Patent Description:
<CIT> discloses an open bolt firing mechanism for an automatic firearm.

Semi-automatic firearms are defined by an action that fires a cartridge, automatically ejects the spent brass, and then loads another cartridge into the chamber for every pull of the trigger. This action type is desirable for its fast operation and minimal input required by the operator, but is banned by law in some locations.

To comply with such firearm restrictions, the intended operation of an interrupted semi-automatic action is such that when the trigger is pulled, the action fires the cartridge, automatically ejects the spent brass, and then locks the bolt in the open/rearward breech position. The action remains in the open breech position until the operator releases the trigger, and then intervenes to manually release the bolt back into battery with the barrel, which is its former ready-to-fire forward closed breech position. As the bolt travels into battery, it automatically loads another new cartridge into the chamber of the barrel from the magazine. This action must be repeated to cycle the action each time the firearm is discharged.

Prior designs of interrupted actions have various configurations of actuator mechanisms for holding the hammer rearward and manually releasing the bolt. Some designs may be cumbersome for users, are not compact adversely affecting the appearance and handling of the firearm, or have complex mechanisms.

Improvements in interrupted actions for firearms is desired.

The present invention provides a non-limiting embodiment of an improved interrupted semi-automatic action ("interrupted action" for short) with bolt release mechanism for a firearm which not only overcomes the foregoing detriments of past interrupted action designs, but also provides a dual acting safety feature in the form of a trigger interlock. In a first position, the trigger interlock safety prevents the bolt from being released while in the rearward open breech position via actuating the bolt release mechanism until the user or operator fully releases the trigger after being pulled. This prevents the firearm from automatically firing unintentionally if the bolt were released while the trigger was still pulled. In a second position, the trigger interlock safety prevents the trigger from being actuated until the bolt release actuator is returned by the user to its unactuated position after the bolt is released. Both safety features are provided by a combination of interacting features of the present bolt release mechanism and trigger, as further described herein.

To create the interruption in the cycling of the action, the present hammer is designed to catch the bolt whenever it is in the rearward open breech position. The hammer is biased upwards against the underside of the bolt via spring force. When the bolt is in the rear position, a catch feature such as a retention notch in one embodiment on the underside of the bolt allows for the hammer to rotate up while still cocked into the notch and catch/arrest the forward travel of the bolt to interrupt the action. This operation contrasts to regular full semi-automatic actions which automatically releases the bolt after a fresh ammunition cartridge has uploaded into the breech area from the spring loaded magazine. In order to then release the present bolt forward back into battery requires the hammer to be pulled down out of this notch by manual intervention, which defines an interrupted action type firing system. In one non-limiting embodiment, this may be achieved by manual actuation of the bolt release mechanism.

The bolt release mechanism in one embodiment may generally comprise the combination of a spring-loaded disconnect lever selectively engageable with the hammer when in the rearward cocked position holding the bolt rearward as stated above, and a user-operated actuator which can be a pivotably slideable release button in one non-limiting embodiment operably interacting with the lever. In one embodiment, the release button may be mounted at the rear of the receiver axially inline with the firearm and arranged for engagement by the user's thumb via an upward action. This mounting arrangement advantageously provides a compact design and aesthetically pleasing appearance of the bolt release mechanism without obtrusive lateral projections which can interfere with handling and storage of the firearm. When actuated, the present release button operates to rotate the disconnect lever downwards, which in turn breaks the temporary engagement between the hammer and bolt. The bolt is released forward back into battery with the barrel to close the breech for the next shot.

The release button may further comprise a trigger block which forms the above mentioned safety feature that prevents the button from being actuated when the trigger is pulled, or visa-versa. The trigger block may comprise a blocking protrusion on the trigger which is selectively engageable with a locking feature on the release button depending on the state of the trigger (i.e. pulled or not).

The present interrupted action may be used in a long gun such as without limitation a centerfire rifle in one implementation; however, the present interrupted action may be used in other types of firearms with comparable applicability such as for example shotguns. Accordingly, the interrupted action is not limited to use in any particular type of firearm.

