Abstract:
A single action, semi-automatic handgun has a slide, a firing pin assembly disposed in a hollow interior of the slide, and a trigger bow assembly disposed in a frame of the handgun below the slide. The trigger bow assembly comprises a trigger bow configured for reciprocating sliding motion. The trigger bow has a trigger bow lever configured for reciprocating sliding motion in plane generally transverse to the movement of the slide. The hand gun further comprises a sear assembly with a sear having a tab and a sear pin. The sear tab releasably engages the firing pin assembly and the sear pin releasably engages the trigger bow lever in a manner to enable successive discharging of the handgun upon successive actuation of the trigger of the firearm.

Description:
[0001]    RELATED APPLICATION DATA 
         [0002]    This application claims the benefit of provisional application Ser. No. 61/587,496, filed Jan. 17, 2012, the disclosure of which is incorporated by reference herein. 
     
    
     BACKGROUND 
       [0003]    This disclosure relates to a firing system for a model 1911 handgun. The firing system includes a striker-fired mechanism that does not incorporate a pivoting hammer to actuate the firing pin. In the system described below, the handgun may be prepared for firing by racking the slide to draw a round to the chamber. This eliminates the need to lock the hammer before firing as is customarily performed during the ordinary use of a model 1911 handgun. Accordingly, this disclosure includes modifying existing model 1911 handguns to incorporate a hammerless, striker-fired system. Additionally, the disclosure relates to a model 1911 handgun which may be constructed with a hammerless, striker-fired system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  shows a cross-sectional model view of a model 1911 handgun of the present disclosure in a cocked position with the main parts used to retrofit a model 1911 handgun into a hammerless, striker-fired system (i.e., firing pin assembly, sear assembly and trigger bow assembly) being shown in cross hatching. 
           [0005]      FIG. 2  shows the hand gun of  FIG. 1  with the firing pin assembly impacting a cartridge at discharge of the hand gun. 
           [0006]      FIG. 3  shows the main parts used to retrofit a model 1911 handgun into a hammerless, striker-fired system. 
           [0007]      FIG. 4  shows a sear of the sear assembly; 
           [0008]      FIG. 5  shows a sear housing of the sear assembly; 
           [0009]      FIG. 6  shows a trigger bow of the trigger bow assembly; 
           [0010]      FIGS. 7   a - 7   c  show views of a trigger bow lever of the trigger bow assembly; 
           [0011]      FIG. 8  shows a rear view of the trigger bow lever of  FIG. 6  and the bottom portion of the sear of  FIG. 4 ; 
           [0012]      FIG. 9  shows a perspective view of the trigger bow assembly, sear assembly and firing pin assembly with the slide and receiver removed for ease of illustration; 
           [0013]      FIG. 10  shows an alternative perspective view of the trigger bow assembly, sear assembly and firing pin assembly with the slide and receiver removed for ease of illustration; and 
           [0014]      FIG. 11  shows an alternative perspective view of the trigger bow assembly, sear assembly and firing pin assembly with the slide and receiver removed for ease of illustration. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    The terms up, down, left, right, horizontal, and vertical are used for purposes of ease of illustrating the disclosed embodiments and the relative orientation of the parts as shown in the drawings. The terms are not intended to limit any disclosed embodiment in any way. 
         [0016]      FIG. 1  shows a cross-sectional model view of a model 1911 handgun of the present disclosure in a cocked position with the main parts used to retrofit a model 1911 handgun into a hammerless, striker-fired system (i.e., firing pin assembly, sear assembly and trigger bow assembly) being shown in cross hatching.  FIG. 2  shows the hand gun of  FIG. 1  with the firing pin assembly impacting a cartridge at discharge of the cartridge. Although a model 1911 hand gun is referenced throughout and shown in the drawings, the principles described herein may be applied in the context of any single-action, semiautomatic weapon system. 
