Abstract:
A gunstock is presented which is individually capable of mounting a diverse assortment of long gun firearms. It is comprised of three primary components, these being a buttstock, a bedding chassis, and a forestock. These components are removably attached to one another, thereby permitting selective assembly and disassembly of the gunstock. The bedding chassis, which is the component that is attached to the firearm&#39;s action and barrel assembly, can be configured to accommodate various types of firearms. The utility of the gunstock derives from the fact that different types of firearms can be mounted to individual bedding chassis, which can be removably and interchangeably installed in the gunstock. Further, the bedding chassis acts as a base onto which components with varied configurations can be attached, permitting a firearm to be modularly reconfigured as circumstances warrant.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    Not applicable  
         STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not applicable  
         REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC OR APPENDIX  
         [0003]    Not applicable  
         BACKGROUND OF THE INVENTION  
         [0004]    The present invention relates to gunstocks. In particular, a modular gunstock is disclosed which is comprised of three main elements, these being a buttstock and pistol grip assembly, a forestock, and a base chassis which can be configured to accept numerous types of firearms. In the current art, gunstocks are typically manufactured to individually match a particular type of barrel and action assembly. Each type of firearm requires its own variety of fitted gunstock, with variations driven by the manufacturer&#39;s layout of the action, the caliber of bullet to be fired, and the contours of various barrel types and sizes. Barrels and actions are mounted to a stock in specific geometric relationships; trigger assemblies, magazine receptacles, bedding screws, recoil lugs, and barrel contours are differently oriented for each type of firearm. There is significant deviation in form between various manufacturers, and particularly extreme variation between small and large caliber firearms. It can readily be imagined that an obstacle to the manufacture of gunstocks is that each must be individually crafted to match the type of firearm that it is made for.  
           [0005]    The prior art includes a diverse variety of gunstocks. Historically they were made of wood, and in recent years plastics, composite materials, assorted metals, and the like have been used. Of the many forms that they have taken, an example that can be considered as a standard gunstock in terms of its general exterior shape is disclosed in U.S. Pat. No. 6,301,817 to Hogue et al. This stock typifies a common feature of gunstocks, in that they are usually crafted as a single unit that includes a buttstock portion, some sort of pistol grip, and a forestock portion. Requirements in the art have stimulated many variations in the basic geometry, and improvements have included removable or folding buttstocks, adjustable cheek pieces, and adjustable and/or recoil reducing butt pad assemblies. It can generally be said, however, that gunstocks of the prior art have been made to exactly conform to the geometry of a specific type or variety of firearm. Although their external appearance may be similar, a stock that fits a firearm from one manufacturer cannot be attached to a firearm of another manufacturer. There are further variances within the family of firearms of each manufacturer. Often, a change in caliber or other small design change requires an individually fitted gunstock. These realities result in several obstacles within the art. A manufacturer of gunstocks must have specific tooling, patterns, molds, and the like for each type of firearm for which a stock will be produced. There is bulk and expense in supporting the variety, and opportunities are lost for the manufacture of gunstocks for rifles if one is not tooled to support a certain variety. Another disadvantage of prior art gunstocks is that the user of firearms must have a specific gunstock for each type of firearm that is used, and can not transfer one variety of firearm to another variety&#39;s gunstock. In the example of a game hunter on safari, where varied calibers of firearms would be employed, it would be more convenient to transport only the barreled actions of the various firearms with one or two stocks for the whole of them than it would be to transport several complete rifles. In an alternative example of an Olympic athlete training for a sporting event, it would be beneficial to be able to transfer an air rifle or small caliber rifle used for indoor training to a gunstock that the athlete will be using with a different rifle for outdoor competition.  
           [0006]    The use of bedding plates or blocks in the manufacture of gunstocks is widely established. Their primary utility is in making the rifle fire more predictably, with consistent and reliable accuracy, and their use can add simplicity to the manufacturing process. U.S. Pat. No. 4,385,464 to Casull discloses one example, which is typical of the art in that the bedding plate is permanently attached to the gunstock. This makes the finished product into a single unit that has many of the aforementioned disadvantages. U.S. Pat. No. 6,487,805 to Reynolds discloses a firearm assembly that includes a firearm with a removable bedding block. This invention, while excellent in its purpose and application, has many of the aforementioned disadvantages, including that each individual stock is generally to be used in conjunction with only one type of firearm.  
           [0007]    There exists a need for a gunstock that can be used with a more diverse variety of firearms, and there exists a further need for a gunstock that is less cumbersome to manufacture.  
