Patent Publication Number: US-7905041-B1

Title: Stabilized rifle barrel and rifle

Description:
This application claims priority from U.S. application 60/848,124 as filed on Sep. 29, 2006. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to firearms. 
     More particularly, the present invention relates to firearms with removable barrels. 
     BACKGROUND OF THE INVENTION 
     In the field of firearms, and in particular rifles, accuracy is of extreme importance and is a characteristic easily affected by changes in the firearm. Of paramount importance is preventing barrel deflection. Any deviations in the barrel, such as caused from vibration, oscillations and the like, will change the flight path of a bullet. As the distance the bullet travels increases, the deviation increases. Thus a small change in the barrel orientation can result in large deviations from the desired point of impact. Accuracy in a rifle is typically determined by the distribution of bullet impact points on a target. A small grouping indicates greater accuracy than a larger grouping. Any change in the barrel itself or with respect to the rest of the firearm will adversely affect accuracy by preventing small groups due to the variability of the bullet flight path. Many firearms have been developed to increase accuracy, by stabilizing the barrel. However these systems do not permit easy removal of a barrel and make use of accessory devices difficult. 
     It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art. 
     An object of the present invention is to provide an accurate firearm with easily removable barrel. 
     Another object of the present invention is to provide an exchangeable barrel employed with a full rail and handguard assembly. 
     Yet another object of the present invention is to provide a stabilized barrel system. 
     SUMMARY OF THE INVENTION 
     Briefly, to achieve the desired objects of the instant invention in accordance with a preferred embodiment thereof, provided is a firearm including a support block having a forward end and a rearward end and carrying a receiver on a top surface thereof intermediate the forward end and the rearward end. A rearward barrel guide having a thrust coupling extending radially outwardly therefrom, the thrust coupling engaging an engagement element located at the forward end of the support block, thereby aligning the rearward barrel guide with the support block. Also provided is a barrel having a breech end and a muzzle end, the breech end is received through the rearward barrel guide and coupled to the receiver. A forward barrel guide is fixed to the barrel intermediate the muzzle end and the breech end. A handguard assembly is received over the barrel and coupled to the rearward barrel guide and the forward barrel guide, stabilizing the barrel. 
     In a specific aspect, the rearward barrel guide includes a tab extending from a rear surface thereof. The tab is received in a slot formed in a forward surface of the receiver, aligning the rearward barrel guide with the receiver. 
     In yet another aspect, the handguard assembly includes a rearward wedge block carried between an outer surface of the rearward barrel guide and an inner surface of the handguard, and is movable between a disengaged position and an engaged position. The rearward wedge block is forced against the rearward barrel guide in the engaged position, frictionally holding the handguard assembly to the rearward barrel guide. A forward wedge block is carried between an outer surface of the forward barrel guide and an inner surface of the handguard, and is movable between a disengaged position and an engaged position. The forward wedge block is forced against the forward barrel guide in the engaged position, frictionally holding the handguard assembly to the forward barrel guide. 
