Patent ID: 12222178

DETAILED DESCRIPTION

The details of one or more embodiments of the present invention are set forth in this document. Modifications to embodiments described in this document, and other embodiments, will be evident to those of ordinary skill in the art after a study of the information provided herein. The information provided in this document, and particularly the specific details of the described exemplary embodiment(s), is provided primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom. In case of conflict, the specification of this document, including definitions, will control.

While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that are embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention. Those of ordinary skill in the art will recognize numerous equivalents to the specific apparatus and methods described herein. Such equivalents are considered to be within the scope of this invention and are covered by the claims.

While the terms used herein are believed to be well understood by one of ordinary skill in the art, a number of terms are defined below to facilitate the understanding of the embodiments described herein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the subject matter disclosed herein belongs. The terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present invention. Terms such as “a,” “an,” and “the” are not intended to refer to only a singular entity, but rather include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the invention, except as set forth in the claims.

As described herein, an “upright” position is considered to be the position of apparatus components while in proper operation or in a natural resting position as described and shown herein, for example, inFIG.1. The upright firing position of a firearm is a generally level firing position. As used herein, the terms “aft” and “rear” means in a direction toward a rear end of a firearm, while the terms “front” and “forward” means in a direction extending away from the rear of the firearm toward the muzzle of the firearm. In some cases, the term “forward” can also mean forward beyond the muzzle of the firearm. “Vertical,” “horizontal,” “above,” “below,” “side,” “top,” “bottom,” “upper,” “lower,” and other orientation terms are described with respect to this upright position during operation, unless otherwise specified, and are used to provide an orientation of embodiments of the invention to allow for proper description of example embodiments. A person of skill in the art will recognize, however, that the apparatus can assume different orientations when in use.

The term “when” is used to specify orientation for relative positions of components, not as a temporal limitation of the claims or apparatus described and claimed herein unless otherwise specified.

The terms “above”, “below”, “over”, and “under” mean “having an elevation or vertical height greater or lesser than” and are not intended to imply that one object or component is directly over or under another object or component.

The phrase “in one embodiment,” as used herein does not necessarily refer to the same embodiment, although it may. Conditional language used herein, such as, among others, “can,” “might,” “may,” “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features, elements and/or states are in any way required for one or more embodiments.

All measurements should be understood as being modified by the term “about” regardless of whether the word “about” precedes a given measurement.

All references to singular characteristics or limitations of the present disclosure shall include the corresponding plural characteristic(s) or limitation(s) and vice versa, unless otherwise specified or clearly implied to the contrary by the context in which the reference is made.

All combinations of method or process steps as used herein can be performed in any order, unless otherwise specified or clearly implied to the contrary by the context in which the referenced combination is made.

The methods and devices disclosed herein, including components thereof, can comprise, consist of, or consist essentially of the essential elements and limitations of the embodiments described herein, as well as any additional or optional components or limitations described herein or otherwise useful.

Referring generally toFIGS.1-14and19-20, there is depicted a personal defense weapon in the form of an AR-style firearm10equipped with a compact stock24(i.e., a PDW stock) constructed in accordance with an embodiment of the present invention. The firearm10depicted is configured as a shotgun for firing 12-gauge shotshells, but can be configured to fire other cartridges. The firearm10generally includes a barrel14, a lower receiver16, an upper receiver18detachably connected to the lower receiver16, a bolt assembly20, a magazine22, and the compact stock24(discussed in more detail below).

The upper receiver18is connected to the lower receiver16by a forward take down pin26at a first, front connection point26P and a rear take down pin28at a second, rear connection point28P rearward of the first connection point26P. As best shown inFIG.14, the lower receiver16can have one or more recesses or grooves30for receiving one or more protrusions or tabs32of the upper receiver18. The front connection point26P is located adjacent to the front edge of the lower receiver16. The rear connection point28P is located proximate the rear end of the lower receiver16. The upper receiver18is rotatable about the forward take down pin26relative to the lower receiver16when the rear pin28has been removed and the buffer assembly12and buffer biasing member52are either removed or retracted as described below. Rotation of the upper receiver18about the forward take down pin26is often desired to access the bolt assembly20and required when assembling and disassembling AR-style firearms before and after maintenance or repairs, respectively. The bolt assembly20includes a bolt, an extractor36, and a bolt knob38. A handguard40is secured to the forward end of the upper receiver18to protect the hand of a user from heat evolved from the barrel14. The magazine22is received in the lower receiver16and supplies cartridges to the firearm10.

