Patent Description:
An example of a magazine for firearm is disclosed in <CIT> and <CIT>.

Non-rotary magazines of the box type used for long guns generally include a body case or housing) defining an internal cavity which holds a vertical stack of ammunition cartridges. The magazine may be removably detached to the underside of the firearm below the action. The cartridges in the magazine are typically arranged in a vertical stack. The bottom end of the case is closed and top end forms an opening for loading cartridge into the magazine and dispensing them into the breech area of the firearm action. A follower biased in an upward direction by a spring mechanism urges the stack of cartridges upwards towards the top opening. A pair of laterally spaced feed lips formed on or attached to the magazine case at the top end engages the uppermost cartridge to retain the spring-based cartridges in the magazine. When the action is cycled by discharging the firearm or manually, the bolt or breech block strips and chambers the uppermost cartridge from the magazine.

Some box type magazines have a relatively large profile and project a significant distance below the mid-stock of the rifle or shotgun (i.e. portion of stock partially encasing the receiver). This is visually and physically obtrusive which may interfere with handling of the firearm.

An improved firearm magazine having a compact and low profile design without sacrificing capacity is desired. Smooth and reliable feeding of individual cartridges from the magazine into the action of the firearm is further desirable.

The present disclosure provides an improved ammunition magazine for a long gun such as without limitation a rifle or shotgun. The present magazine includes a compact, low profile housing which sits substantially flush with underside of the mid-stock to which it is detachably mounted. Several unique features of the magazine disclosed herein contribute to the low profile design, smooth and reliable cartridge feeding, and overall functionality of the magazine. For example, the main spring has a unique configuration and folding features which produces a low profile when fully compressed, thereby enabling the provision of a compact magazine design without reduced shell or cartridge capacity. The follower may be a tilting design with a specially contoured cartridge support surface which advantageously provides positive cartridge feeding action without hang-ups or jams. In one embodiment, the magazine has a main case or housing configured to hold a plurality of cartridges in a vertical double/staggered stack to single feed design arrangement. The magazine has a capacity for holding four cartridge rounds in one implementation such as short action calibers (. <NUM> Winchester,. <NUM> Winchester, <NUM>-<NUM> Remington, <NUM> Creedmoor, and <NUM> Creedmoor). However, other embodiments may hold more or less and different size cartridges.

In one aspect, a magazine for a firearm comprises: a housing defining a horizontal centerline axis, a vertical centerline axis perpendicular thereto, and an interior cavity configured to hold a plurality of ammunition cartridges; the housing including an open top end, a bottom end, a front wall, a rear wall, and pair of opposing lateral right and left sidewalls extending between the front and rear walls; a compressible main spring disposed in the cavity; an elongated follower disposed in the cavity and biased in an upwards direction by the main spring, the follower being moveable between a lower position and an upper position for dispensing cartridges; a guide boss protruding laterally outwards from each one of a pair of lateral sides of the follower, each guide boss slideably engaging a corresponding vertical guide slot formed in the sidewalls of the housing for guiding upwards and downwards movement of the follower; wherein the follower is angularly tiltable relative to the housing of the magazine about a lateral pivot axis defined by the guide bosses. Each vertical guide slot may have a closed top end to restrict a vertical range of movement of the follower and an open bottom end for insertion of the guide bosses into the guide slots in some embodiments. The guide bosses may be cylindrical. The follower is movable between a horizontal position and an angled position.

In another aspect, a magazine for a firearm comprises: a housing defining a longitudinal axis, a vertical centerline axis, and an interior cavity configured to hold a spring biased stack of ammunition cartridges; the housing including an open top end, a bottom end, a front wall, a rear wall, and pair of opposing lateral sidewalls extending between the front and rear walls; the sidewalls of the housing each including a plurality of longitudinally spaced apart mounting teeth; a floor plate detachably coupled to the bottom end of the magazine, the floor plate including a plurality of longitudinally spaced apart mounting teeth mutually engageable with the mounting teeth on each of the sidewalls of the magazine; the floor plate longitudinally slideable forward and rearward on the housing between a locked position in which the mounting teeth of the floor plate are engaged with the mounting teeth of the housing, and an unlocked position in which the mounting teeth of the floor plate are disengaged from the mounting teeth of the housing; wherein the floor plate is removable form the housing when in the unlocked position, and the floor plate is not removable from the housing when in the locked position.

The features of the exemplary embodiments will be described with reference to the following drawings where like elements are labeled similarly, and in which:.

All drawings are schematic and not necessarily to scale. Parts given a reference numerical designation in one figure may be considered to be the same parts where they appear in other figures without a numerical designation for brevity unless specifically labeled with a different part number and/or described herein.

The features and benefits of the invention are illustrated and described herein by reference to exemplary ("example") embodiments.

In the description of embodiments disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as "lower," "upper," "horizontal," "vertical,", "above," "below," "up," "down," "top" and "bottom" as well as derivative thereof (e.g., "horizontally," "downwardly," "upwardly," etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation.

The terms "shell," "cartridge," and "round" are used interchangeably herein in reference to describing firearm ammunition, and therefore should not to be construed as limiting the invention or the claims appended hereto. For convenience and brevity, further description of ammunition which follows will generally use the non-limiting term of "cartridge.

A detachable firearm magazine according to a non-limiting embodiment may be used in semi-automatic/autoloading and bolt action long guns such as rifles or shotguns, or other types of firearms including some pistols. In the illustrated embodiment of a firearm, the magazine is shown as configured for use in a manually operated centerfire bolt action rifle. It will be appreciated, however, that the magazine may also be adapted for use in a rimfire rifle as well as the other types of firearms noted above. Accordingly, the type of firearm and ammunition does not necessarily limit the scope or applicability of the invention which has broad use.

<FIG> show one non-limiting embodiment of a detachable box style magazine according to the present disclosure for a firearm, which incorporates several features that collectively provide a compact magazine design with reliable cartridge feed mechanism.

Referring initially to <FIG> and <FIG>, a firearm <NUM> includes a chassis or stock <NUM> which supports a receiver <NUM> and barrel <NUM> which may be detachably or permanently coupled to the receiver. Barrel <NUM> defines a longitudinal axis LA coinciding with the axial centerline of a longitudinally-extending bore <NUM> which defines the projectile passageway from the rear breech end to front muzzle end of the barrel. The rear end of the bore is diametrically enlarged and defines the chamber <NUM> configured for supporting and holding an ammunition cartridge C which may be uploaded into the action by the present magazine <NUM>. The area in the receiver at the open rear entrance to the chamber <NUM> defines the breech area <NUM> which communicates with magazine <NUM> for uploading cartridges into the firearm.

