Abstract:
Elements of the present invention relate to the application of force to a bolt carrier within a firearm when the firearm becomes inoperable. Some elements relate to the application of force by leverage applied with a bar inserted through a weapon&#39;s magazine well. Some elements relate to a bar end with prongs that provide for clearance of a weapon&#39;s bolt shaft while engaging the weapon&#39;s bolt carrier. Some elements relate to accommodation of multiple weapon dimensions with a single tool.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The application claims priority to U.S. Provisional Patent Application No. 62/203,169 titled “Apparatus for Field Maintenance of Jammed Firearms” which was filed Aug. 10, 2015. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to methods and apparatus for restoration of functionality to weapons when they become jammed. 
         [0004]    2. Background and Related Art 
         [0005]    Most modern firearms employ cartridges that are cycled into and out of a weapon&#39;s chamber for firing a projectile at a target. These cartridges are typically made of brass or another metal alloy that resists corrosion and has low friction characteristics. Some cartridges are made from steel, but have a lacquer coating or some other coating to impede corrosion. Steel cartridges are typically vastly inferior to brass, but are produced more economically. 
         [0006]    A typical rifle cartridge may be described with reference to  FIGS. 1 and 2 , which is a side view of a typical rifle cartridge. A typical rifle cartridge  1  comprises a brass or metallic body  2  with a rim  6  at the base of the cartridge and extractor groove  8  for manipulating the cartridge during loading and extraction operations. The shoulder  10  and neck  12  serve to taper a larger cartridge down to the diameter of the bullet or projectile  4 . A cartridge is typically hollow and is filled with a specific amount of propellant, otherwise known as gun powder. The projectile  4  is typically placed into the open end of the cartridge neck with a friction fit so that it does not slide out before firing. 
         [0007]      FIG. 2  shows an end view of the cartridge shown in  FIG. 1  with the outer diameter of the cartridge base defined by the rim  6 . This typical cartridge is a centerfire cartridge wherein the center of the cartridge base comprises a hole  20  into which a primer is friction fit. The primer serves to ignite the propellant in the cartridge when the primer is struck by the firing pin of a weapon. 
         [0008]    The typical cartridge shown is the most common in military, hunting, target and other sport rifles and has a rebated rim that has an outer diameter typically slightly smaller than the body diameter of cartridge. However, another common cartridge type has a rim that protrudes beyond the diameter of the cartridge with no extractor groove. 
         [0009]    A cartridge is typically manipulated into and out of a weapon&#39;s firing chamber by the weapon&#39;s action. Many types of actions are in use today, but the most common are manual actions, such as the bolt action, lever action and pump action, the semi-automatic action and the automatic or fully-automatic action. 
         [0010]    The manual action weapons require manual manipulation of a bolt, lever or sliding forearm “pump” to manually extract and load cartridges from and into the firing chamber. A semi-automatic weapon automatically loads and extracts a cartridge into and out of a weapon once each time the trigger is pulled. The user needs only to pull the trigger each time he/she desires to fire the weapon until the magazine is empty. A fully-automatic weapon&#39;s action loads cartridges into and out of the weapon automatically and continuously as long as the trigger remains pulled and the magazine contains cartridges. 
         [0011]    When a cartridge is bent, deformed, dirty, corroded or has otherwise lost its standard geometric and/or frictional properties or when the weapon is dirty, corroded, damaged or otherwise impaired, the cartridge may become difficult to load or unload or may even jam somewhere in the action or in the firing chamber. This jamming is common when old, low-quality and/or dirty ammunition is used or when a weapon is dirty, unlubricated and/or damaged. 
         [0012]    The AR-10 rifle is a semi-automatic, 7.62×51 mm NATO caliber weapon designed by Armalite Corporation. Several variants and copies have been manufactured and are still manufactured today. It uses a direct impingement gas action with a rotary bolt locking mechanism. The direct impingement gas operation design directs hot exhaust gases from the weapon barrel, through a tube, against a bolt key and then into the bolt carrier. This design allows hot combustion gases to flow over the bolt carrier and action of the weapon. After extended use, these combustion gases will cause a buildup of residue that can cause the action to jam. 
