Abstract:
A stock for a small arms weapon which may include a proximal end surface and a distal end surface, the distal end surface including a first opening extending toward the proximal end surface. The stock further may include a multi-lobe chamber connected to the first opening. The multi-lobe chamber may include a primary lobe for housing a receiver extension. The primary lobe may include a track for supporting a bottom surface of a receiver extension. The primary lobe further may include a first side lobe adjacent to the first wall, and a second side lobe adjacent to the second wall. A first insert may be disposed in the first side lobe and a second insert may be disposed in the second side lobe for isolating movement between the stock and a receiver extension disposed in the track.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of application Ser. No. 29/478,023 filed Dec. 30, 2013, the disclosure of which is incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a stock for a small arms weapon. More particularly, the invention relates to a stock having a vibration isolator and a compartment which contains a capsule for storing spare parts. 
     BACKGROUND 
     Small arms may be defined as man-portable individual or crew-served weapon systems used against protected and unprotected personnel and light/unarmored vehicles. Man portable individual weapon systems such as an M4 carbine or AR-15 type firearm may be configured to mission requirements or individual preferences. For example, the stock of these weapons may be customized or adjusted for a user&#39;s size or preference. Adjustable stocks, however, may be connected loosely to these weapons, causing unwanted noise and movement. Additionally, these weapon systems may include laser pointers, fire control devices, night vision devices, optics, thermal weapon sights and other devices. Many of these accessories require one or more batteries to operate. 
     SUMMARY 
     Hence, the present invention is directed toward a stock of a small arms weapon having a vibration isolator. The present invention also is directed to a compartment in the stock that stores a sealed capsule which may be used to store a spare battery. The invention also is directed toward a method of preventing and isolating vibration in an adjustable stock for a small arms weapon. 
     One aspect of the present invention relates to a stock for a small arms weapon that may include a first member having a first longitudinal axis which comprises a distal end surface and a proximal end surface spaced from the distal end surface along the first longitudinal axis. The distal end surface may include a first opening extending toward the proximal end surface and a multi-lobe chamber connected to the first opening. The multi-lobe chamber may include a primary lobe for housing a receiver extension. The primary lobe may include a track for supporting a bottom surface of a receiver extension, a first wall for supporting a first side surface of a receiver extension, and a second wall for supporting a second side surface of a receiver extension. The multi-lobe chamber further may include a first side lobe adjacent to the first wall and a second side lobe adjacent to the second wall. 
     Moreover, the stock may include a first insert disposed in the first side lobe for preventing and isolating movement between the first side of the stock and a receiver extension disposed in the track. The first insert may include a first side leaf member. The first side leaf member may include a first side base for supporting a receiver extension disposed in the track and a first side resilient cantilever extending from the base for isolating movement between the first side of the stock and a receiver extension disposed in the track. The resilient cantilever may deform under pressure applied by a receiver extension disposed in the track opposite the first side leaf member to isolate movement between the first side of the stock and the receiver extension. A second insert may be disposed in the second side lobe for isolating movement between the second side of the stock and a receiver extension disposed in the track. 
     In another aspect, the first insert may comprise three first side leaf members. Additionally, the second insert may include a second side leaf member that includes a second side base, and a second side resilient cantilever extending from the second side base such that the second side resilient cantilever deforms under pressure applied by a receiver extension disposed in the track opposite the second side leaf member to isolate movement between the second side of the stock and the receiver extension. 
     In another aspect, a connecting member may join the first insert and the second insert to form a shim and a damper in the multi-lobe chamber for preventing and isolating movement between the stock and a receiver extension connected to the stock. 
     In another aspect, the first member may further include an exterior surface and a portion of the connecting member may form a part of the exterior surface. 
     In another aspect, the proximal end surface may include a fastener attachment site and a back plate secured to the proximal end surface. Additionally, the proximal end surface may include a second opening connected to the multi-lobe chamber. The back plate may cover the second opening. 
     In another aspect, the stock may include a second member connected to the first member. The second member may include a third end adjacent to the proximal end, and a fourth end spaced from the distal end. The second member may further include an interior compartment that is configured and dimensioned to house a cylindrical capsule. The cylindrical capsule may include a tubular member and a cap. The cap further may include a plug for sealing the tubular member. Additionally, the cap may include a cantilevered block, and the tubular member may include a projection such that the cap may be rotated with respect to the tubular member to interlock the projection and the cantilevered block. 
     In another aspect, the capsule further may include a rail and the interior compartment may include a channel and a catch disposed in the channel such that the rail and the catch may cooperate to lock the capsule in the interior compartment. 