A generally cylindrical bolt <NUM> (visible through the cartridge ejection port of the receiver <NUM> is slideably mounted inside a longitudinal chamber of the receiver for rearward and forward movement via manual operation of the bolt handle <NUM> to both eject the spent cartridge casing after firing, and load a fresh cartridge into the barrel chamber <NUM>. The front of the bolt <NUM> defines the breech face for forming a closed breech when in battery with the barrel <NUM> when the bolt is in the forward position, or an open breech spaced axially rearward for unloading/loading cartridges via the magazine <NUM>. A trigger-actuated firing mechanism <NUM> mounted in the receiver <NUM> includes a movable trigger <NUM> for discharging the firearm. The firing mechanism <NUM> operably cooperates with a cockable spring-biased striking member such as a hammer (not shown) which in turn strikes a firing pin to strike and detonate a chambered cartridge C. Such features and operation are well known in the art.

Magazine <NUM> may include front and rear retention features which removably and detachably mount the magazine to the stock <NUM> of the firearm. Referring to <FIG> and <FIG>, magazine <NUM> is vertically located and secured to firearm <NUM> at rear by a rear retention tab <NUM> formed in stock <NUM> at the rear of magazine well <NUM>, and a latch mechanism comprising a spring loaded pivotably movable latch lever <NUM> at the front mounted to the front wall <NUM> of the magazine adjacent to the magazine well. Magazine <NUM> includes a stepped rear mounting protrusion or tab <NUM> on rear wall <NUM> which engages rear retention tab <NUM> of the stock disposed inside the downwardly open magazine well <NUM>. Latch lever <NUM> engages a stepped front mounting protrusion or tab <NUM> inside the front of the magazine well. Lever <NUM> is vertically elongated and includes an upper retention end <NUM> configured with downward facing retention surface <NUM>-<NUM> arranged to engage stock mounting tab <NUM> and a lower operating end <NUM> accessible via a downwardly open recess <NUM> in the bottom of the stock <NUM> adjoining the magazine well <NUM>.

Latch lever <NUM> is mounted to front wall <NUM> of magazine <NUM> via a laterally oriented pivot pin <NUM> received in a pair of laterally open pin apertures <NUM>-<NUM> defined by mounting protrusions <NUM>-<NUM> (see, e.g. <FIG>). Latch lever <NUM> is pivotably movable about pivot pin <NUM> (which defines a latch lever pivot axis) between latched and unlatched positions. Latch spring <NUM> automatically biases the latch lever <NUM> (i.e. upper retention end <NUM>) forwards and towards the latched position engaged with magazine mounting tab <NUM> of the stock. Moving the lower operating end <NUM> of the lever rearward rotates the retention end <NUM> in turn forward to the unlatched position of the latch lever to disengage mounting tab <NUM> therefrom for releasing the magazine <NUM> from the stock to load loading fresh cartridges into the magazine.

When the magazine <NUM> is fully mounted to the stock <NUM> of firearm <NUM> as shown in <FIG>, the bottom surface of the magazine may be substantially flush with the underside bottom surface <NUM> of the stock adjacent to the magazine well <NUM> in one embodiment. This facilitates handling, holding, and aiming of the firearm without interference from a downwardly projecting magazine. The term "substantially" connotes that there may be some slight insignificant variances in the flush mounting due to tolerance stack when affixing one component (e.g. magazine) to another component (e.g. stock) resulting from manufacturing and fit-up tolerances.

Magazine <NUM> will now be further described. For convenience of description which follows and reference, the magazine may be considered as defining a vertical centerline axis Cv and a horizontal centerline axis Ch extending perpendicular thereto and in an axial direction parallel to longitudinal axis LA of the firearm. The vertical and horizontal centerline axes Cv, Ch intersect at the geometric centerline of the magazine. The term "longitudinal" as used herein connotes a direction or orientation along the elongated horizontal length of the firearm or magazine. The term "transverse" connotes a direction which is at an angle to and would cross the longitudinal axis LA or horizontal centerline axis Ch.

Referring initially and generally to <FIG> and <FIG>, the magazine <NUM> has a longitudinally elongated case or housing <NUM> forming a body that defines an internal cavity <NUM> configured for holding a plurality of cartridges C. Magazine <NUM> has greater longitudinal length than lateral width or height. Cavity <NUM> extends from the top to bottom ends and front to rear ends of the magazine defining a substantially hollow housing construction. Cartridges C may be arranged and held in vertically stacked relationship comprised of a double staggered column or stack of cartridges (i.e. each cartridge is laterally offset slightly from the superseding cartridge below, as shown in <FIG>). In one embodiment, a <NUM>° angle may be formed between the axes of the three cartridges in the lower staggered portion of the cartridge stack in the magazine.

As the cartridges C advance upwards in the magazine to the top position in the stack ready for chambering, the uppermost cartridge will fall and be centered on the vertical centerline axis Cv of the magazine as shown in <FIG>. Cartridges below the uppermost cartridge in the stack will be laterally offset to one side or the other of axis Cv. In one embodiment of a magazine <NUM> having a four round capacity, two cartridges C below the uppermost one will offset to one side of axis Cv and a single cartridge will be offset to the opposite side of axis CV as shown in <FIG>.

The housing <NUM> of the magazine <NUM> may have a horizontally elongated rectangular shape having a greater length than height. Housing <NUM> comprises a partially open top end <NUM>, open bottom end <NUM>, front wall <NUM>, rear wall <NUM>, and pair of opposing spaced part sidewalls <NUM> extending therebetween along the longitudinal axis. The walls <NUM>-<NUM> may be configured such that opposite walls (e.g. sidewalls <NUM> and the front and rear walls <NUM>, <NUM>) may be orthogonally oriented and parallel to each other. The magazine housing <NUM> may be formed of a suitable preferably lightweight but durable metallic or non-metallic material such as without limitation a metal (e.g. aluminum) or preferably a polymer/plastic in one non-limiting embodiment.