         [0013]    The AR-15 is another Armalite-designed weapon that is basically a scaled down version of the AR-10 using the 5.56×45 mm caliber NATO cartridge. It uses the same basic design as the AR-10 and suffers from the same weaknesses in design. The AR-15 was modified for the US military and adopted as the M16 and M4 select-fire, fully-automatic weapons. When put into widespread military use in Vietnam, the M16 suffered from frequent jamming unless cleaned properly and used with ammunition employing clean-burning propellant. 
         [0014]    As the design is a military standard, dozens of manufacturers now manufacture AR-15 or AR-15 style weapons. In fact, it is one of the most popular and ubiquitous rifles in the U.S. civilian market today while the M16 is an extremely common military weapon used in dozens of military forces across the world. 
         [0015]    Other weapons with the same basic design include the DPMS Panther Arms LR-308, LRAP4 and GII AP4; the Colt MARC 901 rifles; and the Lewis Machine and Tool LM308SS in 7.62×51 mm caliber and many well-known models in 5.56×45 mm caliber from DPMS Panther Arms, Colt, LMT, Rock River Arms, Bushmaster, STAG Arms, Bravo Company USA, CMMG, Daniel Defense, Noveske, Sig Sauer, Smith &amp; Wesson, Ruger and others. 
         [0016]    Many automatic and semi-automatic weapons are susceptible to jamming if they are poorly lubricated or dirty as the actions are operated by gas pressure and spring return mechanisms that are specifically tuned for the forces encountered during normal operation. Hence, when friction forces build up, the weapon simply stops functioning because the spring forces are not balance to overcome the increased frictional forces in the action. With a manual action, the user can simply increase the force on the bolt, but with a semi-automatic, the spring force cannot be increased and the weapon jams. 
         [0017]    While the AR-10 and AR-15 function well when cleaned and maintained properly and used with high quality ammunition, they can jam frequently when poorly lubricated and/or dirty. Typically, when the weapon jams, the bolt carrier, bolt or cartridge become stuck in the chamber or receiver. When this occurs, the action must be forced open manually. 
       BRIEF SUMMARY OF THE INVENTION 
       [0018]    An apparatus is provided for convenient opening of a jammed action in a semi-automatic or automatic weapon. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0019]    The objects and features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
           [0020]      FIG. 1  shows a typical, prior-art rifle cartridge in a side view. 
           [0021]      FIG. 2  shows the typical, prior-art rifle cartridge of  FIG. 2  in an end view. 
           [0022]      FIG. 3  shows an embodiment of the present invention in a flat format; 
           [0023]      FIG. 4  shows an embodiment of the present invention with dimensions relative to generic firearm dimensions; 
           [0024]      FIG. 5  shows an embodiment of the present invention with angular bend points; 
           [0025]      FIG. 6  shows an embodiment of the present invention with curved curve points; 
           [0026]      FIG. 7  shows an embodiment of the present invention in relation to an exemplary bot carrier group; 
           [0027]      FIG. 8  shows an embodiment of the present invention in relation to an exemplary lower receiver of a weapon; 
           [0028]      FIG. 9  shows a prior art exemplary lower receiver with integral magwell; 
           [0029]      FIG. 10  shows a section view of an embodiment of the present invention in relation to an exemplary magwell with dimensions; 
           [0030]      FIG. 11  is a side sectional view of an embodiment of the present invention in relation to an exemplary prior art lower receiver with integral magwell; 
           [0031]      FIG. 12  is a top view of an embodiment of the present invention in relation to an exemplary lower receiver with integral magwell. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    A description of embodiments of the present invention will now be given with reference to the Figures. It is expected that the present invention may take many other forms and shapes, hence the following disclosure is intended to be illustrative and not limiting, and the scope of the invention should be determined by reference to the appended claims. 
         [0033]    Some embodiments of the present invention can be described with reference to  FIG. 3 . 
