Abstract:
A gun stock for a shoulder mounted firearm has a rear face with an upper portion extending downward from the heel of the stock at a first angle from about 0° to 10°, and a lower portion extending downward from the upper portion to the toe of the stock and forming a second angle greater than the first angle, preferably about 35° from vertical. The rear face may be part of a butt plate arranged as a door to cover a storage compartment in the stock, attached to the stock with a hinge at the toe and a latch at the heel. This configuration reduces the likelihood that the toe of the stock will catch on the shooter&#39;s armor or uniform, and places the hinge forward of the toe such that the butt plate may swing under the stock and out of the way when the storage compartment is opened.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority of U.S. Provisional Application No. 61/431,096, filed on Jan. 10, 2011, which is incorporated by reference herein in its entirety. 
     
    
     FIELD 
       [0002]    The present disclosure relates to a butt stock for a firearm, and particularly to a stock with an improved rear face contour and an internal storage compartment. 
       BACKGROUND 
       [0003]    In the discussion of the background that follows, reference may be made to various structures and/or methods. However, the inclusion of such references should not be construed as an admission that all or any of these structures and/or methods constitute prior art. Applicant expressly reserves the right to contest whether any of such structures and/or methods qualify as prior art. 
         [0004]    The discussion in this background section and in the descriptions of the invention may use terms that correspond to the more common uses of the items being described, without intending to exclude other less common usage. For example, the term “rifle” is used because the butt stocks are described in relation to their more common usage on tactical rifles, but there is no intent to exclude the use of the same butt stock on a smooth bore weapon or other types of firearm. Likewise, the butt stocks are described in relationship to the more common usage on a weapon with adjustable length extender/buffer tubes, without intending to exclude their use on a solid or fixed length gun stock. 
         [0005]    With the above qualification in mind, a variety of rifle butt stocks are known for use with an extender tube to adjust the length of pull (LOP), and are available as a replacement stock or as an original equipment stock, such as, for example, the Colt M4 sliding stock. The extender tube connects to a buffer tube (which may include internal recoil attenuating buffers) connected to the receiver, and has position locking holes spaced along the tube to move the butt stock toward or away from the receiver to select the LOP. 
         [0006]    In most butt stocks, the rear face (or butt plate) of the stock is typically shaped in a shallow concave configuration common to most sporting rifle stocks, or in a straight configuration as found on many tactical rifles. However, both such configurations have a sharp bottom corner toe that can snag on armor webbing when a rifleman is wearing body armor, which tends to pull the butt plate away from shoulder contact. In recognition of the snagging problem, some recent stocks have used a rounded toe at the bottom corner. 
         [0007]    Most often the butt stock used with extender/buffer tubes is a molded plastic piece with hollow interior portions that can be used to store cleaning supplies, batteries or other small items. The usual method of access to such storage areas is by removable butt plates, or by trapdoor type covers that pivot away from the stock to expose the storage compartment. There is, however, ample opportunity for improvement in storage compartment access. 
         [0008]    There has also been a recognition that handheld electronic devices such as a GPS, cellular phone, or a combination of navigation and communications device would be better secured in tactical situations if they can be attached to the weapon, rather than kept in a belt holster or uniform pocket. If the rifleman is using the handheld device when a situation requires immediate shouldering of the weapon, wasting time to place the device back into its holster, or trying to hold the device while mounting the weapon, detracts from the attention that should be directed to evaluating and meeting the threat. Taping the device along the stock is a make-shift solution. A short accessory rail along the stock would be an improvement over taping, as would a waterproof pocket attached to or embedded into the stock. There is, however, ample opportunity for improvement in attaching handheld devices to a weapon. 
       SUMMARY 
       [0009]    A butt stock is described with an improved rear face configuration. Another aspect of the described butt stock includes improved storage compartment access. 
         [0010]    An embodiment of the stock has a heel, a toe, and a rear face comprising an upper straight portion extending downward from the heel and forming a first angle in the range of 0 degrees to 10 degrees from vertical, and a lower straight portion extending downward from the upper flat portion to the toe and forming a second angle in the range of 10 degrees to 40 degrees from vertical. In disclosed embodiments, at least a portion of the rear face comprises an elastomeric surface. The rear face may comprise a surface material having a high coefficient of friction when pressed against clothing or body armor. Moreover, at least a portion of the rear face may include a plurality of transverse ridges. 
         [0011]    The rear face of the stock may form part of a butt plate attached to the stock. The butt plate may be arranged to form a door covering a storage compartment in the body of the stock. Such a butt plate can include a hinge on its bottom pivotally coupling the butt plate to the stock body, thereby enabling the butt plate to pivot away from the stock body to expose the storage compartment. A latch on the top of such a butt plate secures the top of the butt plate to the top of the stock body to close the door to cover the storage compartment. The hinge may comprise a pivot pin, and the latch may comprise a spring-loaded bolt. A button actuator may be recessed into the stock body and used to depress the spring loaded bolt to open the latch. Further, a gasket along an inside edge of the butt plate may be included to create a watertight seal when the butt plate is closed and latched. The stock body may comprise a foam block in the storage compartment having at least one cutout for receiving at least one item for storage, and at least one quick access tab for removing the stored item. 