         BRIEF SUMMARY OF THE INVENTION  
         [0008]    The present invention is based on the discovery that a gunstock can be devised such that a bedding plate becomes the structural core of the gunstock, and thence can act as a chassis onto which other parts are attached. Components can be removably attached to it in such a way that inter-changeable bedding chassis can be used with inter-changeable forestock and buttstock assemblies. There is a resulting improvement in manufacturing, where the components of the gunstock become modular. The stock is apportioned in a way that makes pieces smaller and easier to manufacture, and conducive to individual re-design. When the joining points of components are standardized, parts become universally inter-changeable with other stocks of like design. The manufacturer can thereby make one type of buttstock or forestock for a complete line of products, and focus the necessary tooling changes for the variety of firearms on the smaller bedding chassis portion of the stock rather than on the complete product. Several improvements are offered to the user of the product. Rather than purchase several custom stocks for various firearms, just one stock can be used; smaller and less expensive bedding chassis are purchased for whichever guns are to be used. Individual forestock or buttstock assemblies can be replaced with ones of a different configuration to permit use of a firearm in varied shooting applications. Further, the present invention can be broken down for packing into a smaller container for travel than is necessary with a gunstock typical of the prior art.  
           [0009]    More particularly, the gunstock of the present invention is comprised of three main components, the buttstock, the forestock, and the bedding chassis. These components are removably attached to one another, making the gunstock of modular construction. Each component can be removed and replaced with a component of a different shape or design as long as the mounting junctions are held constant. Further, the bedding chassis is contrived such that it can be manufactured with different patterns cut into its top and bottom portions, and with different variations extending through its vertical axis. This permits a variety of firearm types to be mounted on a partially standardized bedding chassis. Because the bedding chassis is always made with the same side profile and end configuration, the mounting junctions with the buttstock and forestock are held constant. Because the buttstock and forestock comprise the majority of the external structure of the gunstock, it can be seen that a variety of firearms can be mounted in what can be viewed as the main portion of the gunstock simply by inter-changing the bedding chassis.  
           [0010]    The bedding chassis is the structural core of the present gunstock. It is the component to which is attached the firearm proper, generally including the barrel and action, which together are commonly referred to as a barreled action. Barreled actions are most frequently attached to gunstocks with two or more threaded screws that extend through the gunstock and thread into the bottom portion of the action. In the present invention, the bedding chassis takes the place of the central interior portion of the gunstock where the action is attached, and provides an external transition to the buttstock. The bedding chassis is constructed such that it accepts the recoil forces of the firearm, and transfers them onto the shooter&#39;s shoulder via the buttstock. Further, it provides a secure and stable platform onto which the barreled action is mounted, thereby providing the firearm with consistent accuracy. The present embodiment uses aluminum for the construction of the chassis, although other suitably rigid materials may be used.  
           [0011]    The buttstock portion of the gunstock is comprised of a pistol grip, a butt, a cheek piece, and a butt plate. In the present embodiment, it is constructed of milled aluminum, although other suitable materials can be used, including other metals, wood, plastic, and composite materials. In the preferred embodiment, the butt plate and the cheek piece are removably attached, and may be adjusted in orientation via an arrangement of fasteners, slots, and spacers. Other means for adjustment common to the art may be used, or these components may be fixedly attached to the buttstock. The buttstock is removably attached to the bedding chassis via a tapered dovetail joint. The configuration of this joint is such that the forward portion of the buttstock is comprised of a male dovetail. This has a relatively large flat frontal face that directly abuts a mirror-image flat face on the rearmost portion of the bedding chassis. The bedding chassis, in turn, has the female dovetail portion of the joint constructed around the aforementioned face.  
           [0012]    The forestock portion of the gunstock is an elongated handgrip, and is generally shaped such that its underside has contoured edges suitable for allowing a comfortable grasp with the hand. Its topside is generally the portion that shields the barrel of the rifle from the hand grasping the forestock, and is generally constructed as a channel in which the barrel is cradled. The barrel does not touch the forestock, a technique in rifle construction that is called a floating barrel. In the present preferred embodiment, the aft portion of the forestock is formed into a deeper channel than that of the forward portion. This deeper channel has shallow receiving slots fashioned into its interior sidewalls that are exact negative impressions of the exterior sidewalls of the bedding chassis. At the aft end of the forestock, the deeper channel is exposed with an open end, and the sidewall receiving slots are openly exposed at this end. This permits the bedding chassis to be inserted therein. When the bedding chassis is nested in these slots, it is removably held in place by threaded screws or the like that insert through holes in the sidewalls of the forestock, and which thread into matched receptacles in the bedding chassis.  
           [0013]    It can be seen that when the three major portions of the gunstock are all fastened in place, a substantially rigid structure is achieved, which has all of the benefits of gunstocks of the prior art, and eliminates many of their disadvantages. It can further be seen that this invention is a substantial departure from gunstocks of the prior art, in particular with regards to the ability to interchangeably mount a variety of firearms, and in the modular nature of its construction.  