         [0034]    These embodiments comprise a substantially rigid bar  30  that is approximately 0.5 cm thick  31  throughout its length and 2.5 cm wide at a wide end  32  while being approximately 1.8 cm wide at a narrow end  33 . The wide end  32  of the bar  30  terminates in two wide-end prongs  35  on either side of the bar. These prongs  35  may be approximately 0.15 cm wide and may taper to a point at their ends. The gap  36  between the prongs  35  is approximately 2.3 cm wide (transverse to the bar&#39;s longitudinal axis) and approximately 1.5 to 2.5 cm deep (along the bar&#39;s longitudinal axis). In an exemplary embodiment, the wide-end prong length or wide-end gap depth may be 2.0 cm. 
         [0035]    The narrow end  33  of the bar  30  may also terminate with two narrow-end prongs  37 , which are approximately 0.4 cm wide. The gap  38  between the two narrow-end prongs  37  may be approximately 1.0 cm wide and approximately 1 cm deep along the longitudinal axis of the bar. In an exemplary embodiment, the narrow-end prong length or narrow-end gap depth may be 1.8 cm. 
         [0036]    The taper  34  from the wide-end width of approximately 2.5 cm and the narrow-end width of 1.8 cm may occur at almost any place along the length of the bar, but, in a preferred embodiment, will occur at a location that is at least approximately 7.5 cm from the ends of the narrow-end prong tips, thereby making the narrow portion  33  of the bar  30  at least approximately  7 . 5  cm in length. In some embodiments, the narrow portion  33  of the bar  30  may extend almost the entire length of the bar  30  such that the taper  34  occurs near the wide-end prongs  35 . 
         [0037]    Embodiments of the present invention may be constructed of various materials such as steel, aluminum, brass and other metals and alloys as well as carbon fiber, high-strength plastics, fiberglass, fiberglass-reinforced plastic and combinations thereof. The thickness of the bar  30  may vary depending on the strength and rigidity of the materials employed. 
         [0038]    Some embodiments of the present invention may be described with reference to  FIG. 4 . These embodiments are described with relative dimensions that relate to common weapon dimensions. In these embodiments, the bolt manipulation bar  50  comprises a narrow end  55  and a wide end  54 . Each end  54 ,  55  may terminate with two prongs  56 ,  57 . In these embodiments, the narrow end  55  of the bar has a narrow-end length “A”  45  that is at least as long as the distance from the center of an AR-15/M16 rifle bolt to the base of the magazine well (magwell) on the AR-15/M16 rifle. These embodiments may further comprise a narrow-end width “B”  46  that is slightly less than the width of an AR-15/M16 magwell from side to side so that the narrow end  55  will fit into an AR-15/M16 magwell without an interference fit. 
         [0039]    These embodiments may further comprise a gap width “C”  47  that is slightly wider than the diameter of an AR-15/M16 bolt shaft such that the prongs  56  at the narrow end  55  of the bar  50  will fit around the AR-15/M16 bolt shaft to engage the bolt carrier. These embodiments may further comprise a gap depth “D”  48  that is at least ½ the diameter of the AR-15/M16 bolt shaft diameter. 
         [0040]    At the wide end  54  of the bar, some embodiments may comprise a wide-end width “E”  51  that is slightly less than the width of an AR-10 magwell such that the wide end  54  of the bar will fit into an AR-10 magwell without an interference fit. These embodiments may further comprise a wide-end gap width “G”  53  that is slightly larger than the diameter of an AR-10 bolt shaft such that the prongs  57  at the wide end  54  of the bar  50  may extend around the sides of an AR-10 bolt shaft. Some embodiments may further comprise a wide-end gap depth “F”  52  that is approximately ½ the diameter of an AR-10 bolt shaft, again allowing engagement of prongs  57  around the AR-10 bolt shaft. 
         [0041]    Other embodiments of the present invention may be described with reference to  FIG. 4 . 
         [0042]    These embodiments are described with relative dimensions that relate to generic firearm dimensions. In these embodiments, the bolt manipulation bar  50  comprises a narrow end  55  and a wide end  54 . Each end  54 ,  55  may terminate with two prongs  56 ,  57 . In these embodiments, the narrow end  55  of the bar has a narrow-end length “A”  45  that is at least as long as the distance from the center of a first firearm bolt to the base of the magazine well (magwell) of the first firearm. These embodiments may further comprise a narrow-end width “B”  46  that is slightly less than the width of a first firearm magwell from side to side so that the narrow end  55  will fit into a first firearm magwell without an interference fit. 
