Patent Publication Number: US-7721482-B1

Title: Folding front sight

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   The present patent document claims priority to earlier filed U.S. Provisional Patent Application Ser. No. 61/025,365, filed Feb. 1, 2008, the entire contents of which are incorporated herein by references. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to firearms and more specifically to a collapsible front sight for rifles and carbines. 
   2. Background of the Related Art 
   Referring now to  FIG. 1 , for 40 years, the current standard front sight  10  attached to a barrel  12  of the AR-15, M4, and M-16 family of weapons includes a triangle-shaped profile, which is readily identifiable throughout the world. This well thought out and combat proven design includes a rear angled support  14  for greater strength, which gives the front sight  10  its distinct triangle silhouette. The angled support feature also helps deflects branches, wires, and other combat hazards that could get a weapon hung up at the worst of times. 
   However, when enhanced optical sighting systems, such as scopes, are used, the infantryman does not need the front sight and often finds it to interfere with his aiming. Consequently, infantrymen use front sights that fold or collapse or they remove the front sight entirely from the weapon. However, using a prior art folding sight or removing the sight from the weapon necessarily changes the appearance of the weapon. In the case of special operations personnel, having a non-standard looking weapon can compromise the identity of the operative, which in turn can compromise operational security. Accordingly it would be desirable to have a folding front sight that more closely resembles a standard front sight in order to preserve the anonymity of the special operations operative. 
   SUMMARY OF THE INVENTION 
   The folding front sight of the present invention solves the problems of the prior art by providing a front sight with a base with a forward end and a rearward end. A forward sight frame at the forward end of the base is included. The forward sight frame includes a front sight post at an upper end thereof, and is movable between an upright deployed position and a stowed position. A support member has a rear end extending from the rearward end of the base and a forward end engaged with the upper end of the forward sight frame to support the forward sight frame, when the forward sight frame is in the deployed position. The base, the forward sight frame and the support member cooperate to define a triangular silhouette when the forward sight frame is in the deployed position. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where: 
       FIG. 1  is a perspective view of a prior art non-folding front sight; 
       FIG. 2A  is front perspective view of an embodiment of the folding front sight of the present invention; 
       FIG. 2B  is rear perspective view thereof; 
       FIG. 3A  is a right side view thereof; 
       FIG. 3B  is a side cross-section view through line  3 B- 3 B of  FIG. 2B ; 
       FIG. 4  is a front view thereof; 
       FIG. 5  is a rear view thereof; 
       FIG. 6  is a top view thereof; 
       FIG. 7  is a bottom view thereof; 
       FIG. 8  is a perspective view showing the folding front side mounted to a barrel of a rifle and stowed in its folded state; 
       FIG. 9  is perspective view of an alternative embodiment of the folding front sight of the present invention that includes a removable bayonet lug; and 
       FIG. 10  is an exploded view of an alternative embodiment of the folding front sight of the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to  FIGS. 2-8 , the folding front sight of the present invention is shown generally at  100 . The folding front sight  100  includes a base  102  having a front portion  104  and a rear portion  106 ; a forward sight frame  108  having a front sight post  110  is pivotally attached to the front portion  104  of the base  102 . Extending from the rear portion  106  is an extendable slide arm assembly  112 , which is connected to the rear portion  106  of the base  102  and the forward sight frame  108 , which will be further described below. 
   The front and rear portions  104 ,  106  of the base  102  include a pair of clamps  114 ,  116  configured to secure about a barrel of a weapon, such as an M-16 or AR-15 rifle or carbine as shown in  FIG. 8 . Threaded apertures  118  are provided near the bottom of the front and rear portions  104 , 106  to receive screws (not shown) used to tighten and retain the clamps  114 ,  116  on the barrel of the firearm. 
   Optionally, a bayonet lug  120  may be formed to the front face of the forward most clamp  114 . The bayonet lug  120  configured to receive and retain a bayonet, such as a standard USGI M7 Bayonet, to the barrel of the weapon. 
   Optionally, a sling swivel mounting structure  122  may depend below the rearward most clamp. The sling swivel mounting structure  122  is configured for attaching a sling swivel and sling (not shown) thereto. Specifically, the sling swivel mounting structure  122  includes a pair of tabs  124 . Each tab has a hole  126  formed therethrough. A sling swivel may be secured to the sling swivel mounting structure  122  by pinning it through the holes  126  on the tabs  124  as is known in the prior art. 
   Connecting the front and rear portions  104 ,  106  of the base  102  together is a center member  128 . A gas tube fitting  130  is formed through the rear portion  106  of the base  102  and into the center member  128 . The gas tube fitting  130  is configured to receive a gas tube (best seen in  FIG. 1  at  16 ) for gas-operated automatic and semi-automatic weapons. The gas tube is retained in the gas tube fitting  130  by a pin (not shown) inserted through an aperture  132  formed on the center member  128  and into the gas tube fitting  130 . Another aperture  131  is formed through the clamp  116  on the rear portion  106  and is in communication with the gas tube fitting  130 . When placed on a firearm, the aperture on the clamp  116  is aligned with an aperture on the barrel in order to make the gas-operation reloading of the firearm function. 
   Extending upwardly from the front portion  104  of the base  102  is the forward sight frame  108 . The forward sight frame  108  includes a sight with a height adjustable front sight post  110 . The forward sight frame  108  is pivotally connected to the front portion  104  of the base  102  and configured to fold rearward towards the rear portion  106  of the base  102 . The forward sight frame  108  includes a back surface having slot  134  with a pair of raised lips  136  that forms a track, best seen in  FIGS. 2A and 6 . 
   The slide arm assembly  112  includes a slide arm base  138 , a spring  139  (best seen in  FIG. 3B ) received into the slide arm base  138 , a slide arm  140  slidably received into the slide arm base  138  and engaging the spring, and a knuckle  142  pivotally attached to the slide arm  140 . The knuckle  142  slidably engages the track on the forward sight frame  108  and a pair of opposing feet  144  engages each of the recesses formed by the raised lips  136  on the track, respectively. A set screw  146  prevents the knuckle  142  from coming free from the track. The bottom surface of the knuckle  142  includes a recess to receive a head of the set screw  146 . One end of a slide arm  140  is pivotally connected to the knuckle  142  and the other end of the slide arm  140  is received in one end of a slide arm base  138 . The spring  139  biases the slide arm  140  outwardly from the slide arm base  138 . The other end of the slide arm base  138  is pivotally connected to the rear portion  106  of the base  102 . As can be seen in  FIG. 3A , the silhouette of the slide arm assembly  112 , center member  128  and forward sight frame  108  form a unique triangle shape that has made the M-16 and AR-15 instantly recognizable. 
   A user can stow the folding sight  100  of the present invention by pressing down on the knuckle  142 . As the knuckle  142  is pressed down it slides along the track on the forward sight frame  108 . As a consequence, the slide arm  140  is compressed into the slide arm base  138 , thereby compressing the spring  139  contained therein. Once the recess on the knuckle  142  contacts the head of the set screw  146 , the forward sight frame  108  pivots downwardly towards the rear portion  106  of the base  102  until the forward sight frame  108  lies substantially flush against the slide arm assembly  112  and the slide arm assembly  112  lies substantially flush against the center member  128  of the base  102 , as shown in  FIG. 8 . 
   The folding front sight  100  may be deployed by pivoting the forward sight frame  108  forwardly to its upright position. The spring  139  within the slide arm base  138  biases the slide arm  140  outwardly with sufficient force to provide a snap-action to the folding front sight  100 . 
   In addition to the spring  139  contained in the slide arm assembly  112 , spring-biased ball detents may be included in the forward sight frame  108 . The spring biased ball detents are configured to selectively engage detents formed on the front portion  104  of the base  102 . The spring-biased ball detents may be included to help keep the forward sight frame  108  from being unintentionally pivoted downwardly. 
   Referring now to  FIGS. 9 and 10 , an alternative embodiment of the folding front sight of the present invention is shown generally at  200 , which includes a removable bayonet mounting structure  202 . Like, the preferred embodiment  100 , the alternative embodiment  200  includes a base portion  204  with a front portion  206  and a rear portion  208 . A pair of clamps  210 ,  212  depends from front and rear portions  206 ,  208  the base portion  204 , respectively. The rearward most clamp  212  includes a sling swivel mounting structure  214 , including a pair of opposing tabs  216  with through holes  218 . The forward most clamp  210 , however, lacks an integral bayonet lug. Instead the forward most clamp  210  includes a pair of opposing slots  220  configured to receive the bayonet mounting structure  202 , which will be further described below. 
   The bayonet mounting structure  202  includes a center member  222  having a front end and a rear end. A bayonet lug  224  extends from the front end. The bayonet lug  224  is configured to receive and retain a bayonet, such as a standard USGI M7 Bayonet, to the barrel of the weapon. The bayonet lug  224  also includes a pair of laterally extending support tabs  226 , which are configured to slide into slots  220  on the forward most clamp  210 . 
   The rear end of the center member  222  includes a through hole  228  configured to align with and be secured to the sling swivel mounting structure  214 . It is important to note that the in this embodiment a sling swivel may not be mounted to the sling swivel mounting structure  214  at the same time as the bayonet mounting structure  202 . 
   The alternative embodiment may include some or all the features described above for the preferred embodiment. 
   Therefore, it can be seen that the present invention provides a unique solution to the problem of providing a folding front sight that mimics that appearance of a standard front sight. 
   It would be appreciated by those skilled in the art that various changes and modifications can be made to the illustrated embodiments without departing from the spirit of the present invention. All such modifications and changes are intended to be within the scope of the present invention.