In one aspect, a firearm with interrupted action comprises: a longitudinal axis; a receiver defining a longitudinally-extending cavity; a barrel supported by the receiver; a trigger movably mounted to the receiver; a bolt slideably mounted in the cavity of the receiver for movement between a forward position in battery with the barrel and a rearward position; a cockable hammer operably interacting with the trigger, the hammer pivotably movable about a pivot axis between a rear cocked position and a forward fire position via pulling the trigger; the hammer configured and operable to retain the bolt in the rearward position after a trigger pull to fire the firearm; and a bolt release mechanism operably interacting with the bolt, the bolt release mechanism comprising a user-actuated release button and a spring-biased disconnect lever coupled to the release button; wherein actuating the release button when the bolt is in the rearward position releases the bolt.

In another aspect, a firearm with interrupted action comprises: a longitudinal axis; a receiver defining a longitudinally-extending cavity; a barrel supported by the receiver; a bolt slideably mounted in the cavity of the receiver for movement between a forward position in battery with the barrel and a rearward position; a hammer pivotably movable about a pivot axis between a rear cocked position and a forward fire position, the hammer operably engageable with the bolt after firing the firearm to retain the bolt in the rearward position; a trigger comprising a sear protrusion operably engaged with the hammer to retain the hammer in the rear cocked position; and a user-actuated bolt release mechanism configured to selectively engage the hammer; wherein actuating the bolt release mechanism when the hammer is retaining the bolt in the rearward position rotates the hammer which releases the bolt.

In another aspect, a firearm with interrupted action comprises: a longitudinal axis; a receiver defining a longitudinal cavity; a barrel supported by the receiver; a bolt slideably movable in the longitudinal cavity of the receiver between a forward position in battery with the barrel and a rearward position; a trigger operable to fire the firearm; a hammer pivotably movable about a pivot axis between a rear cocked position and a forward fire position, the hammer operably engageable with the bolt after firing the firearm to retain the bolt in the rearward position; a user-actuated bolt release mechanism configured to selectively engage the hammer; the bolt release mechanism comprising a user-actuated release button and a disconnect lever operably interacting with the hammer; an operating spring biasing the disconnect lever into an upward position protruding at least partially into the longitudinal cavity of the receiver; wherein when the bolt moves from the forward position to the rearward position, the bolt engages and pushes the disconnect lever downwards into engagement with the hammer which is held in the cocked position by the disconnect lever; wherein actuating the bolt release mechanism when the hammer is retaining the bolt in the rearward position rotates the hammer which releases the bolt.

In another aspect, a firearm with interrupted action including a trigger interlock safety comprises: a longitudinal axis; a receiver defining a longitudinal cavity; a barrel supported by the receiver; a bolt slideably movable in the longitudinal cavity of the receiver between a forward position in battery with the barrel and a rearward position; a hammer pivotably movable about a pivot axis between a rear cocked position and a forward fire position, the hammer operably engageable with the bolt after firing the firearm to retain the bolt in the rearward position; a user-actuated bolt release mechanism configured to selectively engage the hammer, the bolt release mechanism when actuated movable to return the bolt to its forward position when the hammer is retaining the bolt in the rearward position; a movable trigger operable to fire the firearm, the trigger comprising a trigger block protrusion selectively engageable with the bolt release mechanism; the trigger and bolt release mechanism cooperatively configured to form the trigger interlock safety; wherein the trigger interlock safety is operable such that when the bolt release mechanism is in a first actuated position, the trigger cannot be moved to a pulled state.

A method for operating a firearm with an interrupted action is provided. The method includes: providing a firearm including a receiver, a barrel supported by the receiver, a bolt in a forward closed breech position in battery with the barrel, a hammer movable between a rearward cocked position and a spring-biased forward fire position for discharging the firearm, a trigger operable to restrain the hammer in the rearward cocked position, and a bolt release mechanism comprising a user-movable release button and a disconnect lever pivotably coupled to the release button; pulling the trigger which moves from a forward position to a rearward position; moving the hammer from the rearward cocked position to the forward fire position to discharge the firearm; automatically cycling the bolt rearward under recoil to an open breech position upon discharge of the firearm; restraining the bolt in the rear open breech position with the hammer; moving the release button in an upward direction which correspondingly moves the disconnect lever in a downward direction; displacing the hammer downwards with and by the movement of the disconnect lever; and disengaging the hammer from the bolt which is released and travels forward back to the closed breech position.

