Patent Publication Number: US-8985006-B1

Title: Trigger assembly

Description:
BACKGROUND 
     1. Field of the Invention 
     The present invention relates generally to a trigger assembly for a firearm. 
     2. Related Art 
     The AR-15 is a popular rifle and includes a safety selector that engages a trigger to resist the trigger from being pulled when the selector is set on safe. The trigger, in turn, has an edge that engages an edge of a hammer. Pulling the trigger pivots the edge of the trigger out of engagement with the edge of the hammer, allowing a spring to pivot the hammer into contact with a firing pin. The engaging edges of the trigger and the hammer may inadvertently disengage upon impact, such as a rifle drop, allowing the rifle to misfire. 
     SUMMARY OF THE INVENTION 
     It has been recognized that it would be advantageous to develop an additional safety for the AR-15 type or style of firearm or rifle. In addition, it has been recognized that it would be advantageous to develop an additional safety for trigger assemblies of firearms. Furthermore, it has been recognized that it would be advantageous to develop a secondary safety in addition to a primary safety for trigger assemblies of firearms. 
     The invention provides a trigger assembly for use with a firearm. The trigger assembly has a hook carried by and pivotal with a selector to engage an aft tab of a hammer in the safe position of the selector. 
     In accordance with a more detailed aspect of the invention, the selector can engage both a trigger and the hammer in the safe position. A cam of the selector can engage a trigger and the hook of the selector can engage the tab of the hammer in the safe position. The selector can have a shank extending through a bore of the hook. The shank and the bore can be keyed to one another. The hook can be carried by a shank of the selector. The hook can have a forked collar with the bore extending through the collar, and a slot extending into the collar transverse to the bore and exposing the shank of the selector, and thus a cam of the selector. 
     In addition, the invention provides a trigger assembly for use with a firearm and having a hammer configured to be pivotally coupled to the firearm and positioned to selectively strike a firing pin in a bolt mechanism of the firearm. The hammer has an aft tab. A trigger is pivotally coupled to the firearm and releasably engages the hammer to selectively engage and hold the hammer, and to selectively release the hammer to strike the firing pin when pulled by a user. A selector is pivotally coupled to the firearm and releasably engages the trigger to selectively engage and hold the trigger from being pivoted, and to release the trigger to be pulled by the user. The selector has at least a safe position to hold the trigger, and a fire position to allow the trigger to be pulled. A hook is fixedly mounted to the selector and pivotal therewith between the safe and fire positions. The hook engages the tab of the hammer in the safe position. 
     Furthermore, the invention provides a trigger assembly in combination with a firearm. The trigger assembly has a hammer pivotally coupled to the firearm and positioned to selectively strike a firing pin in a bolt mechanism of the firearm. The hammer has a hammer pivot, a tab aft of the pivot, and a lower edge beneath the pivot. A trigger is pivotally coupled to the firearm and releasably engaging the hammer to selectively engage and hold the hammer, and to selectively release the hammer to strike the firing pin when pulled by a user. The trigger has a trigger pivot, a fore edge forward of the trigger pivot and selectively engaging the lower edge of the hammer, and an aft arm. A selector is pivotally coupled to the firearm and releasably engages the trigger to selectively engage and hold the trigger from being pivoted, and to release the trigger to be pulled by the user. The selector has at least a safe position to hold the trigger, and a fire position to allow the trigger to be pulled. The selector has a shank disposed over the aft arm of the trigger with a cross-sectional shape with a lobe abutting to the aft arm of the trigger in the safe position, and a notch aligned with the aft arm of the trigger in the fire position. A hook is fixedly mounted to the selector and pivotal therewith between the safe and fire positions. The hook engages the tab of the hammer in the safe position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention; and, wherein: 
         FIG. 1  is a perspective view of a trigger assembly in accordance with an embodiment of the present invention shown in a lower receiver of a firearm with a portion of the lower receiver removed for visibility; 
         FIG. 2  is a perspective view of the trigger assembly of  FIG. 1  again shown in the lower receiver of the firearm with the portion of the lower receiver removed for visibility; 
         FIG. 3  is a right side view of the trigger assembly of  FIG. 1  again shown in the lower receiver of the firearm with the portion of the lower receiver removed for visibility; 
         FIG. 4  is a left side view of a portion of the firearm, namely the upper and lower receivers, with the trigger assembly of  FIG. 1  disposed therein, and showing a safety selector lever in a safe position; 
         FIG. 5  is a perspective view of the trigger assembly of  FIG. 1  shown in the safe position and the cocked position; 
         FIG. 6  is a perspective view of the trigger assembly of  FIG. 1  shown in the safe position; 
         FIG. 7  is a side view of the trigger assembly of  FIG. 1  shown in the safe position; 
         FIG. 8  is a perspective view of a hook and the safety selector lever of the trigger assembly of  FIG. 1 ; 
         FIG. 9  is a perspective view of the safety selector lever of the trigger assembly of  FIG. 1 ; 
         FIG. 10  is a perspective view of the hook of the trigger assembly of  FIG. 1 ; 
         FIG. 11  is a cross-sectional side view of the trigger assembly of  FIG. 1 , taken along line  11  of  FIG. 5 , shown in the safe position; and 
         FIG. 12  is a cross-sectional side view of the trigger assembly of  FIG. 1 , shown in a fire position. 
     
    
    
     The trigger assembly shown in the drawings is configured for an AR-15 type or style of rifle, and the firearm shown in the drawings is an AR-15 type or style of rifle. In the drawings, only the upper and lower receiver of the rifle are shown, with a barrel removed from the upper receiver, and with a buttstock and a receiver extension or tube and associated spring and buffer assembly removed from the lower receiver. 
     Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. 
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENT(S) 
     As illustrated in  FIGS. 1-12 , a safety or secondary safety or hammer safety, indicated generally at  10 , in an example implementation in accordance with the invention is shown for a trigger assembly  14  of a firearm  18 . The safety  10  can provide a positive and physical engagement with a hammer as a secondary safety, while a primary safety engages a trigger. Thus, the safety  10  provides an additional safety feature to the firearm  18  and resists inadvertent firing, such as might occur with a rifle drop. 
     The firearm  18  is shown and described as an AR-15 type or style of rifle. The firearm  18  can thus have upper and lower receivers  22  and  24  coupled together. The upper receiver  22  can carry the bolt or bolt carrier  26  and associated components, including a firing pin  28 . (For clarity, the upper receiver is shown with various components removed, including the barrel, charging handle, etc. In addition, a portion of the upper receiver has been removed to view the bolt carrier. Thus, various components are not visible, including the ejection port and cover, forward assist plunger, etc.) The lower receiver  24  can carry the trigger assembly  14 . (For clarity, the lower receiver is shown with various components removed, including the buttstock, receiver extension or tube, buffer assembly, pistol grip, etc. In addition, a portion of the lower receiver has been removed to view the trigger assembly.) The firearm  18  is shown and described as an AR-15 type or style of rifle by way of example. It will be understood by those of skill in the art, that the safety  10  of the present invention can be used with other types and styles of trigger assemblies and firearms. 
     The trigger assembly  10  is shown and described as an AR-15 type or style of trigger assembly. In addition, the trigger assembly  10  is shown and described as a semi-automatic type or style of trigger assembly. It will be understood by those of skill in the art that the trigger assembly can be configured for other types and styles of firearms, or for use with automatic firearms, such as an M16 type or style of rifle. The trigger assembly  10  includes a hammer  30  pivotally coupled to the firearm (e.g. the lower receiver  24 ) and positioned to selectively strike the firing pin in the bolt mechanism or carrier of the firearm. The hammer  30  can have a hammer pivot  34  (about a hammer retaining pin). A hammer spring can bias the hammer to pivot forwardly or towards the firing pin. The hammer can have an edge, such as a lower edge  38  beneath the pivot (in the cocked position of the hammer), to be used by the trigger to hold the hammer against the spring in the cocked position. The hammer can extend rearward from the pivot in the cocked position, and can have an aft tab  42  aft of the pivot (in the cocked position). Thus, the aft tab  42  can be distal with respect to the pivot. 
     The trigger assembly  10  includes a trigger  50  pivotally coupled to the firearm and releasably engaging the hammer  30  to selectively engage and hold the hammer, and to selectively release the hammer to strike the firing pin when pulled by a user. The trigger  50  can have a trigger pivot  54  (about a trigger pin). A trigger spring can bias the trigger to hold the hammer. The trigger  50  can have a fore edge  58  forward of the trigger pivot and selectively engaging the lower edge  38  of the hammer  30 . Thus, the edges  38  and  58  of the hammer  30  and the trigger  50 , respectively, engage to hold the hammer in the cocked position, as shown, and selectively disengage to allow hammer fall, or the spring to pull the hammer into contact with the firing pin. In addition, the trigger  50  can have an aft arm  62  aft or rear of the pivot to form a part of the safety, as discussed below. 
     The trigger assembly can also include a disconnector  66  with a hook engaging an intermediate hook at an intermediate location on the hammer. The disconnector catches and holds the hammer after firing (and after the bolt carrier has returned the hammer) and while the trigger is still being held, to prevent the hammer from returning to the firing position under the influence of the spring while the trigger is still pulled. After the trigger is released, the disconnecter releases hammer so that it is ready to fire again. 
     The trigger assembly includes a selector  70  pivotally coupled to the firearm (such as the lower receiver) and releasably engaging the trigger  50  to selectively engage and hold the trigger from being pivoted, and to release the trigger to be pulled by the user. The selector has at least a safe position ( FIGS. 7 and 11 ) to hold the trigger, and a fire position ( FIG. 12 ) to allow the trigger to be pulled. The selector  70  can have a shank  74  or pin disposed over the aft arm  62  of the trigger  50  with a cross-sectional shape or cam  78 , such as a lobe  82  abutting to the aft arm  62  of the trigger in the safe position, and a notch  86  aligned with the aft arm of the trigger in the fire position. 
     The selector  70  can have two halves affixed together, including a first engagement side  90  and a second side  92 . The first engagement side  90  can have an enlarged head  94  disposed on one side of the shank  74  and outside the firearm (or lower receiver), a slot  96  in the head receiving the shank therein. The first engagement side  90  can also have a selector arm  98  disposed outside the firearm (or lower receiver) and attached to the enlarged head and engageable by a user to pivot the selector. The head  94  can have an indicator pointing to indicia on the firearm or lower receiver to indicate the position of the selector (such as on safe or fire). The second side  92  can have the shank  74  and an enlarged head  100  disposed on the opposite side of the shank from the head  94  of the first engagement side  90 . The heads  94  and  100  are disposed outside the firearm (or lower receiver) while the shank  74  or pin extends through the firearm (or lower receiver) and forms a pivot for the selector. 
     The shank  74  can have a cross-sectional shape that is oblong forming a cam  78  with a long side forming a lobe  82  configured to abut to the aft arm  62  of the trigger  50  in the safe position, and a short side forming a notch  86  configured to align with the aft arm of the trigger in the fire position. The cam or oblong cross-sectional shape can be formed by forming the notch  86  in the circular or round cross-sectional shape of the shank  74 . 
     The safety  10 , the trigger assembly  14  and the selector  70  have a hook  110  fixedly mounted to the selector or shank, and pivotal therewith between the safe and fire positions. The hook  110  engages the tab  42  of the hammer  30  in the safe position, as shown in  FIG. 11 . Thus, the selector  70  engages both the trigger  50  and the hammer  30  in the safe position by the cam  78  and the hook  110 , respectively. The cam  78  of the selector  70  engages the trigger  50 , or aft arm  62  thereof, and the hook  110  of the selector engages the tab  42  of the hammer  30  in the safe position. The hook  110  can include a collar  114  with a bore  118  therein to receive the shank  74  of the selector, and a hook projection  122  extending from the collar to engage the tab of the hammer. The hook or hook projection can extend forwardly when the selector is in the safe position. A transverse slot  126  can be formed in the collar  114  perpendicular to an axis of the bore  118  and the pivot axis of the selector, forming a forked collar. The shank of the selector can extend through the bore of the hook, and the hook can be carried by a shank of the selector. The slot can extend into the bore  118  and can expose two adjacent sides of the bore, and thus can expose the lobe  82  and the notch  86  of the selector, or shank or cam thereof. Thus, the hook  110  has a forked collar  114  with the bore  118  extending through the collar, and a slot  126  extending into the collar transverse to the bore and exposing the shank of the selector, and thus a cam of the selector. The bore  118  of the hook  110  can have a cross-sectional shape matching or mating with the shank. Thus, the shank and the bore are keyed to one another. As discussed above, the shank can have two-halves that can be affixed together to retain the hook therebetween. 
     While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.