Abstract:
Heat Mitigating handguards for rifles and method of manufacture thereof. The handguards are made from advanced thermoplastics that mitigate heat transfer, are 20% lighter than aluminum with like strength characteristics.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of priority of U.S. provisional application No. 62/045,708, filed Sep. 4, 2014, the contents of which are herein incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a weapon handguard and the method of manufacture thereof. More particularly, to the heat mitigating capabilities of the thermoplastic weapon handguard, and the method of molding during the manufacturing process. 
         [0003]    Existing aluminum handguards absorb extremely high levels of radiant barrel heat generated by firing the rifle and transfer that heat through the handguard directly to the operator. Radiant heat from the barrel or suppressor can rapidly reach &gt;800° F. As heat transfer occurs, aluminum handguards can quickly exceed temperatures over 200° F., well above the pain threshold for human skin and can literally burn the skin. This heat transfer creates significant degradation of shooter effectiveness, a measurable decrease in accuracy over longer distances, and loss of basic control during maneuver. These effects, either singularly or in combination reduce the overall effectiveness of the shooter. 
         [0004]    Handguards mitigate or outright negate nearly all of the heat related problems of current handguards. They remain comfortable to the touch, well below the pain threshold for human skin while constantly tested against standard protocols of 210 rounds fired on automatic. By removing heat from the shooting equation, the shooter can focus on marksmanship principles that improve accuracy during sustained engagements and control during maneuver. 
         [0005]    As can be seen, there is a need for an improved insulation unit for rifles. 
       SUMMARY OF THE INVENTION 
       [0006]    In one aspect of the present invention, a thermally protective handguard for a firearm, comprises at least one handguard member comprising a plurality of ventilation apertures defined between an outer surface and an inner surface of the handguard member, and a plurality of elevated ridges extending upwardly from the outer surface of the handguard. The handguard may further comprise a first and a second handguard member, the first handguard member is adapted to cover an upper portion of a barrel of the weapon, the second handguard member is adapted to cover a lower portion of the weapon barrel. In another aspect of the invention, the handguard assembly may further comprise a mounting ring assembly, having a top mounting ring and a bottom mounting ring, the top mounting ring comprising a plurality of holes for receiving a fastener to secure the first handguard member to the top mounting ring. 
         [0007]    In other aspects of the invention, the mounting ring assembly further comprises an annular groove defined in an inner surface of the top mounting ring and the bottom mounting ring. The mounting ring assembly providing a clamping attachment between the top mounting ring and the bottom mounting ring. 
         [0008]    In another aspect of the invention, the handguard assembly may further comprise a barrel nut having a substantially ring shaped cylinder and a plurality of slots defined in an outer surface of the barrel nut. The barrel nut may be clamped by the mounting ring assembly within the annular groove. 
         [0009]    In yet another aspect of the invention, the handguard member is formed from a nano-enhanced polymeric material comprising: a composition of carbon tube nano fiber material, and micro-sphere glass material. 
         [0010]    These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1 : Is a perspective view of a short handguard. 
           [0012]      FIG. 2 : Is a perspective view of a long upper handguard. 
           [0013]      FIG. 3 : Is a perspective view of a long lower handguard. 
           [0014]      FIG. 4 : Is a perspective view of a top mounting ring. 
           [0015]      FIG. 5 : Is a perspective view of a bottom mounting ring. 
           [0016]      FIG. 6 : Is a side elevation view of a barrel nut. 
           [0017]      FIG. 7 : Is an end view of the barrel nut from a receiver end of the barrel nut. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
         [0019]    Broadly, an embodiment of the present invention provides technology advancements that make it possible to solve long standing heat related problems through the development and use of advanced materials with comparable strength characteristics of traditional aluminum weapon handguard systems, while still capable of protecting the shooter from related radiant barrel heat. The present invention includes a rifle handguard that is distinguished by high heat protective qualities, lightweight design, durability, and resistance to extreme environments. But most importantly, it serves as thermal insulation that mitigates most or outright negates nearly all of the heat related attributes of the current handguard systems, while maintaining existing battle tested design of current weapons handguard systems. 
