Abstract:
In one aspect, a firearm system allows multiple modular firearm configurations, thereby providing significant customizability of the firearm by the user. All of the components necessary to fire the weapon are carried on a common receiver assembly. Interchangeable slide assemblies and handgrip modules can be detachably connected to the common receiver to substitute one firearm size, handgrip circumference, and/or munitions caliber for another. For example, the handgrip module can be substituted so as to change the size of the firearm and/or the slide assembly can be changed for purposes of changing the caliber of the firearm. In another aspect, an improved firing pin safety, which is capable of use in a one-piece machined slide, and which is additionally capable of being manufactured as a stamped sheet metal part, is provided.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the priority benefit under 35 U.S.C. § 119(e) of U.S. provisional patent application No. 60/969,047 filed Aug. 30, 2007. The aforementioned application is herein incorporated by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    The present disclosure relates generally to the art of firearms. In a first aspect, the present disclosure relates to a modular firearm system that is customizable with respect to firearm size, handgrip size, caliber, or any combinations thereof. In a second aspect, the present disclosure relates to an improved firing pin safety for a firearm having a one-piece machined slide. The present developments find particular application in conjunction with a double-action semi-automatic pistol and will be described with particular reference thereto. It is to be appreciated, however, that the present invention is amenable to other like single-action or double-action semi-automatic pistols. 
       SUMMARY 
       [0003]    The embodiments disclosed herein allow for multiple modular firearm configurations, thereby providing significant customizability of the firearm by the user. As will be appreciated upon a reading and understanding of this disclosure, all of the components necessary to fire the weapon are carried on a common receiver assembly. Interchangeable slide assemblies and handgrip modules can be detachably connected to the common receiver to substitute one firearm size, handgrip circumference, and/or munitions caliber for another. For example, the handgrip module can be substituted so as to change the size of the firearm and/or the slide assembly can be changed for purposes of changing the caliber of the firearm. In a further aspect, an improved firing pin safety system is provided. In yet another aspect, a method and apparatus for seating a rear sight assembly within the slide assembly are provided. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    The invention may take physical form in certain parts and arrangements of parts, a preferred embodiment and method of which will be described in detail in this specification and illustrated in the accompanying drawings, which form a part hereof, and wherein: 
           [0005]      FIG. 1  is a pictorial view of an exemplary customizable firearm embodiment; 
           [0006]      FIG. 2  is an exploded view of the firearm appearing in  FIG. 1 , illustrating a slide assembly and a handgrip assembly, either or both of which may be interchangeably received on a receiver assembly; 
           [0007]      FIG. 3  is an exploded view of the slide assembly; 
           [0008]      FIG. 4  is an exploded view of the receiver assembly; 
           [0009]      FIG. 5  is an exploded view of the handgrip module; 
           [0010]      FIG. 6  is an exploded view of the magazine; 
           [0011]      FIG. 7  illustrates a firearm system having plural interchangeable slide assemblies and plural interchangeable handgrip modules; 
           [0012]      FIG. 8  is an enlarged front view of an integral hammer stop and rear sight with firing pin safety; and 
           [0013]      FIG. 9  is a fragmentary side cross-sectional view showing the trigger, hammer, and firing pin safety assemblies in detail. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]    Referring now to the drawing figures, wherein like reference numerals refer to like or analogous components throughout the several views, and with particular reference to  FIGS. 1 and 2 , a firearm denoted generally as  10  includes a slide assembly A, a receiver assembly B, and a handgrip assembly C. A magazine D is removably received within an interior compartment defined by a generally hollow handgrip portion  228  of the handgrip assembly C. 
         [0015]    As best seen in  FIGS. 2 and 3 , the slide assembly A includes a slide  12  having an axial channel  16  and a barrel  20  received within the channel  16 . A recoil spring  24  is coaxially received about a recoil spring guide  28  for returning the slide  12  into a state of battery. 
         [0016]    The slide assembly A contains an extraction assembly, including an extractor  30 , an extractor pin  34 , an extractor spring  38 , and an extractor spring pin  42  for extracting a cartridge from the chamber of the barrel  20 . Other extractors and extraction assemblies as are generally known to those skilled in the art are also contemplated. 
