U.S. patent application number 10/424331 was filed with the patent office on 2004-10-28 for universal modular gunstock.
Invention is credited to Eberle, Glen Richard.
Application Number | 20040211104 10/424331 |
Document ID | / |
Family ID | 33299333 |
Filed Date | 2004-10-28 |
United States Patent
Application |
20040211104 |
Kind Code |
A1 |
Eberle, Glen Richard |
October 28, 2004 |
Universal modular gunstock
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'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.
Inventors: |
Eberle, Glen Richard;
(Boise, ID) |
Correspondence
Address: |
GLEN EBERLE
2410 HILLWAY DR.
BOISE
ID
83702
US
|
Family ID: |
33299333 |
Appl. No.: |
10/424331 |
Filed: |
April 28, 2003 |
Current U.S.
Class: |
42/71.02 |
Current CPC
Class: |
F41C 23/00 20130101;
F41C 23/14 20130101 |
Class at
Publication: |
042/071.02 |
International
Class: |
F41C 023/00 |
Claims
I claim:
1. A gunstock for long gun firearms comprising, in combination: a
rigid bedding chassis constituting the portion of the gunstock to
which the action of a firearm will be attached, said chassis having
a top side, a bottom side, a forward end, a rearward end, a left
side, and a right side; a buttstock that is removably attached to
the bedding chassis at the rearward end of said chassis, said
buttstock having a forward end and a rearward end, an upper extent,
and a lower extent, a right side, and a left side, and said
buttstock having an elongated portion to facilitate the engagement
of said gunstock with the shoulder of a user, and said buttstock
having a hand grip portion; and a forestock that is generally
formed as an elongated channel, with a forward end, an aft end, a
top side, a bottom side, a right sidewall, and a left sidewall,
said top side having a channel in its forward portion suitable to
accommodate a rifle barrel, and said forestock having a portion
that is configured to accommodate the removable attachment of the
forestock to said bedding chassis.
2. The gunstock of claim 1, wherein a joint is formed between the
buttstock and the bedding chassis, such that the buttstock has one
element of the joint at its forward extent, and the bedding chassis
has the other element of the joint at its rearward extent, and such
that when these two elements are joined a single joint is formed;
and said joint also being fitted with a fastening device, such that
said buttstock and said bedding chassis are thereby removably
attached to one another.
3. The gunstock of claim 2, wherein said joint is a dovetail joint
with two elements, which when assembled fill a volume of space,
with a top side, a bottom side, a left side, and a right side, and
such that the joint is formed when one element of the joint is
inserted into the other element of the joint, with the inserted
element being moved into its fitted position along a directional
axis.
4. The gunstock of claim 3, wherein said dovetail joint manifests a
lateral taper, such that one end of the joint, this being
perpendicular to said directional axis of insertion, is of lesser
lateral width than the opposed end of the joint, this also being
perpendicular to said directional axis of insertion, such that when
the elements are assembled, the innermost element of the joint has
a directional limit to its travel within the outermost element of
the joint.
5. The gunstock of claim 1, wherein the forestock has a fitted
receptacle for the bedding chassis, such that when the chassis and
the forestock are assembled they are in a predictable and
consistent relationship to one another.
6. The gunstock of claim 5, wherein the forestock has orifices that
are oriented such that they permit passage of fastening devices
there through and into the bedding chassis, and said bedding
chassis being fitted with bores placed in such a manner as to
accommodate said fastening devices, such that when the bedding
chassis and forestock are assembled and the fastening devices are
installed, the forestock is removably held fast to the bedding
chassis.
7. The gunstock of claim 5, wherein the forestock is provided with
shallow recesses on its left and right interior sidewalls, said
recesses being fitted to accommodate the respective left and right
side profiles of the bedding chassis where these parts will come
into contact.
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'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'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'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] FIG. 1 is an exploded perspective view of the preferred
embodiment of the present invention.
[0015] FIG. 2 is a perspective view of the preferred embodiment in
its assembled state.
[0016] FIG. 3 is a perspective view of an alternative embodiment of
the present invention.
[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] 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] FIG. 6 is a perspective view of a left-side bedding chassis
nesting insert.
[0020] FIG. 7 is a partial perspective view of the buttstock,
showing the dovetail joint element.
[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.
* * * * *