The compact stock24generally includes a housing46, a receiver extension48, a buffer assembly12, a buffer biasing member52, a buffer locking mechanism54, a butt member42, a pair of buttstock rods44, a pair of fasteners132, and a pair of rod biasing members134. The housing46is configured to be attached to a rear end of the lower receiver16via the receiver extension48, as described in more detail below, such that the receiver extension48extends through the housing46. The housing46defines a pair of rod bores56in which the rods44are axially receivable to mount the rods44to the housing46. The rods44include a plurality of spaced pairs of notches (unnumbered) defined therein. A selectably releasable spring-loaded latch124mechanism pivotably connected to the housing46is biased to engage a pair of notches in the rods44and thereby secure the rods to the housing46. The rods44in turn mount the butt member42to the housing46. Each pair of notches along the parallel rods44define a different position in which the butt member42can be fixed relative to the housing46, such that the compact stock24is retractable and extendable. Activating the latch124mechanism allows repositioning of the butt member42relative to the housing46.

The receiver extension48includes a buffer bore72for receiving the buffer assembly12therein. The exterior surface of the front end of the receiver extension48is threaded to be threadingly engaged with a threaded aperture63in an upwardly extending lobe64(i.e., stock mount) of the lower receiver16. The receiver extension48may comprise any desired material, such as metal or polymer. The buffer assembly12and buffer biasing member52are at least partially housed in the receiver extension48. The buffer assembly12is configured to reciprocate between a retracted position (see, e.g.,FIGS.6and11) wherein the buffer assembly12is completely contained within the receiver extension48, and an extended position (see, e.g.,FIG.5A) wherein the buffer assembly12is in-battery within the upper receiver18of the firearm10.

A front end of the housing46is configured to mate with the rear end with the lower receiver16. The housing46defines a male mating feature58at its front end, facing the lower receiver16, for mating with a corresponding female mating feature or recess60on the lower receiver16(seeFIG.17). The male mating feature58is in the form of a protrusion58that extends longitudinally forward from the front end of the housing46. When assembled, the protrusion58engages and fits within the corresponding recess60in the lower receiver16, which prevents a rotational movement of the housing46relative to the lower receiver16about a longitudinal axis of the receiver extension LA. The protrusion58can have any desired shape and size, and the recess60can have a complimentary or corresponding shape and size. For instance, the protrusion58can have a circular cross-section and the recess60can have a complimentary or corresponding circular cross section in which the circular protrusion58is receivable. The housing46may comprise any desired material, such as metal or plastic.

As best shown inFIGS.2-3, the housing46defines a longitudinal through hole62through which the receiver extension48is receivable to secure the housing to the lower receiver16. The through hole62has a front opening and a rear opening opposite the front opening. A rear portion74of the receiver extension48extends rearwardly out of the rear opening of the through hole62at the rear end of the housing46. The rear portion74of the receiver extension48is configured as a hex head so as to allow a user to engage the head with a corresponding tool (e.g., a wrench) in order to more easily thread the forward end of the receiver extension48into the threaded aperture63of the lower receiver16.

The through hole62can have a uniform or non-uniform surface profile such that the diameters of its openings can be the same or differ. For instance, the rear opening of the through hole62may have a diameter that is greater than the diameter of the front opening. The diameter of the front opening of the through hole62can substantially match the diameter of a threaded aperture63in the upwardly extending lobe64at the rear end of the lower receiver16, and the diameter of the rear opening of the through hole62can correspond to the outer diameter of the receiver extension48.

Receiver Extension Locking Mechanism

Referring now toFIGS.2and12, the compact stock24includes a novel receiver extension locking mechanism126. The receiver extension locking mechanism126secures the housing46to the lower receiver16of the firearm10and prevents the receiver extension48from inadvertently backing out of the threaded aperture63in lobe64of the lower receiver16during normal use and operation of the firearm10. The receiver extension locking system126includes features on the housing46and the receiver extension48, which can be integrally formed thereon or attached thereto.

