or shotguns) and machine guns or the like are aimed at their targets with greater accuracy by using sights. Many sights can be mounted onto firearms, for example, telescopic sights (or scopes), iron sights, red dot sights, and laser sights.
Despite these existing sighting systems, aiming errors still occur. Those errors depend to some degree on the skill of shooter, but also the quality and caliber of the firearm and other exterior conditions such as the range to the target, the movement of the target, the ambient light, and the wind. The aiming error becomes a considerable issue when the firearm is used by security forces in civilian zones where there exists a risk of hitting an innocent bystander or other friendly by accident.
The prior art reveals processing of data affecting the bullet trajectory in order to correct the aim or provide warnings to the user (where data received from sensors mounted onto the firearm or entered by the user is processed and provides for the automatic adjustment of aim, stabilization as well as the display of data related to aiming error) these existing aids focus on perfecting the aim. Potential for error still exists, however, and a shot fired might fall within an area surrounding the point of aim. Therefore, there is a need for a device that will clearly and quickly indicate the probable hit zones around the aiming point to let the user better decide whether or not to shoot.

SUMMARY OF THE INVENTION

In order to address the above and other drawbacks there is provided a method for supporting a decision to fire a projectile from a firearm having a firearm accuracy and pointed towards an intended target and an unintended target. The method comprises pre-calculating as a function of the firearm accuracy a first region surrounding a point of aim within which a projectile issued from the firearm will strike with a known probability, aiming the firearm at the intended target, delineating the first region about the point of aim with a laser affixed to the firearm, and not firing when at least a portion of the unintended target is within the first region.
There is also provided a method of providing a visible gun sight for a firearm having an accuracy. The method comprises pre-determining as a function of the firearm accuracy a first region surrounding a point of aim within which a projectile issued from the firearm will strike with a known probability, aiming the firearm at the intended target, and outlining the first region about the point of aim with a laser affixed to the firearm.
Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the appended drawings:

FIG. 1 discloses a laser sight mounted on a firearm and used to project the risk zone map on the target in accordance with an illustrative embodiment of the present invention;

FIG. 2A discloses a risk zone map projected on a flat surface by the splatter indicator sight in accordance with an illustrative embodiment of the present invention;

FIG. 2B discloses the risk zone map of FIG. 2A projected on a target;

FIG. 2C discloses the risk zone map of FIG. 2A projected on a target located in a crowd of innocents or friendlies;

FIG. 3A and FIG. 3B disclose a risk zone map in accordance with a first alternative embodiment of the present invention;

FIG. 4A and FIG. 4B disclose a risk zone map in accordance with a second alternative embodiment of the present invention;

FIG. 5A and FIG. 5B disclose a risk zone map in accordance with a third alternative embodiment of the present invention;

FIG. 6A and FIG. 6B disclose a risk zone map in accordance with a fourth alternative embodiment of the present invention; and