In various embodiments, the method further includes any or all of the following. The bolt simultaneously engaging the disconnect lever and hammer. The step of automatically cycling the bolt rearward further comprises engaging the bolt with the disconnect lever which rotates the disconnect lever downwards to contact the hammer without releasing the bolt by breaking engagement between the hammer and bolt. The step of automatically cycling the bolt reward comprises tilting the bolt relative to a longitudinal axis of the firearm defined by the barrel to engage the disconnect lever. The step of pulling the trigger simultaneously includes engaging a portion of the trigger with the release button which blocks movement of the release button. The trigger comprises a trigger block protrusion which engages a locking recess in the release button to block movement of the release button. The step of moving the release button is preceded by a step of releasing the trigger which disengages the trigger block protrusion from the locking recess of the release button which allows movement of the release button upwards. The step of moving the release button upwards after releasing the trigger includes simultaneously blocking movement of the trigger while the release button remains upward to prevent a second trigger pull. The method includes moving the release button downwards which unblocks the trigger for the second trigger pull. The step of pulling the trigger further comprises disengaging a sear protrusion of the trigger from the hammer which is configured to hold the hammer in the rearward cocked position when the trigger is in the forward 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 shown and/or 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 described herein. Any references herein to a whole figure number (e.g. <FIG>) shall be construed to be a reference to all subpart figures in the group with an alphabetical suffix (e.g. FIGS. 1A, 1B, etc.) unless otherwise indicated.

The features and benefits of the invention are illustrated and described herein by reference to preferred but non-limiting exemplary ("example") embodiments. This description of the embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. Accordingly, the invention expressly should not be limited to such embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features; the scope of the invention being defined by the claims appended hereto.

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. Terms such as "attached," "affixed," "connected," "coupled," "interconnected," and similar refer to a relationship wherein structures may be secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.

As used throughout, any ranges disclosed herein are used as shorthand for describing each and every value that is within the range.

<FIG> depict a firearm <NUM> including a bolt release mechanism <NUM> according to the present disclosure. In one non-limiting embodiment, the firearm as illustrated may be a rifle. However, the firearm could be another type of long gun (e.g. shotgun, carbine, etc.) or other firearm. Accordingly, the invention is not limited in its applicability to rifles alone.

Firearm <NUM> includes a longitudinal axis LA, receiver <NUM>, barrel <NUM> coupled thereto, an axially movable bolt <NUM>, and a trigger-actuated firing mechanism <NUM> supported by the receiver and including a movable trigger <NUM> for firing the firearm. Bolt <NUM> cooperates with a manually retractable spring-biased slide <NUM> located laterally adjacent to and engaging the bolt (see, e.g. <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>). Slide <NUM> is longitudinally elongated and biases bolt <NUM> forward towards the closed breech position. Slide <NUM> includes a block shaped front portion <NUM>-<NUM> which is arranged beneath the barrel and a rearwardly extending and laterally offset rear portion <NUM>-<NUM>. Bolt <NUM> includes a laterally/transversely projecting slide protrusion <NUM> received in a corresponding slide receptacle <NUM> (see, e.g. <FIG>). In one embodiment best shown in <FIG>, receptacle <NUM> may be an elongated slot including a front upwardly angled section <NUM>-<NUM> and a rear horizontal section <NUM>-<NUM>. Bolt slide protrusion <NUM> travels in the slot between each section when the action is cycled. The slide <NUM> includes a laterally projecting slide handle <NUM> for manually cycling the bolt rearward.

The firearm includes an axially elongated chassis or stock <NUM> configured for holding by the user which supports the receiver <NUM> and barrel <NUM>. A downwardly open magazine well <NUM> is formed by the receiver which holds a removable conventional ammunition magazine <NUM> (each shown in dashed lines) detachably mounted in the well. Such magazines may be a box-type magazine which holds a spring-biased vertical stack of ammunition cartridges C which are automatically uploaded into the breech area <NUM> for chambering into the barrel <NUM> by the bolt <NUM> when cycling the action. In one embodiment, the cartridge C may be a centerfire cartridge with a centrally located percussion cap disposed in the rear exposed end of the base of the cartridge. This type of cartridge is well known to those skilled in the art without further elaboration. Other embodiments may be chambered for conventional rimfire cartridges. The magazine <NUM> is removably retained in the magazine well <NUM> by a spring-biased magazine latch <NUM>.

Barrel <NUM> includes an axial bore <NUM> extending longitudinally and axially from a rear breech end <NUM> to a front muzzle end <NUM> from which a bullet or slug is discharged from the firearm. The centerline of bore <NUM> is coaxial with and defines the longitudinal axis LA of the firearm. The rear breech end <NUM> of the barrel <NUM> defines a rearwardly open diametrically enlarged chamber <NUM> configured for holding a cartridge C.