The receiver extension locking system126includes a pair of mating surfaces70,88respectively located on the housing46and the receiver extension48. The mating surfaces70,88matingly engage with one another when the receiver extension is received through the through hole62of the housing46and threaded into the threaded hole63of the lower receiver16. Mating engagement of surfaces70,88applies axial pressure to the rear of the housing46, thereby securing the housing46to the lower receiver16. Mating engagement of mating surfaces70,88also simultaneously secures the receiver extension48to the housing46and prevents the receiver extension48(and by extension, the housing) from becoming detached from the lower receiver16. The mating surfaces70,88can be tapered and have a substantially matching or complimentary slope or taper. By “substantially matching” it is meant that the slope or taper of each surface70,88is such that sufficient friction is created between surfaces70,88when they are matingly engaged to maintain mating engagement of the surfaces during normal use and operation of the firearm. The taper can be a 5-degree or less taper. In one embodiment, the taper is a four-degree taper.

In the depicted embodiment, the receiver extension48includes an annular protrusion84extending radially outward from the exterior surface of the receiver extension48. The annular protrusion84is in the form of a conical frustum which has a flat front face86, an angled side face88, and a flat rear face90. The mating surface88of the receiver extension48includes at least a portion of the angled side face88. Similarly, the housing46includes a tapered mating section66adjacent the rear opening of the through hole62. The tapered mating section66defines a flat end wall68and an angled side wall70that extends from the flat end wall68to the rear opening of the through hole62. The mating surface70of the housing46includes at least a portion of the angled side wall70.

In some embodiments, more than one portion of the annular protrusion84, such as the front face86and angled side wall88, can engage with more than one portion of the tapered mating section66of the through hole62in the housing46. For example, in some embodiments, the front face86of the annular protrusion84can contact the flat end wall68of tapered mating section66after the angled side wall88of the annular protrusion84contacts the angled side wall70of the mating section66. In this way, the end wall68inside the housing46serves as a positive stop that contacts the front face86of the annular protrusion84and thereby prevents a user from over-tightening the receiver extension48in the lower receiver lobe64. Overtightening the receiver extension48is disadvantageous because it can damage components of the firearm10or the compact stock24(such as the housing), prevent proper functioning of the firearm10, and inhibit disassembly of the firearm10for repairs or maintenance.

Buffer Assembly

Referring toFIGS.1-14, the buffer assembly12generally includes a cylindrical buffer body50, a buffer pad100, a buffer weight98, and a buffer plug102. The budder body50defines an open rear end51, a bore or interior space92accessible through the open rear end51, and a threaded hole94extending through the front end thereof that is in fluid communication with the interior space92. The buffer pad100is received in the interior space92against a forward interior surface of the buffer50. The buffer weight98is received in the interior space92. The buffer plug102is received in and closes the open rear end51of the buffer body50so that the pad100and weight98cannot exit the interior space92through the open rear end51.

The buffer assembly12can also comprise a locking buffer rod104and a timing pin106for mounting the buffer weight98, the buffer pad100, and buffer plug102to the buffer body50. The timing pin106secures the buffer50, the locking buffer rod104, and the plug102together so that they reciprocate together with one another in time as buffer assembly12. The locking buffer rod104is insertable through each of the buffer weight98, the buffer pad100, and buffer plug102and threadable into the threaded hole94. The timing pin106is then insertable through corresponding aligned coaxial pin holes50TP,102TP,104TP within each of the body of the buffer body50, the buffer plug102, and the locking buffer rod104(seeFIGS.4A-4B) to secure the buffer weight98, the buffer pad100, and buffer plug102to the buffer body50and lock the various components together as buffer assembly12. In this way, coaxially aligned pin holes50TP,102TP,104TP form a timing pin passage in which timing pin106is receivable. The locking buffer rod104and timing pin106can comprise any desired material, such as metal.

The timing pin aperture104TP in the timing rod104is sized to receive the timing pin106. In some embodiments, the timing pin aperture104TP is non-circular and generally oval-shaped. In one embodiment, the timing pin aperture104TP is sized and shaped to allow the locking buffer rod104to move axially forward and rearward a small amount (i.e., no more than the length of the threaded forward portion of the locking buffer rod104) while the timing pin106is received in the pin hole104TP. The benefits of this arrangement are explained below with respect to the buffer locking mechanism54.

The buffer body50also defines an annular protrusion96on its exterior circumferential surface. The annular protrusion96is sized and shaped to be engaged by the buffer biasing member52. In the depicted embodiment, the buffer biasing member52is a metal compression spring52in which the buffer assembly12is receivable. Put differently, the buffer assembly12is axially receivable inside the coils of the buffer biasing member52such that a front end of the biasing member52contacts a rear face of the annular protrusion96. As such, the buffer biasing member52is configured to bias the buffer assembly12toward the extended position in-battery within the upper receiver18and outside of the receiver extension48.

