Patent Publication Number: US-9410760-B2

Title: Sear assembly for hammerless, striker fired handgun

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of provisional application Ser. No. 62/030,814, filed on Jul. 30, 2014, the disclosure of which is incorporated by reference herein. This application is a continuation in part of application Ser. No. 29/499,396, filed Aug. 14, 2014, currently pending, the disclosure of which is incorporated by reference herein. 
    
    
     BACKGROUND 
     A hammerless, striker fired model 1911 handgun and associated methods is disclosed in U.S. Pat. No. 8,720,096, the disclosure of which is incorporated herein by reference. This disclosure relates to an improved firing system for such a hand gun. In particular, the firing system is a striker fired mechanism that replaces the pivoting hammer system that actuates the firing pin and uses the remaining components of the handgun. The system may utilize other existing components found on pivoting hammer actuating-type firearms. For instance, as described below in further detail, the sear assembly may be installed in a conventional pivoting hammer actuated-type system and cooperate with an existing trigger mechanism to allow its use. The handgun may be constructed with the disclosed hammerless, striker fired system. In the alternative, the handgun may be retrofitted with the disclosed hammerless, striker fired system replacing the pivoting hammer that ordinarily actuates the firing pin. Such an assembly is shown in co-owned application Ser. No. 29/499,396, the disclosure of which is incorporated herein. Accordingly, this disclosure incorporates methods of modifying existing handguns to incorporate a hammerless, striker fired system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of a trigger, trigger bow, sear assembly, and firing pin. 
         FIG. 2  shows a side elevational view of the components of  FIG. 1 . 
         FIG. 3  shows a perspective view of a trigger, trigger bow, sear assembly with a sear cover plate removed to show the internal components of the sear assembly, and a firing pin. 
         FIG. 4  is a side elevational view similar to  FIG. 3 . 
         FIG. 5  is a view similar to  FIG. 3  with a disconnector member of the sear assembly removed to show additional detail of the components of the sear assembly. 
         FIG. 6  is a top plan view of the components of  FIG. 2 . 
         FIG. 7  is a top plan view of the sear assembly of  FIG. 2 . 
         FIG. 8  is a bottom plan view of the sear assembly of  FIG. 2 . 
         FIG. 9  is a back view of the sear assembly of  FIG. 2 . 
         FIG. 10  is a perspective view of the sear assembly of  FIG. 2 . 
         FIG. 11  is an alternate perspective view of the sear assembly of  FIG. 2 . 
         FIG. 12  is an alternate perspective view of the sear assembly of  FIG. 2 . 
         FIG. 13  is a view similar to  FIG. 3  showing additional detail of the disconnector flat spring. 
         FIG. 14  is a rear view of the sear assembly. 
     
    
    
