HIGHLY STABLE TARGET SLEEVE IDENTIFIABLE TO THERMAL WEAPON SIGHTS

FIELD OF THE INVENTION

The present invention relates to a lightweight portable target cover. More particularly, the present invention relates to a target cover system for firearms training targets equipped with a target cover that tightly covers a firearm training target for firearms using thermal sights to determine shooting precision and accuracy.

BACKGROUND OF INVENTION

The military and, to a lesser extent, the law enforcement community use thermal weapon sights to aim their weapons. These thermal sights do not “see” light as our eyes do; rather, they detect infrared heat emanating from the surfaces of all the objects in A scene. While training with such sights, the users need special targets visible to the thermal sights.

Many different types of targets have been used in the market. For example, various slips have been used as a cover over thermal targets. In this case, a rigid target backer made of plastic or wood, which is only visible to the naked eye, is covered with the slip over the thermal target causing it to be identifiable to thermal weapon sights. However, traditional slips placed over thermal targets have been deficient in their ability to provide a stable thermal image, because they fit loosely on the target backer. The loose fitting target do not mimic the shape of the target backer effectively, which can make the target less identifiable to the users. The target surface may not be flat resulting in a lower contrast image. Additionally, the consistency of the image can suffer as a result of any movement or shift in the slip. The loose fitting target can shift its position relative to the target backer especially in adverse weather conditions, limiting target identification, thereby lessening the training value.

In an attempt to address this problem of instability, adhesives have been used to adhere thermal targets directly onto the target backers. While this can be somewhat effective to stabilize the slip cover, it reduces the flexibility and different modes of use for training. Some types of training techniques can be performed with only bare target backers. Thus, a slip cover cannot be temporarily donned or permanently adhered onto the target during such training techniques.

Accordingly, there is a need for a cover system for a target identifiable by thermal weapon sights that provides stability, consistent images, and interchangeability for different target types having various shapes and sizes. Further, there is a need for a cover that is adjustable to snugly conform to a target backer and can be maintained taut to resist shifting upon the target backer.

BRIEF SUMMARY OF THE INVENTION

The present invention may satisfy one or more of the above-mention desirable features. Other features and/or advantages may become apparent from the description which follows.

A thermal sleeve cover for covering a target backer, according to various embodiments, can include a target layer material and an adjustment mechanism. The target layer material may include emissivity and reflecting properties identifiable by a thermal sensor detecting device and is configured having at least one adjustable opening. The adjustment mechanism is operatively engaged with the at least one adjustable opening to selectively adjust one or more areas of the target layer material to adjust frictional forces at interfaces between surfaces of the thermal sleeve cover and all covered surfaces of the target backer to maintain a predetermined tautness of the target layer material fitted snugly over the target backer.

A thermal sleeve cover for covering a target backer, according to various embodiments, can include a first material, a second material, and a third material. The first material may include a target layer having emissivity and reflecting properties and is identifiable by a thermal sensor detecting device. The target layer may be a thermal film having a low emissivity of approximately 25% or less in a thermal infrared wavelength range. The second material may include a first friction material that exhibit gripping and tear resistant properties. The second material may be a flexible, non-stretching fabric material. The third material may include a second friction material that exhibits a shape memory property. The third material may be a four way stretch material. The second material may connect to the first material and the third material to form the thermal sleeve cover that is configured for covering a portion of at least one surface of the target backer to maintain a predetermined tautness of the target layer that results from frictional forces at interfaces between surfaces of the thermal sleeve cover and all covered surfaces of the target backer to prevent movement of the thermal sleeve cover relative to the target backer. A stretching tension force is applied to the thermal sleeve cover to maintain the predetermined tautness to control the thermal identification of the target layer by the thermal sensor detecting device.

In the following description, certain aspects and embodiments will become evident. It should be understood that the invention, in its broadest sense, could be practiced without having one or more features of these aspects and embodiments. It should be understood that these aspects and embodiments are merely exemplary and explanatory and are not restrictive of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are not limiting and are incorporated in and constitute a part of this specification, illustrate several embodiments and, together with the description, serve to explain the disclosed principles.

FIG. 1 illustrates a front view of an embodiment of a thermal sleeve cover according to the present teachings;

FIG. 2 is a graph of a low emissivity film spectrum.

FIG. 3A is a thermal image of a thermal sleeve cover obtained using a conventional thermal sight according to the present teachings;

FIG. 3B illustrates a thermal sleeve cover positioned in an example surrounding background for thermal identification by a conventional thermal sight according to the present teachings;

FIG. 4A is an exploded view of a target cover system according to the present teachings;

FIG. 4B illustrate an example of the thermal sleeve cover of FIG. 1 stretched over and conforming to target backers having different sizes according to the present teachings;

FIG. 4C illustrates a front perspective view of the thermal sleeve cover stretched over and conforming to a target backer.

FIG. 5 is a side view of the thermal sleeve cover of FIG. 1 stretched over and conforming to a target backer according to the present teachings;

FIG. 6A is a back perspective view of another exemplary embodiment of a thermal sleeve cover stretched over and conforming to a target backer, wherein the thermal sleeve cover comprises an elastic adjustment element according to the present teachings;

FIG. 6B is a back perspective view of yet another exemplary embodiment of a thermal sleeve cover stretched over and conforming to a target backer, wherein the thermal sleeve cover comprises an elastic adjustment element according to the present teachings;

FIG. 7 is a front view of another exemplary embodiment of a thermal sleeve cover configured to stretch over and conform to a target backer, wherein the thermal sleeve cover comprises discrete inelastic adjustments element according to the present teachings;

FIG. 8A is a front view of yet another exemplary embodiment of a thermal sleeve cover configured to stretch over and conform to a target backer, wherein the thermal sleeve cover comprises discrete inelastic adjustment elements according to the present teachings;

FIG. 8B is a cut-away view of connection points of the adjustment element of FIG. 8A according to the present teachings;

FIG. 8C is a back view of an exemplary embodiment of the discrete inelastic adjustment elements of FIG. 8A according to the present teachings; and

FIG. 8D is a back view of yet another exemplary embodiment of the discrete inelastic adjustment elements of FIG. 8A according to the present teachings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

Reference will now be made to various embodiments, examples of which are illustrated in the accompanying drawings. However, these various exemplary embodiments are not intended to limit the disclosure. On the contrary, the disclosure is intended to cover alternatives, modifications, and equivalents.

