Abstract:
A passive safety for an AR platform firearm includes a sliding or pivoting rotating safety which is normally active to prevent trigger movement as would cause the firearm to discharge, and even when any active safety on the firearm is in a “fire” position. The passive safety is deactivated when an operator grips the firearm in a normal position to engage and pivot the trigger to discharge the firearm. Alternative embodiments are disclosed.

Description:
RELATED APPLICATION 
       [0001]    Applicant claims the benefit of the filing date of Sep. 12, 2014 U.S. Provisional Patent Application Ser. No. 62/049,436 which application is expressly incorporated herein as if fully set forth below. 
     
    
     FIELD OF INVENTION 
       [0002]    This invention relates to a grip-mounted safety device for a firearm. More particularly, it relates to a passively deactivated safety device integrated into the grip of a firearm so as to allow it to fire only when the trigger is pulled while the user is maintaining a proper grip. More specifically, one preferred embodiment of this invention contemplates a grip safety particularly usefully embodied in an “AR” platform firearm. 
       BACKGROUND OF THE INVENTION 
       [0003]    A wide variety of safety devices have been used in firearm designs in order to reduce the chance of an unintended discharge. Some safeties are internal and prevent discharge if, for example, the firearm is dropped. Other safeties are external and may be “passive” or “active.” An active safety requires the user to perform a specific operation to disengage the safety, such as sliding a member, moving a lever, or rotating a selector switch. Passive external safeties include devices on the trigger or grip which are automatically deactivated when the firearm is properly held and the trigger is intentionally pulled. Some firearms include a combination of more than one internal, external, passive, or active safety devices. 
         [0004]    A grip safety is a lever or other member situated on the grip of a firearm which must be displaced by the operator&#39;s hand, as a natural consequence of holding the firearm in a firing position, in order for the firearm to fire. The function of a grip safety is momentary in that the safety is deactivated only while the shooter maintains a proper hold on the grip and is reactivated automatically preventing discharge when the shooter releases it. The safety thus prevents discharge of the firearm in the absence of a proper, safety disengaging, grip. 
         [0005]    A “single action” firing mechanism is one in which the hammer or striker is fully cocked and only a pull of trigger is necessary to cause it to discharge. Single action firearms are more likely to use an external manual safety to prevent accidental discharge. Some single action firearms, such as the M1911 pistol, also include a grip safety for added protection. A typical AR platform firearm, such as an AR15-style firearm, including the M16, M4, pistol configurations, and (other variants), has a single action type firing mechanism and employs only an active, external safety that is manually manipulated between “safe” and “fire” positions. If the manual safety is actively deactivated (selector switch set to “fire”), a loaded AR15-type firearm will discharge if the trigger is actuated, even if the operator is not properly gripping the firearm in a shooting position. 
         [0006]    The use of passive safeties may have traditionally been considered less important on a rifle than on a pistol because rifles are not usually placed in a holster, a pocket, or a bag, the act of which can result in a foreign object engaging and actuating the trigger. In tactical situations, however, an operator may be more likely to quickly transition between use of a rifle and handgun and/or to allow the rifle to hang from a one or two point sling while performing some other close quarters task, such as reaching for other equipment or handcuffing a prisoner. If a chamber-loaded AR15-type rifle is allowed to hang from a sling with the manual active safety disengaged, it can and will discharge when any object presses the trigger, releasing the hammer. Unintentional discharge is an obviously serious consequence at any time and particularly when the firearm muzzle is not being safely controlled. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention provides a grip safety, such as for an AR platform firearm including an AR15-type rifle, to prevent unintentional discharge unless it is being properly gripped by the operator. 
         [0008]    Other aspects, features, benefits, and advantages of the present invention will become apparent to a person of skill in the art from the detailed description of various embodiments with reference to the accompanying drawing figures, all of which comprise part of the disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Like reference numerals are used to indicate like parts throughout the various figures of the drawing, wherein: 
           [0010]      FIG. 1  is a partially cut-away illustrative side view of the right-hand side of a typical AR15-style lower receiver with an installed fire control group and a grip safety according to one embodiment of the present invention with the hammer engaged on a trigger sear surface; 
           [0011]      FIG. 2  is a partially cut-away isometric view (from a slightly rearward right-hand perspective) of a similar AR15-type lower receiver with a grip safety according to a second embodiment of the present invention. 
