Abstract:
A sighting assembly for a firearm includes a scope and a mounting clamp. The mounting clamp includes a ring cap and a ring base that cooperate to surround and hold the scope. The mounting clamp has a rail clamp that includes a plurality of crowned portions that are configured to physically contact and grip a mounting rail.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/294,407 filed Jan. 12, 2010, where this provisional application is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present invention relates generally to mounting clamps for firearms. More specifically, the invention relates to mounting clamps capable of coupling an accessory to a mounting rail of a firearm. 
         [0004]    2. Description of the Related Art 
         [0005]    Telescopic sights are used in a wide range of different fields. Telescopic sights, such as scopes, are often used to aim firearms, such as rifles or handguns. A user can peer through the scope to view a target up close. Conventional scope rings for holding scopes are often coupled to accessory rails of firearms. Unfortunately, these scope rings have flat surfaces that physically contact the accessory rails and result in edge loading.  FIGS. 1 and 2  show a conventional scope ring  56  that has a rail clamp  60  with flat surfaces  62 ,  64 ,  66 ,  68  that physically contact an accessory rail  70 . The rail clamp  60  and/or accessory rail  70  can be damaged (e.g., deformed) due to high stresses, especially if the accessory rail  70  is not properly sized (e.g., undersized) with respect to the rail clamp  60 . Such rail clamps thus often compromise rail engagement precision. If the scope ring is repeatedly removed and reinstalled, rail engagement precision can be significantly compromised. 
       BRIEF SUMMARY 
       [0006]    At least some embodiments disclosed herein are directed to a sighting assembly with at least one mounting clamp configured to grip a telescopic sight. The mounting clamp can be coupled to a mounting rail without creating appreciable localized stresses in the mounting rail and/or mounting clamp so as to avoid or limit damage to the mounting rail and/or mounting clamp. The mounting clamp can be a scope ring or other type of clamp for holding the telescopic sight, or other type of sighting device or accessory (e.g., a handle, a bipod, sling attachment device or point, a light, etc.). 
         [0007]    A mounting clamp has, in some embodiments, one or more crowned portions for physically contacting a mounting rail. The crowned portions cooperate to grip the rail and to minimize, limit, or substantially eliminate stress concentrations in the rail. 
         [0008]    In some embodiments, a rail clamp includes a plurality of crowned surfaces surrounding a mounting rail channel which is sized to receive a mounting rail. The crowned surfaces can deform due to applied loads to keep stresses at or below a desired level. For example, the crowned surfaces can flatten out to keep stresses in the mounting clamp and/or mounting rail below the yield strength of the mounting clamp or the yield strength of the mounting rail, or both. 
         [0009]    In some embodiments, a mounting clamp has one or more crowned portions positioned to engage a mounting rail. When installed, the crowned portions distribute clamping forces along a section of the rail. In certain embodiments, the crowned portions extend along most or substantially all of a length of a mounting rail channel. A mounting rail can be inserted into the mounting rail channel of the mounting clamp. In some embodiments, the crowned portions are sufficiently curved so as to elastically deform to accommodate relatively high clamping loads, thereby reducing applied stresses. 
         [0010]    In some embodiments, a scope mounting clamp is coupleable to a firearm. The scope mounting clamp includes a plurality of deformable portions that are configured to physically contact and grip a mounting rail. Non-planar surfaces of the deformable portions help minimize, limit, or substantially eliminate edge loading. In some embodiments, the deformable portions are crowned regions of the mounting clamp surrounding a channel or opening in which the mounting rail can be placed. 
         [0011]    The deformable portions can define V-shaped gaps, U-shaped gaps, wedge-shaped gaps, or other types of gaps for receiving edges, or other features, of the mounting rail. In certain embodiments, a pair of deformable portions defines a generally V-shaped gap that receives a portion of the mounting rail. Another pair of deformable portions defines another generally V-shaped gap for receiving another portion of the mounting rail. 
         [0012]    A scope mounting clamp, in some embodiments, includes a clamp member and a main body. The clamp member includes a first crowned portion. The main body includes a plurality of second crowned portions. The clamp member and the main body define a mounting rail channel. The first crowned portion and the second crowned portions surround the mounting rail channel and are configured to physically contact and grip a mounting rail of a firearm when the mounting rail is positioned in the mounting rail channel. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0013]    Non-limiting and non-exhaustive embodiments are described with reference to the following drawings. The same reference numerals refer to like parts or acts throughout the various views, unless otherwise specified. 
           [0014]      FIG. 1  is an elevational view of a conventional scope ring coupled to an accessory rail. 
           [0015]      FIG. 2  is a detailed view of a portion of the conventional scope ring and the accessory rail of  FIG. 1 . 
           [0016]      FIG. 3  is an isometric view of a firearm and a viewing assembly coupled to the firearm, in accordance with one embodiment. 
           [0017]      FIG. 4  is a front elevational view of a mounting clamp attached to a mounting rail. 
           [0018]      FIG. 5  is a detailed view of a portion of the mounting clamp and a portion of the mounting rail of  FIG. 4 . 
           [0019]      FIG. 6  is a cross-sectional view of the assembly of  FIG. 4  taken along a line  6 - 6  of  FIG. 4 . 
           [0020]      FIG. 7  is a perspective view of a mounting clamp, in accordance with one embodiment. 
           [0021]      FIG. 8  is another perspective view of the mounting clamp of  FIG. 7 . 
           [0022]      FIG. 9  is a perspective view of a clamp member, in accordance with one embodiment. 
           [0023]      FIG. 10  is a side elevational view of the clamp member of  FIG. 9 . 
           [0024]      FIG. 11  is a front elevational view of the clamp member of  FIG. 9 . 
           [0025]      FIG. 12  is a front elevational view of a mounting clamp attached to a mounting rail according to another embodiment. 
           [0026]      FIG. 13  is a detailed view of a portion of the mounting clamp and a portion of the mounting rail of  FIG. 12 . 
           [0027]      FIG. 14  is a front elevational view of a mounting clamp attached to a mounting rail according to another embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]      FIG. 3  shows a viewing assembly  100  mounted on a firearm  102 . The viewing assembly  100  includes a sight  110  and a pair of mounting clamps  120   a ,  120   b  (collectively “ 120 ”). The mounting clamps  120  are coupled to a mounting rail  128 . To move the scope  110 , the mounting clamps  120  can release the mounting rail  128  and can be coupled at appropriate locations along the rail  128 . The mounting clamps  120  can provide relatively large clamping forces without damaging (e.g., marring, denting, bending, scratching, or otherwise permanently deforming) the clamps  120  and/or the mounting rail  128 . 
         [0029]    The mounting rail  128  can be an accessory rail or other type of rail or feature to which components can be coupled. The mounting clamps  120  may be repeatedly removed and reinstalled without re-zeroing (recalibration) of firearm  102 , even if the mounting rail  128  is undersized or oversized with respect to a rail channel  129  ( FIG. 4 ). 
         [0030]    The firearm  102  of  FIG. 3  is a rifle with a butt stock  170 , a firing mechanism  172 , and a barrel  174 . The firing mechanism  172  receives ammunition from a magazine  176 . The viewing assembly  100  can be coupled to different types of firearms, such as a handgun (e.g., a pistol, a revolver, etc.), an air gun, or other type of device used to shoot projectiles, such as a crossbow. 
         [0031]    The sight  110  can be a telescopic sight or other aiming device. Sights can include optical components, such as optical trains, objective lenses, ocular lenses, reticles, and other lenses that cooperate to provide desired viewing functionality. The sight  110  of  FIG. 3  is a scope that includes a windage and elevation adjustment mechanism  130 . A user may rotate dials  132 ,  134  to establish the desired windage or elevation setting. The illustrated adjustment mechanism  130  is positioned between the mounting clamps  120   a ,  120   b . The scope  110  may also include other types of controls or adjustment mechanisms. 
         [0032]    The illustrated scope  110  also includes an objective  150 , an eyepiece  160 , and the tubular section  140  extending between the objective  150  and the eyepiece  160 . The objective  150  carries objective lenses, and the eyepiece  160  carries ocular lenses. Imaging optics (e.g., an erector assembly, zoom assembly, reticle, combinations thereof, or the like) can be within and protected by the tubular section  140 . Light can propagate through the imaging optics to provide an image to the observer. 
         [0033]    The mounting clamps  120   a ,  120   b  of  FIG. 3  can be generally similar to each other. The following description of one of the mounting clamps applies equally to the other, unless indicated otherwise. 
         [0034]    Referring to  FIGS. 4 and 5 , the mounting clamp  120  includes a rail clamp  200  that can grip the mounting rail  128  while keeping stresses in the mounting rail  128  at or below an acceptable level, even if the mounting rail  128  is undersized or oversized with respect to the rail channel  129 . A main body  198  of the clamp  200  and a clamp member  300  define the rail channel  129 . Crowned portions  210   a ,  210   b ,  210   c ,  210   d  (collectively  210 ) can elastically and/or plastically deform to manage such stresses. The following description of one of the crowned portions applies equally to the others, unless indicated otherwise. 
         [0035]    The illustrated crowned portion  210   a  includes a substantially non-planar surface  220   a  that physically engages and bears against a substantially flat surface  230  of the mounting rail  128 . If clamping forces are increased, the non-planar surface  220   a  can flatten to increase the contact area to manage stresses and avoid or reduce edge loading. As such, high clamping forces can be achieved without damaging the rail clamp  200  and/or the mounting rail  128 . 
         [0036]    The crowned portion  210   a  can have a radius of curvature selected based on the size, configuration, and/or tolerances of the mounting rail  128  and, in some embodiments, based on desired contact pressures and desired load distributions. In some non-limiting embodiments, the radius of curvature of the crowned portion  210   a  can be at least about 0.4 inches. Such embodiments are well suited to control compressive loads at interfaces to provide a uniform load distribution along the rail  128 . In other embodiments, the radius of curvature can be in a range of about 0.04 inches to about 1.0 inches. Other radii can also be used, if needed or desired. 
         [0037]    In some embodiments, the non-planar surface  220   a  has a partially circular profile, partially elliptical profile, nonplanar profile, or the like. For example, the non-planar surface  220   a  can also be an arcuate surface, as illustrated. The crowned portion  210   a  can be crowned with respect to a generally straight axis and includes a first outer portion, a second outer portion, and an inner portion between the first outer portion and the second outer portion. The inner portion has a height that is greater than the height of the first outer portion and the height of the second outer portion. 
         [0038]      FIG. 6  shows the mounting clamp  200  engaging the mounting rail  128 . To securely grip the rail  128 , a nut  309  (see  FIG. 4 ) can be torqued down to apply a force to a central region  308  of a clamp member  300 . When the rail  128  is compressed, the crowned portions  210  bear against the mounting rail  128  to provide generally uniform loads. In this manner, more uniform loads can be applied as compared to conventional clamps. 
         [0039]    With continued reference to  FIG. 6 , the crowned portion  210   d  extends longitudinally along the mounting rail  128 . The crowned portion  210   d  includes a first portion  311   a  that presses against the mounting rail  128  and a second portion  311   b  that pushes against another portion of the mounting rail  128 . The first and second portions  311   a ,  311   b  are longitudinally crowned with respect to a long axis  315 . One or both of the first and second portions  311   a ,  311   b  can have a variable height with respect to the long axis  315  to provide relatively large contact areas to manage stresses in the rail  128 . Central regions of the first and second portions  311   a ,  311   b  can protrude into the rail channel  129 . Thus, crowned portion  210   d  can be crowned transversely and/or longitudinally with respect to a mounting rail channel  129  of the scope mounting clamp. 
         [0040]      FIGS. 7 and 8  show clamp surfaces  220   a ,  220   b ,  220   c  (collectively  220 ). Each of the clamp surfaces  220  extends along the rail channel  129 . 
         [0041]      FIGS. 9-11  show the clamp member  300  including the spaced-apart crowned portions  210   d ,  250 . The crowned portions  210   d ,  250  engage the rail  128  and a main body  252  of the clamp  120 , respectively, as shown in  FIG. 5 . 
         [0042]    Referring again to  FIGS. 4 and 5 , the crowned portions  210   a ,  210   d  cooperate to hold one side of the rail  128  while the crowned portions  210   b ,  210   c  hold the other side of the rail  128 . The crowned portion  250  engages the main body  252  of the clamp  120  (see  FIG. 5 ). The crowned portion  250  can bear against an engagement surface  260  of the main body  252  to allow pivoting of the clamp member  300  such that the crowned portions  210   a ,  210   b ,  210   c ,  210   d  contact corresponding surfaces  240   a ,  240   b ,  240   c ,  240   d  of the rail  128 . As the clamp member  300  is moved towards the rail  128 , the applied loads can be increased. The crowned portions  210  slide along and bear against the respective surfaces  240 , and can also flatten out to help distribute those loads. As such, the clamp  120  can securely grip a wide range of different types of rails  128 , even if the rail  128  is undersized or oversized with respect to the clamp  200 . 
         [0043]      FIGS. 12 and 13  show a mounting clamp  320  that includes a main body  324  having crowned portions  310   a ,  310   b  positioned to contact an upper surface  313  of a rail  314 . The crowned portions  310   a ,  310   b  are positioned on either side of a center plane  316  of the rail  314 . The number, spacing, and configurations of the crowned portions can be selected based on the desired clamp forces. 
         [0044]    A crowned portion  340  of a clamp member  342  contacts a lower rail surface  344  of the rail  314 . An abutment  352  has a crowned portion  355  that contacts a lower rail surface  356 . The clamp  320  can be securely fixed to the rail  314  without contacting the upper rail surfaces  345 ,  347 . When the clamp member  342  is moved inwardly (indicated by an arrow  360  of  FIG. 12 ), the crowned portion  340  can slide along the lower rail surface  344  towards the rail center plane  316 . A side edge  347  of the rail  314  is pushed between the crowned portions  310   b  and  340 . As the applied force is increased, the pressure between the crowned portions  310   a ,  310   b ,  340 ,  355  and the rail  128  can be increased without producing high stresses at the rail edges  371 ,  372 ,  373 ,  374 . The rail edges  371 ,  372  are held in a gap  380  (illustrated as a U-shaped gap in  FIG. 13 ) between the crowned portions  310   a ,  355 . 
         [0045]      FIG. 14  shows a mounting clamp  400  that includes a pair of clamp members  402 ,  404  integrally formed with a main body  408 . The clamp member  402  includes a crowned portion  412 . The clamp member  404  includes a crowned portion  414 . The main body  408  includes crowned portions  418 ,  419 . The crowned portions  412 ,  414 ,  418 ,  419  define, at least in part, a mounting rail channel  422 . 
         [0046]    To couple the mounting clamp  400  to a rail  430 , a fastener  432  can be used cause a clamp portion  440  to collapse inwardly. An elongated slot  442  allows the clamp members  402 ,  404  of the clamp portion  440  to move towards one another to collapse the clamp portion  440 . In this manner, the clamp members  402 ,  404  can cooperate to grip the rail  430 . 
         [0047]    Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as “comprises” and “comprising,” are to be construed in an open, inclusive sense, that is as “including, but not limited to.” 
         [0048]    It should be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the context clearly dictates otherwise. 
         [0049]    The embodiments, mounting clamps, features, systems, devices, methods and techniques described herein may, in some embodiments, be similar to any one or more of the embodiments, mounting clamps, features, systems, devices, materials, methods and techniques described in U.S. patent application Ser. No. 12/510,973 and U.S. Provisional Patent Application 61/294,407. U.S. patent application Ser. No. 12/510,973 filed Jul. 28, 2009 is incorporated herein by reference in its entirety. In addition, the embodiments, features, systems, devices, materials, methods and techniques described herein may, in certain embodiments, be applied to or used in connection with any one or more of the embodiments, features, systems, devices, materials, methods and techniques disclosed in the above-mentioned U.S. patent application Ser. No. 12/510,973 and U.S. Provisional Patent Application 61/294,407. For example, the mounting clamps and this features disclosed in U.S. patent application Ser. No. 12/510,973 may incorporate the embodiments disclosed herein. 
         [0050]    In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.