FIG. 7 is a block diagram of the splatter indicator sight components in accordance with an illustrative embodiment of the present invention.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention is illustrated in further details by the following non-limiting examples.
Referring now to FIG. 1, and in accordance with an illustrative embodiment of the present invention, a firearm comprising a splatter indicator sight, and generally referred to using the reference numeral 10, will now be described. The firearm 10 comprises a splatter indicator sight 12 comprising a laser (not shown) emitting a laser beam 14 co-aligned with the muzzle 16. The indicator sight 12 is illustratively mounted within the chamber 18 which also houses the recoil spring (not shown). Alternatively, the indicator sight 12 could be positioned on top of a firearm 10 or below the barrel on a dovetail, MIL-STD-1913 Picatinny rail or similar mount.
Still referring to FIG. 1, many aiming errors are directly caused by the user. For example, parallax is created when the user moves in relation to the sight 12. Additionally, normal shaking of the hand holding the firearm 10 can be amplified when the user finds himself within a stressful situation. Also, when a shot is fired, recoil can further amplify the movement of the hand holding the firearm 10.
Referring now to FIG. 2A in addition to FIG. 1, in an illustrative embodiment of the present invention, the laser beam 14 emitted or projected by the indicator sight 12 forms a pattern 20, or risk zone map, when projected on a surface located in front of the firearm 10 and surrounding the point being aimed at 22. The contour(s) 24 defined by the risk zone map 20 can adopt various shapes according to the values of the different data taken into account. In the present illustrative embodiment the contour(s) 24 are represented by an oval shape since the aiming error will presumably be greater relative to the upper/lower axis A of the firearm 10. The risk zone map 20 defines the limits of the most probable hit zones (in other words, a predetermined level of probability that a projectile issued from the firearm will strike within a defined region) according to calculations which will be described in more detail hereinbelow.
Referring now to FIG. 2B, when the firearm 10 is aimed at a target 26, the risk zone map 20 is projected onto the target 26 surrounding the point being aimed at 22. In the context of FIG. 2B, the risk zone map 20 indicates that there is less risk of shooting an innocent or other friendly as only the target 26 is found within the risk zone map 20.
On the other hand, and referring now to FIG. 2C, the risk of hitting an innocent or other friendly by accident is increased as, although the point being aimed at 22 falls on a target 26, innocents or other friendlies as in 28 also fall within the risk zone map 20. Additionally, referring back to FIG. 2A, in a particular embodiment a readable character symbolic of the predetermined level of probability that a projectile issued from the firearm will strike within a defined region can be displayed adjacent the defined region(s).
Referring now to FIG. 3A and FIG. 3B, in a first alternative illustrative embodiment the risk zone map 20 is characterized by a central point 30 surrounded by a circle 32 indicating a region within which the risk of accidentally shooting an innocent is high. In this regard, and as will now be understood by a person of ordinary skill in the art, the circle 32 is projected as a cone such that the diameter of the circle 32 increases with an increase in distance between the indicator sight (reference 12 in FIG. 1) and the target 26.
Referring now to FIG. 4A and FIG. 4B, in a second alternative illustrative embodiment the risk zone map 20 is characterized by a target-like series of concentric circles as in 34. The risk of accidentally hitting an innocent decreases with an increase in the relative diameter of a given circle as in 34. Each of the increasing circles as in 34, for example, could represent an incremental increase of the Minute of Arc (MOA).
Referring now to FIG. 5A and FIG. 5B, in a third alternative illustrative embodiment the risk zone map 20 is characterized by a cross-hair comprising a pair of crossing elements as in 36 arranged at right angles to one another.
Referring now to FIG. 6A and FIG. 6B, in a fourth alternative illustrative embodiment the risk zone map 20 is characterized by a cross-hair reticule comprising a pair of crossing elements as in 36 arranged at right angles to one another and with the addition of cross-hatch as in 38 on each of the pair of crossing elements as in 36. Illustratively, and similar to that as described above in regards to FIG. 4A and FIG. 4B, the relative distance of the cross-hatch as in 38 from the point of crossing 40 of the crossing elements as in 36 could represent a relative increase or decrease in the MOA.
A variety of approaches may be used for generating and projecting the risk zone map 20 on a target 26 using a laser 14.
For example, in a first illustrative embodiment of same, the actual lasing action can be used to set the desired beam divergence. In other configurations a laser will generate a beam with a given divergence (typically on the order of 0.5-10 mrad) and then the desired spread angle will be set with external collimating optics. Lasing action in the laser cavity can be controlled to some degree with the configuration of the laser cavity, adjusting parameters such as mirror curvature, spacing, selection of location of the beam waist, inter-cavity apertures, bore diameter, etc. Specifically, in semiconductor (diode) lasers, an apparent point source can be generated by ion milling (or similar) a convex high reflector mirror into the diode laser's cavity.
In a second illustrative embodiment divergence of the laser can be introduced using a collimating telescope. In this regard, a single, solid cone of light is generated from a single laser source and a Galilean or Keplerian telescope is placed in the beam to collimate, or decollimate, the emitted laser beam. These telescopes may use two or more optics. Adjustment between the separation distance of these two optics in either telescope (focus) can provide for a change in the divergence angle of the emitted beams.
In the above two embodiments, it may also be desirable to utilize a beam diffuser, of which a number of known types exist, to generate a more uniform beam profile (top hat), prior to adjusting the beam divergence. This provides for much more uniform laser spot illumination assisting visibility and more carefully defining the edge of the desired spot.
In a third illustrative embodiment a diffuser may be used in conjunction with the laser 14 to generate a cone angle. Rather than using a telescope to change the natural divergence of the generated beam, a diffuser may be designed and used to generate a cone of light of the desired angle. Although “opal glass” or rough surface glass diffusers are common and could potentially be used, a Holographic Optical Element (HOE) diffuser is preferable.