         [0020]    The present invention utilizes high grade engineered advanced thermoplastic material to upgrade the design and capabilities of existing weapon handguard systems. This material maintains critical properties such as strength, toughness, operational durability and abrasion resistance. The present invention allows significant airflow to cool the barrel to within the manufacture specifications. The handguard of the present invention promotes and facilitates the attachment of peripheral device attachments, while being reconfigurable and modular in design and practical use. The handguard does not in negatively affect the operation of the weapons system, such as its accuracy, function, reliability, or cooling. 
         [0021]    The present invention includes: a combination of polymeric materials that includes one or more types of fibers that are used to form any portion of the handguard; mounting rails or peripheral devices; a combination of polymeric materials that includes one or more types of nanoparticles that are used to form any portion of the handguard, mounting rails or peripheral devices; using polymeric-based materials with one or more nanoparticles, where the nanoparticles introduce increased or decreased multiple functionalities such as heat-insulation+/−strength+/−toughness+/−hardness+/−electrical conductivity+/−sensing. 
         [0022]    The present invention further includes a method of molding nano-enhanced polymeric materials into the desired shapes and sizes, in a plurality or combination of colors; a method of molding nano-enhanced polymeric materials into the desired shapes and sizes, to include labels, logos, and any their desired marking; a method of forming the polymeric-based materials and material configurations through use of a mold; a method of forming the polymeric-based materials and material configurations through use of a mold that may include heat and/or pressure and/or catalysts sufficient to cause an alteration of the material such that it facilitates the forming of such materials in a mold; and a method of forming the polymeric-based materials and material configurations through use of a mold that may include heat and/or pressure and/or catalysts sufficient to cause an alteration of the material such that it facilitates the hardening or curing of such materials in a shape defined by the mold. 
         [0023]    Referring now to the Figures, the present invention may comprise the following components: an Upper Handguard-Short as seen in reference to  FIG. 1 ; an Upper Handguard-Long  12 , as seen in reference to  FIG. 2 ; a Lower Handguard-Long,  FIG. 3 ; an Upper Mounting Ring  16 , as seen in reference to  FIG. 4 ; a Bottom Mounting Ring  18 , as seen in reference to  FIG. 5 , and a Barrel Nut  20 , as seen in reference to  FIGS. 6 and 7 . 
         [0024]    The long free floating handguard  12  &amp;  14  is designed for the M4A1 Carbine so that the only point of contact between the rifle and the handguard  12  &amp;  14  is at the barrel nut  20 . In this configuration, there is no interference with the barrel while shooting. Two piece designs allows the upper handguard  12  and lower handguard  14  hand guards to be installed without removing the front site of the rifle, clamping securely to the barrel nut  20  with only two locking screws, saving time and maintenance costs. The upper portion of the handguard  12  may be made from the highest performing melt-process-able thermoplastic material with superior resistance to elevated temperatures. The material is capable of performing under severe stress conditions at continuous temperatures to 500° F. (260° C.). It&#39;s extremely low coefficient of linear thermal expansion and high creep resistance deliver excellent dimensional stability over its entire use range. It has a Tg (glass transition temperature) of 537° F. (280° C.). 
         [0025]    The handguard  12  is approximately 13 inches long and covers the top half of the weapons barrel. To ensure proper fitting on automatic rifle (AR) weapon variants, a slot  13  may be cut into the top of the handguard  12  to accommodate the front sight and gas tube assemblies. 
         [0026]    The mounting rail incorporated into the top and sides of the upper handguard  12  carries the official title MIL-STD-1913. It is also known by the NATO designation STANAG 2324. This bracket is used on various weapons systems in order to provide a standardized mounting platform for telescopic sights and other accessories, such as tactical lights and laser sighting modules. The upper handguard  12  assembly attaches to the weapon&#39;s upper receiver by means of an attachment bracket discussed below. Preferably, the upper handguard  12  may have a plurality of holes  11  on each side for mounting screws, four equally spaced on each side, for attaching with corresponding holes  15  defined the lower portion  14 . 