More specifically, when the buffer assembly12and the buffer biasing member52are properly installed in an assembled firearm10, the buffer biasing member52biases the buffer assembly12forwardly through an opening34in the upper receiver18toward the extended position (see, e.g.,FIGS.5and14) wherein the buffer assembly12is in-battery within the upper receiver18of the firearm10. In operation, the buffer assembly12reciprocates back and forth within the upper receiver18and the receiver extension48such that the buffer assembly12reciprocates in and out of each of the upper receiver18and the receiver extension48as the biasing member52compresses and decompresses during cycling of the firearm10. In the retracted position, the buffer assembly12and buffer biasing member52are completely contained within the receiver extension48. In some embodiments, the rear end of the buffer plug102can contact an interior wall of the rear end of the receiver extension48when the buffer assembly12is in the retracted position. This minimizes wasted space inside the receiver extension48and thereby reduces the overall length of the firearm10.

Buffer Assembly Locking Mechanism

The buffer assembly12can also include a novel buffer assembly locking mechanism54. The buffer locking mechanism54allows a user to quickly and easily lock or secure the buffer assembly12and the buffer biasing member52in the retracted position (see, e.g.,FIGS.2,6, and11) wherein the buffer assembly12is completely contained within the receiver extension48. By “completely contained within” the receiver extension48, it is meant that no portion of the buffer assembly12or the buffer biasing member52extends forwardly out of the open forward end of the receiver extension48that is engaged with the threaded aperture63in the lobe64of the lower receiver16to impede pivotable movement of the upper receiver18relative to the lower receiver16about the forward take down pin26while the rear take down pin28is removed from the upper18and lower16receivers. Put another way, the rear end of the upper receiver18is freely pivotable about the forward take down pin26upward and forward relative to the lower receiver16(see, e.g.,FIG.14) while the rear takedown pin28is removed from the upper18and lower16receivers and the buffer assembly12and buffer biasing member52are secured within (and therefore completely contained within) the receiver extension48in the retracted position. This function of the buffer assembly locking mechanism54not only allows a user to more quickly and easily access the bolt assembly20without first disassembling the upper and lower receivers16,18, it also makes overall disassembly and reassembly of the firearm10much quicker and easier than currently available PDW firearms and compact stocks.

To explain, conventional non-compact AR-style firearms include a spring-loaded buffer retaining pin (not shown) disposed in the threaded aperture63of the lower receiver16that is arranged to retain the buffer and buffer spring inside a full-size receiver extension housed inside a non-compact stock. However, a conventional buffer retaining pin cannot be used in compact AR-style firearms due to the various size constraints of the platform, including but not limited to the relatively reduced length of compact stock receiver extensions, such as receiver extension48, which typically require that the buffer reciprocate back and forth between (i.e., in and out of) the upper receiver and the receiver extension (compare, e.g.,FIGS.5A and6). A standard AR-style buffer retaining pin is therefore not usable in a compact AR-style firearm with a compact stock because such retaining pins prevent the buffer from extending forwardly out of the receiver extension and into the upper receiver to cycle the firearm.

No known compact AR-style firearms equipped with compact stocks permit rotation of the upper receiver relative to the lower receiver about the forward takedown pin because the buffer spring constantly biases the buffer toward the extended position with the buffer in-battery within the upper receiver and thereby blocks such rotation, as exemplified inFIGS.5A-5B. To explain, althoughFIG.5Bshows the upper receiver18rotated about forward takedown pin26to a desired position, the depiction inFIG.5Bof such rotation is merely aspirational as such rotation is precluded by the presence of the buffer assembly12and buffer biasing member52in the extended position in-battery within the upper receiver18as shown inFIG.5A. Thus, currently available compact AR-style firearms and compact stocks obligate the user to remove both the forward and rear takedown pins in order to completely remove the upper receiver from the lower receiver before a user can access the bolt assembly or further disassemble the firearm. This process is notoriously cumbersome because the user must remove both of the front and rear takedown pins, move the upper receiver upward and forward to carefully separate them, and simultaneously push rearward on the buffer to compress the buffer spring acting thereon in order to detach the upper receiver from the lower receiver. Reversing the process to reassemble the firearm is even more cumbersome, time-consuming, and frustrating.