Throughout the application, description of various embodiments may use “comprising” language, however, it will be understood by one of skill in the art, that in some specific instances, an embodiment can alternatively be described using the language “consisting essentially of” or “consisting of.”

For purposes of better understanding the present teachings and in no way limiting the scope of the teachings, it will be clear to one of skill in the art that the use of the singular includes the plural unless specifically stated otherwise. Therefore, the terms “a,” “an” and “at least one” are used interchangeably in this application.

Unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about” or “approximately.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained. In some instances, “about” or “approximately” can be understood to mean a given value ±5%. Therefore, for example, about 100 degrees Fahrenheit could mean 95-105 degrees Fahrenheit.

Various embodiments of a thermal sleeve cover, system and method described herein provide a target identifiable by thermal weapon sights that is more stable on a target backer providing improved visibility and stability under adverse weather conditions. Rather than sit loosely on the target backer consistent with current technology, the thermal sleeve cover of the present invention covers the target backer in a very taut manner. The tautness creates significant frictional forces between the target and target backer. By being taut, the thermal sleeve cover prevents relative movement between itself and the underlying target backer, and the thermal sleeve cover more effectively assumes the shape of the underlying target backer. In various embodiments, the construction of the thermal sleeve cover achieves the desired tautness of the target by using a first friction material and a second friction material. The first friction material exhibits tear-resistant and gripping properties. The second friction material exhibits a shape memory effect wherein the material will stretch in all directions and return to its original shape when the applied force is removed.

In other embodiments, the thermal sleeve cover may use various means to provide tautness. In some cases, elasticity is used. The elasticity may be fully distributed as in the case of an elastic fabric, or the elasticity may use discrete elastic members such as elastic cords. In other cases, an inelastic string or cord may be used to tighten the target in place.

As shown in FIGS. 1 and 5 and described herein, a thermal sleeve cover 100 includes a thermal film layer 102, an elastic layer 106, and a base layer 104 joined to the thermal film layer 102 and the elastic layer 106. Some embodiments of the thermal sleeve cover 100 may be manufactured without the base layer 104 such that the thermal film layer 102 is coupled directly to the elastic layer 106. In other embodiments, the thermal sleeve cover may be made consisting of only the thermal film layer 102. The term “target sleeve cover” as used herein refers to any covering that can be used to cover a firearm training target. Examples of target sleeve covers include sleeves, slipcovers, slips, envelopes, sheets, sheaths, blankets, overlays, and cloaks, as well as numerous other products configured to cover a firearm training target.

The term ‘thermal film” as used herein generally refers to a film that exhibits low emissivity. The “low emissivity thermal film” refers to a film, layer, sheet, material or structure that emits low levels of radiant thermal (heat) energy while exhibiting high reflectivity of thermal infrared energy. Emissivity is a measure of the heat absorbance and reflectance properties of a material. Low emissivity (“low e” or “low thermal emissivity”) refers to a surface condition that emits low levels of radiant thermal (heat) energy. According to the present teachings, examples of thermal reflecting films include low emissivity film, passive film, no powder film, and reverse polarity film.

FIG. 2 depicts a graph of the spectrum of a low emissivity film. All materials absorb, reflect and emit radiant energy. Emissivity is the value given to materials based on the ratio of heat emitted compared to a perfect black body, on a scale from zero to one. A black body has an emissivity of one (1) and a perfect reflector has a value of zero (0). However, most materials have a high emissivity and low reflectivity, which is the exact opposite of low emissivity thermal films. Because of the disparity, the low emissivity thermal film can be detected by a thermal sight, thermal imaging camera or thermal imaging device, which detects thermal energy in the environment and creates an image of the scene.

In the example of a low emissivity film shown in FIG. 2, the measured reflectance of the thermal film is shown in the range from 2 micron to 12 microns wavelength. The reflectance (R) is approximately 0.9 or 90% for the spectrum, meaning it reflects approximately 90% of radiant thermal energy.

Emissivity (e) is related to reflectivity by the following equation:

e=1−R

Therefore, in this example, the emissivity is approximately 0.1 or 10%. This means that the film absorbs and emits 10% of radiant thermal energy. As mentioned above, the thermal film layer 102 is a film which has low emissivity. In the preferred embodiment, the emissivity of the thermal film layer 102 is typically less than 50%. More preferably, the emissivity of the thermal film layer 102 is less than 25%.

The term “thermal film” as used herein refers to a film, material, or structure that is infrared of the electromagnetic spectrum. The infrared region of the spectrum is divided into near-, mid-, and far-infrared. In the preferred embodiment, the thermal film is selected to operate in the mid- and far-infrared regions of the spectrum. The thermal film must also exhibit characteristics such that it is detectable by a thermal imaging device, such as a FLIR (Forward Looking Infrared Radar or Forward Looking InfraRed) device. The thermal film is continuously visible in both daylight and darkness by such thermal imaging device. With regards to environmental factors, the thermal film is also visible and detectable through fog, smoke and sandstorms.

FIG. 3A depicts a thermal image of a thermal sleeve cover, according to the present invention, which is obtained using a conventional thermal sight. The image appears in black and white contrast, which ensures that the objects are well separated and clearly defined. In general, the thermal sleeve cover 100 is covered with a thermal film layer 102 that is designed to reflect radiated heat, producing a “hot spot” or “cold spot” when viewed through thermal sights to quickly identify the area of interest of a scene and display its relative temperature. When viewing an image with some thermal sights, colors are converted to black and white such that the thermal film projects a black and white contrast to standout from its surrounding, as shown for in FIG. 3A. FIG. 3B depicts thermal sleeve cover 100 positioned within an example surrounding background 200, such as a forest or wooded area. In FIG. 3B, thermal sleeve cover 100 is designed to have the properties and construction described herein with regards to the present invention, such that it is easily detectable and identifiable by a conventional thermal sight. In general, conventional thermal sights are available in monochrome, color or combination options. A monochrome thermal sight displays a heat map of objects within a scene in black-and-white contrast. A color thermal sight, on the other hand, displays the differences in temperature of the objects through various colors, providing a colored heat map. Some thermal sights may be equipped with various color options, allowing a user to choose from White Hot, Black Hot, as well as multi-color modes. All of these types of thermal sights can be employed with the thermal sleeve cover, system, and method of the present invention.