         [0027]    The lower portion of the handguard  14  is made from the highest performing melt-process-able thermoplastic material with superior resistance to elevated temperatures. The material is capable of performing under severe stress conditions at continuous temperatures to 500° F. (260° C.). It&#39;s extremely low coefficient of linear thermal expansion and high creep resistance deliver excellent dimensional stability over its entire use range. It has a Tg (glass transition temperature) of 537° F. (280° C.). 
         [0028]    The handguards  10 ,  12 ,  14  are formed of a thermoplastic base material such as, a carbon fiber nano-tube material, and glass micro-spheres. 
         [0029]    The lower handguard  14  is approximately 13 inches long and covers the bottom half of the weapons barrel. The mounting rail incorporated into the bottom handguard lower carries the official title MIL-STD-1913. It is also known by the NATO designation STANAG 2324. This bracket is used on various weapons systems in order to provide a standardized mounting platform for telescopic sights and other accessories, such as tactical lights and laser sighting modules. The lower handguard assembly  14  attaches to the upper handguard  12  be means of holes  14  and a mounting screws, four equally spaced on each side, for attaching the lower portion  14 . 
         [0030]    The upper and lower handguards  10 ,  12 ,  14  may further comprise a plurality of ventilation apertures  23  defined along the longitudinal length of the handguards. Preferably, the apertures  23  are defined along top and side surfaces to permit ventilation and cooling airflow around the barrel of the weapon. The plurality of ventilation apertures  23  defining a ventilation surface area for the handguard  10 ,  12 ,  14 . 
         [0031]    Additionally, the handguards  10 ,  12 ,  14  may also comprise a plurality of elevated ridges  24  extending upwardly from the outer surface of the handguards. The ridges  24  provide an increased surface area for the radiation and dispersion of heat that may be transferred from the barrel to the handguards  10 ,  12 ,  14 . Some of the ridges  24  may be intersected by the apertures  23  to provide a combined cooling effect. 
         [0032]    The barrel nut  20  serves to securely attach the rifle barrel to the upper receiver  12  and serves as the mounting platform for the Mounting Ring  16  &amp;  18 . The barrel nut  20  comprises an annular ring for surrounding the barrel of the weapon and is secured to the weapon at an aft end of the barrel, proximal to the receiver of the weapon. The barrel nut  20  may further comprise four slots  21  that are preferably equally spaced around the nut  20  that act to allow tightening using a standard AR-15/M-4 barrel wrench. 
         [0033]    The mounting ring  16  &amp;  18  is a two part assembly, comprising an upper mounting ring  16  and a lower mounting ring  18 . The upper and lower mounting rings  16  &amp;  18  are preferably made from aluminum that serves as an attachment base for the thermoplastic handguard assembly  12 . The mounting ring  16  &amp;  18  also serves as the mounting attachment to the weapon by clamping onto the barrel nut assembly  20 . This is accomplished by two screws applying pressure evenly over the barrel nut  20  that is recessed into a grove  25  defined in both the upper  16  and lower  18  portions of the mounting ring. 
         [0034]    The Mounting Ring Top  16  may house six screws  19  that secure the thermoplastic assembly  12  to the mounting ring  16 . The top portion of the mounting ring  16  may also have two optional studs  17  on the weapon receiver side at the top that acts to prevent counter rotation of the handguard assembly  12 . 
         [0035]    As seen in reference to  FIG. 1 , the short handguard  10  is a replacement for the M4A1 Service Carbine. The MIL-STD-1913 rail or STANAG 2324 handguard is a quick and simple two piece drop in design that attaches through use of the weapon&#39;s existing delta ring. The short handguards  10  are not free floated. The short handguard  10  is made from the highest performing melt-processable thermoplastic material with superior resistance to elevated temperatures. The material is capable of performing under severe stress conditions at continuous temperatures to 500° F. (260° C.). It&#39;s extremely low coefficient of linear thermal expansion and high creep resistance deliver excellent dimensional stability over its entire use range. It has a Tg (glass transition temperature) of 537° F. (280° C.). The short handguard  10  is approximately seven (7) inches long and covers the weapons barrel. 