     In another aspect, the stock may include a third member connected to the first and second members which may include a fifth end connected to the distal end of the first member, and a sixth end connected to the fourth end of the second member. The stock may further include a web disposed between the first member and the third member, as well as a spring loaded locking pin disposed in the web such that the locking pin is configured and dimensioned to interlock with a receiver extension disposed in the track to fix the stock to the receiver extension. 
     Also, the present invention relates to a method of assembling a stock for a small arms weapon that includes a vibration isolator. The method may include providing a small arms weapon stock that comprises a first member that includes a proximal end surface and a distal end surface. The distal end surface further may include a first opening extending toward the proximal end surface and a multi-lobe chamber connected to the first opening. The multi-lobe chamber may include a primary lobe for housing a receiver extension. The primary lobe may include a track for supporting a bottom surface of a receiver extension, a first wall for supporting a first side surface of a receiver extension, and a second wall for supporting a second side surface of a receiver extension. Additionally, the multi-lobe chamber may include a first side lobe adjacent to the first wall, and a second side lobe adjacent to the second wall. The method further may include inserting a vibration isolator into the first side lobe and the second side lobe from the proximal end of the stock for supporting a receiver extension disposed in the track and isolating movement between the stock and the receiver extension. Also, the method may include securing a back plate to the proximal end surface to enclose the vibration isolator in the stock. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals (or designations) are used to indicate like parts in the various views: 
         FIG. 1  is a perspective view of an M4 carbine with a gun stock according to the present invention; 
         FIG. 2  is a perspective view of the stock of  FIG. 1 ; 
         FIG. 3  is another perspective view of the stock of  FIG. 1 ; 
         FIG. 4  is an exploded view of a lower portion of the stock, showing a storage capsule; 
         FIG. 5  is an exploded view of the rear portion of the stock, showing the anti-wobble insert and back plate of the stock of  FIG. 1 ; 
         FIG. 6  is another perspective view of the anti-wobble insert. 
         FIG. 7  is a cross-sectional view of the stock of  FIG. 1 , along line  7 - 7  of  FIG. 2 . 
         FIG. 8  is a cross-sectional view of the stock of  FIG. 1 , along line  8 - 8  of  FIG. 7 . 
         FIG. 9  is a cross-sectional view of the stock of  FIG. 1 , along line  9 - 9  of  FIG. 7 . 
         FIG. 10  is a cross-sectional view of the stock of  FIG. 1 , along line  10 - 10  of  FIG. 7 . 
         FIG. 11  is a cross-sectional view of the stock of  FIG. 1 , along line  11 - 11  of  FIG. 7 . 
         FIG. 12  is a cross-sectional view of the stock of  FIG. 1 , along line  12 - 12  of  FIG. 10 . 
         FIG. 13  is a cross-sectional view of the stock of  FIG. 1 , along line  13 - 13  of  FIG. 10 . 
         FIG. 14  is a cross-sectional view of the stock of  FIG. 1 , along line  17 - 17  of  FIG. 7 . 
         FIG. 15  is a perspective view of the catch of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1-3 , the illustrative stock  10  of the present invention may include an upper housing  12  having a distal end  14  and a proximal end  16 , a rear housing  18  situated adjacent the proximal end, and a diagonal member  20  connecting a lower portion of the rear housing to the distal end of the upper housing. The upper housing, rear housing and diagonal member may define an opening  22  in the stock, which extends from one side of the stock to the other side of the stock. The stock may further include a web  24  disposed between the upper housing and a distal part of the diagonal member. As shown in  FIG. 3 , the proximal end  16  of the stock may include a receiver extension attachment site  26 , which may be configured and dimensioned to receive a receiver extension  28 . As shown in  FIG. 1 , the receiver extension may be a receiver extension for an M4 carbine (or AR-15 type weapon)  30 . 
     Referring to  FIG. 7 , the receiver extension may be telescopically received within the receiver extension attachment site and may include a number of locking pin holes  32  for selecting and fixing the position of the receiver extension  28  with respect to the stock  10 . 
     The stock further may include a latch  34  for selectively withdrawing a spring loaded locking pin  36  from the receiver extension pin holes. A lever  38  for the latch  34  may be disposed in the opening  22  in the stock, and the spring loaded locking pin  36  may be disposed in a vertical bore  40  in the web  24 . 
     In the illustrative embodiment, the vertical bore  40  may extend from inside the upper housing  42  through the web  24  to a bottom surface  44  of the diagonal member  20 . The vertical bore  40  may define a side wall. One end of the side wall may open to a track  46  inside the upper housing, which may be configured and dimensioned for slidingly receiving a bottom rail  48  of the receiver extension  28 . The other side of the vertical bore may open to the bottom surface  44  of the diagonal member. 