Although the description refers to the use of a thermal imaging sights, it will be understood that the invention may be applied to any other application for zeroing a weapon equipped with an optical sight. The invention can be used with a system and method for zeroing various types of weapon sights and/or optical sights, such as, for example, laser sights, night vision sights, iron sights (open sights), peep sights, telescopic sights, reflex sights, and holographic sights to ensure calibration of the weapon for accurate engagement of a real-life target that instructs the user exactly how to adjust his or her weapon sight to accurately aim at a target.

As shown in FIGS. 1 and 4A-4C, the system 10 comprises a thermal sleeve cover 100 adapted to be fitted onto a target backer 108. As used herein, the term “target backer” is used to refer to any type of structure capable of being at least partially covered by any of the examples of the thermal sleeve cover described herein. Target backer herein also includes conventional targets and/or target backers. Conventional targets and/or target backers may include a variety of target images, such as a bull's-eye or silhouettes of humans or animals, used to improve shooting accuracy and precision. Conventional targets and/or target backers may be planar, curved, three-dimensional, folded, etc. The conventional target and/or target backer may be portable, self-supporting (e.g., folding or having an integrated back support), supported by a target stand, or positioned to be supported by another structure (e.g. a tree or the ground). In use, when a conventional target or any other structure is covered by the thermal sleeve cover described herein, the thermal film layer of the thermal sleeve cover functions as the “target image”, while the conventional target or other structure functions as the “target backer.”

FIGS. 4A-4C provides an example of thermal sleeve cover 100 including a thermal film layer having a low thermal emissivity surface region 102 and at least one area of a stretchable material (e.g. layer 106) to cover target backers of different sizes. FIG. 4A is an exploded view of an example of placing thermal sleeve cover 100 over target backer 108. In this example, the thermal sleeve cover 108 includes a stretchable material 106 and an opening in the bottom allowing the thermal sleeve cover to be stretched over the target backer 108 such that the target backer 108 fits within the interior of the thermal sleeve cover 100 to construct system 10. This example shows a method of placing the thermal sleeve cover 100 over the top and pulling the thermal sleeve cover downward over the target backer 108. In one example, the thermal sleeve cover 100 may be pulled downward to completely cover and enclose the target backer 108. In other examples, the thermal sleeve cover may be pulled downward to at least partially cover one or more surfaces of the target backer 108. FIG. 4C illustrates the thermal sleeve cover 100 including a stretchable material 106 and an opening at the bottom end allowing the thermal sleeve cover 100 to be stretched over and conform to target backer 108. In the example of FIG. 4C, the thermal sleeve cover 100 is pulled downward to completely cover the top surface and partially cover the sides, front, and back surfaces of the target backer 108, while the bottom surface of the target backer 108 remains uncovered. However, in lieu of pulling the thermal sleeve cover downward onto the target backer, other methods of covering the target backer 108 with the thermal sleeve cover 100, such as, for example, in a front-to-back process can be employed.

In one embodiment, the target backer 108 may be shaped to form, for example, a torso region 110 and shoulder regions 112, mimicking the shape of a human torso region. In other embodiments, the target backer 108 can be designed to have any desired shape, varying thickness (FIG. 4B) and manufactured from various materials, such as cardboard, paper stock, wood, foam, plastic or any other suitable material. The thermal sleeve cover 100 can be shaped to the form of the structure to which it covers. Examples of different structures that thermal sleeve cover 100 can be configured to cover include paper targets, cardboard targets, wood targets, foam targets, plastic targets, 3D targets, block targets, bag targets, hanging targets, curvilinear objects, as well as numerous other products that can be covered by the thermal sleeve cover. Namely, in the exemplary embodiments described and shown herein, the thermal sleeve cover 100 is formed to be of a shape and size that is removably attached onto a torso shaped target backer 108 having a profile similar to an E-type target as specified by the United States Army.

The thermal sleeve cover 100 is designed to conform to the shape of various target backers, by virtue of the construction of the different materials of which the thermal sleeve cover is comprised. The thermal sleeve cover 100 is variably adjustable to the dimensions of the target backer to be covered. As illustrated in FIG. 4B, the same thermal sleeve cover will fit a variety of sizes and shapes of target backers and can be easily and quickly adjusted to fit different target backers having different sizes and shapes. FIG. 4B depicts a first exemplary device 114 having a first thickness t₁and a second exemplary device 116 having a second thickness t₂, which is smaller than first thickness t₁. The thermal sleeve covers 118, 120 of both the first exemplary device 114 and the second exemplary 116 are constructed having the exact same dimensions.

The thermal sleeve cover 100 functions as a cover covering a firearm training target for firearms using thermal sights to determine shooting precision and accuracy. The thermal film layer 102 functions as a target of the thermal sleeve cover 100 during shooting of the firearm. The thermal sleeve cover 100 is stretched taut over the target backer 108 to provide a substantially flat surface of the thermal film layer 102. The thermal sleeve cover is stretched taut enough to conform to the shape of the target 108 underneath. It is preferred that the stretching tension force for conforming the thermal sleeve cover against the target 108 underneath is within a range of approximately 0.5 pound force (lbf)-3 lbf such the thermal sleeve cover is stretched to maintain a predetermined tautness.

In some embodiments, thermal film layer 102 may comprise multiple regions of a thermal film layer having the same or different levels of thermal emissivity. The multiple regions may be connected to form a single thermal film layer having the same thermal emissivity (for example, a low emissivity region). In other embodiments, the thermal film layer may include a plurality of separate and distinct regions wherein some regions have different emissivity levels. Using multiple regions having different emissivity levels can enable, for example, the use of a single thermal sleeve cover with multiple types of weapon sights and/or optical sights. Namely, each region of the thermal film layer may have a different optical property, enabling calibration of a variety weapon sighting technologies, including a night vision sight, a thermal imaging sight, and an aiming laser sight, using the single thermal sleeve cover.