The top end <NUM> of the magazine is substantially open and includes a pair of laterally spaced and inwardly angled or curved cartridge feed lips <NUM>. The feed lips are configured to engage and retain the uppermost cartridge <NUM> in the stack. This prevents the column or stack of cartridges C from being vertically ejected from the magazine by the spring feed mechanism further described herein. The feed lips <NUM> thus define an opening therebetween smaller than the lateral width of the cartridge.

The cartridges C may be a centerfire type cartridges as illustrated in some embodiments. Referring to <FIG>, cartridge C includes a rear head or base <NUM> having an annular extraction rim <NUM> and a centered primer cap (not shown), a bottle-shaped case including a longitudinally straight rear portion <NUM> adjacent to the base, diametrically narrow neck <NUM> at front, and stepped or angled shoulder <NUM> at the transition therebetween. A projectile <NUM> (e.g. slug or bullet) is inserted and mounted in the open neck end of the cartridge. Other configurations and/or types of cartridges such as rimfire cartridges may be used.

In one embodiment, best shown in <FIG> and <FIG>, the feed lips <NUM> may be configured and positioned to engage the generally parallel and longitudinally straight opposing upper side portions <NUM> of the cartridge case between the shoulders and the base <NUM>. In one embodiment, the feed lips <NUM> may be formed integrally with the housing <NUM> as a unitary structural portion thereof. In such an embodiment, the upper portions of housing sidewalls <NUM> may gradually converge inwardly toward vertical centerline axis Cv of the magazine to form feed lips <NUM>. In other possible constructions, the feed lips <NUM> may be separate elements rigidly affixed to the upper portions of the magazine sidewalls. In either case, the magazine housing <NUM> and feed lips <NUM> are preferably rigid in structure to prevent the feed lips from bending and inadvertently allowing the uppermost cartridge in the stack to escape vertically between the lips.

The feed lips <NUM> extend axially forward from a point proximate to the rear wall <NUM> of magazine housing <NUM> and terminate at a point spaced rearward from the front wall <NUM> by a sufficient horizontal distance to allow the cartridges to be axially/horizontally stripped from or inserted into the magazine beneath the feed lips <NUM>. In one embodiment, the feed lips may terminate approximately midway between the front and rear walls of the magazine. Such arrangements of feed lips are well known in the art.

According to one aspect of the invention, magazine <NUM> includes a unique internal spring feed mechanism for automatically uploading cartridges into the breech area of the firearm <NUM> for chambering and firing. Referring initially to <FIG>, <FIG>, <FIG>, and <FIG>, the spring feed mechanism is disposed in the cavity <NUM> of the magazine housing <NUM>. The feed mechanism may include an axially/horizontally elongated follower <NUM>, main spring <NUM>, and bottom floor plate <NUM> which attaches to the bottom end of the magazine housing <NUM>, as further described herein. The spring <NUM> biases the follower and stack of cartridges supported thereon upwards towards the open top end <NUM> of the magazine. These components are further described below.

One desirable aspect of the present magazine design is that it preferably should be substantially a flush fit to the pre-existing stock (see, e.g. <FIG>). This means that space is at premium inside the internal cavity of the magazine for housing the internal spring feed mechanism components. One thing that limits amount of available space inside the magazine for holding cartridges is the solid height of the main spring when in a fully compressed condition. In a traditional flat wire magazine spring (see, e.g. <FIG>), the solid height is limited by the folds which end up stacking on top of each other, thereby detrimentally increasing the compressed height of the spring with a fully loaded magazine. In order to decrease the solid height of the spring in a way which maintains the desired cartridge capacity of the magazine and provide for substantially flush underside mounting to the stock, the magazine main spring <NUM> in the present magazine includes cutaway parts of the spring fold described below (see, e.g. <FIG>). This advantageously allows the otherwise stacked spring folds to rest instead side to side next to each other, thereby cutting the compressed solid height in approximately half (compare <FIG> present design to <FIG> standard design). These cutout features are also advantageously used to control and limit the front to back movement of the spring <NUM> in the final assembly and interaction with the floor plate and follower.

<FIG> and <FIG> show magazine main spring <NUM> isolated from other components of the magazine. In one embodiment, as depicted, the main spring <NUM> may be an accordion or corrugated type contractible and expandable flat spring having a continuous structure and undulating zig-zag configuration formed from a triple folded single flat piece of spring material having a greater width than thickness. The spring <NUM> is configured such that no portion or segment of the spring crosses another portion or segment in the same horizontal reference plane when in a fully expanded condition. In some embodiments, the spring <NUM> may be a constant force spring; however, variable force springs may be used as well. Spring <NUM> includes a single bottom terminal end <NUM> and a single top terminal end <NUM> each of which are fixedly attached to the floor plate <NUM> and follower <NUM> respectively as further described below.

The main spring <NUM> has a body with a folded length L, full width W1, and a uniform thickness T. Specially located partial width portions with a width W2 less than width W1 are provided and associated with a special flat-folding feature of the invention further described herein. Widths W1 and W2 may each be greater than the thickness T. In the flat condition prior to bending, spring <NUM> has a rectangular shape with opposing straight or linear longitudinally-extending parallel sides <NUM> preferably uninterrupted by any recesses or cutouts. After bending to the accordion shape by any suitable spring bending/forming method, the longitudinal sides <NUM> remain free of any recesses or cutouts. Spring <NUM> may be formed of any metallic spring material suitable for the application.

Spring <NUM> includes an axially (horizontally) elongated top leg <NUM>, an axially elongated bottom leg <NUM>, an axially elongated upper intermediate leg <NUM> joined to the top leg by a recurvant top bend <NUM>, and an axially elongated lower intermediate leg <NUM> joined to the bottom leg by a recurvant bottom bend <NUM>, and a recurvant intermediate bend <NUM> disposed between bends <NUM>, <NUM> joining the upper and lower intermediate legs together. Top and bottom bends <NUM> and <NUM> are partial width bends having a width W2 less than the full width intermediate bend <NUM>. In one embodiment, width W2 at bends <NUM>, <NUM> and immediately adjoining portions of the spring body as shown is about <NUM>/<NUM> the full width W1 of the spring. Bends <NUM>, <NUM> are located adjacently at one end of the spring (i.e. rear end when mounted in the magazine) and full width bend <NUM> is located at the opposite end of the spring.