In a fourth illustrative embodiment, HOEs are designed and used to shape light to precise shapes and patterns as they provide a low cost and optically efficient means to make complex projection patterns. In particular, both binary and diffractive optics, which are closely related, are included here. Employment of a custom pattern/angle HOE or other phase mask may be used for some implementations.
In a fifth illustrative embodiment, rear illumination and subsequent collimation of a window or mask pattern can be used. This would typically be a glass or plastic window with a pattern applied opaquely, such as chrome on glass, a chemically etched or laser cut stainless steel stencil or similar. A lens or lens system is used downstream of the window to gather light and collimate to the desired angle of divergence. The pattern disc may be somewhat diffuse in nature.
In a sixth illustrative embodiment, the risk zone map 20 is the result of a vector scan which traces the desired image or pattern using a rapidly moving spot. Scanning of simple patterns such as circles can be achieved with a spinning off axis mirror, wedge cut refractive optic or the like. Complex patterns can be achieve by spinning HOE scanner optics, or more conventionally with XY galvanometer scanners. The same result might also be achieved with MEMs scanning devices such a DLPs, GLVs and related technologies.
In a seventh illustrative embodiment, areas can be delineated with the use of multiple static spots rather than full vector or filled patterns. This is discussed more below as an additional claim as a way to increase the image brightness.
The visibility of the laser light on a target is determined by the energy density at the target location reflected back to the viewer's location. Even low power laser light may be quite visible when viewed at a significant distance if it remains in a small spot. However, if the angle of divergence is significant, and/or the spot is large, as it may be at long distances, practical and/or safe levels of laser light may not be as visible as would be desirable when the spot spreads to a large diameter. In order to address this problem, one solution is to delineate the diameter of an imaginary circle or box with two or more individual low divergence (small diameter) beams to maintain brightness with low levels of power. These multiple beams could be generated with multiple lasers, or with discrete optics or HOE, diffractive or binary optics to generate multiple beams from a single input beam (single laser).
As discussed above, the effect of the offset and/or parallax between the path of the bullet and the path of the laser light can affect can vary from moderate to insignificant depending on the distance from the firearm to the target. Indeed, if the laser is simply a cone of light being emitted from a device mounted, for example, to the top of the barrel of the firearm, for example like a riffle scope, there is offset between the origin of the path of the laser light and the path of the projectile (bullet). If the natural fall of the bullet is not taken into account, both the laser light and the bullet will travel a straight path, separated by 1-2 inches. If the target is at a significant distance, this offset is likely insignificant due to the inherent spread pattern or error in the bullets flight path. However, if the target is close to the weapon there will be offset, or alternately parallax.
In order to address this problem, the end of the barrel can be fitted with a mechanism such that the beam or beams are emitted uniformly around or directly down the axis of the barrel. This can be achieved in a couple of different manners.
Firstly, a reflector can be placed at some angle at the end of the barrel (typically 45 degrees). This reflective optic, such as a flat mirror will have a hole in the center to allow the passage of the projectile, while still allowing reflection of the light in a path concentric with the projectile.
Secondly, an optic can be used to collimate the light around the path of the projectile which is not a planar (flat) mirror, but may be a concave optic such as an off axis parabola. These approaches would also have a hole in the center, through which the projectile can pass.
Thirdly, a diffractive, holographic, binary or phase grating can be used to shape the light into the desired collimated pattern without a concave shape/curved surface.
Depending on the use environment, front surface mirrors may be desired.
Alternatively, one beam could be emitted above or below the barrel and one to the right or left of the barrel. In this way, the user imagines the intersection of a horizontal and vertical line as the center of emission, and then uses the location of the two beam spots to construct a square or circle which represents the risk zone map.
Also, for special single use conditions, a pellicle beam splitter can be placed directly over the end of the barrel at some angle, typically 45 degrees. The pellicle beams splitter is made from a very thin optically reflective layer of cellulous, mylar or similar material. The thickness of this material can be just a few microns such that it is an extremely thin weak film which will be pierced with milligrams of force and thus not affect the projectile, thereby allowing the emitted laser light to be aligned precisely with the bore of the weapon with zero offset or parallax. It can be noted that the pellicle beam splitter is effectively a tympanic membrane and will respond to acoustic vibrations (sound), this may limit its use in some situations. Alternately, a solid but very thin glass beam splitter could be used and shatter upon use.
Referring now to FIG. 7, an illustrative embodiment of the electronics 42 used to drive the laser beam 14 will now be described. The electronics 42 comprises a CPU 44 which receives data from one or more sensors as in 46, processes the data according to a program (not shown) stored in a Read Only Memory (ROM) 48 and/or Random Access Memory (RAM) 50 as well as user inputs (also now shown) received via a user interface (I/O) 52 and illustratively stored in the RAM 50. In this regard the user interface 52 could be provided by one of a number of means including user selectable buttons (not shown), infrared, USB or the like. The CPU 44 provides control signals to a laser driver 54 which drives the laser beam 14 to project the risk zone map (reference 20 in FIG. 1). Additionally, a source of power 56, such as a battery or the like, is provided to power the electronics 42 and the laser beam 14. Referring back to FIG. 1 in addition to FIG. 7, control of power supplied by the source of power 56 to the electronics 42 and the laser beam 14 can be controlled, for example, by slightly depressing the trigger 58 or through provision of a switch (not shown) or the like.
Still referring to FIG. 7, the sensors as in 46 may comprise one or more of a variety commercially-available electronic sensors such as accelerometers or the like. Listed below are examples of data that can be taken into consideration for calculating the risk zone map 20:

- target data: distance, height, speed;
- meteorological data: wind direction and speed, temperature, pressure, humidity;
- spatial data: movement of firearm (banking, rotation, lateral, up-down);
- ammunition data: cartridge info, bullet weight, ballistic coefficient;
- weapon data: weapon length (farthest distance to which an averagely-trained soldier can hit a man-sized target).

Still referring to FIG. 7, one parameter of interest which can be used as a basis for determining the proportions of the risk zone map 20 is the maximum effect range. In this regard, firearm manufacturers typically determine for each firearm a distance at which an averagely trained soldier using the particular firearm is able to hit a man-sized target (typically 46 cm×91 cm or 18″×36). Some typical values for some known firearms are provided below:

- M9 9 mm Glock/Berrette 50 m
- M4 5.56 mm Carbine 200 m

Another parameter of interest (discussed briefly above) and which may also be used to determine the proportions of the risk zone map 20 is the MOA. MOA is a unit of angular measurement equal to one sixtieth ( 1/60) of one degree. One (1) MOA is one inch at 100 yards (91 meters). MOA is often used when characterizing the accuracy of rifles and indicates that, under ideal conditions, the firearm in question is capable of repeatedly producing a group of shots whose center points (center-to-center) fit within a circle, the diameter of which can be subtended by that amount of arc.
Although the present invention has been described hereinabove by way of specific embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims.

Claims

1. A method for supporting a decision to fire a projectile from a firearm having a firearm accuracy and pointed towards an intended target and an unintended target, the method comprising:

pre-calculating as a function of the firearm accuracy a first region surrounding a point of aim within which a projectile issued from the firearm will strike with a known probability;

aiming the firearm at the intended target;

delineating said first region about the point of aim with a laser affixed to the firearm; and

not firing when at least a portion of the unintended target is within said first region.

2. The method of claim 1; wherein said delineating comprises outlining said first region with said laser.

3. The method of claim 1; wherein said region is circular.

4. The method of claim 1; wherein said laser emits light in a visible spectrum.

5. The method of claim 1, further comprising displaying a reticule about the point of aim using said laser.

6. The method of claim 5, wherein said reticule comprises a pair of crosshairs, each of said crosshairs further comprising a pair of cross hatches.

7. The method of claim 1, wherein the firearm has an accuracy rated as units of Minute of Arc (MOA) and further wherein said first region is a circle whose radius is subtended by said units of MOA.

8. The method of claim 1, wherein said projected risk zone map comprises a ring defining said first region.

9. The method of claim 1, wherein said delineated region comprises an oval ring.

10. The method of claim 1, further comprising pre-calculating a second region within which a projectile issued from the firearm will strike with a second predetermined probability and delineating said second region about the point of aim with said laser.

11. The method of claim 10, wherein the firearm has an accuracy rated as one Minute of Arc (MOA) and further wherein said first region is a circle whose radius is subtended by one (1) MOA and said second region is a circle whose radius is subtended by two (2) MOA.

12. The method of claim 1, wherein said laser further projects a readable character symbolic of said first pre-calculated probability adjacent said first region.

13. The method of claim 1, wherein said first region is pre-calculated based on a parameter selected from a group of parameters consisting of MOA, target data, meteorological data, spatial data, ammunition data, weapon data and combinations thereof.

14. The method of claim 1, wherein the firearm has a maximum effective range and wherein said region delineated by said laser is substantially the same size as a man's head and torso when said first region is delineated on a surface located at said maximum effective range from the fire arm.

15. The method of claim 14, wherein said first region measures 18 inches×36 inches when said first region is delineated on a surface located at said maximum effective range from the fire arm.

16. A method of providing a visible gun sight for a firearm having an accuracy comprising:

pre-determining as a function of the firearm accuracy a first region surrounding a point of aim within which a projectile issued from the firearm will strike with a known probability;

aiming the firearm at the intended target; and

outlining said first region about the point of aim with a laser affixed to the firearm.