Abstract:
Provided is a trigger guard for an AR15-type firearm lower receiver, attachable and removable without application of impact force. It includes an elongated trigger guard member having forward and rear ends with a rear transverse opening positioned to align with mounting openings on the receiver. A mounting pin has a size no greater in cross-section than that of the mounting openings on the receiver and a spring engagement means thereon. A deflectable spring means is operably positioned in the transverse opening to be deflected when the pin is inserted in the transverse opening and to engage the spring engagement means on the mounting pin when the mounting pin reaches a preselected position.

Description:
RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/008,718, filed Jun. 6, 2014. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to a trigger guard for use with a standard or mil-spec AR15/M16 lower receiver. More specifically, this trigger guard can be installed without the use of specialized tools and with reduced risk of damage to the mounting tabs on the lower receiver. 
       BACKGROUND OF THE INVENTION 
       [0003]    A standard or mil-spec lower receiver for an AR15- or M16-platform rifle uses a lower trigger guard that is a separate piece and is attachable at forward and rearward ends to standardized mounting points on the lower receiver body. The standard trigger guard mounts at its rearward end by use of a roll pin hammered or pressed through a first tab extending from the lower receiver, through a transverse opening in the trigger guard, and through a second opening in a second mounting tab on the lower receiver. The forward end has a spring detent on the right side which is inserted to releasably engage an opening in the right side forward mounting tab extending from the lower receiver. 
         [0004]    The nature of a common roll pin (also called spring pin or tension pin) is that it has a body diameter which is larger than the hole diameter for which it is intended to be used, and a chamfer on one or both ends to facilitate starting the pin into the hole. The body of the pin is split longitudinally or helically, providing a spring action that allows the diameter of the pin to compress as it assumes the diameter of the hole. The radially outward force exerted by the pin against the hole wall retains it in the hole, making it a self-retaining fastener. Installation requires, however, that the roll pin be hammered or forcibly pressed into position. In the case of the AR15/M16-platform lower receiver, the mounting holes for the trigger guard are in relatively thin tabs extending from the lower receiver body. If care is not taken as the trigger guard roll pin is hammered or pressed into place, a mounting tab can be broken. This is one of the most common breakage points on the lower receiver, often occurring during initial assembly. 
         [0005]    An alternative attachment means for a trigger guard that does not add unnecessary bulk, parts, or complexity and that can be installed without having to hammer or force a roll pin through the mounting tabs of a lower receiver is desired. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides a trigger guard for an AR15-type firearm lower receiver that is attachable and removable without application of impact force. It includes an elongated trigger guard member having forward and rear ends with a rear transverse opening positioned to align with mounting openings on the receiver. A mounting pin is provided having a size no greater in cross-section than that of the mounting openings on the receiver and a spring engagement means thereon. A deflectable spring means is operably positioned in the transverse opening to be deflected when the pin is inserted in the transverse opening and to engage the spring engagement means on the mounting pin when the mounting pin reaches a preselected position. 
         [0007]    The trigger guard member may also be curved to provide an enlarged trigger opening. At least one elastomeric buffer member may be positioned on the trigger guard member to contact a surface of the receiver when installed to prevent movement between the installed trigger guard and the receiver. if desired, an elastomeric buffer member may be placed adjacent both the forward and rear ends of the trigger guard member. 
         [0008]    Other aspects, benefits, and features of the present invention may be apparent to a person of skill in this art by reference to the following specification, drawing figures, and claims, all of which are part of the disclosure of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0009]    Like reference numerals are used to indicate like parts throughout the various figures of the drawing, wherein: 
           [0010]      FIG. 1  is an isometric exploded view of an AR15-type lower receiver along with a prior art trigger guard and a trigger guard according to the present invention; 
           [0011]      FIG. 2  is an isometric exploded view of a trigger guard according to the present invention; 
           [0012]      FIG. 3  is a longitudinal side sectional view taken substantially along line  3 - 3  of  FIG. 2 ; 
           [0013]      FIG. 4  is a top plan view thereof; 
           [0014]      FIG. 5  is a rear end view thereof; 
           [0015]      FIG. 6  is a side elevation view thereof; 
           [0016]      FIG. 7  is a cross sectional view taken substantially along  7 - 7  of  FIG. 6 ; and 
           [0017]      FIG. 8  is a bottom plan view thereof. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Referring to the various figures of the drawing, and first to  FIG. 1 , therein is shown at  10  is a standard and well-known AR15-type lower receiver for a firearm. The receiver  10  is shown in a “stripped” condition, wherein it comprises a single piece of material on which none of the additional required parts have been installed. 
         [0019]    Among other functions, the lower receiver  10  provides a housing for the various parts that make up the fire control group (not shown). At a lower rear location on the receiver  10 , there is a standardized mounting means  12  for a pistol grip. Forward of that location is an area enclosed on forward, upper and rearward sides that defines a trigger area with open left and right sides where the user&#39;s finger may be inserted for actuating the trigger. At the lower end of the forward boundary are a pair of spaced-apart forward mounting tabs  16 . An opening  17  is provided in the forward tab  16  on the right side for receiving a spring detent, as will be explained in greater detail below. At the bottom end of the rearward boundary, there are right and left rear mounting tabs  18  with transversely aligned openings  19 . 