In one embodiment, the foregoing reduced partial width bends and portions of the spring <NUM> are formed by inwardly open lateral cutouts <NUM>. A mated pair of cutouts <NUM> are provided which advantageously allows adjacently located bends top and bottom bends <NUM>, <NUM> of the spring to nest together laterally in a side to side relationship when the spring is in a fully compressed condition (see, e.g. <FIG>). In prior art flat accordion or corrugated type springs shown in <FIG> and described above, adjacent bends are vertically stacked one above the other which increases the folded height of the spring and reduces magazine cartridge capacity without increasing the height of the magazine case which is contrary to providing a magazine capable of flush mounting with the underside of the stock. By stark contrast, the present spring <NUM> with cutout <NUM> allows adjacent bends of the spring body to lie in the same horizontal reference plane in lateral side to side relation, which dramatically reduces the folded height of the spring thereby facilitating the goal of flush magazine mounting to the stock.

The spring cutouts <NUM> include a right cutout <NUM>-<NUM> laterally open to the right lateral sidewall <NUM>-<NUM> of the magazine housing <NUM> and an adjacent left cutout <NUM>-<NUM> laterally open to the left lateral sidewall <NUM>-<NUM> of the housing. The paired cutouts <NUM> face laterally inwards towards each other and are arranged in direct opposing relationship to each other. Right cutout <NUM>-<NUM> is formed at rear bottom bend <NUM> and immediately adjoining portions of the spring body in the intermediate lower leg <NUM> and bottom leg <NUM>. Left cutout <NUM>-<NUM> is formed at rear top bend <NUM> and immediately adjoining portions of the spring body in the intermediate upper leg <NUM> and top leg <NUM>. Both cutouts may have a rectilinear shape. The cutouts <NUM> may be formed by any suitable method such as cutting, stamping, or other.

Referring now generally to <FIG>, <FIG>, <FIG>, and <FIG>, the front terminal end <NUM> of the spring top leg <NUM> is affixed to the underside or bottom surface of the follower <NUM>. In one embodiment, the end of the top leg <NUM> may be bifurcated and includes an endwise and forwardly open mounting slot <NUM> which is axially elongated. Slot <NUM> may be centered on the end. The slot <NUM> slideably receives and engages a spring retention protrusion <NUM> formed on the bottom surface <NUM> of the follower <NUM> for securing the top end <NUM> of the spring. Protrusion <NUM> may have an inverted T-shape in one embodiment. The top leg <NUM> slides underneath a laterally broadened bottom portion of the retention protrusion <NUM> and is trapped between the protrusion and the underside of the follower. A transversely oriented top abutment surface <NUM> may be provided forward of the retention protrusion <NUM> on the underside of the follower <NUM>. Surface <NUM> forms a hard stop which is arranged to engage the terminal front end <NUM> of the spring top leg <NUM> and prevent over-insertion of the leg beneath the protrusion. A transversely oriented rear abutment surface <NUM> may be formed on follower <NUM> which is positioned to engage the upper cutout <NUM>-<NUM> on spring <NUM>. Abutment surface <NUM> forms a rear hard stop which restricts possible front to rear movement of the top spring leg 93to prevent removing the spring leg from beneath the front retention protrusion <NUM> when the spring is fully compressed or when installing the spring and follower assembly in the magazine.

The bottom leg <NUM> of the spring is affixed to the top of the floor plate <NUM>. In one mounting arrangement, with particular emphasis on <FIG> and <FIG>, the floor plate <NUM> includes a pair of laterally spaced apart and inwardly extending retention tabs <NUM> proximate to the front end of the plate that slideably engage the bottom leg <NUM> of the spring <NUM> for securing the spring thereto. The tabs <NUM> are configured to form a recess underneath which engages the lateral longitudinal edges of the spring bottom leg <NUM>. Transversely oriented bottom abutment surface <NUM> formed on the floor plate <NUM> abuttingly engages the terminal front end <NUM> of the spring bottom leg <NUM> when the spring is inserted beneath the retention tabs <NUM>. This limits the insertion of spring bottom leg <NUM> beneath the retention tabs to ensure proper fixation and mounting of the spring with the floor plate. A pair of laterally spaced apart guide tabs <NUM> may be formed rearward of retention tabs <NUM> on floor plate 68to keep the rear portion of the spring bottom leg <NUM> centered on floor plate. In addition, a transversely oriented rear abutment surface <NUM> may be formed on floor plate <NUM> which is positioned to engage the lower cutout <NUM>-<NUM> on spring <NUM>. Abutment surface <NUM> forms a rear hard stop which restricts possible front to rear movement of the bottom spring leg <NUM> to prevent removing the spring leg from beneath the front retention tabs <NUM> when the spring is fully compressed or when installing the spring and floor plate assembly in the magazine.

It bears noting that the two rear bends <NUM>, <NUM> and remaining portions of spring <NUM> rearward of the fixedly secured front terminal ends <NUM>, <NUM> are not secured to either the follower <NUM> or floor plate <NUM>. This increases the flexibility of the spring thereby providing a greater angular degree of tilt possible with the tiltable follower <NUM>. Accordingly, the present main spring <NUM> has only two points of fixation to the magazine assembly. Both the top terminal end <NUM> and bottom terminal end <NUM> are substantially vertically aligned and secured to the magazine assembly nearest the front wall of the magazine <NUM> as seen in <FIG>. The rear bends <NUM>, <NUM> similarly are substantially vertically aligned to allow assumption of their nested positioning when the spring is fully compressed.

Both the top and bottom legs <NUM>, <NUM> of main spring <NUM> may be fixedly (but releasably in some embodiments) attached to the follower <NUM> and floor plate <NUM> outside of the magazine <NUM>. This allows the completed spring, follower, and floor plate assembly to be assembled and inserted upwardly into cavity <NUM> of magazine <NUM> as a unit.

Other suitable types of spring may be used in other embodiments to bias the follower upwards in the magazine towards the top end, including without limitation coil or compressions type springs formed from oblong or circular spring coils or flat spring coils. Some embodiments may also include more than one spring. Accordingly, various other aspects of the invention are not limited necessarily by the type or number of springs used. These alternate type of springs generally cannot fold as flat as present main spring <NUM> due to its unique design, however, and may therefore reduce the cartridge holding capacity of the magazine.

