Patent Publication Number: US-7900546-B2

Title: Rifle charging handle with ambidextrous latch

Description:
REFERENCE TO RELATED APPLICATION 
     This is a Continuation application of U.S. patent application Ser. No. 10/876,742 of the same title, filed Jun. 25, 2004, now U.S. Pat. No. 7,240,600. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to firearms, and more particularly to mechanisms for securing and releasing the action of an auto-loading rifle. 
     BACKGROUND OF THE INVENTION 
     The M-16 military rifle and its civilian counterparts have a T-shaped charging handle that is operated to open the rifle&#39;s action by pulling the bolt rearward. The handle has an elongated body with a crossbar at the rear end, so that a user generally operates the action by hooking the forefinger and middle finger of the right had over the ends of the crossbar and pulling it to the rear. The forward end of the handle engages the rifle&#39;s bolt. In the conventional rifle, the handle includes a spring-loaded L-shaped latch that pivots about a vertical axis in the left portion of the crossbar. The latch has a first leg that extends laterally from the axis, partially protruding forward of the left portion of the crossbar. A second leg of the latch extends forwardly, and has a hook that engages a recess in the receiver in which the draw bar reciprocates. The latch is spring-biased so that the hook presses into the receiver recess when the charging handle is in a forward position. This prevents the handle from moving rearward except when a user applies pressure to the first leg of the latch, which occurs naturally when deliberately pulling on the crossbar of the charging handle. This conventional latch is described and illustrated in U.S. Army Field manual FM 23-9, U.S. Army Technical manual TM 9-1005-249-10, and U.S. Army Technical manual TM 9-1005-319-10, which are incorporated herein by reference. 
     While effective in many instances, the existing latch configuration is not entirely suitable for operation in alternate modes than my be necessary. For instance, when an optical scope is mounted to the top of the receiver, there may be inadequate space for the user to hook two fingers over the charging handle crossbar. Consequently, a user seeking to draw the charging handle must access the handle crossbar from the side. In some instances, the user may not readily be able to access the left side, and the right side may be more reachable. However, because of the latch location, the user is forced to use the left side, which may be difficult, impossible, or slower than accessing the right end of the cross bar. 
     A modified latch (Tactical Latch 249-02, Badger Ordnance, North Kansas City, Mo.) has been suitable for some applications. The modified latch has an enlarged paddle on the first leg extending laterally beyond the left end of the charging handle crossbar. This makes the latch more accessible, and is advantageous for close quarters battle applications. It can be reached more readily by the alternate hand of the user, which may reach over or under the rifle to contact the protruding latch. However, this is less well suited to applications where protruding elements are subject to breakage or catching on other equipment. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the limitations of the prior art by providing a charging handle for a rifle having a housing. The handle has a body with an elongated bar having a forward end and a rear end. The bar has a bolt engaging element at the forward end, and a crossbar having an intermediate portion connected to the rear end of the bar. The crossbar has opposed ends extending laterally of the bar. First and second latch elements are connected to the body. The first latch element has a housing-engaging element that engages the housing when the handle is in a forward position. The first and second latch elements are engaged to each other such that pivoting of the second latch element disengages the housing-engaging element from the housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of a rifle with a charging handle according to a preferred embodiment of the invention. 
         FIG. 2  is an enlarged sectional view of the handle taken along line  2 - 2  of  FIG. 1 . 
         FIG. 3  is an enlarged view of the latch components of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
       FIG. 1  shows an M-16 or AR-15 rifle  10  having an upper receiver  12  mated to a lower receiver  14 . A buttstock  16  is connected to a rear end  20  of the lower receiver, and a barrel and handguard (not shown) are connected to a forward end  22  of the upper receiver. 
     A T-shaped charging handle  24  has an elongated body  26  with an elongated bar  30  having a forward end  32  with a hook  34  that engages a bolt (not shown). The bolt reciprocates within the upper receiver between a closed position in which the bolt is forward, and an open position in which the bolt is shifted rearward. The handle body  26  has an integral crossbar  36  connected to the rear end of the elongated bar. The crossbar is symmetrically positioned, perpendicular to the bar  30 , with the crossbar having a right end  40  and left end  42  (directions indicated from the perspective of an operator aiming the rifle) protruding in opposite directions to equal distances. 
     Each end of the handle&#39;s crossbar is cut with a horizontal slot  44 ,  46  that is parallel to the major plane defined by the handle, and horizontal when the rifle is oriented for normal operation. As shown in  FIG. 2 , each slot extends medially toward a midline  50  of the handle, but to a limited depth toward the midline so that a web  52  remains to provide structural integrity of the handle. Thus, the upper and lower portions of the crossbar at the middle are vertically connected to prevent deflection and to provide strength. Two lateral passages are defined in the web  52 . A forward passage  54  has upper and lower surfaces aligned with the upper and lower surfaces of the slots  44  and  46 . A spring aperture  56  is defined in the web. The aperture is a right-to-left cylindrical bore having a diameter equal to the slot width, and is positioned rearward of the forward slot, and forward of the rear edge of the crossbar  36 . 
     The handle includes a left latch element  60  and a right latch element  62 , each partially received in the respective left slot  44  and right slot  46 . The handle body  26  defines a pair of spaced apart pivot holes  64 ,  66 , each receiving a press fit roll pin  70 . The pivot holes are positioned in alignment with the forward aperture  54 , and are spaced apart more widely than the width of the web  52 . The latches are planar bodies having a thickness slightly less than the gap formed by the slots, so that they can pivot readily without excessive friction. 