         [0043]    These embodiments may further comprise a gap width “C”  47  that is slightly wider than the diameter of a first firearm bolt shaft such that the prongs  56  at the narrow end  55  of the bar  50  will fit around the first firearm bolt shaft to engage the bolt carrier. These embodiments may further comprise a gap depth “D”  48  that is at least ½ the diameter of the first firearm bolt shaft diameter. 
         [0044]    At the wide end  54  of the bar, some embodiments may comprise a wide-end width “E”  51  that is slightly less than the width of a second firearm magwell such that the wide end  54  of the bar will fit into a second firearm magwell without an interference fit. These embodiments may further comprise a wide-end gap width “G”  53  that is slightly larger than the diameter of a second firearm bolt shaft such that the prongs  57  at the wide end  54  of the bar  50  may extend around the sides of a second firearm bolt shaft. Some embodiments may further comprise a wide-end gap depth “F”  52  that is approximately  1 / 2  the diameter of a second firearm bolt shaft, again allowing engagement of prongs  57  around the a second firearm bolt shaft. 
         [0045]    Further embodiments of the present invention may be described with reference to  FIG. 4 . These embodiments are described with relative dimensions that relate to common weapon dimensions. In these embodiments, the bolt manipulation bar  50  comprises a narrow end  55  and a wide end  54 . Each end  54 ,  55  may terminate with two prongs  56 ,  57 . In these embodiments, the narrow end  55  of the bar has a narrow-end length “A”  45  that is at least as long as the distance from the center of an AR-15/M16 rifle bolt to the base of the magazine well (magwell) on the AR-15/M16 rifle. These embodiments may further comprise a narrow-end width “B”  46  that is slightly less than the width of an AR-15/M16 magwell from side to side so that the narrow end  55  will fit into an AR-15/M16 magwell without an interference fit. 
         [0046]    These embodiments may further comprise a gap width “C”  47  that is slightly wider than the diameter of an AR-15/M16 bolt shaft such that the prongs  56  at the narrow end  55  of the bar  50  will fit around the AR-15/M16 bolt shaft to engage the bolt carrier. These embodiments may further comprise a gap depth “D”  48  that is at least ½ the diameter of the AR-15/M16 bolt shaft diameter. 
         [0047]    At the wide end  54  of the bar, some embodiments may comprise a wide-end width “E”  51  that is slightly less than the width of a DPMS LR-308 magwell such that the wide end  54  of the bar will fit into a DPMS LR-308 magwell without an interference fit. These embodiments may further comprise a wide-end gap width “G”  53  that is slightly larger than the diameter of a DPMS LR-308 bolt shaft such that the prongs  57  at the wide end  54  of the bar  50  may extend around the sides of a DPMS LR-308 bolt shaft. Some embodiments may further comprise a wide-end gap depth “F”  52  that is approximately ½ the diameter of a DPMS LR-308 bolt shaft, again allowing engagement of prongs  57  around the DPMS LR-308 bolt shaft. 
         [0048]    In some embodiments of the present invention the narrow-end and/or wide-end gap depths may be less than ½ the diameter of a rifle bolt and prong lengths may than stated above while still allowing at least partial engagement of the prongs with the bolt carrier. These embodiments may comprise smaller gap depths and prong lengths. 
         [0049]    Some embodiments of the present invention may be described with reference to  FIG. 5 . In these embodiments, the bar  60  is not a flat bar, but is bent at bend points  61  and  62 . These bends provide a fulcrum that is closer than the bottom edge of the magwell thereby increasing leverage on the bolt during use as compared to a flat bar. Accordingly, the distances  63 ,  64  are less than the distance from the center of a weapon&#39;s bolt or barrel axis to the base of the magwell. In some embodiments the distances  63  and  64  may be different to accommodate two different weapons. In some embodiments, these weapons may be the AR-15/M16 and the AR-10. In some embodiments, these weapons will be the AR-15/M16 and the DPMS LR-308. 