The present inventor has solved this problem by providing the buffer assembly locking mechanism54described herein. The locking mechanism54is configured for releasably and selectably securing the buffer assembly12and the buffer biasing member52in the retracted position within the receiver extension48so that the buffer assembly12and the biasing member52do not interfere with rotation of the upper receiver18about the forward takedown pin26during assembly or disassembly of the firearm10. The locking mechanism54can comprise a locking feature112that is selectably insertable through the receiver extension48to releasably engage the buffer assembly12or a part coupled to the buffer body50and thereby secure the buffer assembly12in the retracted position within the receiver extension48.

Referring again toFIGS.1-14, in one embodiment, the buffer locking mechanism54can include the locking buffer rod104and a locking pin112. The locking buffer rod104is releasably connected to the buffer body50. The locking buffer rod104can be threaded into a threaded hole94defined through a forward wall of the buffer body50(seeFIG.4). Each of the buffer pad100, buffer weight98, and buffer plug102can also include a through hole (unnumbered) in which the locking buffer rod104is receivable. When the buffer assembly12is assembled with the locking buffer rod104threaded into the hole94, the locking buffer rod104extends rearwardly through the buffer pad100, buffer weight98, and buffer plug102. A rear end of the locking buffer rod104extends rearwardly beyond the buffer plug102when the buffer assembly12is assembled. The rear end of the locking buffer rod104that extends rearwardly beyond the buffer plug102when the buffer assembly12is assembled defines a rod head108. The rod head108includes an annular groove110defined therein. The annular groove110defines a mating surface for receiving and engaging locking pin112. The locking buffer rod104may comprise any desired material, such as metal.

The rear end74of the receiver extension48includes a primary hole76extending longitudinally therethrough. The hole76extends longitudinally through the end face78of the receiver extension48(seeFIGS.3and8). The longitudinal hole76is coaxial with a longitudinal axis LA of the receiver extension48and the buffer bore92. The primary hole76is shaped and sized to receive the rod head108. The rear end74of the receiver extension48also includes a secondary hole80extending through the receiver extension48. The secondary hole80extends through the rear end of the receiver extension48transverse to and off-center from the longitudinal axis LA. The transverse secondary hole80intersects the primary longitudinal through hole76, as best shown inFIGS.8and11. The transverse secondary hole80can be located on a side face or flat portion82of the hex head of the rear end74of the receiver extension48. The transverse secondary hole80is shaped and sized to receive the locking pin112therein.

The head108of the locking buffer rod104is receivable in the primary longitudinal hole76of the receiver extension48when the buffer assembly12is in the retracted position. The buffer assembly12can be placed in the retracted position by manually charging the AR-style firearm10to compress the buffer biasing member52. The locking pin112is then selectably insertable through the transverse secondary hole80and removably receivable in the annular groove110of the rod head108when the head108is received in the primary longitudinal hole76of the receiver extension48to secure or lock the buffer assembly12in the retracted position. More specifically, the locking pin112matingly engages the annular groove110to prevent the buffer biasing member52from biasing the buffer assembly12forwardly out of the receiver extension48and into the upper receiver18of the firearm10when the rod head108is received in the primary longitudinal hole76and the locking pin112is received in the transverse secondary hole80and annular groove. The locking pin112need not be fixedly attached to the firearm10. The locking pin112can be removably attached to the stock24or other member of the firearm10.

As a result of the buffer assembly12and buffer biasing member52being completely contained and secured within the receiver extension48by locking pin112as shown inFIG.6, the upper receiver18is free to pivot about the forward takedown pin26(when the rear takedown pin28is removed) unimpeded by the buffer assembly12and the buffer biasing member52. Additionally, when the buffer assembly12is secured in the retracted position, the buffer rod head108rests in the primary longitudinal hole76, which can be an indicator hole76, at the rear portion74of the receiver extension48. This provides a visual indicator that the buffer assembly12and the buffer biasing member52are secured in the retracted position within the receiver extension48.

A user may “tune” both how far the rod104protrudes from the receiver extension48and how tightly or loosely the locking pin112is retained in the annular groove110and transverse secondary hole80by threading the front end of the locking buffer rod104further into the threaded hole94in the forward wall of the buffer body50. To explain, threading the rod104further into the buffer body50translates the annular groove110forward relative to the transverse secondary hole80, whereas threading the rod104rearwardly out of the buffer body50(i.e., backing the rod104out of hole94) translates the annular groove110rearward relative to the transverse secondary hole80. In this way, a user can select both (i) how far the head108of the rod104protrudes rearwardly out of the primary longitudinal hole76in the rear of the receiver extension48while the buffer assembly12is in the retracted position, and (ii) how closely the annular groove110aligns with transverse secondary hole80.