         [0012]    In addition, the butt plate may cover an open end of one or more slots on the stock body that form part of a bracket support structure. When the butt plate is pivoted away from the stock body to expose the open ends of the slots, a bracket with flanges can be installed onto or removed from the stock body by sliding the flanges through the open ends of the slots. Such a bracket may form part of an accessory mounting system to receive an accessory such as a handheld electronic device. The accessory may be received by clipping it to the bracket. 
         [0013]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The following detailed description can be read in connection with the accompanying drawings in which like numerals designate like elements and in which: 
           [0015]      FIGS. 1A and 1B  are a side and rear view, respectively, of an embodiment of a butt stock. 
           [0016]      FIGS. 2A and 2B  are a side and rear view, respectively, of another embodiment of a butt stock. 
           [0017]      FIG. 3  is a perspective view of an embodiment of a bracket for mounting an accessory to a butt stock as in one of  FIGS. 1A and 2A . 
           [0018]      FIG. 4  is a perspective view of an accessory mounted in the bracket of  FIG. 3 . 
           [0019]      FIG. 5  is a perspective view of an embodiment of a bracket for mounting an accessory to a butt stock as in  FIG. 2A . 
           [0020]      FIG. 6  is a perspective view of an accessory mounted in the bracket of  FIG. 5 . 
           [0021]      FIGS. 7A and 7B  are a side and perspective view, respectively, of an embodiment of a butt stock showing a hinged butt plate and storage compartment. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]      FIGS. 1A ,  1 B,  2 A, and  2 B show two similar but different embodiments of a butt stock  10  having a body  15  and a tube cylinder  12  at the top of the body  15  to receive the extender tube of a rifle (not shown) and a trigger latch  20  for engaging and disengaging the latch with position holes in the extender tube that are common to adjustable length stocks of this type. In the depicted embodiments, the body  15  of the butt stock  10  includes dual sling attachment bushings  22 . The butt stock  10  is preferably made from a light-weight molded plastic, as commonly used in this type of adjustable stack, although other materials may be used. 
         [0023]    The butt stock  10  further includes a butt plate  14  located at the rear of the butt stock  10 . The butt plate  14  may function as a trap door covering a rear-opening storage compartment in the butt stock  10  that can be used to hold replacement batteries or other items. The butt plate  14  has a dual sloped shape, with a lesser slope above an inflection point  40  and a greater slope below the inflection point  40 . The inflection point  40  is positioned below the main body of the butt stock  10 . More particularly, the butt plate  14  includes an upper generally straight portion  44  that may slope slightly forward from its upper edge heel  45  to the inflection point  40 , and a lower generally straight portion  42  at a greater forward slope from the inflection point  40  to its lower edge toe  43 . 
         [0024]    The slope angle of the lower portion  42  is greater than the slope angle of the upper portion  44  with respect to a vertical plane from the heel  45 . The slope of the upper portion  44  may range from about 0° to about 10°, preferably about 4°. The slope of the lower portion  42  may range from about 25° to about 45°, preferably about 35°. 
         [0025]    This dual sloped profile of the butt plate  14  enables a smooth and rapid mount to the aiming position even when a rifleman is wearing body armor. Instead of a sharp bottom corner toe that can snag on the armor webbing and pull the butt plate away from shoulder contact, as may occur with a conventionally shaped butt stock, the forward angled lower portion  42  of the butt plate  14  allows the rifleman to raise the weapon and draw it back into shoulder contact without snagging. If the toe  42  of the butt plate  14  contacts the armor padding, the forward angle of the lower portion  42  causes the butt stock  10  to rotate into shoulder contact rather than pull away. 
         [0026]    The butt plate  14  is preferably made from a plastic piece over-molded with a synthetic rubber cover. The cover may include a pattern of horizontal grooves to provide a non-slip surface. 
         [0027]    A hinge plate  46  extends forwardly from the toe  43  on each side of the butt stock  10 . The hinge plates  46  supports the ends of a hinge pin  18  that extends through a lower end of the body  15 , thereby enabling the butt plate  14  to pivot with respect to the body  15  of the butt stock  10 . 
         [0028]    As illustrated in  FIGS. 7A and 7B , a spring loaded latch bolt  80  secures the butt plate  14  to a strike plate  82  in the butt stock  10  when the butt plate  14  is in a closed position, concealing a storage compartment cavity  84  within the butt stock  10 . A button actuator  16  on a side of the butt plate  14  is provided to release the spring loaded latch bolt  80  to allow the butt plate  14  to pivot open on pivot pin  18 . In the depicted embodiment, the button actuator  16  is recessed into the butt plate  14 , and requires the button actuator  16  to be pushed in and downward to prevent accidental unlatching. 