         [0017]    Referring to  FIGS. 1 and 2 , the handgun  20  has a slide  22  and a receiver  24  mounted on the slide with rails for relative horizontal (in FIGS.  1 , 2 ) reciprocating motion between the receiver and slide. At the breech end of the slide, a firing pin bore  26  is provided. Inside the firing pin bore  26 , a firing pin assembly  30  is provided. The firing pin assembly includes a firing pin  32  and a firing pin spring  34  with the firing pin spring disposed between a sleeve  36 , and a washer or spring cup  38 . The firing pin  32  has a distal end which impacts the cartridge when the hand gun is discharged. The firing pin has a proximal end with a firing pin lug  40 . The firing pin  32  is adapted for reciprocating motion inside the firing pin bore  26 . The firing pin sleeve  36  is split to accommodate the reciprocating motion of the firing pin lug  40 . The firing pin spring  32  may be preloaded in the firing pin bore between the firing pin sleeve  36  at the proximal end of the firing pin and the firing pin washer or spring cup  38  at the distal end of the firing pin. The firing pin bore  26  may be sized such that the firing pin spring, firing pin sleeve, and firing pin washer preload the firing pin spring in the firing pin bore. A breech closure  42  together may be provided on the breech end of the slide. When the hand gun is ready for fire, the firing pin would be positioned to the right of the sear  50  as shown in  FIG. 1 . When the hand gun is to discharge or impact a cartridge, the firing pin and sear are positioned as shown in  FIG. 2 . 
         [0018]    The firing pin lug or nose  40  extends downward from the slot of the slotted firing pin sleeve  36  into the hollow interior of the slide to engage the sear assembly  50 . The sear assembly includes a sear  52  which is movable upward from the receiver into the hollow interior of the slide to engage the firing pin lug or nose, and downward into the receiver out of the hollow interior of the slide to release the firing pin lug or nose. When the sear  52  engages the firing pin lug  40  (i.e., positioned to the right of the sear as shown in  FIG. 1 ), the firing pin is urged by spring pressure from the cartridge. Accordingly, when the sear  52  disengages or releases from the firing pin lug  40 , the firing pin  32  is thrust forward under pressure from the firing pin spring  34  such that the distal end of the firing pin impacts the cartridge to discharge the hand gun. In  FIG. 2 , the firing pin is shown in the firing position engaging a cartridge. In other words, in  FIG. 2 , the sear block has released or disengaged from the firing pin lug forcing the firing pin under spring pressure against the cartridge. 
         [0019]    FIGS.  3  and  9 - 11  provide further detail of the firing pin assembly including the firing pin  32 , the firing pin spring  34 , the firing pin sleeve  36 , and the firing pin washer or spring cup  38 .  FIG. 3  also shows the breech closure  42 . The breech closure fits on the breech end of the slide in a manner so as to replace the hammer mechanism ordinarily found at the breach end of the model 1911 handgun. The breech closure  42  may be sized to preload the firing pin spring in the firing pin bore between the firing pin spring and the firing pin washer or spring cup. For instance, in a retrofit of an existing model 1911 hand gun slide or the assembly of a striker fired hand gun as disclosed herein, after the firing pin assembly  30  is installed in the firing pin bore  26 , the breech closure  42  may be installed at the breech end of the slide to enclose the slide, thereby holding the firing pin assembly in the firing pin bore.  FIGS. 1 and 2  show a fastener hole provided in a top portion of the breech closure  42  to secure the breech closure to the slide  22  and enclose the firing pin bore  26  at the breech end of the slide. 
         [0020]      FIGS. 4 and 5  show components of the sear assembly  50 . Additional detail of the sear assembly  50  is shown in  FIGS. 9-11 . The sear assembly comprises the sear  52 , a sear housing  54 , and sear spring  56 .  FIG. 3  shows the sear spring  56 ,  FIG. 4  shows the sear  52 , and  FIG. 5  shows the sear housing  54 . Toward the rear, top end of the receiver  24 , the sear assembly  50  is installed. The sear housing  54  is shaped to fit in the cavity ordinarily occupied by the hammer mechanism found in a model 1911 handgun.  FIG. 9  shows the relative position. For instance, with the slide and grip disassembled from the receiver, the cavity at the rear top end of the receiver may be accessed and the sear housing may be installed into the cavity. The sear housing  54  comprises a generally square piece having a central channel  58  extending generally vertically and at a slight angle (as shown in  FIGS. 1 and 2 ) from the top to the bottom of the sear housing. The sear  52  is disposed in the central channel  58  and the central channel is adapted for easy installation and removal of the sear into and out of the channel. Accordingly, the central channel may have a rectangular (or square) cross section. The sear housing  54  also has a recess  60  formed for holding the sear spring  56 . The sear spring  56  may comprise a torsion spring with first and second ends  62 , 64 . The first end  62  may be disposed in a lobe of the sear spring recess  60  and the second end  64  may extend through a hole  66  formed in an upper end of the sear  52 . The sear spring  56  urges the sear  52  upward ( FIGS. 1 and 2 ) into engagement with the firing pin lug  40 . 