         [0050]    Some embodiments of the present invention may be described with reference to  FIG. 6 . In these embodiments, the bar  70  is not a flat bar, but is curved at curve points  71  and  72 . These curves provide a fulcrum that is closer than the bottom edge of the magwell thereby increasing leverage on the bolt during use as compared to a flat bar. Accordingly, the distances  73 ,  74  are less than the distance from the center of a weapon&#39;s bolt or barrel axis to the base of the magwell. In some embodiments the distances  73  and  74  may be different to accommodate two different weapons. In some embodiments, these weapons may be the AR-15/M16 and the AR-10. In some embodiments, these weapons will be the AR-15/M16 and the DPMS LR-308. 
         [0051]    Some embodiments of the present invention may be described with reference to  FIG. 7 .  FIG. 7  is a diagram illustrating the prior art bolt carrier group  80  of an AR-15/M16 rifle. The bolt carrier  85  is actuated by gas pressure on the gas key  87 . The bolt  83  has a bolt shaft  84  that slides into a bolt hole  88  in the bolt carrier  85  and rotates within the bolt hole  88 . Locking lugs  89  on the bolt engage a barrel extension (not shown) to lock the bolt in place during firing. In normal use, the bolt  83  will rotate the locking lugs  89  in the barrel extension to fire a cartridge and subsequently rotate again, in response to gas pressure on the gas key  87  to disengage the barrel extension and allow movement of the bolt to extract the spent cartridge and chambering of a new cartridge. 
         [0052]    In a typical weapon, when assembled, the bolt carrier group  80  resides in an upper receiver (not shown) which is assembled with a lower receiver (partially shown) which comprises a magazine well  82 . When fully assembled, the magazine well  82  is oriented below the bolt carrier as shown in  FIG. 7 . If the weapon becomes jammed, embodiments of the present invention  86  may be inserted into the magazine well (magwell)  82  and these embodiments  86  may be manipulated to engage the bolt carrier and pry against the bolt carrier so as to apply force against the bolt carrier and force it open. Once the bolt is opened, the weapon may be rendered safe for transport or for immediate maintenance. 
         [0053]    Some embodiments of the present invention may be described with reference to  FIG. 8 . These embodiments are illustrated with reference to a prior art lower receiver  91  for an AR-15/M16 rifle. This lower receiver  91  comprises an integral magwell into which a magazine may be inserted for feeding cartridges into the weapon during semi-automatic or automatic use. Embodiments of the present invention  90  may be inserted into the magwell  92  for manipulation of a bolt carrier (not shown in  FIG. 8 , but shown in  FIG. 7 ) that resides above the magwell  92 . As illustrated, it is evident that these embodiment must have a width  46 ,  51  (shown in  FIG. 4 ) that is less that the width of the magwell  92  to allow movement within the magwell  92 . However, these embodiments must be wide enough to accommodate prongs  93  that are spaced far enough apart to accommodate the bolt shaft  84  between them. 
         [0054]      FIG. 9  is a side view of a prior art AR-15/M16 lower receiver  101  with an integral magwell  100  into which embodiments of the present invention  102  may be inserted. Typical dimensions of the lower receiver and magwell are illustrated therein. 
         [0055]      FIG. 10  is a sectional view of a prior art AR-15/M16 magwell  110  showing a section of an embodiment of the present invention  111  inserted in the magwell. Typical magwell dimensions are shown therein. The magwell width  112  is shown at 0.898 inches with a tolerance of +−0.010 inches. Accordingly, the width of an embodiment of the present invention that accommodates this weapon must be less than 0.888 inches. To allow clearance for uninhibited, non-interference movement within the magwell, an exemplary embodiment may have a width of less than 0.75 inches. 
         [0056]      FIG. 11  is a diagram showing a sectional side view of a prior art AR-15/M16 lower receiver  101  with integral magwell  100 . An embodiment of the present invention  102  is inserted into the magwell  100 . Typical dimensions are shown thereon in inches. 
         [0057]      FIG. 12  is a diagram showing top view of a prior art AR-15/M16 lower receiver  101  with integral magwell  100  and an embodiment of the present invention  102  inserted into the magwell  100 . Typical dimensions are shown thereon in inches. 
         [0058]    The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.