         [0017]    In the depicted preferred embodiment, the extractor  30  is a pivoting type extractor having a bearing surface  31  that engages a forward end  33  of the extraction pin  34 . The extractor  30  is pivotable about a pivot point  35 , e.g., when chambering a round. After a round is fired, the extractor  30  pulls the cartridge out of the firing chamber and holds the cartridge in position for ejection by the ejector  72  (see  FIG. 4 ). A rearward end  37  of the extractor pin  34  engages a forward end  39  of the spring  38 , e.g., via a snap fit. A rearward end  41  of the spring  38  engages a forward end  43  of the extractor spring pin  42 . The extractor spring pin  42  also includes a conical portion  316 , which engages the rear sight assembly  36  to seat and retain the rear sight, as described below. 
         [0018]    The slide assembly A also includes front and rear sights  32  and  36 , respectively, and an ignition system comprising a firing pin  50  and firing pin spring  46  housed within the slide  12 , a firing pin retaining pin  58 , and a firing pin safety  54 , which is discussed in greater detail below. In the depicted embodiment, the rear sight assembly  36  also includes an integrated hammer stop  40 , although a hammer stop and rear sight that are separate may also be employed. 
         [0019]    Referring now to  FIG. 4 , the receiver assembly B includes a frame or receiver  44  including opposing and upstanding side members  48  and  52  and which are connected in opposed and spaced apart relation via front base member  56  and rear base member  60 . 
         [0020]    The sidewalls  48 ,  52  of receiver  44  include front and rear rail members  64  and  68 , respectively, which are slidingly received within complimentary axially extending channels  18  formed within the channel  16  of the slide  12  to permit relative axial movement between the slide  12  and the receiver  44 . 
         [0021]    An ejector  72  is formed on the sidewall  52  of the receiver  44  for pushing the cartridge out of the ejection port or aperture  14  of the slide  12  during rearward travel of the slide  12  during operation, e.g., ejecting a spent cartridge when firing the firearm or for manually extracting the cartridge. 
         [0022]    The receiver  44  also includes a mounting point for the barrel control means. In the depicted embodiment, barrel movement is controlled by a transversely extending pin or the like  76 , which is received through opposing, aligned openings  80  in the sidewalls  48  and  52 . In operation, the barrel control member  76  engages locking/unlocking lugs  84  and  88 , defining an inclined channel  92 , to unlock the barrel as the slide moves in the forward direction and to lock the barrel as the slide moves in the rearward direction. 
         [0023]    In the depicted embodiment, the barrel control member  76  also provides a mounting point for a slide catch lever assembly comprising a slide catch lever  96  and slide catch lever spring  100 . It will be recognized that in alternative embodiments a separate or dedicated slide catch lever pin, separate from the barrel control member, could be used as well. 
         [0024]    The pin  76  is received through openings  104  formed in the slide catch lever  96  to pivotally mount the slide catch lever to the receiver  44 . The spring  100  bears against an arm portion  108  of the slide catch lever  96  to urge the slide catch lever  96  to the normal, non-rotated position. 
         [0025]    The magazine assembly D, as best seen in  FIG. 6 , includes a magazine tube  112  for holding rounds of munitions to be fired, a magazine base plate  116 , a magazine spring  120 , and a magazine follower  124 . The magazine follower  124  includes a slide catch shelf  128  which engages the slide catch lever  96  when the magazine is empty, i.e., when the last round has been fired or when an empty magazine is inserted into the handgrip interior compartment. The slide catch shelf  128 , at the urging of the magazine spring  120 , moves the slide catch lever  96  into a rotated position, overcoming and compressing the slide catch lever spring  100 . 
         [0026]    Referring now to  FIGS. 3 and 4 , the slide catch lever  96  includes slide engagement members  132 , which are sized to engage complimentary notches  136  formed in the slide  12 . In this manner, when the last round is fired, the engagement members  132  engage the notches  136  and the slide  12  is locked in an axial position relative to the receiver  44  that is out of battery. When the slide catch lever  96  is in the non-rotated position, the engagement members  132  are seated in notches  140  in the receiver and notches  144  in the handgrip module C. The engagement members  132  thus are externally accessible and may be manually operated to selectively lock and unlock the slide  12  relative to the receiver  44 . 
         [0027]    The receiver  44  also provides a means for mounting a trigger  148 , a hammer  150 , and the mechanical linkage therebetween. The trigger  148  is pivotally mounted in openings  154  in the receiver sidewalls  48 ,  52 , about a pivot point  152  and includes a trigger shoe  156  for actuation with a user&#39;s finger for firing a round. 
         [0028]    The trigger  148  also includes an arm  158  having protrusion  160  thereon, which engages a complimentary sized opening  162  in a trigger bar  164 . During operation, as the trigger  148  is rotated, the trigger bar is moved forward and is cammed downward by an inclined surface  168  running on a hammer pivot pin  172  received in openings  176  of the receiver  44  sidewalls  48  and  52 , the hammer pivot pin  172  also extending through an opening  174  in the hammer  150  to pivotally mount the hammer  150  on the receiver  44 . The trigger bar  148  includes a hammer-engaging tab  180 , which engages a protrusion or shoulder  184  within an arcuate channel  196  in the hammer  150 . 
         [0029]    The trigger bar  164  engages the hammer  150  when the trigger  150  is in its rest or non-rotated position. As the trigger bar  164  moves in response to rotation of the trigger  148 , the hammer  150  rotates. One or more captured hammer springs  182   a ,  182   b  are received within a cavity formed in the hammer  150  and are retained therein by a hammer spring seat pin  188  which is received through openings  192  in the receiver sidewalls  48  and  52  and the arcuate channel  196  of the hammer  150 . As the hammer is rotated in response to a trigger pull, the springs  182   a ,  182   b  are compressed by the relative movement of the hammer spring seat pin  188  as it travels in the arcuate channel  196 . In the depicted preferred embodiment, the springs  182   a  and  182   b  are coaxial coil springs having opposite directions of helical twist to avoid binding with each other as the springs are compressed. 
         [0030]    Further rotation of the trigger causes the hammer engaging tab  180  to move out of contacting relation with the hammer  150  when the trigger  148  is pivoted. The energy stored by the compression of the hammer springs  182   a ,  182   b  causes the hammer to rotate with force against the firing pin  50  to fire the weapon. 
         [0031]    The movement of the trigger bar  168  also rotates a safety lever  200  having an arm  204  engaging the firing pin safety  54 . The firing pin safety  54  includes a shoulder  212 , which is urged downward into engagement with a slot  216  in the firing pin  50  by a firing pin safety spring  220 . In this manner, the rotation of the safety lever  200  during a trigger pull moves the safety  54  out of engagement with the firing pin  50 , so that the firing pin  50  becomes free to move. 
         [0032]    A trigger bar spring  224 , which may be a torsion spring, provides the force to move the trigger bar  148  up and back, that is, the upward force keeps the trigger bar engaged with the hammer  150  and the backward force resets the trigger bar to the rest position after a round is fired. 
         [0033]    Referring now to  FIG. 5 , the grip module C includes the handgrip portion  228 , a trigger guard  232 , and a dust cover portion  236 . Because the handgrip module C has none of the components required to fire the weapon, it may be readily interchanged with other handgrip modules of different size. For example, in certain embodiments, a firearm system may include a plurality of handgrip modules, which allows the users to select from a plurality of weapon sizes, e.g., full size, compact, and subcompact sized handguns. Furthermore, for each given size of handgrip module C, there may be provided a plurality of handgrip  228  circumferences, e.g., small, medium and large. In this manner, the interchangeable handgrip modules C provide a firearm system that is highly customizable to the hand size or other size preferences of the user. For example, in a preferred embodiment of a system having three firearm sizes (i.e., full-size, compact, and sub compact) and, for each firearm size, three handgrip  228  sizes (e.g., small, medium and large), there are nine combinations of firearm size and handgrip circumference. 
         [0034]    The handgrip portion  228  includes a hollow interior portion which receives the magazine D, which feeds rounds into a magazine well portion  240  of the receiver  44 . The hollow interior compartment defined by the handgrip portion  228  defines an extension of the magazine well  240 . 
         [0035]    Referring now to  FIGS. 4 and 5 , the receiver  44 , which carries and locates everything required to fire a round, is received within a channel  244  in the handgrip module C. A notch  248  formed in the rear of the channel  244  receives an extension tab  252  of the receiver  44  and locates the receiver at the appropriate position within the channel  244 . 
         [0036]    The trigger shoe  156  passes through an opening  256  in the channel  244  and extends into the region bounded by the trigger guard  232 . The dust cover portion  236  houses the barrel  20 , recoil guide  28 , and recoil spring  24 , and prevents external contaminants from fouling the recoil mechanism. 