According to the present invention, the tautness creates significant frictional forces between the target 102 of the thermal sleeve cover 100 and target backer 108. By being taut, the thermal sleeve cover prevents relative movement between itself and the underlying target backer, and the thermal sleeve cover more effectively assumes the shape of the underlying target backer. In various embodiments, in addition to the stretching tension force, the construction of the thermal sleeve cover helps to achieve the desired tautness of the target by using a first friction material and a second friction material. The first friction material exhibits tear resistant and gripping properties. The second friction material exhibits a shape memory effect wherein the material will stretch in all directions and return to its original shape when the applied force is removed. The shape memory of the second friction material enables the thermal sleeve cover 100 to stretch and adapt to target backers of various shapes and sizes. Therefore, the thermal sleeve cover can snugly fit onto and cover the target backer to form a fabric tube sleeve, for example, with an opening at least one surface of the thermal sleeve cover.

With reference now to FIGS. 1 and 5, in at least one exemplary embodiment, the thermal sleeve cover 100 comprises a thermal film layer 102, an elastic layer 106, and a base layer 104 located between the thermal film layer 102 and the elastic layer 106. In some embodiments, the base layer 104 serves as the first friction material, and the elastic layer 106 serves as the second friction material. Thus, in the preferred embodiment, the thermal sleeve cover 100 is made of at least a thermal film layer 102, a base layer 104 having tear resistant and gripping properties, and an elastic layer 106 having shape memory properties. One or more of the layers may be comprised of a single continuous piece of material or may include multiple pieces of material connected together.

The thermal film layer 102 having the characteristics, as described above, functions as a target. The thermal film layer 102 may be in the form of a flexible sheet or in the form of a liquid coating to be applied to a surface of the base layer 104. According to the preferred embodiment, the thermal film layer 102 is manufactured in the form of a flexible sheet that is cut to the desired shape and dimensions. In one embodiment, the thermal film layer 102 is coupled (e.g. mounted, attached or fixed) to the base layer 104 by stitching to form a two-layer target surface. However, other joining techniques or methods of attachments may also be used such as laminating with an adhesive to permanently attach the thermal film layer 102 to the base layer 104.

The base layer 104 with the thermal film layer 102 attached thereon is connected with the elastic layer 106. In one example, the base layer 104 and the elastic layer 106 are joined together at their respective edges by stitching or other fastening means to create a tubular shape having, for example, an opening on only one surface of the thermal sleeve cover 100. However, in other embodiments, the tubular shape may be configured to have a first open end and a second open end. It should be understood that while stitching can be used to join the base layer 104 to the elastic layer 106, other methods of attachment may also be used such as clips, buttons, zippers, hook-and-loop strips, snaps, buckles, or other fastening means.

In various embodiments, the opening can be located on the top surface, bottom surface, side surface, or back surface of the thermal sleeve cover 100. With applied force, the thermal sleeve cover 100 can be stretched onto the target backer 108. The thermal sleeve cover 100 can be slipped onto the target backer 108 via an opening such that the target backer is inserted into the interior of the thermal sleeve cover to provide a form-fit cover. The thermal sleeve cover 100 is configured to be an appropriate size that the fabric becomes taut when placed over the target backer. The thermal sleeve cover 100 is manufactured to be of an approximate size so that it is adjustable to fit a variety of target backer shapes and sizes.

The thermal sleeve cover is not limited to any particular shape or configuration and may be manufactured to have various shapes. One skilled in the art will readily appreciate, depending upon the structure to be covered, that other shapes of the tube profiles may also be suitable, including, for example, round, square, rectangular, hexagon, pentagon, trapezoid, octagon, oval, triangle, or I-shaped.

The base layer 104 functions to impart resistance, gripping, rigidness, and non-stretching at this region of the thermal sleeve cover. The base layer 104 also helps to prevent shifting to maintain the thermal sleeve cover's position on the target backer 108. The gripping properties of the base layer 104 is high enough such that the thermal sleeve cover 100 does not shift or move relative to the target backer. In order to reduce or prevent shifting or movement of the thermal sleeve cover 100, the material of base layer 104 exerts a frictional force on target backer 108 and thereby also tends to keep the thermal sleeve cover 100 substantially in its original position on the target backer 108. Such forces counteract against outside forces, such as adverse weather conditions, that would otherwise cause the thermal sleeve cover to shift, move or slide across the target backer 108. The frictional force produced by the base layer 104 is intended to mitigate such shifting, moving or sliding effect.

The base layer 104 may comprise a resistant fabric, such as a ripstop fabric that is a woven material which resists tearing and ripping due to its crosshatched threading. Thus, the ripstop fabric portions discussed herein may be non-stretch materials. In one embodiment, the ripstop fabric of the base layer 104 is a nylon ripstop fabric, which is a light-weight nylon fabric made by weaving nylon threads throughout a base material in interlocking patterns. During the weaving process, thicker threads become interwoven to reinforce the weave in a crosshatch pattern. The crosshatch pattern is interlocking. This means that the threads weave over and under one another, locking them into place when tightened. This weave technique creates a binding property that allows the nylon ripstop to be strong and long lasting. The nylon ripstop of the base layer 104 is a non-stretchable material that is resistant to tearing and deformation. One advantage of using nylon ripstop for the base layer 104 is that the thermal film layer 102 can be joined thereon by stitching to provide the thermal sleeve cover 100 with durability and toughness, while being resistant to tearing.

The base layer 104 can be selected from a fabric having a between 40 denier and 100 denier, and specifically about 70 denier. However, in some embodiments, the denier of the fabric can be greater than 100 denier. The denier is used to determine the fiber thickness. Namely, denier is used to indicate the size of the yarn used in a fabric. The specific denier of the material of the base layer 104 can be selected based on the desired fiber durability and strength for the particular application.

In one preferred embodiment, the base layer is made of 70 denier, 100% nylon ripstop fabric. However, in various embodiments, the ripstop fabric can consist of a woven fabric made of from about 70% to about 100% nylon. The interlocking thread patterns of the ripstop fabric stop any tear from spreading and provides durability, while the material can be made relatively thin. In lieu of or in addition to having nylon as the base material, many different base materials can be used to make the base layer 104, including cotton, silk, polyester, or polypropylene. In these embodiments, the nylon content can be limited to the crosshatched threads that make the material tear and run resistant. In the event of a material defect or inadvertent tear, such a defect or tear is restricted from propagation by reason of the nylon construction of the material.