It bears noting that by eliminating a separate retainer plate as used in some magazine designs to attach the spring to the floor plate, the height of the magazine advantageously may be reduced thereby forming a more compact design which contributes to flush mounting of the magazine with the underside of the stock adjacent to the magazine well. This also reduces the number and cost of components of the magazine. In other possible embodiments, a spring retainer plate may be used if needed.

Floor plate <NUM> has a horizontally elongated flattened U-shaped body in transverse cross section. Floor plate <NUM> includes a front end <NUM>, rear end <NUM>, opposing vertical lateral sidewalls <NUM> extending between the ends, and a bottom wall <NUM> defining a top surface <NUM> and opposing bottom surface <NUM>. Sidewalls <NUM> extend upwardly from bottom wall <NUM> at its peripheral edges and define an upwardly open receptacle <NUM>-<NUM> configured for receiving the bottom edge of the magazine housing <NUM> (see, e.g. <FIG>). The bottom wall <NUM> which may be slightly arcuately curved in transverse cross section from side to side to create a smooth profile and flush fit-up with the underside of the stock <NUM>. The floor plate <NUM> is configured for attachment to the bottom end <NUM> of the magazine housing <NUM> and closes the otherwise open bottom end. In one embodiment, the floor plate <NUM> may be detachably mounted to the magazine.

According to another aspect of the invention, the floor plate <NUM> is detachably secured to the bottom end <NUM> of magazine <NUM> via a unique slideable and interlocking coupling mechanism. Referring generally to <FIG>, <FIG>, <FIG>, and <FIG>, the bottom end <NUM> of magazine housing <NUM> and mating top end of floor plate <NUM> may be castellated in configuration to form the interlocked and meshed coupling between the floor plate and housing. In one non-limiting embodiment, each lateral sidewall <NUM> of floor plate <NUM> includes a plurality of laterally and inwardly extending mounting flanges or teeth <NUM> which interlock with mating plurality of laterally and outwardly extending flanges or teeth <NUM> formed on the bottom end of each lateral side <NUM> of the magazine housing <NUM> (see, e.g. <FIG>). Floor plate <NUM> and housing <NUM> thus each include two laterally spaced and longitudinally-extending linear arrays or rows of mating mounting teeth. Laterally open insertion cutouts or gaps <NUM> and <NUM> are formed between each set of adjacent teeth <NUM> and <NUM>, respectively. Gaps <NUM> are vertically and inwardly open. Gaps <NUM> are vertically and outwardly open. The gaps allow vertical insertion of the floor plate teeth <NUM> between and through the housing teeth <NUM>, and vice-versa for interlocking the teeth as further described herein. Teeth <NUM> and <NUM> may be rectilinear shaped in one embodiment such as generally rectangular cuboids.

Each of the two linear arrays or rows of mounting teeth <NUM>, <NUM> on the floor plate <NUM> and magazine housing <NUM> respectively each include at least two mounting teeth, and preferably at least three mounting teeth. In one non-limiting embodiment, as depicted, each row may include seven mounting teeth <NUM>, <NUM>. The number of teeth on the floor plate and magazine housing may be the same in some embodiments.

The floor plate <NUM> is longitudinally slideable forward and rearward on the magazine housing <NUM> between a locked position in which the mounting teeth <NUM> of the floor plate are engaged with the mounting teeth <NUM> of the housing, and an unlocked position in which the mounting teeth of the floor plate are disengaged from the mounting teeth of the housing. In the locked position, teeth <NUM> of the floor plate are located between gaps <NUM> and positioned directly above the teeth <NUM> of the housing vertically floor plate creating an interference which prevents removal of the floor plate from the housing. In the unlocked position, the teeth <NUM> of the floor plate are located directly above gaps <NUM> and between the teeth <NUM> of the housing which allows the floor plate to be withdrawn downwards between the housing teeth and removed form the housing.

The coupling mechanism further includes a cantilevered and resiliently flexible "snap-fit" tab <NUM> at the rear end <NUM> of the floor plate <NUM>. The snap fit tab <NUM> may be integral to the rear of the floor plate and formed as a unitary structural part thereof in one embodiment. In other embodiments, the tab <NUM> may be separate component affixed to the floor plate. Tab <NUM> has a front end anchored to bottom wall <NUM> of the floor plate <NUM> and an opposite rear operating end accessible to the user even when the floor plate is fully mounted to the magazine <NUM>. A rearwardly open recess <NUM> formed in the rear wall <NUM> of the magazine housing <NUM> provides access. In one embodiment, snap fit tab <NUM> may be centered between the sidewalls <NUM> of the floor plate <NUM> (best shown in <FIG>). Tab <NUM> may be formed as an integral unitary structural part of the floor plate <NUM> as shown.

In other possible implementations, it bears noting that the magazine mounting teeth <NUM> may protrude laterally inwards towards magazine cavity <NUM> (instead of outwards as previously described herein) and the floor plate mounting teeth <NUM> may protrude laterally outwards (instead of inwards). The invention is thus not limited to any particular one of these arrangements.

A method for assembling magazine <NUM> will now be described. In one embodiment, the main spring <NUM> preferably may be first attached to the follower <NUM> and floor plate <NUM>. The first step of assembly is for the user to slide the bottom leg <NUM> of main spring <NUM> under the retention tabs <NUM> in the floor plate until it reaches the hard stop abutment surface <NUM> at the front (see, e.g. <FIG>). The spring <NUM> is prevented from moving rearward relative to the floor plate by the abutment surface <NUM> at the rear. The next assembly step is to attach the main spring <NUM> to the follower <NUM> by sliding the top leg <NUM> of the main spring under the retention protrusion <NUM> on the follower until it hits the hard stop abutment surface <NUM> at the front (see, e.g. <FIG> and <FIG>). The spring <NUM> is prevented from moving rearward relative to the follower by the abutment surface <NUM> at the rear. It bears noting that in some sequences, the spring may be attached to the follower first before the floor plate. Since the floor plate <NUM> is a larger and wider structure than the follower <NUM>, it facilitates assembly by attaching the spring to the floor plate first.