Receiver <NUM> defines an axially elongated internal cavity <NUM> which slidably carries and supports the bolt assembly <NUM>. Longitudinal cavity <NUM> extends along the longitudinal axis LA between an open front end <NUM> of the receiver in communication with the barrel chamber <NUM> for loading cartridges therein from the magazine <NUM> breech area via breech arear <NUM>, and a closed rear end <NUM> defined by vertical rear end wall <NUM>. Barrel <NUM> is coupled to the front end <NUM> of the receiver. In the illustrated embodiment, front end <NUM> defines a receptacle <NUM>-<NUM> configured to mate with the rear breech end <NUM> of barrel <NUM> (see, e.g. <FIG> and <FIG>). In one embodiment, barrel <NUM> may be threadably coupled to the receiver; however, other mounting arrangements may be used. In one non-limiting embodiment, the receiver <NUM> includes a right ejection port <NUM> and left ejection port <NUM> formed on opposite lateral sides <NUM> of the receiver.

The firing mechanism <NUM> further includes a pivotably cockable hammer <NUM>. Hammer <NUM> is pivotably movable about a transverse pivot axis, defined by transversely oriented hammer pivot pin <NUM>-<NUM>, between a rear angled or cocked position and an upright/vertical forward fire position via pulling the trigger <NUM>. Hammer <NUM> is biased forward by hammer spring <NUM> towards the fire position. Referring to hammer <NUM> in the upright or vertical position for convenience of reference only, the hammer <NUM> may be considered to have a generally T-shaped body including an elongated mounting portion <NUM>-<NUM> having an enlarged bottom end <NUM>-<NUM> configured to receive pivot pin <NUM>-<NUM>, and an opposite head comprising a front striking surface <NUM>-<NUM>, rearwardly swept hammer catch <NUM>-<NUM>, and a top actuating surface <NUM>-<NUM> extending therebetween. The front striking surface <NUM>-<NUM> may be substantially flat and arranged to strike the rear end of firing pin <NUM> slideably carried by the bolt <NUM> in a longitudinal firing pin bore <NUM>. The front tip of firing pin <NUM> is arranged to strike a chambered cartridge C when the firing pin is driven forward by the hammer <NUM>. Rear hammer catch <NUM>-<NUM> may be arcuately curved and configured with a catch or hook for holding the hammer <NUM> in the cocked position, as further described herein. The hook may be formed on the underside of catch <NUM>-<NUM> in one embodiment as shown. In one embodiment, the hammer body may be a monolithic unitary structure in which the mounting portion <NUM>-<NUM> and head with foregoing appurtenances are formed as integral parts thereof.

Trigger <NUM> is mounted for pivotable movement about a pivot axis defined by transverse trigger pivot pin <NUM>-<NUM> in one non-limiting embodiment. Pivot pin <NUM>-<NUM> may be mounted to trigger housing <NUM> in one non-limiting embodiment (see, e.g. FIG. The trigger <NUM> is configured and operable to operably interface and interact with the hammer <NUM> and bolt release mechanism as further describe herein. Trigger <NUM> has an elongated body comprising a downwardly extending curved finger grip portion <NUM>-<NUM>, upwardly extending sear protrusion <NUM>-<NUM>, and a cantilevered rearwardly extending blocking leg <NUM>-<NUM> comprising a trigger block protrusion <NUM> which forms the dual acting trigger interlock safety with the bolt release mechanism <NUM>, as further described herein. The finger grip portion <NUM>-<NUM>, blocking leg <NUM>-<NUM> and sear protrusion <NUM>-<NUM> may each elongated structures. Sear protrusion <NUM>-<NUM> may comprise a catch or hook configured and operable to selectively engage the hammer catch <NUM>-<NUM> for holding the hammer in the rearward cocked position, and to disengage the hammer catch for releasing the hammer to strike the firing pin <NUM> and discharge the firearm. The hook may be formed on the rear side of sear protrusion <NUM>-<NUM> in one embodiment as shown. In one embodiment, the trigger body may be a monolithic unitary structure in which the blocking leg, sear protrusion, and finger grip portion are formed as integral parts thereof. Accordingly, pulling finger grip portion <NUM>-<NUM> concomitantly rotates both blocking leg <NUM>-<NUM> and sear protrusion <NUM>-<NUM> in unison therewith.