To release the buffer assembly12from the retracted position, a user need only withdraw the locking pin112from the transverse secondary hole80of the receiver extension48. This causes the locking pin112to disengage from the mating surface of the annular groove110in the locking buffer rod104, which in turn allows the buffer biasing member52to return the buffer assembly12to the forward extended in-battery position within the upper receiver18of the firearm10.

Referring now toFIGS.15-18, in another embodiment, the locking mechanism54can comprise a lever action locking stopper mechanism114connected to the housing46of the compact stock24. The lever action locking stopper mechanism114comprises a lever116pivotably connected to the housing46via a pivot pin, a lever biasing member118disposed between a forward end of the lever116and the housing46, a locking pin120adjacent to the forward end of the lever116, a pin biasing member122disposed between the housing46and the locking pin120, and a pin hole125defined though a sidewall of the receiver extension48. Locking pin120differs in form from locking pin112in that locking pin120includes a conical head121and a flange123spaced from the head121. The conical head121is configured to interface with the annular protrusion96on the buffer body50. The flange123of the locking pin120is configured to interface with the pin biasing member122, which can be a compression spring122. A depression127in which the pin head121is receivable is formed on an interior surface of the receiver extension48around the pin hole125. The surface of the receiver extension48on which the depression127is formed is a surface of the bore72of the receiver extension. The head121of the locking pin120is received inside the bore76of the receiver extension48. The shaft of the locking pin extends through the pin hole125such that the flange123sits outside the receiver extension48. The pin biasing member122is disposed around the shaft of the locking pin120between the housing46and the flange123. The pin biasing member122biases the locking pin120toward a retracted position wherein the locking pin head121is received in the depression127such that the head121sits flush with the interior surface of the receiver extension48.

The locking pin120is extendable through the pin hole125into the receiver extension48by depressing the portion of the lever116which rests adjacent the locking pin120. Depressing the portion of lever116adjacent the locking pin120causes the lever116to contact the locking pin120. This moves the locking pin120upward, causing the flange123to compress the biasing member122against housing46and move the locking pin120upward and further into the interior of the receiver extension48. Movement of the locking pin120further into the interior of the receiver extension48while the buffer assembly12is being held in the retracted position (e.g., while the firearm10is charged by manually pulling a charging handle thereof rearward) places the locking pin head121axially in front of the annular protrusion96on the buffer body50. With the locking pin head121in front of the annular protrusion96on the buffer body50, a user may cease charging the firearm (e.g., by releasing the charging handle). The buffer biasing member52will then attempt to decompress and bias the buffer assembly12forward. This biases the annular protrusion96on the buffer body50into contact with the locking pin head121. Contact with the locking pin head121automatically halts further forward movement of the buffer assembly12, and thereby automatically secures or locks the buffer assembly12in the retracted position within the receiver extension48. This allows the user to then remove the rearward takedown pin28and freely pivot the upper receiver18about the forward take down pin26of the firearm10to access the bolt assembly20or disassembly the firearm10. In this way, the locking pin120function as a stopper which contacts the front of the annular protrusion96and holds the buffer assembly12in the retracted position. The size and shape of the head121of the locking pin120can correspond to the size and shape of the annular protrusion96of the buffer body50. For example, the annular protrusion96can define a recess or groove127on a forward surface thereof that is complimentary in shape to the conical head121of the locking pin120, as exemplified inFIGS.17-18.

Recoil Damping System

Referring now toFIGS.1,3, and19-20, the compact stock24further includes a recoil damping system130. The recoil damping system130is configured to dampen the recoil of the AR-style firearm10felt by a user upon discharge of the firearm. The recoil damping system130includes the butt member42, the pair of buttstock rods44, the pair of fasteners132, and the pair of rod biasing members134.

As noted above, the rods44are adjustably connected to the housing46via the rod through holes56in the housing46and the stock locking member124. The butt member42is removably connected to the rods44by the pair of fasteners132. In the depicted embodiment, each fastener132is a metal shoulder screw having a head and a narrower shaft with a smooth portion adjacent the head and a threaded portion adjacent the smooth portion, while each biasing member134is a metal compression spring.