         [0020]    A tool-less trigger guard according to the present invention is shown at  20  in  FIG. 1 . A prior art trigger guard is shown in  FIG. 1  at  20   a . At the forward end  22  of the prior art trigger guard  20   a  is a standard spring detent (not shown) housed in a forward transverse opening  24 . At the rear end  26 , there is another transverse opening  28  that is sized to receive a roll pin  30 . 
         [0021]    To install the prior art trigger guard  20   a,  the rear end portion  26  is placed between the rear tabs  18  so that the transverse opening  28  is aligned with the tab openings  19 . While supporting the lower receiver body  10  against a solid surface, the roll pin  30  is carefully tapped or pressed through a first tab opening  19 , through the rear transverse opening  28  of the trigger guard  20   a,  and then through the opposite tab opening  19 . The forward end  22  can then be swung into position, displacing the detent until it is aligned with the detent opening  17 . To remove the prior art trigger guard  20   a , the forward detent is depressed using a tool or small object through the outside of the detent opening  17  to release the forward end  22  of the trigger guard  20   a.  To remove the rear connection, a pin punch or drift must be used to drive the roll pin  30  out of engagement with the rear tab openings  19  and rear transverse opening  28  of the trigger guard  20   a.  This removal procedure again poses some appreciable risk that one of the rear mounting tabs  18  will be broken or damaged. 
         [0022]    Referring now also to  FIGS. 2-8 , therein is shown the various parts and features that comprise the tool-less trigger guard  20  of the present invention. Describing first the attachment features, at the forward end  32  of the trigger guard body  20  there is a forward transverse opening  34  configured to receive and retain a detent member  36  and a spring  38 . A cross bore opening  40  is formed to intersect the transverse opening  34  and receive a retaining pin  42  after insertion of the detent member  36  and spring  38 . This forward attachment mechanism is substantially the same as is used for attaching the forward end of a prior art trigger guard  20   a,  described above. At the rear end  44  of the trigger guard body  20  is a rear transverse opening  46  that is positioned to align with the rear tab openings  19  of the lower receiver  10 . Rather than being attached by means of a roll pin, the present invention uses a cross pin  48  sized to fit easily through the rear tab openings  19  and the rear transverse opening  46 . At a selected point along the length of the cross pin  48 , preferably near the center, there is an annular groove  50 . A passageway is formed from the rear end  44  of the trigger guard  20  that is positioned to partially intersect with the rear transverse opening  46 . Referring now in particular to  FIGS. 3 and 5 , the passageway includes a first, larger diameter opening  52  of a first, limited depth and a second, smaller diameter opening  54  which extends to a depth sufficient to at least partially intersect the rear transverse opening  46 , offset from the center thereof. A wire spring  56  is inserted into the openings  52 ,  54  and is positioned to engage the groove  50  of the cross pin  48  when it is inserted into the rear transverse opening  46 . The smaller diameter opening  54  is sized to closely fit the wire spring  56 , holding it in place by friction. The larger diameter opening  52  allows access to an end of the wire spring  56  for removal without having any part of the wire spring  56  protrude beyond the profile of the trigger guard  20 . 
         [0023]    Installation of the trigger guard  20  may be accomplished without risking damage to the rear mounting tabs  18  of the lower receiver  10 . The trigger guard  20  is positioned so that the rear transverse opening  46  is in alignment with the rear tab openings  19 . Then the cross pin  48  is inserted through the openings  19 ,  46  without hammering and without the potentially adverse consequences of forcing an oversized roll pin through the openings  19 ,  46 . The only significant resistance to insertion of the cross pin  48  is as the wire spring  56  is slightly deflected until the cross pin  48  reaches the fully installed position and the wire spring  56  comes to rest in engagement with the annular groove  50 . The cross pin  48  can then be removed, if necessary, simply by pushing it out with any object sized to fit within the openings  19 ,  46 . No special tool, such as a hardened pin punch, is required, since no hammering or other impact is necessary. 
         [0024]    If desired, buffers  58  made of an elastomeric material, such as nitrile rubber or Buna-N, can be situated at upper surfaces of the forward and rear ward ends  32 ,  44  of the trigger guard  20 . For example, the buffers  58  may be configured to be at least partially received into openings  60  for secure mounting. The buffers  58  are positioned to bear against lower surfaces  62 ,  64  on the receiver  10  when the trigger guard  20  is installed. Because the cross pin  48  provides a “looser” fit than a roll pin  30 , the trigger guard  20  may be allowed some minimal, but undesired, movement. Use of the buffers  58  provides minimal, but adequate, compression force to eliminate any such movement. 
         [0025]    The trigger guard  20  of the present invention can be made in any desired functional or ornamental variation. As shown in  FIGS. 2 ,  3  and  6 , the illustrated embodiment is provided with an outward (downward) curve to enlarge the trigger area  14  and accommodate a gloved trigger finger. As also shown in  FIGS. 2 ,  4  and  8 , the width of the trigger guard  20  between the forward and rearward ends  32 ,  44  can be widened to substantially match the overall width and contour of the forward and rear mounting tabs  16 ,  18 . 
         [0026]    While an exemplary embodiment of the present invention has 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 considered as illustrative only of the principles of the invention and, since modifications and changes will be apparent 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 resorted to, falling within the scope of the invention.