Patent Publication Number: US-7913441-B1

Title: Scope mount

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit of U.S. provisional patent application Ser. No. 61/027,047 filed Feb. 8, 2008, the entire disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND OF INVENTION 
     Soldiers are required to acquire, identify, and accurately fire on enemy targets at distances in excess of 100 meters and may use weapon-mounted sights. These sights may be mounted on small arms such as the M4A1 carbine and other weapons and are used to provide better target observation during day and night time missions. These sights may incorporate night vision or infrared technology or may be aligned with a device incorporating night vision or infrared technology. 
     Night vision devices are typically equipped with one or more image intensifier tubes to allow an operator to see visible wavelengths of radiation (approximately 400 nm to approximately 900 nm). They work by collecting the tiny amounts of light, including the lower portion of the infrared light spectrum, that are present but may be imperceptible to our eyes, and amplifying it to the point that an operator can easily observe the image. 
     Devices with infrared sensors allow an operator to see people and objects because they emit thermal energy. Some of these devices operate by capturing the upper portion of the infrared light spectrum, which is emitted as heat by objects instead of simply reflected as light. Hotter objects, such as warm bodies, emit more of this wavelength than cooler objects like trees or buildings. Since the primary source of infrared radiation is heat or thermal radiation, any object that has a temperature radiates in the infrared. 
     Fusion systems have been developed that combine image intensifiers with infrared sensors. The image intensification information and the infrared information may be fused together to provide a fused image that provides benefits over just image intensification or just thermal sensing. 
     A weapon-mounted housing may be used to hold the image intensifier tube or infrared sensor to a host weapon. The housing may provide protection from unintended contact or debris and may be coupled to a weapon with a suitable attachment mechanism, for example a rail grabber or other clamp. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the present invention, together with other objects, features and advantages, reference should be made to the following detailed description which should be read in conjunction with the following figures wherein like numerals represent like parts: 
         FIG. 1  is an isometric view of a weapon system consistent with an exemplary embodiment. 
         FIG. 2  is an enlarged isometric view of a portion of the weapon system of  FIG. 1 . 
         FIG. 3  is an exploded isometric view of an electro-optical sighting device and mount assembly consistent with an exemplary embodiment. 
         FIG. 4A  is an exploded profile view of the electro-optical sighting device and mount assembly of  FIG. 3 . 
         FIG. 4B  is an exploded end section view of the electro-optical sighting device and mount assembly of  FIG. 3  taken through line  4 B- 4 B. 
         FIG. 5A  is first cross sectional view of the mount assembly of  FIG. 3 . 
         FIG. 5B  is a second cross sectional view of the mount assembly of  FIG. 3 . 
         FIG. 6  is bottom view of the mount assembly of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is an isometric view of a weapon system  100  and  FIG. 2  is an enlarged isometric view of a portion of the weapon system  100  consistent with an exemplary embodiment. The weapon system  100  may include a weapon  104  having a generally longitudinally extending mounting rail  102  and an electro-optical sighting device  200 . The sighting device  200  may have an optical axis OA and the weapon  104  may have a barrel axis BA. The sighting device  200  may have a housing  202 ,  202 A,  202 B for providing protection to internal components from unintended contact or debris. The sighting device  200  may be removably coupleable to the weapon  104  such as the M4A1 carbine with a suitable mounting assembly  204 . For use after the sighting device  200  is coupled to the weapon  104 , the housing  202  may have one or more adjustors to allow an operator to boresight the sighting device  200  with a projectile point of impact on a target at a known distance or with a boresight alignment tool, for example a barrel mounted boresight laser. The adjustors may be orthogonally offset 90 degrees from each other to provide elevation and windage adjustment. Springs or other biasing mechanisms may be used to provide a counter force to the adjustors. Alternatively, electrically controllable actuators, for example MEMS or piezoelectric actuators, may be used to provide elevation and windage adjustment. 
     Host weapons are subject to shock from being dropped and when fired can generate shock pulses in excess of 800 Gs. Sighting device have electronics, including image intensifier tubes, focal plane arrays, displays, and optics that may be damaged or become misaligned if excessive shock is imparted thereto. 
       FIG. 3  is an exploded isometric view,  FIG. 4A  is an exploded profile view, and  FIG. 4B  is an exploded end section view of the electro-optical sighting device  200  and mount assembly  204  and  FIG. 5A  is a cross sectional profile view and  FIG. 5B  is a cross sectional end view of the mount assembly  204  consistent with an exemplary embodiment. An electro optical component  214 , for example an image intensifier tube, a focal plane array, or a display, may be mounted at least partially within the housing  202  along with other support electronics. A pad  206  with through holes  206 A may be disposed between a base  208  and the housing  202 . One or more fasteners  212 , for example screws, may extend through a washer  210 , the base  208 , the pad  206  and into one or more openings  202 D, for example threaded openings, in the housing  202 . The pad  206  may be made of an elastomer, for example silicone rubber having a 30-70 Shore A durometer reading and be 0.040-0.075″ thick. The pad  206  may be adhered to the base  208 . The fasteners  212  may be torqued to set a preload in the pad between 10 and 30%. The fasteners  212  or openings  202 D may have a threadlocker applied thereto to prevent the fasteners from backing out. The fasteners  212  may have a threaded portion  212 A, a shoulder portion  212 B, and a head portion  212 C. 
     The base  208  may have a fixed portion  208 D shaped to cooperate with the profile of the rail  102  along a first side of the rail and a clamping portion  220  (see  FIG. 6 ) that can be selectively moved into engagement with an opposing side of the rail  102 . A user may rotate a handle  222  coupled to the clamping portion  220  to lock/unlock the mount assembly  204  to/from the rail  102 . The base  208  may have a cross piece  208 C that fits in cross slots in the rails  102  to resist longitudinal travel (along the X axis). A mounting assembly may have multiple clamping portions without departing from the invention. Other mounting assemblies including “rail grabbers” with a jaw or jaws that move generally perpendicular to the longitudinal axis of the rail  102  may be used without departing from the invention. U.S. Pat. No. 4,310,980; U.S. Pat. No. 4,383,371; U.S. Pat. No. 4,446,644; U.S. Pat. No. 4,845,871; U.S. Pat. No. 5,555,662; U.S. Pat. No. 7,188,978, and U.S. Pat. No. 7,272,904 disclose mounting methods and are herein incorporated by reference in their entirety. 
     The base  208  may have one or more through holes  208 B and a counterbore  208 A. The through holes  208 B may have a first dimension D 1  in the Y axis and a second and larger dimension D 2  in the X axis. The through holes  208 B may be elongated in the X axis to allow the shoulder portion  212 B of the fastener  212  to extend therethrough to allow movement in the X axis, but limit travel in the Y axis. The through holes  208 B may be further elongated in the X axis to allow downwardly projecting bumpers  206 B from the pad  206  to extend therein. The tolerancing between the shoulder portion  212 B of the fastener  212  and the width of the through hole  208 B (in the Y axis) being tighter than the tolerancing between the shoulder portion and the length of the through hole (in the X axis). For example, the tolerancing between the shoulder and the width of the slot may be designed to be a reliable running fit (e.g. RC4-RC7) or loose running fit (e.g. RC8-RC9) with the tolerance in the X axis in excess of 0.025″ being acceptable. The length of the shoulder portion  212 B may be controlled to provide adequate compression of the pad  206 . A top surface  240  of the base  208  may be contoured to mate with a bottom surface  242  of the housing  202 . 
     The fasteners  212  may be aligned along the X axis. Due to the sizing of the fasteners  212 , the openings  208 B and the downwardly projecting bumpers  206 B, the sighting device  200  may move along the X axis when the weapon  104  is fired and then return to its neutral position. The sizing of the fasteners  212  and the openings  208 B limiting travel in the Y axis and therefore maintaining alignment of the optical axis OA of the sighting device  200  parallel with the barrel axis BA of the weapon  104 . 
       FIG. 6  is a bottom view of the mount assembly  204 . The downwardly projecting bumpers  206 B from the pad  206  provide cushioning along the X axis. 
     It will be understood that the foregoing is only illustrative of the principles of the invention and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. Various aspects disclosed in the exemplary embodiments may be incorporated with aspects disclosed in other exemplary embodiments without departing from the scope of the invention. Persons skilled in the art will also appreciate that the present invention can be practiced by other than the previously described exemplary method, which are presented for purposes of illustration rather than of limitation and that the present invention is limited only by the claims that follow.