The base layer 104 is joined or otherwise connected to the thermal film layer 102 and the elastic layer 106 by stitching or other fastening means. In the preferred embodiment, the thermal film layer 102 is joined to the nylon ripstop of the base layer 104 by stitching such that the two layers function as a unitary sheet. The thermal film layer 102 is securely fixed to the fibers of the base layer 104.

In one embodiment, the thermal film layer 102 can be formed to resemble the shape of the target backer 108. The thermal film layer 102 may be joined to the base layer 104 in a manner that the front dimensions of the thermal film layer 102 are smaller than the front dimensions of the base layer 104 such that the thermal film layer 102 appears to be surrounded by the base layer 104. It is noted that these dimensions are exemplary and that the thermal film layer 102 may be formed in larger or smaller sizes.

With continued reference to FIGS. 1 and 5, the base layer 104 is also joined to the elastic layer 106 of the thermal sleeve cover 100 by stitching. As mentioned above, the elastic layer 106 may function as the second friction material that exhibits a shape memory effect wherein the material will stretch in all directions and return to its original shape when the applied force is removed. The shape memory of the second friction material enables the thermal sleeve cover 100 to stretch and adapt to target backers of various shapes and sizes. Therefore, the thermal sleeve cover can snugly fit onto and cover the target backer to form a fabric tube sleeve with an opening, for example, on only one surface of the thermal sleeve cover. The shape memory material comprises an elastic material wherein the change in the amount of stretch is effective to change the frictional force at the interface between the thermal sleeve cover 100 and the target backer 108. By controlling the amount of stretch of the elastic material, the frictional force levels between thermal sleeve cover 100 and target backer 108 can be controlled.

In various embodiments, the elastic layer 106 may be comprised of a sheet of elastically resilient fabric or other material having four way stretch capabilities. The sheet of elastically resilient fabric or four way stretch material may include one or more panels joined by stitching. A material with four way stretch capabilities will stretch in both directions, crosswise and lengthwise. In other words, a four way stretch material will stretch in all directions.

Due to the four way stretch fabric material, the elastic layer 106 stretches and recovers both width and lengthwise. The elastic layer 106 is an elastically resilient layer operable to permit the expansion of the thermal sleeve cover 100 when tension is applied. The elastic layer 106 is formed to exhibit four way stretch allowing the thermal sleeve cover 100 to closely conform to the target backer 108 so that it easily and smoothly fits over various shapes and curvature. In the example of FIG. 5, the elastic layer 106 is an outer layer that extends from the top and side edges of the base layer 104 and surrounds the top, side and back portions of the target backer. Because of its four way stretch capability of the elastic layer 106, when the force is removed, the thermal sleeve cover 100 returns back to its original shape.

In some embodiments, the four way stretch material of the elastic layer 106 may stretch equally in all directions. In other embodiments, the stretch material may stretch more in one direction than the other. In one of the preferred embodiments, the elastic layer 106 is a knit material. In other embodiments, the elastic layer 106 may be comprised of any of various different four way stretch materials such as spandex, spandex blend, rubber/latex, neoprene rubber, elastane, nylon, warp-knit, PowerNet, tricot, weftlock and the like.

In various embodiments, the elastic properties may comprise stretch and compression such that the thermal sleeve cover 100 follows the target backer contours and compresses the target backer to limit shifting movement thereon. One of the features that may be considered when determining as to how the thermal sleeve cover 100 compresses the target backer 108 is the elastic properties that render the cover an effective stretching element acting on the curvilinear features of the body of the target backer. In general, for elastic fiber materials, the compression pressure of less than 20 mmHg is categorized as mild, 20-40 mmHg as medium, 40-60 mmHg as strong, and greater than 60 mmHg as very strong. In some embodiments, the compression pressure of the elastic material may be in a range of 20 mmHg to greater than 60 mmHg.

It should be understood that while stitches (sewing) can be used to join the layers, other methods of attachments may also be used such as different stitching patterns, adhesive, welding, bonding, staples, snaps, buckles, clips, hook-and-loop (VELCRO®), buttons, hooks, taping, twine, clamps or the like. There is no restriction on the order in which the layers are joined.

In general, the structure of the thermal sleeve cover 100 comprises a thermal film portion, a resistant, non-stretchable portion and an elastic four way stretchable portion. Each of the portions of the thermal sleeve cover can be selected to exhibit specific desired properties based on various factors, for example, such as emissivity, wavelength, elasticity, rigidness, resistance, denier, ripstop fabric, and thickness. In the preferred embodiment, thermal sleeve cover 100 may include some, all, or a combination of one or more of the following characteristics: a thermal film layer with emissivity less than 25%, a base layer of a resistant, non-stretchable portion made of nylon ripstop, and an elastic layer made of a four way stretchable knit.

The combination of these properties enables the manufacture of a thermal sleeve cover 100 that is identifiable by thermal weapon sights and is more stable on a target backer 108, which provides improved visibility and stability under adverse weather conditions. Rather than fit loosely on the target backer like conventional target sleeves, the thermal sleeve cover 100 of the present invention covers the target backer in a very taut manner. The tautness creates significant frictional forces between the thermal sleeve cover 100 and target backer 108. By being taut the thermal sleeve cover 100 will not shift and more effectively assumes the shape of the underlying target backer 108. The thermal sleeve cover 100 can use various mechanisms to provide tautness. In some cases, elasticity can be used. The elasticity may be fully distributed as in the case of an elastic fabric, or the elasticity may use discrete elastic members such as elastic cords. In other cases, inelastic string or cord may be used to tighten the target in its place. In some embodiments, the desired tautness can be achieved through only mechanical means. In other embodiments, the system can be manufactured as an easy-to-use portable, battery-operated electronic device to achieve the desired tautness.