         [0037]    A take down lever  260  passes through openings  264  in the handgrip module C and aligned openings  268  in the receiver sidewalls  48  and  52 . A sealing ring or gasket  270  between the take down lever  260  and the opening  264  provides a seal against the entry of external contaminants into the channel  44 . The take down lever  260  locates and provides the primary locking position of the barrel  20 . 
         [0038]    A magazine catch assembly includes a magazine catch  272 , a magazine catch stop  276 , and a magazine catch spring  280  for removably securing the magazine D in the interior compartment of the handgrip. The magazine catch  272  is manually depressible to remove the magazine D from the handgrip module C. 
         [0039]    The handgrip module C may include a window or aperture  284  through which a serial number or other serialized indicia can be visualized, the serialized indicia appearing on the corresponding aligned portion of the exterior-facing surface of the sidewall  48 . The window may optionally include a pane or transparent material received within the aperture. In this manner, any of a plurality of handgrip modules C may be interchanged for a single, serialized firearm. 
         [0040]    In addition to the interchange of handgrip modules C to provide a firearm having a desired firearm size and/or handgrip circumference as described above, the firearm system in accordance with this disclosure may also include multiple interchangeable slide assemblies A which may be slidably and interchangeably received on the rails  64 ,  68 . In certain embodiments, the plurality of interchangeable slide assemblies A may be sized to correspond to the selected handgrip size, e.g., full-size, compact, and subcompact. In further embodiments, for any given size of slide assembly, there may be a plurality of munitions caliber options available. The slide assembly A may be adapted by providing an appropriate barrel  20  for firing cartridges of a variety of caliber sizes including, but not limited to, 9 millimeter, .357 Sig, S&amp;W .40, and .45 Auto caliber sizes. 
         [0041]    It will be recognized that, depending on the various calibers selected, it may or may not be necessary to interchange the handgrip module C when a different caliber slide assembly A is selected. When exchanging slide assemblies A for different calibers having the same axial length, a common handgrip module C may be used for such different calibers, wherein it is only necessary to exchange the magazine D. However, it is also contemplated that, even for calibers having different lengths, a common handgrip module C can be employed, for example, using different magazines D and spacers within the interior compartment of the handgrip module C as necessary to compensate for a selected caliber, as required. 
         [0042]    The interchangeability of modular components is illustrated in  FIG. 7 . In the illustrated embodiment, a plurality (up to some number N) of slide assemblies A 1  to A N  are interchangeably attachable to the common receiver assembly B. Likewise, a plurality (up to some number M) of handgrip modules C 1  to C M  are interchangeably attachable to the common receiver B. 
         [0043]    In this manner, in a preferred embodiment having three different firearm sizes, one serialized subassembly can be used by the consumer to make three sizes of gun (e.g., subcompact, compact, or full size). In an especially preferred embodiment wherein each of the three firearm sizes has three handgrip circumferences (e.g., small, medium, and large, there are a total of nine firearm size and handgrip circumference configurations. 
         [0044]    In a preferred embodiment where there are four calibers (e.g., 9 mm, .40 S&amp;W, .357 Sig, and .45 Auto) any of the previous 9 firearm size/handgrip circumference configurations can be combined with any of the four calibers to provide 32 possible combinations of size, grip, and caliber so that the consumer can tailor their gun to meet their specific requirements. It also allows law enforcement agencies to issue the same model of gun to everyone in their organization, but still be able to customize the ergonomics to fit an ever-growing range of officers. The system also allows rapid and facile reconfiguration of the firearm, with reconfiguration taking less than one minute. It will be recognized that other numbers of firearm size, handgrip size, and/or caliber may be provided. 
         [0045]    Although the preferred embodiment described herein provides for variability of firearm size, handgrip circumference, and caliber, it will be recognized that systems may be provided wherein one or more of these variables remain constant. For example, systems having interchangeable handgrip modules C and slides A for providing variable firearm sizes and/or handgrip circumferences for a single caliber are contemplated. Likewise, systems having interchangeable handgrip modules C and slides A for providing variable firearm sizes and/or variable calibers, without necessarily providing variable handgrip sizes within each firearm size, are also contemplated. Similarly, systems having interchangeable handgrip modules C and slides A for providing variable handgrip circumferences and/or variable calibers, all within a single firearm size, are also contemplated. 
         [0046]    In a further aspect of this disclosure, referring now to  FIGS. 8 and 9 , there is provided an improved firing pin safety for use in a one-piece machined slide. Although the firing pin safety described herein may be used in connection with the slide assembly A as detailed above, it will be recognized that the firing pin safety herein is also amenable for use in other firearms having a one-piece machined slide. 