With respect to the trigger interlock safety of the present invention, blocking leg <NUM>-<NUM> of trigger <NUM> may be arranged on the finger grip portion <NUM>-<NUM> of the trigger below pivot pin <NUM>-<NUM>. The blocking leg may be a substantially linearly straight structure in one construction; however, non-linear configurations including curved structure may be used. Trigger block protrusion <NUM> in one embodiment may project perpendicularly and transversely upwards from blocking leg <NUM>-<NUM> to engage a downwardly open locking recess <NUM> of the bolt release mechanism <NUM> (see, e.g. <FIG>). In other possible arrangements, trigger block protrusion <NUM> may project obliquely with respect to blocking leg <NUM>-<NUM> of the trigger.

In one embodiment, the linear projection of trigger block protrusion <NUM> outwards from blocking leg <NUM>-<NUM> may be adjustable outward and inwards in the vertical direction. In such embodiments, the trigger block protrusion <NUM> may be formed by threaded cylindrical plug <NUM>-<NUM> threadably engaged with corresponding threaded through bore <NUM> formed proximate to rear end of the blocking leg <NUM>-<NUM>. A spring-biased detent <NUM> engages the plug <NUM>-<NUM> to prevent the plug from loosening once adjusted to the desired projection distance by the user during operation of the firearm. In other embodiments, the trigger block protrusion <NUM> may alternatively be integrally formed with blocking leg <NUM>-<NUM> and non-adjustable. Operation of the trigger block protrusion <NUM> will be described in detail further below with discussion of the bolt release mechanism.

Trigger <NUM> is pivotably movable between an upright or vertical unpulled condition, and an angled pull condition. In the pulled condition with the finger grip portion <NUM>-<NUM> angled rearwards, the sear protrusion <NUM>-<NUM> is angled forwards and the blocking leg <NUM>-<NUM> is angled upwards to engage the bolt release mechanism <NUM>. Trigger spring <NUM>-<NUM> biases the trigger towards the unpulled condition.

In one embodiment, the trigger <NUM> and hammer <NUM> may be mounted in a separate removable trigger housing <NUM> detachably coupled to the receiver <NUM>. This facilitates assembly and maintenance of these firing mechanism components. Any means may be used to couple the trigger housing to the receiver, such as without limitation fasteners, interlocking tabs, or other fastening devices. Trigger guard <NUM> protects against inadvertent actuation of trigger <NUM> and firing of the firearm. It bears noting that the bolt release mechanism (i.e. release button <NUM> and disconnect lever <NUM>) may be mounted separately to the receiver <NUM> due to the unique and convenient in-line placement of the mechanism with the receiver in the present invention, which advantageously maintains a compact firearm both functionally and aesthetically.

Bolt <NUM> has an elongated generally cylindrical body comprising a front end <NUM>, rear end <NUM>, and opposing top and bottom surfaces <NUM>-<NUM>, <NUM>-<NUM> extending between the ends. Front end <NUM> defines a vertically oriented forward facing breech surface or face <NUM>-<NUM> for forming a closed breech. Firing pin <NUM> is slideably disposed in the cylindrical axial firing pin bore <NUM> of the bolt body which extends between the front and rear ends <NUM>, <NUM> of the bolt <NUM>. Bore <NUM> has a rear opening which opens through rear end <NUM> of bolt <NUM> and a front opening which opens through the front end <NUM> of the bolt. The rear end of the firing pin <NUM> protrudes beyond the rear end <NUM> of the bolt from the firing pin bore <NUM> for contact by the released hammer <NUM> when the trigger <NUM> is pulled to discharge the firearm. The front end of the firing pin is selectively projected forward from front end <NUM> of bolt <NUM> when the hammer strikes the rear end of firing pin to contact and detonate a chamber cartridge. Bolt <NUM> further includes an angled or rounded cam <NUM> arranged to engage the disconnect lever of the bolt release mechanism <NUM>, as further described herein. In one construction, the cam <NUM> may be formed at the bottom of the rear end <NUM> of the bolt at the bottom corner (see, e.g. <FIG>).