         [0029]    A gasket  86  may be provided on an inside surface of the butt plate  14  disposed to engage an outer edge of the storage compartment  84  to create a watertight seal when the butt plate  14  is closed and latched. The storage compartment may also contain a foam block  87  with a quick access tab  88  attached. The block may, for example, have cutouts  89  for batteries, such as  123 A size lithium batteries, although other or additional cutout patterns can be used. The foam keeps items stored in the storage compartment from rattling, and the tab allows the foam block or the part itself to be extracted quickly. 
         [0030]    When the latch is released by the button actuator  16 , the butt plate  14  pivots downward and forward under the force of gravity. The forward slope of the lower portion  42  of the butt plate  14 , combined with the forward extending hinge plates  46 , place the hinge point  18  well in front of the heel  45  of the butt plate  14 . This configuration enables the butt plate  14  to swing below the body  15  of the butt stock  10  and well out of the way when inserting or removing batteries or other small items in the storage compartment. 
         [0031]    The body  15  of the butt stock  10  may also include an accessory attachment groove or slot  24 , for example, a slot on each side of the body  15  having one end  27  that terminates in the body  15  and another end that opens onto a rear face  25  of the body  15 . When the butt plate  14  is closed, the slot  24  extends slightly beyond a front face  47  of the butt plate  14  and terminates in the butt plate  14 . In the depicted embodiment, the slot  24  is positioned near the top of the body  15 , just below the tube cylinder  12  for the extender tube. Identical slots  24  are located on both sides of the body  15 . The slots  24  can be used to attach an accessory bracket for holding a communication/navigation device to the butt stock  10 , as described below, or to attach an adjustable position cheek rest or other accessory. 
         [0032]    An exemplary accessory bracket  70  is shown in  FIG. 3 . The bracket  70  may be made from a resilient plastic material. The bracket  70  includes a curved body  72 , a mounting flange  74  extending inwardly at each end of the curved body  72  toward the concave side of the curved body  72 , and a lower accessory mounting tab  76  and an upper accessory mounting tab  78  extending outwardly from the convex side of body  72 . Each mounting flange  74  may include an enlarged end  75 . 
         [0033]    To mount the bracket  70 , the butt plate  14  is released and swung open to expose the open ends of the slots  24 . The flanges  74  are slid into the slots  24  so that the mounting tabs  76 ,  78  extend over the cheek weld on one side or the other of the butt stock  10 , as desired. The bracket  70  can be installed with the mounting tabs  76 ,  78  on either side of the butt stock  10 . The butt plate  14  is then closed to prevent the bracket  70  from sliding back out of the slots  24 . The optional enlarged ends  75  on the mounting flanges  74  increase the security of the mounting. Once the bracket  70  is installed, a device such as a communication/navigation device  100  can be mounted between the mounting tabs  76 ,  78 , as shown in  FIG. 4 . 
         [0034]    The butt stock  10  of the embodiment shown in  FIG. 2A  includes an integrally molded mounting cage  26  below the body  15 . The cage  26  has a generally rectangular construction, including an upper member  58 , a front member  54 , a lower member  50 , and a rear member  62  that together bound an opening  64 . The cage  26  has slots for bolt and nut attachment of an accessory holder. In particular, the upper member  58  includes a slot  60 , the front member  54  includes a slot  56 , and the lower member  50  includes a slot  52 . 
         [0035]      FIG. 5  shows a bracket  30  configured to be mounted to the cage  26 . The bracket is preferably made from a resilient plastic material, although other materials may be used. The bracket  30  includes a body  38 . A straight flange  34  and an L-shaped flange  36  each extend outwardly from one side of the body  38 , the L-shaped flange  36  having a leg  37  extending generally parallel to the body  38 . Two accessory mounting tabs  31  extend outwardly from an opposite side of the body  38 , each accessory mounting tab being located at or near the ends of the body  38 . The body  38  also includes a threaded bushing  32  configured to receive the threaded barrel of an attachment bolt. 
         [0036]    The flanges  34 ,  36  are spaced apart along the body  38  by a distance approximately equal to the size of the opening  64  between the upper member  58  and the lower member  50  of the cage  26 . When the bracket  30  is mounted to the cage  26 , an outer edge of the straight flange  34  rests on an inner edge of one of the members  50 ,  58 , while an outer edge of the L-shaped flange  36  rests on an inner edge of the other of the member  50 ,  58  with the leg  37  extending over the other member  50 ,  58 . The bracket  30  may be secured by a bolt through the slot  52 ,  60  that corresponds to the bushing  32  in the mounted orientation. 
         [0037]    For example, as shown in  FIG. 6 , the L-shaped flange  36  is hooked over the lower member  50  and the straight flange  34  abuts the upper member  58 . A bolt  80  inserted through the slot  60  is threaded into the bushing  32 . Once the bracket  30  is installed on the cage  26 , an accessory device  100  such as a handheld GPS, cellular phone, or similar electronic accessory can be mounted using the mounting tabs  31 , as shown. 
         [0038]    Although described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, deletions, modifications, and substitutions not specifically described may be made without departing from the spirit and scope of the invention as defined in the appended claims.