Now that the floor plate, follower, and main spring are assembled, they can be mated to the main body or housing <NUM> of magazine <NUM> as a sub-assembly or unit. This is done by sliding the sub-assembly upwards through open bottom end <NUM> into cavity <NUM> of the magazine housing <NUM>, preferably making sure to align and insert the pair of laterally protruding guide bosses <NUM> on the front of the follower <NUM> into their respective pair of mating vertical open guide tracks or slots <NUM> formed on the interior of housing sidewalls <NUM> in magazine cavity <NUM> (see, e.g. <FIG>). Slots <NUM> each have downwardly open bottom ends <NUM> for this purpose and are further described elsewhere herein. The main spring <NUM> will push the follower <NUM> up into the body until it reaches a hard stop formed by the closed top ends <NUM> of the slots <NUM> abuttingly engaging guide bosses <NUM> (see, e.g. <FIG>).

<FIG> are sequential views shows the remaining steps for assembling the floor plate <NUM> to magazine housing <NUM> using the foregoing slideable and interlocking coupling mechanism. Referring to <FIG>, the next step in the process is to vertically align the teeth <NUM> on the floor plate <NUM> with the vertically open gaps <NUM> between the teeth <NUM> on the spring housing <NUM>. The floor plate is positioned beneath the housing <NUM> such that the rear of the plate ajar and protrudes rearward slightly beyond the rear wall <NUM> of the housing as shown. This aligns the forward-most pair of teeth <NUM> on the floor plate <NUM> with the forward-most pair of gaps <NUM> on the magazine housing.

The floor plate is then pushed upwards to pass the floor plate teeth <NUM> through the housing gaps <NUM> to a position above the housing teeth <NUM> (see vertical directional arrows in <FIG>) until the floor plate teeth abuttingly engage a downward facing and longitudinally-extending horizontal stop surface <NUM> formed on each sidewall <NUM> of magazine housing <NUM>. The stop surface <NUM> is spaced from and located at a position above the housing teeth <NUM>. This defines a longitudinally-extending mounting channel <NUM>-<NUM> between the teeth <NUM> and stop surface <NUM> for sliding the floor plate teeth <NUM> forward/rearward during the mounting sequence. Stop surface <NUM> extends for a majority of the entire length of the magazine and ensures the proper full vertical insertion depth of the magazine into the upwardly open receptacle <NUM>-<NUM> of the floor plate <NUM>. This conveniently allows the user to simply push the floor plate <NUM> onto the bottom end of the housing <NUM> to the maximum extent possible until contact is made with the stop surface <NUM>, thereby making any vertical adjustments to the positioning unnecessary. When the floor plate <NUM> is fully coupled to the magazine housing <NUM> as shown in <FIG>, the stop surface <NUM> will engage the top longitudinal edges of the floor plate sidewalls <NUM> to form a flush fit-up.

Once the floor plate <NUM> is fully inserted on the magazine housing <NUM>, the user then slides the floor plate forward towards the front of the magazine (see horizontal directional arrows in <FIG>) until it reaches a rear facing hard stop surface <NUM> formed on the front end of the magazine housing <NUM>. Stop surface <NUM> abuttingly engages the front end <NUM> of the floor plate <NUM>. In this fully forward position of the floor plate <NUM>, each of the floor plate teeth <NUM> becomes positioned immediately above a corresponding one of the magazine teeth <NUM>, thereby trapping teeth <NUM> above teeth <NUM> in an interlocked relationship (see also <FIG>). This physical interference prevents downwards removal of floor plate <NUM> from the magazine housing <NUM> without first sliding the floor plate rearward.

Concurrently with the floor plate <NUM> engaging stop surface <NUM>, an audible "click" sound is heard by the user which signals that the floor plate <NUM> is secured and locked to the magazine housing <NUM>. The "click" heard during assembly is created by the elastically and resiliently deformable "snap fit" tab <NUM> previously described herein lockingly engaging the magazine housing. <FIG> are sequential views showing the sub-process of engaging the snap fit tab <NUM> with the magazine housing. <FIG> shows the floor plate <NUM> the magazine housing <NUM> being moved vertically towards engagement with the floor plate (or vice-versa) during the vertical insertion step already described above (see directional arrows). The rear wall <NUM> of magazine housing <NUM> next makes contact with the top surface <NUM>-<NUM> of the snap fit tab <NUM> immediately forward of a forward sloping inclined ramp <NUM>-<NUM> as shown in <FIG>. This engagement occurs concurrently with the magazine housing <NUM> being fully inserted inside the sidewalls <NUM> of the floor plate <NUM> at the conclusion of the vertical insertion step. The floor plate <NUM> is next slid forward on the housing <NUM> during the horizontal sliding step already described above (see directional arrows). During that process, the bottom edge <NUM>-<NUM> of the magazine rear wall <NUM> begins to slide upwards on snap fit tab ramp <NUM>-<NUM>, which pushes and resiliently deflects or bends the snap fit tab <NUM> downwards at an angle as shown in <FIG>. During assembly of the magazine, the snap fit tab is therefore automatically actuated without intervention by the user. As the floor plate continues to be pushed forward, the rear wall bottom edge <NUM>-<NUM> breaks contact with the ramp <NUM>-<NUM>, thereby causing the snap fit tab <NUM> to spring back upwards to its original undeflected horizontal position (see, e.g. <FIG>). This causes the audible "click" heard by the user. The bottom edge <NUM>-<NUM> of magazine housing rear wall <NUM> now assumes a position behind a rear facing abutment surface <NUM>-<NUM> formed at the back edge of the ramp <NUM>-<NUM>. The bottom edge <NUM>-<NUM> engages an upward facing horizontal rear surface <NUM> on the snap fit tab immediately adjoining the rear end of the ramp. The floor plate <NUM> is now releasably locked to the magazine housing <NUM> via the snap fit tab <NUM>. The floor plate <NUM> cannot be axially slid in a rearward direction relative to the magazine housing to uncouple the floor plate due to interference between the bottom edge <NUM>-<NUM> of the rear housing wall and abutment surface <NUM>-<NUM> of the snap fit tab.

To disassemble the magazine and floor plate, an external rear end portion of the snap fit tab <NUM> remains accessible via recess <NUM> formed in the rear wall <NUM> of the magazine housing <NUM> as shown in <FIG>. The tab <NUM> is can then be manually actuated by applying a downward force F on the tab with a finger or object until the snap fit tab is clear of the bottom edge <NUM>-<NUM> of the magazine housing rear wall <NUM> as shown in <FIG>. This breaks engagement between the bottom edge and blocking surface <NUM>-<NUM> of snap fit tab <NUM> so that the floor plate <NUM> can be freely slid rearwards to uncoupled the floor plate from the magazine housing <NUM>. This provides a unique and easy method of disassembling the magazine.

According to another aspect of the invention, the present follower <NUM> and magazine body or housing <NUM> are cooperatively configured to allow the follower to tilt during the action of dispensing cartridges or loading new cartridges into the magazine <NUM>. Allowing the follower to tilt advantageously permits the magazine to adapt to and accommodate a variety of cartridges with different body tapers. However, allowing a follower to tilt in general may sometimes inadvertently allow the follower <NUM> to jump out of the front of the magazine at the open top forward of the feed lips <NUM> if pressed downwards in the rear due to the biasing action of the main spring <NUM>. The follower <NUM> in the present magazine is able to tilt, but also is provided with a follower retention feature which prevents it from jumping out of the magazine.

Referring to <FIG> and <FIG>, the follower retention feature includes a pair of laterally protruding guide projections or bosses <NUM> disposed on the front of the follower <NUM>. One guide boss <NUM> protrudes outwards from each one of a pair of lateral sides <NUM> of the follower; each guide boss slideably engaging a corresponding vertical guide slot <NUM> formed in the sidewalls <NUM> of the housing within the magazine cavity <NUM>. The guide bosses <NUM> are disposed proximate to a front end <NUM> of the follower and the guide slots <NUM> are disposed proximate to the front wall <NUM> of the magazine. The guide bosses <NUM> are cylinder and round in cross section thereby advantageously increasing the angle to which the follower <NUM> can be tilted without being impeded by the guide slot <NUM>.

The guide slots <NUM> are inwardly open towards magazine cavity <NUM> and preferably extend partially but not completely through the sidewalls <NUM> of the magazine in one embodiment. Guide slots <NUM> include an open bottom end <NUM> for inserting the bosses <NUM> into the slots when assembling the follower <NUM> to the magazine housing <NUM> (see, e.g. <FIG> and <FIG>), and a closed top end <NUM> for retaining the bosses in the slot against the upward biasing force imparted to the follower by main spring <NUM> (see, e.g. <FIG> and <FIG>). The follower <NUM> is angularly tiltable relative to the housing <NUM> of the magazine <NUM> about a lateral pivot axis defined by the guide bosses <NUM>. Because the guide bosses <NUM> travel upwards/downwards in the guide slots <NUM>, the pivot axis may be considered to be vertically movable and adjustable depending on the position of the bosses in the slots.

It bears noting that the guide slots <NUM> serve not only to retain the follower <NUM> in the magazine cavity <NUM>, but also act for smoothly guiding upwards and downwards movement of the follower therein. Interaction between the guide bosses <NUM> and slots <NUM> also control the front of the follower <NUM> when the rear of the follower is tilted all the way down (see, e.g. <FIG>). In the maximum angle of tilt of the follower <NUM>, the rear end <NUM> of the follower may contact the floor plate <NUM> and the forward end <NUM> is adjacent the top opening <NUM> of magazine <NUM> with the guide bosses <NUM> contacting the closed top ends <NUM> of the guide slots <NUM> as shown. This occurs when a downward force F is applied to the rear portion of the follower <NUM> such as when loading the first cartridge C into an empty magazine as seen in <FIG>. When the magazine <NUM> is fully loaded with cartridges, follower <NUM> assumes a horizontal position at the bottom of magazine cavity <NUM> contacting the floor plate <NUM> (see, e.g. <FIG> and <FIG>). Because the front pivot axis of the follower <NUM> defined by the lateral bosses <NUM> is vertically movable relative to the magazine and not fixed in position, the follower may move while maintaining the horizontal position upwards and downwards in the magazine cavity <NUM>, or alternatively an angle position during the action of dispensing cartridges to the breech or loading cartridges into the magazine.

Other aspects of the follower <NUM> including its interaction with the cartridge stack will now be further described with general reference to <FIG>, <FIG>, and <FIG>. Follower <NUM> has a body that is axially elongated in the direction of the longitudinal axis LA and horizontal centerline axis Ch of the magazine <NUM> when mounted therein. The follower <NUM> includes a multi-tiered top surface <NUM>, bottom surface <NUM>, front end <NUM>, rear end <NUM>, and pair of opposed lateral sides <NUM> extending axially along the longitudinal axis between the front and rear ends. As shown in <FIG>, the right lateral side <NUM>-<NUM> may have a greater height than the left lateral side <NUM>-<NUM> due to the arcuately curving top profile of the top surface <NUM>. The follower body may be made of any suitably durable material for reliable operation and dispensing of cartridges from the magazine <NUM>. In some embodiments, the follower <NUM> may be formed of metal or polymer /plastic.

The multi-tiered top surface <NUM> of the follower <NUM> is configured to support the lowermost cartridge C in the stack and may have a stepped configuration from side to side for holding the stack of cartridges in a double staggered stack relationship (see, e.g. <FIG>). This arrangement advantageously increases the capacity of the magazine. Accordingly, top surface <NUM> includes an upper sub-surface <NUM>, a lower sub-surface <NUM>, and an arcuately curved intermediate sub-surface <NUM> adjoining and extending between the upper and lower sub-surfaces. Intermediate sub-surface <NUM> may be considered to have a generally flattened S-shape including a concave arcuately curved lower transition surface <NUM> contiguously adjoining the lower sub-surface <NUM>, a convex arcuately curved upper transition surface143 contiguously adjoining the upper sub-surface <NUM>, and an angled flat surface <NUM> therebetween (see also <FIG>. The upper sub-surface <NUM> and lower sub-surface <NUM> may each substantially flat or planar. These surfaces <NUM>, <NUM> are horizontally oriented and parallel to the horizontal centerline axis Ch of the magazine <NUM> when the follower is in a horizontal position.