     In a further aspect, a barrel stabilizing system for a firearm including a barrel having a muzzle end and a breech end removable coupled to a receiver is provided. The barrel stabilizing system includes an engagement element positioned relative the receiver and a rearward barrel guide having a thrust coupling extending radially outwardly therefrom. The thrust coupling engages the engagement element thereby aligning the rearward barrel guide with the receiver. The breech of the barrel extends through the rearward barrel guide and is coupled to the receiver. A forward barrel guide is fixed to the barrel intermediate the muzzle end and the breech end. A handguard assembly is received over the barrel and coupled to the rearward barrel guide and the forward barrel guide, stabilizing the barrel 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Specific objects and advantages of the invention will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment thereof, taken in conjunction with the drawings in which: 
         FIG. 1  is a side elevational view of a rifle according to the present invention; 
         FIG. 2  is a perspective view of the rifle of  FIG. 1 ; 
         FIG. 3  is an exploded side view of a portion of the rifle of  FIGS. 1 and 2 ; 
         FIG. 4  is an exploded perspective view of the portion of the rifle from the rear quarter; 
         FIG. 5  is an exploded perspective view of the portion of the rifle from the front quarter; 
         FIG. 6  is an exploded perspective view of the portion of the rifle from the top quarter; 
         FIG. 7  is a side perspective view of the portion of the rifle with the handguard assembly removed; 
         FIG. 8  is a exploded perspective view of the portion of the rifle with the handguard assembly removed; 
         FIG. 9  is an exploded view of the support block and associated elements; 
         FIG. 10  is an exploded sectional side view of the portion of the rifle; 
         FIG. 11  is an enlarged perspective view of the receiver and rearward barrel guide; 
         FIG. 12  is a sectional end view of the handguard assembly; 
         FIG. 13  is a partial sectional end view illustrating a clamping block; and 
         FIG. 14  is a perspective view illustrating a replacement barrel. 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     Turning now to the drawings in which like reference characters indicate corresponding elements throughout the several views, attention is directed to  FIGS. 1 and 2  that illustrate a rifle generally designated  10 , incorporating a stabilized barrel system. Rifle  10  in this embodiment is a bolt action rifle having a barrel  12 , a support block  14 , a receiver  15 , a barrel stabilizing system  16  and a butt stock  17 . As can be seen, stabilizing system  16  preferably includes a rail which extends along a handguard and over the receiver in a common plane. This permits multiple interacting ocular devices to be mounted on the rail without the need for adjusting to different height rails, as is typical in the art. In the present embodiment, by way of example, a scope  18  is mounted on the rail with a night vision device  19  mounted in front thereof. Standard equipment such as this can be easily and quickly mounted on the rail without the need for specialized adapters and the like. 
     With momentary reference to  FIG. 8 , barrel  12  includes a breech end  20 , a muzzle end  22 , a shoulder  23  formed therein proximate and directed toward breech end  20  and a shoulder  25  formed therein intermediate muzzle end  22  and breech end  20 , directed toward muzzle end  22 . A receiver engagement portion  28  of barrel  12 , at breech end  20  rearward of shoulder  23  is provided with threading for engagement with receiver  15  in this embodiment although other engagement structures can be employed. The purposes for the structure of barrel  12  will be described presently. 
     Referring now to  FIGS. 3-6  and  10 , exploded views of rifle  10  are illustrated. Support block  14  carries receiver  15  fixedly attached thereto and includes a receiver channel  30  formed in a top portion thereof, a forward end  32  and a rearward end  33 . Receiver  15  is a conventional rifle receiver, and in this embodiment is a receiver for a bolt action rifle of the type configured to receive a bolt  35 . Support block  14  functions as a unifying and aligning element for the entire rifle. It is preferably fabricated of a solid piece of aluminum, although other materials such as steel may be employed, and is the basic element to which all other elements of rifle  10  align. Support block  14  also includes a magazine well  36  depending downwardly opposite receiver channel  30  and intermediate forward end  32  and rearward end  33 . Magazine well  36  is of conventional design and is intended to receive magazines  37  and include the necessary latches and mechanisms for allowing retention and release thereof. In other words, a conventional structure is formed between magazine  37  carried within magazine well  36  and receiver  15 . In this embodiment, a pistol grip  38  and trigger assembly  39  are attached to support block  14  rearward of magazine well  36 . Drop in trigger assemblies are well known in the art and will not be described in detail herein. Rearward end  33  of support block  14 , in this embodiment, is configured to receive butt stock attachment  17  ( FIG. 1 ). It will be understood that rearward end  33  can be configured in a variety of different manners to accommodate different types of butt stocks, or none, as desired. 
     Still referring to  FIGS. 3-6  and  10 , with additional reference to  FIG. 9 , receiver  15  is fixed to support block  14  within channel  30  and extends from forward end  32  toward rearward end  33 . Channel  30  is shaped to cradle receiver  15 , helping to align it with support block  14 . Receiver  15  can be fixed to support block  14  in any convenient manner such as bolts, adhesives, welding and the like, but is preferably attached using screws  42  extending upwardly through support block  14  proximate forward end  32  and rearward end  33  and into receiver  15  further ensuring alignment thereof. Support block  14  additionally carries an engagement element at forward end  32 . In this embodiment the engagement element is a keyhole slot  44  the purpose of which will be described presently. 