     DETAILED DESCRIPTION 
     The terms up, down, left, right, horizontal, and vertical are all used for purposes of ease of illustrating the disclosed embodiments and the relative orientation of the described parts as shown in the drawings. The terms are not intended to limit any disclosed embodiment in any way. 
       FIG. 1  shows several components of the firing assembly including a trigger  10  connected to a trigger bow  12 , a sear assembly  14 , and a firing pin  16 . The trigger  10  and trigger bow  12  are configured for reciprocating sliding motion in the same plane as the slide of the handgun. The trigger bow  12  actuates the sear assembly  14  to release the firing pin  16  in a manner to enable successive discharging of the handgun upon successive actuation of the trigger of the firearm. In  FIGS. 1-6 , the trigger  10  and trigger bow  12  move to the left in the drawings to actuate the sear assembly  14  and the firing pin  16 . 
     The sear assembly  14  comprises a block  18  which is dimensioned to fit in an existing handgun frame, for instance, a model  1911  handgun. The sear block  18  has a cavity  20  which receives the components of the sear assembly and a cover  22  may seal the cavity  20  of the sear block  18 . The internal components housed in the cavity  20  of the sear block  18  include a sear pivot  24 , a sear lever  26 , a sear lever spring  28 , a disconnector  30 , and a sear catch  32 . 
     The sear pivot  24  has a tear drop shape with an outer periphery that forms a cam surface  33 . The sear pivot  24  is arranged for pivoting motion within the cavity  20  of the sear block  18 . The sear pivot  24  is pivotally connected to a sear pivot pin  34  projecting from the sear cavity  20 . The sear pivot  24  has a hole to receive the sear pivot pin  34 . The hole in the sear pivot  24  may formed in a lobe offset from a center of sear pivot. 
     The sear lever  26  is arranged for pivoting motion within the cavity  20  of the sear block  18 . The sear lever  26  is pivotally connected to a sear lever pivot pin  36  projecting from the sear cavity  20 . The sear lever  26  has a hole to receive the sear lever pivot pin  36 . The hole may be generally intermediate first and second ends  38 , 40  of the sear lever  26 . The sear lever second end  40  is operatively connected to the sear catch  32 . The sear lever first end  38  may be configured to be in driving engagement with the cam surface  33  of the sear pivot  24 . The cam surface  33  of the sear pivot  24  may have a ridge which engages the first end  38  of the sear lever  26  thereby enabling the sear lever to rotate clockwise (in the drawings) in the cavity  20  of the sear block  18 . The sear lever spring  28  urges the first end  38  of the sear lever  26  into engagement with the cam surface  33  of the sear pivot  24 . In the drawing  FIGS. 1-6 , the sear lever spring  28  urges the first end  38  of sear lever  26  to the right thereby producing counterclockwise rotation of the sear lever within the cavity of the sear block. The sear lever spring  28  may urge the first end  38  of the sear lever  26  against the sear pivot  24 . The sear lever spring  28  may be a flat spring. 
     The sear catch  32  is arranged for reciprocating sliding motion in a slot  42  formed in the sear block  18 . In drawing  FIGS. 1-6 , the sear catch  32  may move vertically as it reciprocates in the slot  42 . The sear catch  32  extends upward through the slot  42  to engage a lug  44  of the firing pin  16  of the firing pin assembly. The sear catch  32  is connected to the second end  40  of the sear lever  26 . As shown in  FIG. 5 , a hole  46  extends through the sear catch  32 . The hole  46  allows a mechanical fastener to extend therethrough to connect the sear catch  32  to the second end  40  of the sear lever  26 . As the first end  38  of the sear lever  26  compresses the sear lever spring  28 , the second end  40  of the sear lever causes the sear catch  32  to be drawn into the cavity  20  of the sear block  18  thereby retracting the sear catch into the slot  42  and away from the firing pin lug  44 . 
     The disconnector  30  extends across the sear block  18  with a distal portion  48  that engages the trigger bow  12 , and a proximal end  50  that projects from the sear block slot. The disconnector  30  has an enlarged center hole  52  that is in register with the sear pivot pivot pin  34 . The spacing between edges of the enlarged hole  52  of the disconnector  30  and the sear pivot pivot pin  34  allow the disconnector to reciprocate in the sear block slot  42  and move in a direction transverse to the sear block slot. A disconnector spring  54  may urge the disconnector  30  to extend from the sear block slot  42 . The distal portion  48  of the disconnector  30  may have a sear pivot engagement surface  56  and a sear pivot relief area  58 . The proximal end  50  of the disconnector  30  may cooperate with a detent of a slide of the firearm. The proximal end  50  of the disconnector  30  may protrude into the detent. The slide may ride over the top of the disconnector proximal end  50  forcing the disconnector  30  against pressure from the disconnector spring  54  to retract through sear block slot  42  during firing of the handgun. 
     In operation, the trigger  10  moves the trigger bow  12 , and the trigger bow  12  causes the disconnector  30  retract into the sear block slot  42  and engage the sear pivot  24 . In drawing  FIGS. 1-6 , leftward motion of the trigger  10  and trigger bow  12  causes downward and leftward motion of the distal end  48  of the disconnector  30 . As the disconnector  30  engages the sear pivot  24 , the sear pivot cam surface  33  engages the first end  38  of the sear lever  26 , compressing the sear lever spring  28  and rotating the sear lever second end  40  in a manner to retract the sear catch  32  into the sear block slot  42 . In the drawing figures, the sear pivot  24  rotates clockwise when it is engaged by the disconnector  30 , which in turn causes clockwise rotation of the sear lever  26  in the cavity  20  of the sear block  18 . As the sear catch  32  retracts into the sear block slot  42 , the sear catch  32  disengages from the firing pin lug  44  and actuates the firing pin  16  to discharge a round. As the slide recoils after discharging the round, the disconnector  30  is driven into the sear block slot  42 . As the disconnector is driven into the sear block slot  42 , the disconnector distal end  48  moves in a manner such that the sear pivot engagement surface  56  no longer engages the sear pivot  24  and the disconnector relief area  58  becomes aligned with the sear pivot. As the disconnector relief area  58  becomes aligned with the sear pivot  24 , the sear pivot rotates away from the sear lever first end  38 . In drawing  FIGS. 1-6 , as the disconnetor  30  is driven into the sear block slot  42 , the disconnector moves downward to align the disconnector relief area  58  with the sear pivot  24 , which in turn allows the sear pivot to rotate counterclockwise and move downward. The sear lever spring  28  causes rotation of the sear lever  26  in the sear block cavity  20  to reposition the sear catch  42  in engagement with the firing pin lug  44 . The disconnector spring  54  may allow the disconnector  30  to reposition. In drawing  FIGS. 1-6 , the disconnector spring  54  urges the disconnector vertically upward in the sear block slot  42  to reposition the disconnector to enable successive firing of the firearm. The disconnector spring  54  may be a flat spring. The sear lever spring  28  may urge the first end  38  of the sear lever against the sear pivot  24 . In drawing  FIGS. 1-6 , when the disconnector relief area  58  is aligned with the sear pivot  24 , the sear pivot rotates counterclockwise and downward with the sear lever spring  28  urging the first end  38  of the sear lever against the sear pivot  24 . 
     In view of the foregoing, it will be seen that the several advantages are achieved and attained. The embodiments were chosen and described in order to best explain practical applications to thereby enable others skilled in the art to best utilize the various embodiments and modifications as are suited to a particular use contemplated. As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.