Both the upper and lower sub-surfaces <NUM>, <NUM> are each laterally offset from the vertical centerline axis Vc of the magazine <NUM> as shown in <FIG>, <FIG>, and <FIG>. Note that the feed lips <NUM> of the magazine are centered about axis Cv. The intermediate sub-surface <NUM> is intersected by axis Cv. In operation when the plurality of cartridges C are loaded into the magazine by the follower <NUM>, the follower and housing are cooperatively configured such that the cartridges do not engage the flat upper sub-surface <NUM>. This creates a gap G between the lowermost cartridge and follower <NUM> which is maintained while the cartridges are dispensed and the stack travels vertically upwards in the magazine <NUM> as seen in <FIG>. The lateral pressure applied to the stack of cartridges forces each cartridge outwards to create positive engagement with the interior surface of the magazine cavity <NUM> and maintains gap G. Even when a single cartridge is left in the magazine as shown in <FIG> and dispensed, the cartridge does not engage the upper sub-surface <NUM> of the follower due to the offset positioning of upper sub-surface <NUM> to axis Cv. The single cartridge is held beneath the feed lips by the convex upper transition surface <NUM>, which may be considered to define a feed surface laterally offset form vertical centerline axis Vc of the magazine <NUM>.

To smoothly allow the stack of cartridges C to advance upwards in the magazine <NUM> under the biasing force of main spring <NUM>, the interaction between the interior surfaces of magazine cavity <NUM> is controlled by a plurality of raised cartridge contact surfaces. Referring to <FIG> and <FIG>, the cavity of the housing includes a pair of laterally opposing and vertically extending raised front ribs <NUM> which define front cartridge contact surfaces, and a pair of laterally opposing and vertically-extending raised rear ribs <NUM> which define rear cartridge contact surfaces. The ribs <NUM>, <NUM> are disposed on each sidewall <NUM> of magazine housing <NUM> and may be extend vertically from the feed lips <NUM> down to the bottom end of the magazine housing <NUM> for the full height of the cavity <NUM> in some embodiments as shown. Ribs <NUM>, <NUM> are located to contact only the diametrically enlarged rear case of the cartridges rearward of the stepped shoulder. The cartridges C only contact the sidewalls <NUM> of magazine housing <NUM> on each side front and rear cartridge contact surfaces of ribs <NUM>, <NUM> in a lateral direction when moving upwards or downwards in the cavity. This controls the dispensing of the cartridges and smooth feeding by reducing sliding friction forces between the cartridge cases and magazine. Each pair of front and rear ribs <NUM>, <NUM> thus creates two lateral points of sliding contact with the case of the cartridges.

The interior surfaces of the magazine cavity <NUM> may gradually converge going from the bottom of the magazine moving to the top of the magazine towards the feed lips <NUM> for better centering and positioning of the uppermost cartridge C for stripping by the action (i.e. bolt) and chambering. The opening in the top end <NUM> of magazine <NUM> below the feed lips <NUM> may be slightly larger than the width of a single cartridge for positive dispensing action.

Referring to <FIG>, another aspect of the present magazine worth noting is that the top portions of the raised front and rear ribs <NUM>, <NUM> which engage the cartridge case at the portions of foregoing convergence may be shaped to form a continually variable curving spline <NUM> in shape or profile preferably free from any angled corners or straight portions to smoothly guide and transitions the cartridge up to the feed lips <NUM>. Many known magazines may use straight lines and tight angles or radii which can create potential dwell points for cartridges that prevent the round from properly rising upwards without snags or impedance thereby causing feeding jams. The present spline-shaped upper portions of the raised ribs <NUM>, <NUM> prevent cartridges from snagging and provide smooth feeding and dispensing from the magazine. Portions of the front and rear ribs <NUM>, <NUM> below the upper curved spline parts may be vertically straight and parallel to each other.

In one embodiment, the space created in magazine cavity <NUM> between the front and rear ribs <NUM>, <NUM> define an inwardly open recess <NUM>. Follower <NUM> may include a pair of laterally protruding guide wings <NUM> which are each received in one of the recesses <NUM>. The wings <NUM> may be axially elongated having a greater width than the width of the ribs <NUM>, <NUM>. Wings <NUM> slide upward and downward within the recesses as the follower moves up and down. Interaction between the wings <NUM> and corresponding recesses <NUM> help prevent lateral twisting of the follower <NUM> from side to side in the magazine cavity <NUM> to maintain an axially straight follower to prevent binding the follower particularly when in a tilted position as it moves in a guided manner upwards/downwards in the cavity.

Referring to <FIG> and <FIG>, the interior surface of the magazine housing <NUM> further includes a vertically-extending stepped shoulder <NUM> which engages the shoulder <NUM> of each cartridge C at the headspace diameter D1 in the stack to set the headspace at the rear of the barrel chamber. Shoulder <NUM> may extend from the bottom end <NUM> of the magazine <NUM> (see, e.g. <FIG>) upwards and terminate at a point proximate to the feed lip near top end <NUM> (see, e.g. <FIG>). Magazine shoulder <NUM> also serves to restrain axial forward movement or shifting of the cartridges in the interior magazine <NUM> also maintains spacing between the tips of the projectiles <NUM> and front wall <NUM> of the magazine inside cavity <NUM> which prevents cartridge snagging and feed jams.

Claim 1:
A magazine (<NUM>) for a firearm (<NUM>) comprising:
a housing defining a horizontal centerline axis, a vertical centerline axis perpendicular thereto, and an interior cavity (<NUM>) configured to hold a plurality of ammunition cartridges;
the housing (<NUM>) including an open top end (<NUM>), a bottom end (<NUM>), a front wall (<NUM>), a rear wall (<NUM>), and pair of opposing lateral right and left sidewalls (<NUM>) extending between the front and rear walls;
a compressible main spring (<NUM>) disposed in the cavity;
an elongated follower (<NUM>) disposed in the cavity (<NUM>) and biased in an upwards direction by the main spring (<NUM>), the follower being moveable between a lower position and an upper position for dispensing cartridges (C);
a guide boss (<NUM>) protruding laterally outwards from each one of a pair of lateral sides (<NUM>) of the follower (<NUM>), each guide boss slideably engaging a corresponding vertical guide slot (<NUM>) formed in the sidewalls (<NUM>) of the housing (<NUM>) for guiding upwards and downwards movement of the follower;
wherein the follower (<NUM>) is angularly tiltable relative to the housing (<NUM>) of the magazine (<NUM>) about a lateral pivot axis defined by the guide bosses;
wherein the main spring (<NUM>) is an accordion type flat spring formed from a triple folded flat spring material in which no portion of the spring crosses another portion in the same horizontal reference plane when in a fully expanded condition ;
wherein the main spring (<NUM>) comprises a pair of laterally open cutouts (<NUM>) which allows adjacently located bends (<NUM>, <NUM>) of the spring to nest together in a side to side relationship when the spring is in a fully compressed condition.