     Barrel stabilizing system  17  of the present invention includes a handguard assembly  50 , an alignment mount  52 , a rearward barrel guide  54  with rearward wedge block  55  and a forward barrel guide  57  with a forward wedge block  58 . Rearward barrel guide  54  includes an outer surface with an outer diameter and a bore having an inner diameter through which breech end  20  of barrel  12  extends. A flange  60  (best seen in  FIGS. 5 and 10 ) extends radially inwardly from the rearward end of rearward barrel guide  54 , providing a reduced inner diameter, and forming a thrust surface against which shoulder  23  of barrel  12  resides. Receiver engagement portion  28  of barrel  12 , at breech end  20  rearward of shoulder  23 , extends through rearward barrel guide  54 , and is coupled to receiver  15 , such as by threaded engagement. 
     Thus, breech end  20  of barrel  12  is coupled to receiver  15  through rearward barrel guide  54 , with rearward barrel guide  54  residing adjacent, and preferably abutting, receiver  15 . A thrust coupling  62  extends from rearward barrel guide  54  and is coupled to support block  14 . In this embodiment, thrust coupling  62  is received within keyhole slot  44 . As will be apparent from the description, any rearwardly directed forces generated by barrel  12  will be transmitted through rearward barrel guide  54  and thrust coupling  62  into support block  14 . Additionally, rearward barrel guide  54  is aligned with support block  14  by keyhole slot  44 , and in engagement with receiver  15 . The alignment of rearward barrel guide  54  with receiver  15  is further enhanced by tabs  63  extending from the rear face thereof and received in slots  65  formed in the forward face of receiver  15  ( FIG. 11 ). In this manner, when receiver  15  and rearward barrel guide  54  are attached to support block  14  and each engages the other, an aligned system with respect to support block  14  is provided. At this point, breech end  20  of barrel  12  is stabilized and aligned with support block  14  when it is received through rearward barrel guide  54  and threaded into receiver  15 . 
     Forward barrel guide  57  includes an outer surface having an outer diameter, and a bore therethrough having an inner diameter. As can be seen with additional reference to  FIG. 10 , forward barrel guide  57  has a counter bore extending from breech end  20  toward muzzle end  22  with a greater diameter than the bore, thereby forming a shoulder therebetween. Muzzle end  22  of barrel  12  is received through the bore and counter bore with the shoulder of forward barrel guide  57  engaging shoulder  25 . Forward barrel guide  57  is preferably fixed to barrel  12 . In this embodiment, the inner surface of the counter bore of forward barrel guide is threaded to threadably engage corresponding threads on barrel  12  rearward of and adjacent to shoulder  25 . Thus, forward barrel guide is securely attached to barrel  12  and can be further secured by the use of set screws, adhesives or the like, to prevent rotation of forward barrel guide  57  once positioned. While shoulder  25  and threads are employed to secure forward barrel guide  57  in position, it will be understood that other manners of fixedly attaching forward barrel guide  57  to barrel  12  intermediate muzzle end  22  and breech end  20  can be employed. Examples include, welding, machining directly on the barrel and the like. The current embodiment is an easily achievable and readily duplicated method. 
     Alignment mount  52  is coupled to the top of receiver  15  and includes a dovetail pin forming the top surface thereof. Handguard assembly  50  includes a handguard portion  70  having a forward end  72  and a rearward end  73 , and a rail portion  75  along the top surface of handguard portion  70  and extending rearwardly past rearward end  73 . Rail portion  75  includes a channel  76  formed in the bottom which extends the entire length of rail portion  75  including the length along the top surface of handguard portion  70 . Channel  76  of rail portion  75  extending rearward of handguard portion  70  is received by the dovetail pin of alignment mount  52 . Alignment mount  52  guides, aligns and supports rail portion  75 . Rail portion  75  is preferably not fixed to alignment mount  52 , which simply guides and aligns, and also acts as a stop to prevent excessive movement or deformation thereof. 
     Handguard portion  70  is generally tubular with an inner surface defining an inner volume. Channel  76  on the underside of rail  75  extends from forward end  72  to rearward end  73  of handguard portion  70  and is a portion of the inner volume. Barrel  12  is received through handguard portion  70  such that rail portion  75  is received by and overlies alignment mount  52 . Portions of the inner surface at rearward end  73  are received about rearward barrel guide  54  and portions of the inner surface at forward end  72  are received about forward barrel guide  57 . Forward wedge block  58  and rearward wedge block  55  are positioned within channel  76  of the inner volume proximate forward end  72  and proximate rearward end  73 , respectively. Set screws  78  enter wedge blocks  58  and  55  through rail portion  75  and allow wedge blocks  58  and  55  to be moved between a disengaged position and an engaged position, forcing wedge blocks  58  and  55  against forward barrel guide  57  and rearward barrel guide  54 , respectively. By forcing wedge blocks  58  and  55  against barrel nuts  57  and  54 , respectively, barrel  12  is stabilized to handguard assembly  50 . Additionally, handguard assembly  50  is aligned relative support block  14  by rearward barrel guide  54  and alignment mount  52 . After initial assembly and “zeroing”, since barrel  12  is also aligned relative support block  14  as described previously, and then stabilized by wedge blocks  58  and  55  to handguard assembly  50 , barrel  12  and rail portion  75  will always be aligned making any sighting device carried by rail portion  75  “zeroed” automatically even when barrel  12  is removed and replaced. 
     Forces generated by recoil of rifle  10  can potentially move handguard portion  70  in a lateral forward or rearward direction. To prevent this possibility, a stop  86  is threaded into one or more threaded apertures  87  located at rearward end  73  of handguard portion  70 . Threaded apertures  87  are aligned with apertures  88  formed in rearward barrel guide  54 . Stops  86  are threaded through aperture  87  in handguard portion  70  so as to extend into aperture  88 , preventing relative forward and rearward movement. Stops  86  can be screws and the like. 
     When a material such as aluminum is employed for wedge blocks  58  and  55 , steel bearing balls  80  can be employed between set screws  78  (can also be thumb screws for easy removal) and wedge blocks  55  and  58  to diffuse the pressure from set screws  78  and prevent damage to wedge blocks  55  and  58 , as illustrated in  FIGS. 12 and 13 . In this instance, a seat or pair of seats  82  with a radiused bottom is formed in each wedge block  55  and  58 . To protect rail  75 , when constructed of a softer material such as aluminum, steel sleeves  85  can be inserted into the set screw apertures. Thus, set screws  78  are threaded into sleeves  85  and engage bearing balls  80  and forcing them against the radiused bottom of seats  82 , thereby forcing wedge blocks  55  and  58  securely against barrel nuts  54  and  57 , respectively. 
     Employing the stabilizing hand guard system of the present invention permits barrel  12  to be easily and quickly changed simply by loosening forward wedge block  58  (disengaged position), and unscrewing barrel  12  from receiver  15 . A replacement barrel can then be easily inserted. As can be seen with reference to  FIG. 14 , barrel  12  can be replaced with barrel  12 ′. Each barrel  12  and  12 ′ will typically be prepared with a forward barrel guide  57  or  57 ′ fixedly in position. A replacement barrel  12 ′ can be of a different caliber, also requiring replacement of the bolt or bolt head and magazine to accommodate the new caliber, or the same caliber with additional accessories attached such as a suppressor  90 . Additionally, once the hand guard system is substantially rigidly established and aligned, installment of a replacement barrel will result in an aligned barrel with no “zeroing” required. The replacement barrel, once tightened into position, will be aligned properly with support block  14  and thus through the inter-aligned elements to rail  75  and sighting devices carried thereon. In essence, the rearward barrel guide acts as a register for the entire rifle. One positioned, all the other elements can be removed or replaced and when replaced, will register with the rearward barrel guide. 
     Various changes and modifications to the embodiments herein chosen for purposes of illustration will readily occur to those skilled in the art. To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope thereof, which is assessed only by a fair interpretation of the following claims.