An example of preparing a sample of a thermal sleeve cover according to the exemplary embodiments shown in FIGS. 1-5 will now be described. A sheet of thermal film material with emissivity less than 25% was cut to match the shape of an E-Type target for use as a sample for measurement of the physical properties. The E-Type target is a predetermined shape roughly simulating a torso of a human body as specified by the United States Army. The thermal film was sewn onto a base fabric, which was an orange 70 denier, 100% nylon ripstop fabric. The nylon ripstop fabric had the dimensions to be the same size of the thermal film. After sewing the thermal film on the nylon ripstop fabric, an elastic knit fabric was sewn onto the back of the nylon ripstop fabric creating a thermal sleeve cover having a configuration similar to a tube sleeve with an open end and a closed end. The cover's elasticity provided a snug fit, a substantially smooth appearance and facilitated easy removal and replacement of the cover. Being flexible, the thermal sleeve cover was then stretched by applying a force and fitted over a variety of target backers in a taut manner in order to perform rifle training with a thermal weapon sight. In a rifle training test using a thermal weapon sight, results were obtained indicating accurate thermal identification of the target of the thermal film. The form-fitted thermal sleeve cover was easily visible and identifiable by the thermal weapon sights in various adverse weather conditions to generate high quality images wherein the target of the thermal sleeve cover was clearly distinguishable from its surroundings. Due to its elastic properties, the shape of the thermal sleeve cover recovered its original shape after the force applied was relieved when the thermal sleeve cover was removed from the target backer.

The example of preparing the sample of the thermal sleeve cover, which has been described in the foregoing embodiment, has been presented by way of example only, and is not intended to limit or restrict the scope of the invention.

In some embodiments, the system 10 includes a no power thermal film that is capable of providing a clear accurate thermal signature and maintaining a thermal signature even in windy conditions. In this preferred embodiment, no electrical components and no power source is required to provide effective thermal target identification. It will be appreciated that in the preferred embodiment of the illustrative system 10 and device requires no power or control system to provide a highly contrastable image that is easily visible with a thermal sight. By having no batteries and no electrical components, the durable elastic backing of the thermal sleeve cover 100 enables it to easily slip over and fit target backers of various sizes and shapes. The thermal sleeve cover can easily be switched from thermal to non-thermal targets with no hassle.

The elastic properties of the materials enable the thermal sleeve cover 100 to be adjustable to snugly conform to the shape of and remain taut when placed over the target backer. The elastic properties may comprise stretch and/or compression. The tautness feature of the thermal sleeve cover also helps with the thermal identification of the target. Due to the tautness, the target (thermal film layer 102) resists shifting and flapping during adverse weather conditions, like wind and rain, and is easily detectable over a wide range of normally troublesome atmospheric conditions, such as smoke, sandstorms, dust, and mists. In order for a thermal sight to effectively produce good thermal images of the target, the thermal sight must accurately detect the thermal energy emitted by the target object. To create an image, a thermal sight converts the detected infrared (IR) radiation (heat) into visible images that depict the spatial distribution of temperature difference in a scene viewed by the thermal sight. Namely, a thermal sight is a device that forms an image using infrared radiation.

The problem with some conventional targets is that it can be difficult to detect and create an image based on the heat produced by the object under certain adverse conditions, such as weather, nighttime, and atmospheric conditions. It is important to create the best possible image to extract meaningful data regarding the detection, recognition and identification of the target.

The thermal sight senses and displays a spatial distribution of thermal (heat) energy. Generally speaking, the thermal sight provides a display of the spatial distribution of the thermal energy emanating from a scene (thermal image) and the individual target objects of interest within the scene are referred to as thermal signatures. Each signature is a composition of the spectral distribution (wavelength band of infrared-radiation), spatial distribution (size and shape), and intensity distribution (temperature) that allows the thermal sight to distinguish the target object from other signatures and the background of the scene. The thermal sight uses thermal sensors to detect the amount of infrared (IR) radiation (heat) given off by an object. The radiation (heat) that is detected by the thermal sensors generally come from the heat signatures of the target object and its surroundings. The sensors will decode the information, convert it to electrical signals and present it in the form of an image that represents the thermal signal of the object and its environment.

One reason for the importance of the thermal identification of an object is that no matter how great the sensors of the thermal sight are, and how far the scope can zoom in, if the object is not clearly visible and detectable from its surroundings, this may render the thermal sight ineffective for its intended application, such as firearm training to determine shooting precision and accuracy. Thus, the thermal images need to be good enough to unambiguously separate the target signature from the background. In other words, the individual target signal must be clearly identified.

Another factor that can influence the thermal image is the thermal contrast. Thermal images are formed by the radiated thermal contrast (ΔT) which is the emissivity difference between the target object and its background. The temperature and the surface of the object play a major role in the recorded energy distribution that the thermal sight captures. It is more than just detection of the temperature difference that produces the image since “surface” of the target moderates the emissivity.

Thus, the tautness of the surface of the target sleeve cover 100 functions to enhance the thermal identification of the target. As described above, the target (thermal film layer 102) of thermal sleeve cover 100 has low emissivity and is detectable in the Mid Wave Infrared (MWIR) region and the Far Wave Infrared region. The thermal sleeve cover 100 is placed onto the target backer 108 in a taut manner such that the target (thermal film layer 102) is easily detectable by a thermal sight to create a very detailed temperature pattern (commonly referred to as a “thermogram”), which is converted to electrical signals to produce a thermal image that is clearly distinguishable from background clutter. The thermal sleeve cover 100 is visible in both daytime and night-time, total darkness, through smoke, and other low visibility, low-contrast conditions. FIG. 3A depicts a thermal image of thermal sleeve cover 100 of FIG. 1 as detected by a thermal sight wherein the sleeve cover is clearly visible from its surroundings in the thermal image according to the present invention. FIG. 3B depicts thermal sleeve cover 100 positioned within an example surrounding background 200, such as a forest or a wooded area, wherein the thermal sleeve cover 100 is easily detectable during a firearm training to determine a user's shooting precision and accuracy.

Initially, when the thermal sleeve cover is placed over the target backer, the thermal sleeve cover conforms to the shape of the target backer in a tight, form-fitted arrangement having an initial degree of tautness due to the construction of the thermal sleeve cover having elastic properties. As discussed above, the degree of tautness of the surface of the target sleeve cover affects the thermal identification of the target. The tautness of the surface of the target sleeve cover 100 functions to enhance the thermal identification of the target.

It should be noted that the thermal sleeve cover can be placed over the target backer with uniform tension or varying tensions at predetermined areas of the target backer to obtain a desired thermal identification of the target. Additionally, one or more adjustment mechanisms may be operatively associated with the thermal sleeve cover to adjust the target in order to maintain a predetermined tautness in the target relative to the target backer. In some embodiments, the adjustment mechanism may engage portions of the target sleeve cover and apply a force to retain the target sleeve cover such that the target is held at a predetermined tension and/or predetermined flatness. The adjustment mechanisms apply a force to the thermal sleeve cover that controls the stretching tension force and/or the frictional force between the thermal sleeve cover and the target backer. For example, the thermal sensor of the thermal sight can be used to quickly observe and detect the tautness of the target. Based upon the observed thermal identification of the target, the tautness can be further adjusted as needed.

FIG. 6A is a back view of another embodiment of the thermal sleeve cover 126 having an adjustment means of an elastic band provided within the back surface. The adjustment means operates to provide and control the amount of tension applied to the thermal sleeve cover. In conjunction with an initial degree of tautness resulting from the elastic properties of the elastic layer 106 of the thermal sleeve cover, the elastic band provides an example of an additional adjustment means in this embodiment. In FIG. 6A, a hem 122 is provided at the edge of the elastic layer 106 which partially covers the back portion of the target backer 108. A continuous elastic member 124 extends through the hem 122 at the edge section to form an elasticized edging. The elastic member 124 serves, when the thermal sleeve cover 126 is slipped over the target backer 108, to contract, thus pulling in all directions on the thermal sleeve cover toward the center of the back surface of the target backer to draw the target of thermal film layer 102 (which is not shown in this embodiment) smoothly and tautly over the front surface of the target backer.

FIG. 6B is a back view of another embodiment of the thermal sleeve cover 128 having an additional adjustment means of drawstring 130 provided within the back surface. A hem 132 is provided at the edge of the elastic layer 106 which partially covers the back portion of the target backer 108. Drawstring 130 extends through the hem 132 extending along the edge section. Drawstring 130 is adapted to be drawn taut for pulling the thermal sleeve cover 128 snugly over the target backer 108. The two co-extending lengths 134 of the drawstring 130 can be tied to hold the cover securely in place on the target backer. In some embodiments, a drawstring toggle (not shown) may be included for adjusting the length of the drawstring extending therethrough. Drawstring 130 acts to pull the thermal sleeve cover 128 in all directions toward the center of the back surface of the target backer. Thus, the thermal sleeve cover 128 is drawn tightly over the target backer, such that the target of the thermal film layer 102 (which is not shown in this embodiment) fits taut and snugly on the front surface of the target backer. Other embodiments can use rope, lace, cord, bungee, or other materials for drawstring 130.

In some embodiments, the thermal sleeve cover is constructed such that the thermal film layer is not joined, connected, attached or laminated to a fabric layer of similar shape. Rather adjustment means are attached directly to the thermal film layer such that the thermal sleeve cover is adjustable to snugly conform to the target backer. FIG. 7 is a front view of such an embodiment wherein the thermal film layer is not attached to a fabric backing of similar shape. In FIG. 7, discrete elastic members 136a, 138a are attached along an edge of one side of the target of thermal film layer 140, and their connecting members 136b, 138b are attached to an opposing edge of the opposite side. The elastic members 136a,136b, 138a, 138b may be attached using mechanical fasteners or sewing or other means familiar to those skilled in the art. The target of the thermal film layer 140 can be stretched over the front of the target backer 142, and the discrete elastic members 136a,136b, 138a, 138b provide sufficient friction between the target and target backer to prevent movement.

As seen in FIG. 7, the thermal film layer 140 can be held in place by elastic straps 136a,136b, 138a, 138b attached to the respective edges of the thermal film layer 140. In this embodiment, the device includes multiple straps sized and shaped to extend about the target backer 142 and to permit attachment to maintain the target of the thermal film layer 140 in a taut manner. In various embodiments, the thermal film layer 140 can be designed to partially or completely cover one or more surfaces of the target backer 142.

Each of the elastic straps 136a,136b, 138a, 138b includes means to secure the strap about the target backer 142. In the embodiment illustrated, at least one of the straps includes a two-piece, snap-in buckle assembly 144 to facilitate connection of the strap upon the target backer. The two-piece buckle 144 has a female portion 146 and a male portion 148 threaded onto the respective front edges of the thermal film layer 140 and can be releasably engaged with each other. The female buckle portion 146 is adjustably attached to the thermal film layer 140. A strap loop (not shown) is formed when the female buckle portion 146 is connected to the male buckle portion 148. This strap loop is configured to extend around and securely engage the back surface (not shown in this embodiment) of the target backer 142. The strap loop can be adjusted to enlarge or reduce the loop as needed to fit around and securely engage the target backer 142 and to retain the target of the thermal film layer 140 snugly against the target backer. The strap loop can be easily and quickly opened and closed by disengaging or engaging, respectively, the male and female buckle portions. Similarly, to the constructions as described above with regards to the buckle assembly 144, other suitable means, for example, strips of hook and loop fastening material 150 such as that sold under the trademark VELCRO®, can also be provided along the edges of the thermal film layer 140.

According to yet another exemplary embodiment shown in FIGS. 8A-8D, the thermal sleeve cover is constructed such that the thermal film layer is not joined, connected, attached or laminated to a fabric layer. In FIGS. 8A-8D, one or more discrete inelastic members are attached along an edge of the target of thermal film layer 154. FIGS. 8A-8D depict an example of a circular shaped target backer 152 covered with a circular shaped thermal sleeve cover 154. FIG. 8A is a front view of the thermal sleeve cover 154 wherein connection points 156 in the form of holes or mechanical hooks are distributed along the edge of the target. The connection points 156 connect to the thermal sleeve cover 154, which is positioned on the front surface of the target and extends across and to the back surface of the target backer 152. A plurality of connection points 156 tautly attach the thermal sleeve cover 154 to the target backer 152 so that thermal sleeve cover provides an effective thermal identification of the target. FIG. 8B is a cut-away view of the connection points 156 as shown in FIG. 8A, which are depicted in this example as mechanical hooks 158. In FIG. 8B, one or more discrete inelastic ropes 160 can be looped through the mechanical hooks 158 of the connection points 156 connected to the edge of the target 154 and used to draw the target 154 tightly to the target backer 152. In various embodiments, inelastic rope 160 can be a single piece (as shown in FIG. 8C), or more preferentially, many pieces (as shown in FIG. 8D).