         [0036]    The mounting rail incorporated into the bottom handguard lower carries the official title MIL-STD-1913. It is also known by the NATO designation STANAG 2324. This bracket is used on various weapons systems in order to provide a standardized mounting platform for telescopic sights and other accessories, such as tactical lights and laser sighting modules. 
         [0037]    The Handguard System described and claimed herein, is the next generation in tactical rifle hand guards due to the innovative design that utilizes high grade engineered thermoplastic material and a special mix of other advanced materials to upgrade the existing battle tested design of the Picatinny Rail system. The integration of thermo plastic materials enhances critical properties such as strength, toughness, operational durability and abrasion resistance. 
         [0038]    The present invention serves as thermal insulation to the user that mitigates or outright negates nearly all of the heat related attributes of the current rail system. Additionally, the hand-guard/rail system does not in any way affect the operation of the weapons system, such as accuracy, function, reliability, or cooling. The rail system design allows the weapon to vent and cool in accordance with the manufacturers specifications, thus preventing safety hazards such as ammunition cook offs. Using a mold-able thermo plastic material system allows much more innovative designs to emerge in the future, adaptation to a wider variety of weapons, and will reduce overall weight. The handguard  12 ,  12 ,  14  may be designed for the M4A1 Carbine in which the only point of contact between the rifle and the handguard is at the barrel nut  20 . In this configuration, it is the barrel that is free floated, and as such nothing is touching or interfering with the barrel while shooting. The length of handguard  12  &amp;  14  may be about 13″ long and leave the gas bloc or front sight post exposed. Quad rail free float handguards feature four full length Picatinny attachment points for accessories such as tactical lights, fore grips, bipods, and sling swivels. The present invention may be designed for military, law enforcement, and professional shooters, the handguard virtually erases the negative high heat aspects related with sustained rates of fire. Negating the burning hand distraction allows the shooter to hold the rifle as it was designed with a focus on control and accuracy. 
         [0039]    The method of making and attaching the present invention may include the following: attaching the mounting rails to the handguard, using a plurality of mating and/or interlocking grooves, combined with permanent or temporary fasteners; molded-in or formed-in threaded inserts or other receptacles designed to work in conjunction with a mating part of a fastener system; fastener system used to fasten multiple parts of the handguard together with or without the use of hand tools; fastener system used to attach the handguard to the firearm with or without the use of hand tools; a handguard and/or attachment system that provides enough heat insulating effect, such that it does not reach a temperature on the external surface after normal/heavy operational use of the firearm to which it is attached, that causes the user to loosen or alter their grip on the handguard and/or attachment system; a handguard and/or attachment system that provides enough heat-insulating effect, such that it does not reach a temperature on the external surface that causes burns or scarring or material alteration when touched during or after normal/heavy operational use of the handguard to which it is attached; a base handguard without any hand tools, using a permanent or temporary system of fasteners; the base handguard without the use hand tools, using a permanent or temporary system of fasteners; assembling the peripheral device mounting system without the use of hand tools, using a permanent or temporary system of fasteners; using multiple layers of materials to form the handguard or mounting rails or peripheral devices; forming or integrating multiple material layers during the manufacturing process; forming or integrating multiple material layers during the assembly or attachment process(es). 
         [0040]    The present invention solves the problem related to handguard heating and utilizes a material that does not transfer radiant rifle barrel heat through the handguard to the operator. Handguard development is based on the standard infantryman&#39;s basic load (210 rounds) as the primary objective. The handguard should allow the shooter to fire that basic load and still maintain positive control of his weapon, and by positive control, accuracy at all tactical ranges. New handguards may remain relatively comfortable to the touch even as barrel temperatures push to &gt;800 F. This material also withstands the operational environment and abuses inflicted on a small arms weapons system. In order to provide a stable platform, the rail may not flex as the barrel heats and cools. 
         [0041]    It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.