           [0012]      FIG. 3  is a bottom view of the lower receiver of  FIG. 1  illustrating the slot in the receiver accommodating the safety lever; 
           [0013]      FIG. 4  is a side view of one modified embodiment of the safety lever of  FIG. 1 ; 
           [0014]      FIG. 4A  is a rear view of the lever of  FIG. 4 ; 
           [0015]      FIG. 5  is a side view of the operator engagement projection for the lower end of the modified lever of  FIG. 4 ; 
           [0016]      FIG. 5A  is a section view of the projection of  FIG. 5 ; 
           [0017]      FIG. 6  illustrates an enlarged trigger embodiment illustrating the safety notch in the rear extension thereof; and 
           [0018]      FIG. 7  is a partially cut-away isometric view showing the elements of  FIGS. 4 ,  4 A,  5 ,  5 A, and  6  installed in a lower receiver and pistol grip. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    With reference to the drawing figures, this section describes particular embodiments and their detailed construction and operation. Throughout the specification, reference to “one embodiment,” “an embodiment,” or “some embodiments” means that a particular described feature, structure, or characteristic may be included in at least one embodiment. Thus appearances of the phrases “in one embodiment,” “in an embodiment,” or “in some embodiments” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the described features, structures, and characteristics may be combined in any suitable manner in one or more embodiments. In view of the disclosure herein, those skilled in the art will recognize that the various embodiments can be practiced without one or more of the specific details or with other methods, components, materials, or the like. In some instances, well-known structures, materials, or operations are not shown or not described in detail to avoid obscuring aspects of the embodiments. 
         [0020]    Referring first to  FIG. 1 , therein is shown at  10  a lower receiver for an otherwise typical AR15-type firearm. The receiver  10  includes a mechanism known collectively as the fire control group, which comprises a trigger  12  and disconnector  14  mounted to pivot in a limited range of motion on a trigger pin  16 . A hammer  18  is pivotally mounted on a hammer pin  20  and is spring biased (not shown) toward the “dropped” position at which it will strike the firing pin (not shown), all as is well-known. The hammer  18  is held in a “cocked” position, as shown in  FIG. 1 , by engagement between the sear  22  and hammer notch  24 . A selector  26  may be manually pivoted by the operator using an external lever on the opposite side of receiver  10  (not shown) to rotate it between “safe” and “fire” positions. When in the “safe” position, the selector  26  blocks upward movement of a rear extension portion  28  of the trigger  12 . 
         [0021]    A forward extension  30  of the trigger  12  carries the sear  22 . A downward extension  32  of the trigger  12  acts as a lever or crank arm such that manipulation by the operator&#39;s finger causes the entire trigger  12  to pivot in a limited range of movement on the trigger pin  16 . When the downward extension  32  is pulled rearwardly, the rear extension portion  28  is moved upward (as shown by arrows in  FIG. 1 ) if not blocked by selector  26  or other safety disclosed herein. As a consequence of the same action, the forward extension  30  moves downward, causing the sear  22  to disengage from the hammer notch  24  and allowing the hammer  18  to be released and swung by spring force into contact with the firing pin. Each of these extensions  28 ,  30 ,  32  of the trigger  12  mechanically act in the form of a simple “bell crank,” translating motion of one extension in a first direction into motion of another extension in a different direction. The heretofore described parts, mechanism and operation are standard to an ordinary AR15-type firearm. 
         [0022]    The present invention provides a grip safety lever  34  that is pivotally mounted relative to the receiver  10  and/or its pistol grip  36 . Grip  36  has a rear edge as shown, the grip safety lever  34  is mounted on a pivot pin  38 , which is carried by the lower receiver  10 . An upper portion  34   a  of the grip safety member  34  extends through a channel  40  ( FIG. 3 ) formed in the lower receiver  10  and includes a hook  42  that is positioned to engage a safety notch or stop  44  formed at or near the rear end or face of the rear extension  28  of the trigger  12  (see  FIG. 6  for an enlarged view of notch  44 ). The grip safety  34  is spring biased into this engagement position by a spring means, such as a leaf spring  46  (shown in  FIG. 1 ) or some other suitable torsion or coil spring. The grip safety  34  further includes a lower portion  48  that may extend rearwardly from the pistol grip  36  and is exposed for manual engagement through an opening  50  along an upper rear edge of the pistol grip  36  as shown. 
         [0023]    In use, when an operator of the firearm grasps the pistol grip  36  in a manner that allows the trigger finger to reach and actuate the downward extension  32  of the trigger  12 , that grasp will depress the lower portion  48  of the grip safety lever  34 , usually by the palm of the hand or by the web of the hand between index finger and thumb, causing the lever  34  to rotate about the pivot pin  38  (as shown by arrows B in  FIG. 1 ). This pivotal movement causes the hook portion  42  at the upper end of the grip safety lever  34  to be moved away from engagement with the notch  44  on the rear extension  28  of the trigger  12 , allowing the trigger  12  to pivot and release the hammer notch  24  and thus the hammer  18 . When an operator is not grasping the pistol grip  36 , the hook  42  of the grip safety lever  34  remains engaged with the notch  44  of the rear extension  28  of the trigger  12 , preventing its movement (and release of hammer  18 ) even if the selector  26  is set to “fire” (as shown in  FIG. 1 ) and pressure is applied to trigger  12  either manually or by another agent. 
         [0024]    Minimal alteration or modification of the standard design for an AR15-type lower receiver  10  or pistol grip  36  is required for adaptation to the grip safety of the present invention. As described above, a channel  40  ( FIG. 3 ) is provided in the lower receiver  10 . This channel can be behind and generally parallel to the attachment socket  52  that engages a threaded fastener  54  for attachment of the pistol grip  36  to the lower receiver body  10 . As previously noted, the rear extension  28  of the trigger  12  is provided with a notch  44  for engagement of the hook  42 . The pistol grip  36  is provided with an upper opening or channel  56  and the rear edge opening  50  to receive and expose the lower portion  48  of the grip safety  34 . 
         [0025]    Referring to  FIGS. 4 ,  4 A,  5  and  5 A, there is shown a modified embodiment of the safety lever of  FIG. 1 . Safety lever  80  is like that of  34 , excepting its overall shape as shown, formed to pivot about  81  on a pin such as at  38  ( FIG. 1 ) with upper and lower portions  82 ,  83 . Portion  82  includes hook  84  with similar function of hook  43  and notch  44  of  FIG. 1 . Projection  90  is secured to lower portion  83  at end  85  by screws or other fasteners thru holes  87 ,  88 . Projection  90  extends outwardly of grip  36  for operator engagement when properly gripping the firearm.  FIG. 6  shows an embodiment of a trigger member  12  illustrating the safety notch  44  in the rear extension  28  thereof.  FIG. 7  shows a partially cut-away view of the safety lever  80  of 
         [0026]      FIGS. 4 and 4A , projection  90  of  FIGS. 5 and 5A , and trigger member  12  of  FIG. 6  installed in a lower receiver  10  with a pistol grip  36  and spring  46  in the “safe” position. 
         [0027]    Referring now to  FIG. 2 , therein is shown a firearm grip safety according to a second embodiment of the present invention. Like reference numerals will be used to indicate like parts that do not significantly differ from those shown and described with respect to the first embodiment, above. Different reference numerals will be used to identify parts that differ from those of the first embodiment. 
         [0028]    The second embodiment provides a sliding, rather than pivoting, grip safety  58  having a rear portion  60  that is exposed along the upper back edge of the pistol grip  36  and/or lower receiver  10 . It has a forwardly extending portion  62  with a transverse extension  64  at its forward end that underlies the forward extension  30  of the trigger  12  when the grip safety is in the “safe” position. In this position, the forward extension  30  of the trigger is blocked from downward movement, preventing the sear  22  from disengaging from the hammer notch  24  even if the downward extension  32  of the trigger  12  is pulled. The grip safety  58  is biased toward this position by a spring means (not shown), which can be a coil spring, leaf spring, or other suitable substitute. 
         [0029]    When an operator grips the pistol grip  36  in a manner allowing the trigger finger to overlie and actuate the downward extension  32  of the trigger  12 , the web of the operator&#39;s hand covers and depresses the rear exposed portion  60  of safety  58 , causing the grip safety  58  to slide forward (as illustrated by arrow  66 ). When slid forward, the transverse extension  64  is moved forward of the forward extension  30  of the trigger  12 , allowing the trigger  12  to pivot if actuated by the operator&#39;s trigger finger. However, once the operator releases his grip, the grip safety  58  is returned by spring force to its original rearward position (opposite arrow  66 ), causing the transverse extension  64  to underlie the forward extension  30  of the trigger  12 , and preventing actuation of the trigger member  12  even if the manual safety selector  26  is in the “fire” position. 
         [0030]    Accordingly, the present invention provides a passive safety that is disengaged by the operator&#39;s proper grip for firing and that is particularly adaptable to the AR15-type platform. If desired, a lock member (not shown) could be added to the pistol grip  36  or receiver  10  that could be actuated to selectively lock the grip safety lever  24 ,  80  in either the “safe” or “fire” position to override the passive nature of the device. A sliding member in the grip  36  could be positioned to engage the lower portion  48 ,  83  at or near the lower end  85  or to engage the projection  90  and hold the lever  24 ,  80  in either position. Alternatively, a movable member, such as but not limited to a sliding cross bolt member, could be positioned on or in a rear portion of the receiver  10  to engage and selectively hold the upper portion  34   a,    82  of the safety lever  34 ,  80  in either position. 
         [0031]    While specific embodiments of the present invention have been described in detail, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. Therefore, the foregoing is intended only to be illustrative of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not intended to limit the invention to the exact construction and operation shown and described. Accordingly, all suitable modifications and equivalents may be included and considered to fall within the scope of the invention.