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0014]    [0014]FIG. 1 is an exploded perspective view of the preferred embodiment of the present invention.  
         [0015]    [0015]FIG. 2 is a perspective view of the preferred embodiment in its assembled state.  
         [0016]    [0016]FIG. 3 is a perspective view of an alternative embodiment of the present invention.  
         [0017]    [0017]FIG. 4 is a perspective view of a bedding chassis of the present invention showing one variation in the layout of its top surface.  
         [0018]    [0018]FIG. 5 is a perspective view of a bedding chassis of the present invention showing one variation in the layout of its top surface.  
         [0019]    [0019]FIG. 6 is a perspective view of a left-side bedding chassis nesting insert.  
         [0020]    [0020]FIG. 7 is a partial perspective view of the buttstock, showing the dovetail joint element.  
         [0021]    [0021]FIG. 8 is a partial perspective view of the rear portion of the bedding chassis, showing the dovetail joint element included thereon. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    As shown in FIG. 1, the gunstock of the present invention is comprised of three major components, these being a buttstock  1 , a bedding chassis  2 , and a forestock  3 . These components are removably attached to one another. It can readily be seen that the use of the construction devices here described results in a substantially strong, rigid, and ergonomically correct gunstock. Equivalent means of accomplishing the same ends may occur to one skilled in the art, and it is noted that the devices of the present embodiment are not meant to be limiting.  
         [0023]    As best seen in FIGS. 7 and 8, the buttstock has a tapered dovetail-shaped front end  10 , which is exactly sized to fit in the female dovetail  9  on the rearward end of the bedding chassis. The dovetail joint that results from their junction is configured as a large single dovetail joint, of a standard nature with the following exception: the top of the joint is laterally smaller than the bottom of the joint. This results in a tapering joint that requires that the male end, which is affixed to the front of the buttstock, be entered into the female end from the bottom of the female dovetail. The tapered construction results in limiting the amount of upward travel into the joint by the male end, such that it always comes to rest in the exact same location relative to the bedding chassis. When the two halves of the joint are precisely manufactured and fitted to one another, the result is a structure that is strong, has no excess play, and is consistently the same each time that it is assembled. When assembled, this joint is removably held fast by a set screw  5  as depicted in FIG. 1, which is inserted through a threaded bore  11  and is tightened against a small recessed platform  14  cut into the face of the female dovetail joint. The bore  11  is located in the buttstock such that it angles downward on an oblique angle relative to the face of the joint. As a result, when the set screw is tightened against the recessed platform, the male end of the dovetail joint is drawn tightly upwards into the female joint, effectively locking the buttstock and bedding chassis together. It can readily be seen that reversing the orientation of the taper of the dovetail, and making the bottom narrower than the top, results in an equivalent structure which can be used in an alternative embodiment of the present invention.  
         [0024]    Now referring to FIGS. 1 and 6, the forestock is fitted with shallow impressions  6  on the inner sidewalls of its aft portion. These impressions are exactly sized to the side profile dimensions of the bedding chassis, so that when it is inserted, the bedding chassis nests inside the forestock in a specific and consistent location, with minimal play. In the present preferred embodiment, these impressions are formed as open-ended channels, with their open end  21  at the open aft end of the forestock. This permits the bedding chassis to slide into the body of the forestock from the aft end. Orifices  12  fashioned in the sides of the forestock are precisely located external to the shallow impressions, and are matched to threaded bores  13  in the sidewalls of the bedding chassis such that when the bedding chassis is inserted into the forestock, the holes are aligned. Threaded screws  4  are inserted into the holes and tightened, thereby removably fixing the forestock to the bedding chassis. An alternative use of smooth bores  13  and a combination of screws with threaded socket fasteners that extend completely through the chassis in place of screws  4  has been used with good results. FIG. 2 shows the present preferred embodiment in its assembled state.  
         [0025]    Now referring to FIGS. 4 and 5, the bedding chassis will be described. The bedding chassis of the preferred embodiment is constructed of aluminum, which is milled to exact tolerances. Other rigid materials such as hard plastic, composites, reinforced ceramics, and other metal types may be suitable, and other methods of manufacture such as casting or injection molding may give equivalent results. It is imperative, however, that the material composition of the bedding chassis be rigid in order to provide a stable platform for mounting the barreled action of a firearm, and also strong so that the flanges of the dovetail joint do not become frangible or weakened through use.  