The butt member42is a skeletonized buttstock (seeFIG.1) configured for contacting the shoulder of a user and stabilizing the firearm10during discharge. A pair of laterally spaced, left and right fastener bores140are defined in a rear face of the butt member42. The fastener bores140are smooth and sized to receive the head of each fastener132. The butt member42includes a pair of laterally spaced, left and right tubular rod receiving members136which extend forwardly from an interior surface of the butt member42. Each rod receiving member136defines a smooth rod bore138therein in which a rod biasing member134and a rod44is receivable. The rod bores138have a diameter which facilitates smooth insertion and axial reciprocation of the rods44therein without appreciable lateral movement or “wobble” of the rods44in the rod receiving members136. Each rod receiving member136also defines a flat interior wall133in each rod bore138. Each flat interior wall133defines a rear end of the respective rod bore138and a front end of each respective fastener bore140. A smooth fastener access hole142for receiving the shaft of a fastener132therethrough is defined through each interior wall133. The left rod bore138, left fastener access hole142, and left fastener bore140are all coaxially aligned. Likewise, the right rod bore138, right fastener access hole142, and right fastener bore140are all coaxially aligned.

The rod biasing members134are received in the rod bores138of the rod receiving members136against the interior wall133. The rear ends of the rods44are received in the rod bores138against the rod biasing members134. The heads of the fasteners132are received in the fastener bores140such that the smooth portions of the shafts of the fasteners132extend through the fastener access holes142in the interior walls133, through the rod biasing members134, and into the rod bores138. The rod biasing members134are thus disposed around the fasteners132with the rear ends of the biasing members134contacting the flat interior walls133of the rod bores138and the forward ends the biasing members134contacting the rear ends of the rods44. The threaded portions of the fasteners132are received in and threadingly engaged with threaded bores144formed in the rear ends of the rods44. In this way, each fastener132removably connects the butt member42to a respective buttstock rod44.

In some embodiments, the diameter of the rod bores138differs from the diameter of the fastener bores140and the diameter of the fastener access holes142. In other embodiments, the diameters of the rod bores138and fastener bores140can be the same, while the diameter of the fastener access holes142differs from the diameters of the rod bores138and fastener bores140. What matters is that the interior walls133partition the rod bores138from the fastener bores140such that the heads of the fasteners132remain in the fastener bores140while the rods44and rod biasing members134remain in the rod bores138. Consequently, the fastener access holes142should have a diameter smaller than the diameters of the fastener heads132, rods44, and rod biasing members134.

In use, the rearward recoil force generated upon discharge of the firearm10moves the firearm10and the connected rods44rearwardly, which causes the rods44to compress the biasing members134inside the butt member42against the interior walls133. The fasteners132translate rearwardly with the rods44. However, the fasteners132do not exit the fastener bores140because the fastener bores140are sized so to be at least as long as the portion of the fastener shaft extending between the rear end of the rods44and the forward face of the interior wall133(seeFIG.22). In other words, the fastener bores140are at least as long as the distance the rods44travel rearwardly in the rod bores138upon discharge. The rod biasing members134are configured to oppose axial compression and bias the rods44forwardly away from the interior walls133of the butt member42in opposition to the rearward recoil force. The pair of rod biasing members134thus oppose rearward translation of the rods44in the rod bores138, and thereby dampen the recoil felt by a user upon discharge of the firearm10.

Although embodiments of the present invention have been described in detail, it will be understood by those skilled in the art that various modifications can be made therein without departing from the spirit and scope of the invention as set forth in the appended claims. For example, the buffer assembly locking mechanism54can include either or both of the removable locking pin112and the lever-action stopper locking mechanism114. Additionally, although the rod biasing members134are described above as being metal compression springs, other suitable structures made from other suitable materials are contemplated herein and covered by the claims.

This written description uses examples to disclose the invention and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

It will be understood that the particular embodiments described herein are shown by way of illustration and not as limitations of the invention. The principal features of this invention may be employed in various embodiments without departing from the scope of the invention. Those of ordinary skill in the art will recognize numerous equivalents to the specific apparatus and methods described herein. Such equivalents are considered to be within the scope of this invention and are covered by the claims.

All of the compositions and/or methods disclosed and claimed herein may be made and/or executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of the embodiments included herein, it will be apparent to those of ordinary skill in the art that variations may be applied to the compositions and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit, and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope, and concept of the invention as defined by the appended claims.

Thus, although there have been described particular embodiments of the present invention, it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims.