Abstract:
The present invention provides an adjustable cheek rest for installation on the butt stock of a firearm, the cheek rest having an elongate comb adapted to conform to the top portion of the butt stock, the comb being supported on a rail that is fixed to, or removably mounted to, one side of the butt stock. The cheek rest comb is adjustable both longitudinally and vertically with respect to the butt stock to suit the needs of a particular shooter, the comb being attached to the butt stock by a fixture slidably engaging the rail to permit longitudinal adjustment and slidably engaging the comb to permit vertical adjustment. Once adjusted, the comb may be secured in a desired longitudinal and vertical location. A removable rail is also provided for mounting the cheek rest and/or other accessories to a firearm butt stock not having a fixed accessory mounting rail.

Description:
RELATED INVENTION 
     This application is related to and claims priority from U.S. Provisional Application No. 60/859,273, filed on Nov. 15, 2006, entitled “Removable Accessory Mounting Rail for a Firearm,” and U.S. Provisional Application No. 60/814,139, filed on Jun. 16, 2006, entitled “Adjustable Cheek Rest for Firearms,” the disclosures of which are incorporated herein by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to rail mounted accessories for firearms and, more particularly to an adjustable cheek rest that may be installed on a fixed or removable accessory rail on shoulder-mounted firearms such as carbines and rifles. 
     BACKGROUND OF THE INVENTION 
     Adjustable cheek rests on the butt stock of rifles and carbines assist the shooter in getting quickly and comfortably into proper sight alignment. Standard butt stocks do not account for different sizes and shapes of shooter physique, or different type aiming sights and scope mounts. An adjustable cheek rest allows the shooter to customize drop and eye relief adjustments such that when the shooter lays his cheek on the cheek rest, his dominant eye is automatically aligned with the sight system. 
     It has been a long known practice to provide an accessory mounting rail on a firearm for releasably attaching accessories, such as optics and lighting equipment. Common type accessory mounting rails include the Picatinny rails and the Weaver rails. 
     SUMMARY OF THE INVENTION 
     The invention provides a cheek rest assembly adapted for rail-mounted attachment on a firearm butt stock. The cheek rest assembly includes a comb having a generally U-shaped cross-section adapted to substantially conform to the underlying butt stock onto which the comb is mounted. The comb is adjustably mounted to enable adjustment of both the height (i.e., vertical distance when the firearm is leveled parallel to the ground) and longitudinal location of the comb (i.e., position parallel to the length of the firearm) with respect to the butt stock. 
     According to one embodiment, the cheek rest assembly includes a mounting fixture for attaching the comb to the butt stock. The mounting fixture includes a base which supports an arm, the arm having an elongate slot adapted for receiving an internally threaded stud extending from the comb. A mounting plate is received onto the stud, and a capped bolt engages the internal threads of the stud. When the capped bolt is tightened into the threaded stud, the arm is clamped between the washer and the comb, thereby adjustably securing the comb to the arm at a desired location on the arm. The location of the bolt may be adjusted along the elongate slot in arm to provide adjustment in the height of the comb with respect to the butt stock. 
     The base of the mounting fixture comprises a substantially C-shaped cross-section dimensioned for sliding receipt of an accessory rail carried by the butt stock. Sliding movement of the base of the mounting fixture along the accessory rail results in translation of the arm of the mount forward and backward, thereby longitudinally adjusting the comb with respect to the butt stock. Preferably, an engagement mechanism is carried or defined by the base of the mounting fixture for releasably securing the mounting fixture to the accessory rail in a desired location along the butt stock. 
     According one embodiment, the check rest assembly includes a removable accessory rail assembly for a firearm. The removable rail assembly includes a rail body and a mating backing member interconnected to each other for securing the mounting rail to the firearm. The rail body and the backing member are attached to each other through an elongate opening in the butt stock. The rail body and the backing member are preferably attached to each other using threaded fasteners. The rail body includes a mounting platform and a base, the based being adapted to distance the mounting platform from the butt stock to provide access to the mounting platform for releasably attaching an accessory to the mounting platform. The mounting platform preferably includes outwardly protruding lobes for engagement with a cooperatively formed portion of an accessory in the manner of a dove-tail connection for securing the accessory to the firearm. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For the purpose of illustrating the invention, the figures show a form of the invention that is presently preferred. However, it should be understood that this invention is not limited to the precise arrangements and instrumentalities shown. 
         FIG. 1  shows a right-hand side view of the cheek rest assembly according to the present invention mounted to a butt stock for a carbine, the comb of the assembly being in a fully-lowered position with respect to the butt stock. 
         FIG. 2  shows a left-hand side view of the cheek rest assembly of  FIG. 1 . 
         FIG. 3  shows a right-hand side view of the cheek rest assembly of  FIG. 1 , the cheek rest assembly being in a raised position with respect to the butt stock and shown with the mounting plate and the threaded cap of the cheek rest assembly separated from the assembly. 
         FIG. 4  shows a perspective view of the cheek rest assembly of  FIG. 1 , the comb of the assembly being in a raised position with respect to the butt stock, with the mounting plate and the threaded cap removed from the assembly. 
         FIG. 5  shows a right-hand side view of the accessory rail body of the removable accessory rail assembly mounted to the right-hand side of the butt stock. 
         FIG. 6  shows a left-hand side view of the backing plate of the removable accessory rail assembly mounted to the left-hand side of the butt stock. 
         FIG. 7  shows a bottom view of the accessory rail body and the backing member mounted to the butt stock. 
         FIG. 8  shows an exploded bottom view of  FIG. 7 , wherein the accessory rail body and the backing member are removed from the butt stock. 
         FIG. 9  shows a rear end view of the removable accessory rail assembly, including the rail body and backing member, mounted to the butt stock. 
         FIG. 10  shows a sectional view of the butt stock taken through the section  10 - 10  of  FIG. 5 . 
         FIGS. 11A and 11B  show right-hand and left-hand side views, respectively, of the butt stock of  FIG. 1  with the accessory rail body and backing member removed from the butt stock. 
         FIGS. 12A and 12B  show backside and end views, respectively, of the accessory rail body removed from the butt stock. 
         FIGS. 13A and 13B  show backside and end views, respectively, of the backing plate removed from the butt stock. 
         FIG. 14  shows a partial sectional view of the cheek rest assembly if  FIG. 3 , taken through section  14 - 14 . 
     
    
    
     DESCRIPTION OF THE INVENTION 
     Referring to the figures, where like numerals identify like elements, there is shown in  FIGS. 1 through 4  a cheek rest assembly  10  according to an exemplary embodiment of the invention. The cheek rest assembly  10  is shown mounted on a butt stock  12  that is adapted for attachment to a carbine. The cheek rest assembly  10  includes a comb  14 , one side of which defines a contact surface for a shooter&#39;s cheek. In the depicted embodiment of the cheek rest assembly  10  shown in  FIGS. 1 and 2 , the cheek contact area is on the left-hand side comb  14 , for contact with the right cheek of a right-handed shooter. It is understood that the cheek rest assembly may just as readily be oriented with the contact surface on the right-hand side of the comb  14  for use by a left-handed shooter. The cheek rest assembly  10  provides adjustability of both the height of the comb  14  with respect to the butt stock  12  and the location of the comb  14  longitudinally along the butt stock  12 . 
     As shown in  FIGS. 1 through 4 , the comb  14  comprises an elongate body  16  having a substantially U-shaped cross-section that generally conforms to an upper portion of the butt stock  12  when the comb  14  is in the fully-lowered position over to the butt stock  12 . As best illustrated in  FIG. 3 , the comb  14  is connected to a carrier  18  secured to the body  16 . The comb  14 , body  16  and carrier  18  are preferably formed from molded plastic. As shown, the carrier  18  is bolted to the body  16 , but the carrier  18  may also be fastened by other equivalent conventional fastening means to the body  16 , or the carrier  18  may be formed integrally onto the body  16  as a molded unit. 
     With reference particularly to  FIGS. 3 and 4 , the carrier  18  includes a pair of recessed nut mounts  102  each defining an interior for receiving a hexagonal nut  106 , and an aperture for receiving a bolt  108 . The bolts  108  extend through the body  16  and the carrier  18  and are engaged by the nuts  106 , securing the carrier  18  to the body  16 . The carrier  18  further includes an internally threaded stud  30  that extends outwardly therefrom. A pair of substantially vertical guide grooves  22  recessed into a front face of the carrier  18  are disposed on opposite sides of the stud  30 . 
     The cheek rest assembly is installed onto the butt stock using a mounting fixture  24  that has a base  26  and a substantially vertically extending arm  28 . The mounting fixture  24  is used to adjustably position the comb  14  at a desired height over the butt stock  12 , and by moving to a different slot along the rail, locate the comb at a desired longitudinal location along the butt stock  12 . The base  26  is coupled to the rail on the butt stock, and the arm  28  is coupled to the carrier  18 . A stud  30  extends outwardly from the carrier  18  of the comb  14  and is received through an elongate slot aperture  32  defined by branches of the arm  28  of the mounting fixture  24 . A pair of guide tabs  29  projects inwardly from the arm  28 , the guide tabs  29  being disposed on opposite sides of the aperture  32 , as illustrated in  FIG. 14 . The guide tabs  29  are adapted to be received into the corresponding guide grooves  22  in the carrier  18 . The engagement between the guide tabs  29  of the arm  28  and the guide grooves  22  of the carrier  18  positions the comb  14  with respect to the mounting fixture  24  and guides the upward or downward movement of the comb  14  with respect to the butt stock  12 . 
     As best seen in  FIG. 3 , a mounting plate  34  having a central mounting aperture  38  and two lobe extensions  40  is received onto the stud  30  over the arm  28 , the mounting aperture  38  aligning with and receiving the internally threaded stud  30 . The lobes  40  are adapted to overlay the nut mounts  102  of the carrier  18 , thereby concealing and protecting the fasteners  106 ,  108  located within the nut mounts  102 , the lobes  40  having dimples  41  adapted to be seated over the nut mounts  102  to maintain the orientation of the mounting plate  34 . A capped bolt  36  is received through the mounting aperture  38  of the mounting plate  34 , engaging the internal threads of the stud  30 . Tightening the bolt  36  into the stud  30  causes the arm  28  to be clamped between the carrier  18  and the mounting plate  34 , thereby adjustably securing the comb  14  at a desired height with respect to the butt stock  12 . The lobe dimples  41  on the mounting plate  34  maintain the mounting plate  34  in alignment with the arm  28 . When the capped bolt  36  is loosened from the stud  30 , the mounting plate  34  and carrier  18  may be slidably adjusted along the arm  28  to move the comb  14  upward or downward with respect to the butt stock  12 . 
     An accessory mounting rail  42  is preferably mounted on the butt stock  12 , as shown in  FIGS. 1 ,  3 , and  4 . The accessory rail  42  has a roughly T-shaped cross-section and may be dimensioned to be a standard Picatinny or Weaver rail or other similar configuration. 
     In an embodiment of the check rest assembly  10  as shown in  FIGS. 3 and 4 , the base  26  of the mounting fixture  24  has a generally C-shaped cross-section dimensioned to slide over the accessory rail  42  and be locked into position along the rail. Accordingly, when the assembly  10  is mounted to the butt stock  12  via the mounting fixture  24 , the position of the comb  14  may be adjusted longitudinally along the butt stock  12  by sliding the mounting fixture  24  along the accessory rail  42 . The mounting fixture  24  includes a typical engagement latch (not illustrated) for releasably securing the mounting fixture  24  to the accessory rail  42  in a desired location on the rail  42 . 
     For butt stocks that do not have a built-in accessory rail, the present invention also includes a mechanism to allow an accessory rail assembly  44  to be removably mounted on the butt stock  12 .  FIGS. 5 through 8  show an exemplary embodiment of the removable accessory rail assembly  44 . The accessory rail assembly  44  includes an accessory rail body  46  and a mating backing member  48 . As illustrated, the accessory rail body  46  is located on a right-hand side of the butt stock  12  and the mating backing member  48  is located on an opposite left-hand side of the butt stock  12 . The accessory rail assembly  44  is secured to the butt stock  12  by attaching the rail body  46  to the backing member  48  using an attachment means  50  that passes through an elongate aperture  52  in a recessed plate  54  of the butt stock  12 . 
     The rail body  46  extends in a longitudinal direction and has a generally T-shaped cross-section comprising a base  56  and a mounting platform  58  both extending the length of the rail body  46 . The mounting platform  58  is wider than the base  56  and is attached to one side of the base  56 , the mounting platform  58  extending outwardly from the base  56  in opposite directions transverse to the longitudinal rail body  46 . An opposite side  60  of the base  56  contacts the recessed plate  54  and overlays the aperture  52  of the butt stock  12 . The base  56  functions to distance the mounting platform  58  of the rail body  46  from the recessed plate  54  in order to provide access to the mounting platform  58  for attaching an accessory to the rail body  46 . 
     The mounting platform  58  includes a longitudinal slot  64  extending the full length of the mounting platform  58 , and further includes a plurality of laterally-extending cross slots  66 . The slotting of the mounting platform  58  in this manner provides stability to the mounting platform  58  by allowing for expansion and contraction without significant distortion of the mounting platform  58  as the firearm heats and cools. Because the rail body  46  is interconnected to the backing member  48  through the elongate aperture  52  in the recessed plate  54  of the butt stock  12 , the rail body  46  is permitted to expand and contract in the longitudinal direction in reaction to the heating or cooling of the firearm. 
     As shown in  FIGS. 5 ,  7 ,  8 ,  12 A, and  12 B, the mounting platform  58  comprises a plurality of lobes  68  protruding outwardly from the rail body  46 , the lobes  68  being defined by the longitudinal slot  64  and the cross slots  66 . The outwardly protruding lobes  68  are adapted to receive a cooperatively formed mounting portion of an accessory in the manner of a dove-tail connection for securing the accessory to the mounting platform  58  of the rail body  46 . Typically, the mounting portion of the accessory may be of at least two forms. In one form, the mounting portion of the accessory is generally C-shaped and is adapted to slidably engage the outwardly protruding lobs  68  of mounting platform  58  from either end of the rail body  46 . In another form, the mounting portion of the accessory comprises a mechanism for clamping onto the mounting platform  58  so as to envelope the lobes  68 , for example by having first and second portions of the accessory movably connected to each other to move between relatively opened and closed positions, or by having a rail grabbing means such as bolts, thumbscrews, or levers. The depicted rail body  46  is configured as a Picatinny rail. However, the present invention is not limited to any particular rail, and it is envisioned that the rail body  46  could be configured as a Weaver rail or other similar accessory rail form. 
     Referring to  FIGS. 5 through 9  and  11 A through  13 B, the rail body  46  and the backing member  48  of the removable accessory rail assembly  44  are adapted for attachment to each other to secure the rail body  46  to the butt stock  12 . As shown in  FIGS. 11A and 11B , the butt stock  12  includes the elongate aperture  52  in the recessed plate  54  adjacent to a sleeve portion  70  of the butt stock  12 . The aperture  52  provides for passage of connectors between the rail body  46  and the backing member  48 . The rail body  46  and the backing member  48  are secured to each other and to the butt stock  12  using an attachment means  50 , a preferred attachment means  50  being described as follows. As shown in  FIGS. 5 ,  12 A, and  12 B, the rail body  46  comprises an opening  72  for receiving a threaded bolt  80  and another opening  74  for receiving a threaded nut  82 . As shown in  FIGS. 6 ,  13 A, and  13 B, the backing member  48  include an opening  76  for receiving a threaded bolt  80  and another opening  78  for receiving a threaded nut  82 . The interconnecting bolts  72  pass through the elongate aperture  54  in the recessed plate  54  of the butt stock  12  and engage mating nuts  74 , the bolts  72  and the nuts  74  being secured with the respective openings in the rail body  46  and the backing member  48 . It is understood that other attachment means  50  known in the mechanical arts could alternately be used to secure the rail body  46  and the backing member  48  to each other and to the butt stock  12 . 
     As shown in  FIG. 12A , the base  56  of the rail body  46  is not solid but comprising recessed portions  86 , to decrease the contact surface area between the rail body  46  and the butt stock  12 . Limiting the contact area serves to limit the heat transfer between the firearm and the rail body, which decrease the thermal expansion and contraction of the rail body  46  as the firearm heats and cools. Similarly, as shown in  FIG. 13A , the backing member  48  also includes a recessed portion  90  that limits the contact area between the backing member  48  and the butt stock  12 . 
     Referring to  FIGS. 7 and 8 , the base  56  of the rail body  46  may further include an elongate slotted aperture  84  disposed at an intermediate location between the mounting rail  58  and the butt stock  12  when the rail body  46  is mounted to the butt stock  12 . Accordingly, the slotted aperture  84  is adapted to receive a hook, clip, or other looped element, for example for hanging support of the firearm. Referring to  FIGS. 6 ,  8 ,  13 A, and  13 B, the backing member  48  may further include an opening  94  for receiving a bolt and nut combination for mounting another accessory, and an elongate aperture  88  for receiving yet another accessory. The elongate aperture  88  is defined by a portion  92  of the backing member  48 , the portion  92  being thinner than the backing member  48 , the portion  92  further being spaced apart from the butt stock  12  when the backing member  48  is mounted to the butt stock  12 . Accordingly, the slotted aperture  88  is adapted to receive a hook, clip, or other looped element, for example for hanging support of the firearm. 
     As illustrated in  FIGS. 1 ,  2 ,  4  through  8 , and  10  through  11 B, the butt stock  12  includes a spring-loaded pin  98  extending into an interior defined by a sleeve portion  70  of the butt stock  12 . The pin  98  is adapted for engaging receipt in an opening disposed in a tubular member of a carbine for securing the butt stock  12  to the carbine in the manner of a detent mechanism. The butt stock  12  includes a pivoting actuator  96  for retracting the pin  98  with respect to the interior of the sleeve portion  70  to release the carbine from the butt stock  12 . 
     The foregoing describes the invention in terms of embodiments foreseen by the inventor for which an enabling description was available, notwithstanding that insubstantial modifications of the invention, not presently foreseen, may nonetheless represent equivalents thereto.