       FIG. 3  shows the latch elements alone for clarity. The left latch element  60  has an L-shaped profile, with a lever portion  72  extending laterally from a pivot hole  74  that loosely receives the roll pin  70 . A forward edge  76  of the lever portion faces forward, and defines serrations to facilitate a positive contact with an operator&#39;s finger. The forward edge is aligned laterally with the hole  74 , so that the points on the forward edge follow substantially rearward arcs when the left latch pivots counterclockwise as viewed from above. The lever portion includes a spring contact surface  80  that faces medially, and is positioned directly rearward of the hole  74  so that the spring contact surface  80  follows a substantially rightward arc when the left latch pivots counterclockwise. The other portion of the “L” shape is a leg  82  that extends forward of the pivot hole  74 . The leg includes a hook  84  extending medially. The hook that has a forward cam surface  86  that is angled to face forward and medially and a rearward facing catch surface  90 . As thus far described, the left latch is essentially the same as a conventional latch of an M-16 rifle. However, the left latch also includes a medially-extending protrusion  92  in the form of a shaft  94  having a bulbous end portion  96 . The shaft extends radially from the hole  74 , and the end portion has a circular profile with a diameter greater than the width of the shaft. 
     The right latch  62  is in some respects a mirror image of the left latch  60 , except that it lacks the leg  82  or any forward extension, and it has a pair of medially-extending protrusions  100  that define a channel  102  having a centerline extending radially from the hole  74 ′ of the right latch. The channel has parallel sides spaced apart only slightly wider than the diameter of the end portion  96  of the left latch, so that the end portion is closely received in the channel as shown. The close fit of the end portion in the channel prevents looseness than can permit unwanted rattling sounds, and causes the latches to move in concert as one or the other is moved. The lever portion  72 ′ of the right latch has a spring contact surface  80 ′ that faces the opposed contact surface  80 . 
     Referring back to  FIG. 2 , the latches are shown installed in the body. A compression coil spring  104  occupies the spring aperture  56 , and has opposed ends that contact and bias apart the contact surfaces  80 ,  80 ′. This rotationally biases the left latch in a clockwise direction, and the right latch in a counterclockwise direction, each about their respective pivot points  74 ,  74 ′. The solid lines of  FIG. 2  illustrate the latches in a rest or latched condition. In the latched condition, the hook  84  engages a recess  106  defined in the left side of the upper receiver  12 , so that the hook&#39;s catch surface  90  engages a forward-facing rear surface  110  of the recess. This engagement prevents the charging handle from being withdrawn without actuation of either latch. 
     The latches are movable to a retracted position shown in dashed lines in  FIG. 2 . In this position, the forward edge  76 ,  76 ′ of either or both latches is pulled by the operator to the rear, resulting in both edges moving to the rear, and the hook  84  disengaging from the receiver recess  106 . This rearward pressure on the latch or latches also causes the charging handle to be withdrawn rearward from the receiver, cycling the rifle&#39;s bolt to an open condition. If the right latch&#39;s forward edge  74 ′ is pulled back, the rearward one of the channel-defining legs  100  presses forward on the bulbous end  96  of the left latch&#39;s protrusion, so that the spring compresses between the spring contact points  80 ,  80 ′ of the latches, resisting the motion. Thus, the right latch pivots clockwise, and the left latch pivots counterclockwise. Likewise, if the left latch&#39;s forward surface  76  alone is pulled back, the bulbous end  96  of the left latch&#39;s protrusion presses forward on the foreword one of the channel-defining legs  100  achieving the same result. If both latches are pulled, the same result occurs. 
     The forward aperture  54  is sized with adequate front-to-back width to allow motion of the protrusion  92  and legs  100 , permitting the hook to fully engage the receiver when in the latched condition, and to allow the hook to fully clear the receiver and the forward edges  76 ,  76 ′ to retract nearly flush with the forward surfaces of the crossbar. The use of a round protrusion on a narrower shaft in a parallel channel allows a consistently tight fit to be provided throughout the range of pivoting without binding. In alternative embodiments, involute gear geometry forms such as employed in conventional gear teeth may suitably be employed if wear is a concern, so that an entirely rolling contact is employed without any sliding of the surface of one latch with respect to the other. This may be achieved by having a conventional gear tooth on one latch, and a pair of such teeth surfaces on the other latch. In further alternative embodiments, any number of alternative mechanical linkages may employed to link the pivoting motion of the left latch to that of the right latch, and to constrain against relative movement between the latches. Moreover, the elements that engage the latches to each other may be reversed, so that the male element is on the right latch, and the female channel element is on the left latch having the hook element. Other embodiments for other rifles may employ different hook mechanisms, which may engage either or both sides or other surfaces of the receiver. 
     In the preferred embodiment, the pivot pins are spaced apart by a distance of 0.5″. The slots  44 ,  46  have a width of 0.90″, and the latches have a thickness of 0.125″. The forward aperture  54  has a front to rear dimension of 0.40″, and the spring aperture has a diameter of 0.188″. The circular end element  96  of the left latch has a diameter of 0.125″, with the shaft  94  having a width of 0.10″. The channel  102  of the right latch has a width of 0.13, providing a close slip-fit with the element  96 . While the body  26  is manufactured of Aluminum for lightness, and latches are formed of steel for durability. In alternative embodiments, the components may be made of any other suitable materials. 
     This disclosure is made in terms or preferred and alternative embodiments, and is not intended to be so limited.