         [0026]    More particularly, the left and right sides of the bedding chassis come into contact with the inner sidewalls of the forestock when they are assembled together. As shown in FIGS. 4 and 5, the side profile contour of the bedding chassis is made such that it is of a standardized geometric layout. In order to make the strongest possible dovetail joint, the rearmost end of the bedding chassis is made as large as is practical, while keeping it within the confines of the normal volume of this portion of a standard long gun stock. In selecting the side profile of the chassis, consideration was given to the necessary location of the trigger assembly. On the bottom of the bedding chassis there is a first step upward  7  where the trigger finger of a shooter will access the trigger. There is a second upward step  8 , which is included primarily to reduce unnecessary bulk and weight. The locations of the bores  13  were carefully selected so that the screws  4  that will be inserted therein do not conflict with any of the accessories that protrude into the bedding chassis from a barreled action. A location was chosen which does not conflict with the accessory parts of a wide variety of common firearms. In a case where there is a conflict, shorter screws  4  can be used. The orifices entering the chassis on its top surface, which are arranged to accommodate the various parts of the action of a firearm, can be configured in whatever ways are necessary specific to the particular firearm. To demonstrate this principle, FIG. 4 displays a bedding chassis that has a top side layout  20  which would be characteristic of the mounting required for a .22 caliber target rifle made by the German manufacturer Anschutz. The bedding chassis depicted in FIG. 5, which has the same side profile as that of FIG. 4, has a layout on its top side  19  that is characteristic of the mounting required for various large caliber rifles made by the American manufacturer Remington. It may be beneficial to have shaped extensions above the top surface  19  of the chassis in order to match the rounded contour of the bottom of an action. If this is done, it is necessary to make these extensions such that they do not alter the side profile portion of the chassis that contacts the interior slots  6  of the forestock. Setting back the left and right sides of these extensions from the outer sidewalls of the bedding chassis an amount equivalent to the depth of the interior slots  6  is an effective solution. Many firearms require that a recoil lug on the action be in contact with an acceptable receptacle on the gunstock. The bedding chassis of the present invention is configured such that the recoil lugs of most large caliber actions will be in contact with the forward end of the chassis. This effectively transmits recoil forces through the bedding chassis, thence through the buttstock via the dovetail joint, thence into the shoulder of a shooter. Accommodation for recoil lugs which do not exactly fit the standard length of the bedding chassis can be made. In the case where the recoil lug is aft of the forward end of the chassis, a recess can be cut into the top surface  20 . In the case where the recoil lug is forward of the front end of the standard length chassis, a choked-down extension can be fitted to the chassis such that it runs forward inside of the forestock, without interfering with the standard contact profile of the sidewalls of the bedding chassis, and thence can engage the recoil lug.  
         [0027]    In the preferred embodiment shown in FIGS. 1 and 2, the buttstock  1  is fashioned of milled aluminum. It is important that the male dovetail  10  on its forward end be of a strong and rigid material, and that it be perfectly fitted to fill the entire extent of the female dovetail  9 . A combination of other materials may be suitable for the composition of the buttstock, to include wood, plastic, or composite materials. These may be crafted in a shape and configuration common to the art in order to give the present invention a more traditional appearance, as shown in FIG. 3. If wood or a similar relatively soft material is used, it is desirable to have the dovetail joint made of a stronger material such as a metal, which can be attached to the aft major portion of the butt by means of standard techniques of joinery which are common to the art. The buttstock may be fitted with an adjustable butt plate  15  and an adjustable cheek piece  18 , in any of the variations that are known to those skilled in the art. A pistol grip  16  is fitted below the dovetail joint to the lower forward portion of the buttstock, and is oriented and contoured such that it allows an ergonomically correct grasp of the rifle and access to the trigger.  
         [0028]    The forestock  3  forms a shell around the lower portions of the bedding chassis, and extends forward to form an elongated handgrip for that hand which is not holding the rifle at the pistol grip. It can be externally shaped in various ways that are known to the art, and generally will have rounded bottom edges in order to fit the contour of the hand. In the present preferred embodiment, it is constructed of graphite fabric and cured epoxy resin over a foam core. This portion of the gunstock can be crafted in any manner commonly known to those skilled in the art, as long as provision is made for the installation of the bedding chassis. It has been previously noted that the forestock should be fitted with shallow recesses into which the bedding chassis will be nested. Now referring to FIG. 6, the present preferred embodiment utilizes a pair of machined aluminum plates  22 , which are cut on one surface with a precise negative impression  6  of the respective side profile of the bedding chassis. FIG. 6 displays a left side plate. The right side plate would mirror the arrangement of the left side plate and for simplicity is not depicted. These plates are installed permanently in the forestock by means of gluing, and may be installed during the lay-up process or glued in after the rest of the forestock is constructed. It is very important that the plates be installed precisely in position so that both resulting interior sidewalls of the forestock are in perfect alignment with the bedding chassis. In an alternative embodiment, the shallow recesses can be milled or cast directly into the sidewalls of the forestock in lieu of the machined plates. A trigger guard  17  may be installed in the forestock.