     Referring to  FIG. 11 , the web  24  further may include first and second lateral passages  50 ,  52  that intersect the vertical bore  40 . The first lateral passage  50  may be located near the other side of the vertical bore. The second lateral passage  52  may be located between the first lateral passage and the upper end of the vertical bore. The second lateral passage  52  may form a slot in the web. Moreover, the locking pin  36  may include a tip  54  on one end that is configured and dimensioned to securely engage the receiver extension locking pin holes  32 . The locking pin  36  may include an internal bore  56  that extends from the opposite end of the locking pin  36  along the longitudinal axis of the pin toward the tip  54 . The opposite end  58  of the locking pin  36  may include a pair of opposing slots. The locking pin  36  further may include a transverse bore  62  that extends through the locking pin  36 . The transverse bore  62  may intersect the internal bore  56 . 
     The spring loaded locking pin  36  further may include a cross pin  64 , a coil spring  66 , and a set pin  68 . The cross pin  64  may include a side cavity  70 . The tip  54  of the locking pin may be inserted into the vertical slot  40  and the cross pin  64  may be placed through the second lateral passage  52  in the web  24 , as well as the transverse bore  62  of the locking pin. The coil spring  66  may be inserted into the internal bore  56  of the locking pin  36  such that one end of the coil spring is received in the cross pin side cavity  70 . The coil spring may be fully seated by compressing the spring  66  and securing the other end with the set pin  68 . 
     The latch  34  may be formed from the spring loaded locking pin  36  and the lever  38 , which may be pinned to the upper housing  12 . The lever  38  may include a pair of opposing projections  72 , which rest on top of the cross pin  64 . Pulling the lever  38  toward the upper housing  12  rotates the lever and pushes the cross pin  64  away from the housing  12  to retract the tip  54  of the locking pin  36 . The coil spring  66  compresses under the force of the lever  38 . After the lever is released, the coil spring expands and returns the locking pin  36  to the extended position. 
     Referring back to  FIG. 1 , the stock may be configured for modular attachment to an M4 or an AR-15 type firearm. The receiver extension attachment site may be configured and dimensioned, however, to connect with receiver extensions of other weapons. 
     Referring to  FIG. 3 , the stock further may include a cheek wield  74 , a removable back plate  76 , a swivel attachment site  78 , openings  80  for a sling or a sling retention device, as well as a latched compartment  82 . The latched compartment  82  may be disposed in the rear housing between the back plate and the latch. The latched compartment  82  may store a sealed capsule  84  that may be withdrawn from the bottom of the stock  10 . 
     Referring to  FIG. 4 , the capsule  84  may include a cylindrical tube  86  and a cap  88 . The cap may be configured in dimension to seal the top of the capsule. The cap may include an inner surface and a projection  90  that includes a plug  92 . The plug may be received in the tubular member of the capsule. The plug may seal the interior region of the tubular capsule from the external environment. The plug may include an O-ring or similar resilient structure provided that the plug seals the interior of the capsule from the external environment. The cap  88  further may include a locking mechanism  94 . The locking mechanism  94  may be a cantilevered block  96  on the cap of the capsule. The block may include a recess  98  facing the plug. The capsule  84  may include a rail  100  on an exterior surface. The rail  100  may extend parallel to the longitudinal access of the capsule. The rail may include a projection  102  at the base of the capsule. The rail  100  may include a void  104  toward the top of the capsule. Above the rail may be a minor projection  106 . The minor projection  106  may be configured in dimension to mate with the recess  98  on the cantilevered block  96 . 
     The cap  88  may be inserted into the top of the cylindrical tube  86  and rotated. Rotating the cap  88  may cause the minor projection  106  to be positioned inside the recess  98  on the block on the cap. In this configuration, the cap closes the tubular member, the plug seals the tubular member from the exterior environment, and the block and projection lock the cap to the capsule. The locked capsule may be inserted into the latched compartment  82  at the base of the stock. The latched compartment  82  may include a track  108  for receiving the rail  100  of the capsule. 
     Referring to  FIG. 7 , the capsule  84  may be completely inserted into the latched compartment  82  in the stock, so that the bottom portion  110  of the capsule forms a portion of the bottom of the stock. The capsule may be retained within the latched compartment  82  by a catch  114 . As shown in  FIG. 14 , catch  114  may be housed within a recess  116  in the stock. The recess  114  may further house a compression spring  116 . The catch (or automatic latch) may include a keeper  118  that may be positioned within the void  104  in the rail  100  to block relative movement between the stock  10  and the capsule  84 . 
     Referring to  FIG. 15 , the keeper  118  may be C-shaped and include an inclined internal surface  120 . The keeper may include a coil spring connection structure attachment  164  and a retention pin slot  166 . The inclined internal surface  120  may be positioned in the recess  114  of the stock such that the rail  100  of the capsule may progress upward through the keeper  118  and push the keeper inward until the missing portion  104  of the rail passes the inclined surface  120 . At this point, the compression spring  116  may push the keeper  114  outward to lock the cartridge rail  100  in place. To release the capsule  82 , the keeper  118  may be depressed such that the rail  100  is free to pass through the keeper  118 , and the projection  102  on the base of the capsule may be pulled to withdraw the capsule from the latched compartment  82 . 
     Referring to  FIG. 5 , the upper housing  12  may include internal side chambers  122  on either side of the receiver extension track  46 . Each chamber  122  may be configured and dimensioned to receive an insert  124  for isolating movement and damping vibration between the stock and an attached receiver extension. Each insert  124  may be separate from the other insert, or as shown in the illustrative embodiment, may be connected together; for example, by a bridge  126 , to form an integral structure (or vibration isolator)  128 . In the illustrative embodiment, the integral structure  128  is generally U-shaped. The upper housing  12  may include fastener holes  166  for securing the back plate  76  with fasteners  160 . The fastener holes  166  and the fasteners  160  may include mating screw threads. 
     Referring to  FIG. 8 , each insert  124  may include a proximal end  130  that is located near the back plate  76  and a distal end  132  that extends into the side chamber  122  in the upper housing  12  of the stock. Each insert  124  may include one or more leaf springs (or leaf members)  134 . Each leaf member  134  may include a support  136  and a resilient cantilever  138 . The inserts may be positioned within the stock, such that the leaves protrude into the portion of the stock that accommodates the receiver extension  28 . Each insert further may include one or more spacer(s)  140 . The one or more spacer(s)  140  may have an angled face  142  that is configured and dimensioned to provide additional support to the receiver extension. 
     As shown in  FIG. 9 , one or more of the leaf members  134  may deform under pressure from the receiver extension  28  when connected to the receiver extension. The leaf member(s)  134  may push against the housing and receiver extension to provide a snug connection between the stock and receiver extension. In this manner, the inserts and one or more spacers  140  may prevent movement between the receiver extension and the stock, and isolate vibration and reduce noise in the assembly. 
     Additionally, referring to  FIG. 8 , the stock may include another pair of resilient fingers  142 . The resilient fingers  142  may be part of the upper housing  12  internal sidewall  144 . The resilient fingers may be located adjacent to the internal side chambers  122  which receive the insert(s)  124 . The resilient fingers may be located on opposing sides of the receiver extension  28 , such that the receiver extension may contact each resilient finger and displace each resilient finger outwardly to form another snug interface between the stock  10  and the receiver extension  28 . The vibration isolator  128  as a whole or individual insert(s)  124  may be available as replacement parts. 
     Referring to  FIG. 5  a portion  146  of the U-Shaped vibration isolator may form part of the exterior surface of the upper housing. 
     Referring to  FIG. 7 , the back plate  76  may have a rigid component  150  which includes a hook  152 , a rubber coating  154 , and fastener holes  156 . The back plate  76  may be connected to the proximal end of the upper housing  12  and rear housing  18 . For example, the hook  152  may be secured to a mating projection  158  near the rear housing  18  and the upper part of the back plate may be connected to the proximal end of the upper housing  12  with fasteners (e.g., screws)  160 . 
     In a preferred embodiment the stock may be a fiber-reinforced polymer, such as nylon 6/6 with 30% glass, carbon or aramid fiber threads, but any strong and durable material may be used. Additionally, the U-shaped vibration isolator may be formed from the same material. 
     In use, the locking pin  36  of the stock  10  may be retracted with the lever  38 , and the receiver extension  28  may be slid into the receiver extension attachment site  26 . The receiver extension  28  may be advanced into the stock  10  until a set position (or locking pin hole) has been selected by the user. The lever  38  then may be released and the stock  10  manipulated until one locking pin hole  32  in the bottom of the receiver extension  28  interlocks with the locking pin  36 . The resilient fingers  142  and leaf members  134  of the inserts  124  may be compressed by the receiver extension  28  to form a snug connection between the stock  10  and the receiver extension  28  for isolating movement and damping vibration of the assembly. 
     While it has been illustrated and described what at present are considered to be preferred embodiments of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made, and equivalents may be substituted for elements thereof without departing from the true scope of the invention. Accordingly, it is intended that this invention not be limited to the particular embodiments disclosed herein, but that the invention include all embodiments falling within the scope of the appended claims.