         [0021]    The sear  52  may comprise a generally elongated rectangular member with a rectangular (or square) cross section. The sear tab  68  is an upper end of the sear ( FIGS. 1 and 2 ), and a sear pin  70  is provided at an opposite lower end. The sear  52  is sized to removable fit in the sear housing central channel  58 . The sear  52  has generally upward and downward and slightly angled ( FIGS. 1 ,  2 ) reciprocating motion in the sear housing central channel. The upward motion of the sear  52  allows the sear tab  68  to extend into the hollow interior of the slide to engage the firing pin lug  40 . When the sear  52  is moved downward, the sear tab  68  disengages the firing pin lug  40  and moves downward out of the hollow interior of the slide and into the central channel of the sear housing. 
         [0022]    As shown in  FIGS. 4 and 8 , at the lower end of the sear  50 , the sear pin  70  is provided. The sear pin  70  may comprise a pin inserted in a hole through the lower end of the sear and fixed in position with opposite ends of the pin projecting from opposing sides of the sear. Alternatively, the sear pin may comprise cylindrical, pin-like surfaces that may be formed or machined in the bottom of sear on opposite sides of the sear. The sear pin is preferably 0.042″ in diameter. As explained below in greater detail, the sear pin operatively engages the trigger bow assembly to enable discharging of the weapon and resetting the firing pin thereafter. 
         [0023]      FIGS. 6-11  show the trigger bow assembly  80  and components. The trigger bow assembly comprises a trigger bow  82  and trigger bow lever  84 .  FIG. 6  shows a perspective view of the trigger bow  82 , and  FIGS. 7   a - 7   c  show the trigger bow lever  84 . Additional detail of the trigger bow assembly  80  is shown in  FIGS. 10-12 . At the right longitudinal end of the trigger bow  82  (as shown in  FIG. 6 ), the trigger bow has a trigger mount  86  upon which the trigger for the firearm is mounted. At the left longitudinal end of the trigger bow  82  (as shown in  FIG. 6 ) a mount  88  for the trigger bow lever  84  is provided. The trigger bow lever mount  88  comprises two bosses with holes  90  extending therethrough. The mount  88  is preferably aligned and centered relative to the trigger bow width. The mount  88  provides mounting for the trigger bow lever, thereby positioning the trigger bow lever  84  centered around the sear  52 . In  FIG. 6 , the bottom of the trigger bow is shown facing upward and the top of the trigger bow is shown facing downward (relative to  FIG. 1 ). 
         [0024]      FIGS. 7   a - 7   c  shows the trigger bow lever  84 . The trigger bow lever  84  comprises a bifurcated or forked member with a top surface  92  and a bottom surface  94  (relative to  FIG. 7 ). The bottom surface has posts  96 . The posts  96  extend through the holes  90  in the bosses of the trigger bow mount  88  when the trigger bow lever is assembled with the trigger bow. The posts  96  have a distal end with a pin hole  98  extending therethrough. A proximal end of the posts is connected to the forked member bottom surface. The trigger bow lever  84  has sear reset coil springs  100  around each of the posts. When the trigger bow lever  84  is assembled with the trigger bow, each of the sear reset coil springs  100  is disposed between the trigger bow lever forked member bottom surface  94  and a top surface of the bosses of the trigger bow lever mount  88 . The sear reset springs  100  disposed about each post  96  forces the trigger bow lever upward ( FIGS. 1 and 2 ). To retain the trigger bow lever  84  in the trigger bow mount  88 , a securing pin  102  is installed in the pin holes  98  of the distal end of the trigger bow mounting posts  96 . 