         [0047]    Commonly, the firing pin safety in a one-piece machined slide is formed of a relatively heavy piece of metal received within a bore hole formed in the slide. The firing pin safety is urged into engagement with a firing pin safety spring and drop testing requires that the firing pin safety remain engaged with the firing pin when the weapon is dropped from a certain height. Because the firing pin safety is typically formed of a relatively heavy piece of metal in a one-piece machined slide and thus has significant inertia when dropped, a firing pin safety spring with relatively high spring force is required. The spring force of the firing pin safety spring is one of the spring forces that must be overcome by the user when pulling the trigger. Thus, a firing pin safety spring with a high spring force is disadvantageous since it increases the force required to actuate the trigger and fire the weapon. 
         [0048]    The improved firing pin safety system herein allows for the use of a very lightweight firing pin safety member in a one-piece machined slide and the firing pin safety member herein may be produced relatively inexpensively as a stamped sheet metal part. It will be recognized, however that the firing pin safety member herein may be formed of any suitable material, including without limitation, sheet metal, machined metal, a metal injection molded material, a plastic, e.g., injection molded, material, a composite material such as a fiber reinforced resin material, and so forth. Because the firing pin safety member can be fabricated of a material that is relatively low weight, thus providing a firing pin safety member that is low in inertia, a firing pin safety spring with a relatively low spring force can be used to bias the safety member into the locked position, thereby reducing the trigger pull weight while also meeting firearm drop testing requirements. 
         [0049]    As best seen in  FIGS. 3 and 8 , a rear sight  36  includes an integral hammer stop  40 , which also functions as firing pin safety retainer in the depicted preferred embodiment. The firing pin  50  is received through an opening  300  in the hammer stop  40 . The hammer stop  40  is received within a machined slot  304  in the slide  12 . A first, generally semi-cylindrical recess  308  in the rearward-facing surface of the slot  304  cooperates with a second, generally semi-cylindrical recess  312  formed in the forward-facing surface of the hammer stop  40  to define a cylindrical recess housing the firing pin safety spring  220 . It will be recognized that the firing pin safety retainer need not be integral with the rear sight and/or hammer stop, and that other firing pin safety retention configurations are contemplated. For example, a separate or dedicated firing pin safety pin retainer having an opening and semi-cylindrical recess or cavity as described above can be received in the slot  304 . 
         [0050]    In operation, the spring  220  urges the firing pin safety spring  54  downward so that the shoulder  212  of the firing pin safety engages the annular channel  216  in the firing pin  50 , thereby preventing axial movement of the firing pin  50 . When the firing pin safety  54  is urged upward by the arm  204  of the safety lever  200  during a trigger pull operation, thereby compressing the spring  220 , the shoulder  212  moves out of the annular channel  216 , allowing the firing pin to move axially when struck by the hammer  150  to fire the weapon. 
         [0051]    With continued reference to  FIGS. 3 and 8 , the rear sight assembly  36  in accordance with the depicted preferred embodiment also includes a generally partial conical cut out or recess  314 , which engages an aligned, facing, and contacting portion of a conical portion  316  of the extractor spring pin  42  (see  FIG. 3 ). The extractor spring  38  urges the extractor spring pin  42  in the rearward direction. The engaging portion of the conical surface  316  thereby urges the rear sight assembly  36  to the right (in the orientation shown in  FIG. 8 ). 
         [0052]    Also, the extractor spring pin  42  is aligned within the slide assembly such that the longitudinal axis  318  of the extractor spring pin  42  is lower than the vertical midpoint  320  of the partial conical cutout  314 . In this manner, when the conical portion  316  bears against the cutout  314  at the urging of the spring  38 , the rear sight assembly  36  is also urged in the downward direction (relative to the orientation shown in  FIG. 8 ). Thus, the net resultant force on the rear sight assembly  36  as a result of the cooperation between the biased conical portion  316  and the cutout  314  downward and to the right (in the orientation shown in  FIG. 8 ), to thereby retain and seat the rear sight assembly  36  in proper position on the slide  12 . 
         [0053]    The present developments have been described with reference to the preferred embodiments. Modifications and alterations will occur to others upon a reading and understanding of the preceding detailed description of the preferred embodiment. It is intended that the invention be construed as including such modifications and alterations.