FIG. 8C is one example of a back view of FIG. 8A, wherein the discrete inelastic rope is a single drawstring 162 that is laced through the connection points 156. In this embodiment, the thermal sleeve cover 154 (FIG. 8A) can be easily varied to assume various degrees of tautness by changing the tautness of the drawstring cords. The connections points 156 are laced together to provide a drawing effect whereby the target of the thermal sleeve cover 154 can be drawn tautly across the front of the target backer 152. The two co-extending lengths 164 of the drawstring 162 can be tied to hold the cover securely in place on the target backer. In some embodiments, a drawstring toggle (not shown) may be included for adjusting the length of the drawstring extending therethrough. Drawstring 162 acts to pull the thermal sleeve cover 154 in all directions toward the center of the back surface of the target backer. Thus, the thermal sleeve cover 154, shown in FIG. 8A, is drawn tightly over the front of the target backer 152, such that the target of the thermal film layer 154 fits taut and snugly on the front surface of the target backer.

FIG. 8D is another example of a back view of FIG. 8A, wherein an adjustment mechanism 166 is composed of a plurality of inelastic ropes 168 that are connected to the thermal film layer 154 (FIG. 8A) by way of the connection points 156 that extends across and to the back of the target backer 152. The embodiment of FIG. 8D can include a material comprising a top end having a top band edge 170 and a bottom end having a bottom band edge 172. The top band edge 170 and the bottom band edge 172 are coupled to a perimeter edge band 174. In this example, the plurality of elastic ropes 168 attaches to the top band edge, the bottom band edge, and the perimeter band edge, to define a grid configuration (a grid of net and/or mesh fabric) such that the ropes are disposed in an overlaying relationship. In this configuration the net mesh configured as a grid configuration functions as a back surface netting. The netting can be temporarily or permanently affixed to the thermal sleeve cover 154 at the corner points. For example, corner points of the grid may include, for example, respective clips to be temporarily connected to the connection points 156, for example, via mechanical hooks 158 as shown in FIG. 8B. In an example embodiment wherein, the netting is permanently attached to the thermal sleeve cover, the netting can be configured to be sufficiently flexible to accommodate a variety of target backers of various sizes and shapes. In various embodiments, the thermal sleeve cover can be configured such that the netting attaches to a surface other than the back surface, for example, a top, bottom or a side surface.

Although formed generally of inelastic fibers, the use of a material, such as, for example, a knit fabric, permits a construction of a flexible, expandable adjustment mechanism 166. The adjustment mechanism 166 enables the thermal sleeve cover 154 to be selectively adjustable to cover target backer 152. For example, the bottom band 172 includes an adjustment fastener, for example, drawstring 176 for selectively adjusting the size of the thermal sleeve cover 154 (FIG. 8A) and to constrain the thermal film layer against the target backer 152. In this embodiment, drawstring fasteners 176 having co-extending lengths 178 can be selectively adjusted by pulling and tying together the co-extending lengths 178. As a result, the thermal sleeve cover 154, shown in FIG. 8A, is drawn tightly over the front of the target backer 152, such that the target of the thermal film layer 154 fits taut and snugly on the front surface of the target backer.

It should be noted that the adjustability of the thermal sleeve cover need not be accomplished in the manners shown in the various embodiments described in. Hence any suitable fastening configuration can be provided, such as buttons/holes, snaps, clips, clamps, zippers, buckles, hook-and-loop (VELCRO®), buttons, hooks, taping, clamps, wire, cord or the like.

In operation, the thermal sleeve cover is positioned over the target backer so that the target backer is substantially retained tautly within the interior of the thermal sleeve cover. The tautness of the surface of the target sleeve cover fitted over the target backer functions to enhance the thermal identification of the target. In embodiments comprising one or additional adjustment mechanisms, the adjustment mechanism can be adjusted as needed to increase the tautness and the thermal identification of the target by further securely tightening the thermal sleeve cover around the target backer. The thermal sleeve cover can be removed from the target backer by reversing the above process and lifting the thermal sleeve off of the target backer. The thermal sleeve cover can easily be switched from thermal to non-thermal targets with no hassle. The thermal sleeve cover can be easily and quickly readjusted to fit different target backers having different sizes and shapes.

It will be apparent to those skilled in the art that various modification and variations can be made to the thermal sleeve cover, system, and method of the present disclosure without departing from the scope of its teaching. By way of example, the thermal sleeve cover in accordance with the present teachings may include a retractable retention apparatus, which may be connected in various ways, such that it can be operated either manually or electronically (employing a small battery pack) to adjust the length of an adjustment mechanism, such as a rope or drawstring, to control the tautness of the surface of the thermal layer and the accuracy of the thermal identification. The retractable retention apparatus may be an easy-to-use portable retracting and locking device similar to a retractable tape measure, a retractable extension cord, or a retractable dog leash. In this way, the rope is retractable and extendable from the retractable retention apparatus. Optionally, the rope or adjusting means may include measurement indicia, such as measurement lines and numerals, printed thereon that can be used to measure the length of rope or length of the adjusting means extending from and retracting within the retractable retention apparatus and consequently more precisely controlling the amount of tautness exerted upon the thermal sleeve cover and the thermal identification.

In other embodiments, the system may be manufactured as a small portable battery-operated electronic device by designing the system to include a battery for use in conjunction with any of the above described mechanical adjustment means, such as, for example, a rope or a drawstring, to achieve the desired tautness.

Additionally, aspects of the invention described in the context of particular embodiments or examples may be combined or eliminated in other embodiments. Although advantages associated with certain embodiments of the invention have been described in the context of those embodiments, other embodiments may also exhibit such advantages. Additionally, not all embodiments need necessarily exhibit such advantages to fall within the scope of the invention.

HIGHLY STABLE TARGET SLEEVE IDENTIFIABLE TO THERMAL WEAPON SIGHTS

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