         [0025]    The forked member of the trigger bow lever comprises outer guides  104 . As shown in  FIG. 8 , the outer guides  104  constrain and center the sear  52  and the sear pin  70  between the outer guides relative to the trigger bow assembly during movement of the sear. Each outer guide has a generally upward facing ( FIG. 7   b ) and inwardly projecting, sear pin cam release surface  106 , and an opposite, generally downward facing ( FIG. 7   c ) and inwardly projecting, sear pin cam drive surface  108 . The camming surfaces  106 , 108  engage the sear pin  70  to effect motion of the sear  52  upward and downward in the central channel of the sear housing. The trigger bow lever  84  also includes a sear pin relief  110 . The sear pin relief  110  is formed in the center of the trigger bow lever thereby providing the trigger bow lever with a generally U-shaped or bifurcated appearance. The sear pin relief  110  allows the sear pin  70  to move from the sear pin cam drive surface  108  to the sear pin cam release surface  106  during resetting (i.e., upward motion) of the sear  52 . 
         [0026]    In operation, the trigger bow is held in the receiver such that its motion is limited to horizontal reciprocating motion, as shown in  FIGS. 1 and 2 . As the trigger is depressed, the trigger bow  82  is moved rearward, and the trigger bow lever sear pin cam drive surface  108  engages the sear pin  70 . Continued rearward motion of the trigger bow  82  forces the sear pin cam drive surface  108  to engage the sear pin  70  and drive the sear pin  70  downward against and along the sear pin cam drive surface. During this phase, the trigger bow lever  84  travels to its upward-most position relative to the trigger bow lever mount  88  as the sear reset spring  100  urges the trigger bow lever upward. However, the trigger bow lever  84  is held in the upward-most position by the pins  102  provided in the trigger bow lever mounting post pin holes  98 . At the maximum rearward stroke of the trigger bow  82  in the receiver, the sear pin  70  transitions from the sear pin cam drive surface  108  to the sear pin relief  110 . The maximum rearward stroke of the trigger bow  82  corresponds to the downward-most travel of the sear  52 . The downward-most travel of the sear  52  corresponds with releasing of the sear tab  68  from the firing pin lug  40  and discharge of the hand gun as shown in  FIG. 2 . 
         [0027]    When the sear pin  70  enters the sear pin relief  110  between the driving surfaces  106 , 108  of the trigger bow lever  84 , the trigger bow  82  begins to reposition by moving from the rearward position to the forward position through pressure exerted against the trigger bow by a trigger spring (not shown). As the trigger bow  82  is moved forward (thereby resetting the trigger), the sear pin  70  transitions from the sear pin relief  110  and engages the sear pin cam release surface  106 . As the sear pin  70  engages the sear pin cam release surface  106 , the trigger bow lever  84  is driven downward in the trigger bow mount  88  against pressure from the sear reset spring  100 . Once the sear pin  70  clears the sear pin cam release surface  106  at the forward-most travel of the trigger bow  82 , the sear  52  disengages from the trigger bow lever  84 . The trigger bow lever  84  then springs upward under the pressure of the sear reset spring  100  to reset the position of the trigger bow lever  84  above the sear pin  70 . In this position, the sear pin  70  is below the trigger bow lever  84 , and positioned to engage the sear pin cam drive surface  108  once the trigger bow is moved subsequently rearward, for instance, upon depressing the trigger incident to discharge of a subsequent round.  FIG. 2  shows the sear and trigger bow lever in such a configuration. Recoil of the slide after discharge of the hand gun enables the sear to be repositioned to hold the firing pin lug in position for discharge of a subsequent round. Preferably, the motion of the sear in the sear housing affected by the trigger bow lever is approximately 3/64 inches to 1/32 inches. 
         [0028]    The system and methods described above allows for elimination of the hammer firing mechanism ordinarily associated with a model 1911 handgun. In accordance with the description herein, the trigger pull ordinarily associated with a model 1911 handgun (typically, the trigger pull pressure is between 5 and 6 pounds) is preserved. Additionally, the trigger pull distance ordinarily characteristic of a model 1911 handgun (typically less than ¼ inches) is preserved. As described above, the hammer system associated with a conventional model 1911 handgun may be removed and with slight modifications to the slide and installation of the sear assembly, firing pin assembly and trigger bow assembly, a hammerless, striker fired model 1911 handgun may be provided. 
         [0029]    While specific embodiments have been described in detail in the foregoing detailed description and illustrated in the accompanying drawings, those with ordinary skill in the art will appreciate that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed were meant to be illustrative only and not limited as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.