Bolt <NUM> is slideably and axially movable along longitudinal axis LA in the internal longitudinal cavity <NUM> of the receiver <NUM> between forward closed breech and rearward open breech positions. Bolt <NUM> is also automatically moved under recoil forces produced by discharging the firearm via a trigger pull from the forward to rearward position. Longitudinal cavity <NUM> therefore has an axial length sufficient to provide the full range of motion necessary for the bolt <NUM> under recoil to open the breech sufficiently for extracting a spent cartridge casing from barrel chamber <NUM>, ejecting the spent cartridge casing, and uploading a fresh new cartridge from the magazine <NUM> into the breach area for chambering by the bolt during its forward return motion. Slide spring <NUM> biases slide <NUM> (described above) operably engaged with and cooperating with the bolt <NUM> to bias and return the bolt forward to the closed breech position in a conventional manner after the bolt release mechanism is actuated. The slide comprises slide handle <NUM> to manually retract the bolt and open the breech and buffer rod <NUM> which mounts and guides the spring <NUM> in a rearwardly open socket <NUM>-<NUM> formed in the front portion <NUM>-<NUM> of slide <NUM> (see, e.g. <FIG>). Spring <NUM> may be a coil compression spring; however, other type springs may be used in other embodiments.

In some preferred but non-limiting embodiments, longitudinal cavity <NUM> of the receiver may include an angled and downward sloped from front to rear in a rear section <NUM>-<NUM> of the cavity. This properly positions the bolt <NUM> for engagement with the disconnect lever of the present bolt release mechanism, as further described below. Cavity <NUM> thus defines a rear cavity centerline CL1 which is obliquely angled to longitudinal axis LA of the firearm (see, e.g. <FIG>). When the bolt <NUM> reaches its rearward axial position inside the cavity, the bolt axis BA is concomitantly obliquely angled to longitudinal axis LA. The front section <NUM>-<NUM> of the cavity <NUM>, however, has a front cavity centerline CL2 which is parallel to the longitudinal axis LA. This ensures that the bolt <NUM> and particularly the front breech face <NUM>-<NUM> of bolt <NUM> is square with the rear breech end of the barrel to properly support the base of the cartridge and pressure seal the chamber <NUM>.

The bolt release mechanism <NUM> components and operation will now be described in greater detail. Referring generally to <FIG>, the bolt release mechanism includes disconnect lever <NUM> and an actuator which may be in the form of the pivotably slideable release button <NUM> operably interacting and cooperating with the lever for releasing the bolt forward back into battery with the barrel after each shot. Disconnect lever <NUM> is pivotably coupled to release button <NUM> via transverse pivot pin <NUM>. The ends of pin <NUM> may terminate at the right and left lateral sides <NUM> of the release button (right and left based on view forward by the user at the rear of the firearm) and therefore do not engage the receiver <NUM> or stock <NUM> in the illustrated embodiment. Accordingly, pivot pin <NUM> does not form a pivot axis for the release button, but rather only for the disconnect lever <NUM>.

In one embodiment, release button <NUM> may have a generally L-shaped body including an exposed rear actuating portion <NUM>, and forward coupling portion <NUM> for mounting disconnect lever <NUM> thereto via transverse pivot pin <NUM>. Coupling portion <NUM> extends forwardly from actuating portion <NUM> inside stock <NUM> below the rear end of the receiver <NUM>. By contrast, actuating portion <NUM> is inline with the rear end <NUM> of receiver <NUM> and slideably engages the rear end, as further described herein.

Release button <NUM> is vertically movable via actuating portion <NUM> between a downward unactuated position and upward actuated position for releasing the bolt forward from its rear position engaged by the hammer <NUM> to reclose the breech.

Actuating portion <NUM> has a block-like structure including a rear downwardly angled and forward sloping rear wall <NUM> (top to bottom) defining an actuating surface <NUM>-<NUM> arranged and configured for engagement by user's thumb or finger to actuate the bolt release mechanism, a front wall <NUM>, a top wall <NUM>, bottom <NUM>, and opposing lateral sides <NUM> extending between the front and rear walls. Top wall <NUM> projects rearward farther than an overhangs bottom wall <NUM>. Actuating portion <NUM> is positioned adjacent and mounted to the rear end <NUM> of the receiver <NUM> via a pair of laterally spaced mounting arms <NUM>. Arms <NUM> extend in a forward direction from the release button and selectively engage laterally open longitudinal slots <NUM> formed in each lateral side <NUM> of the rear end <NUM> of the receiver (see, e.g. <FIG>). In one embodiment, the terminal front ends of mounting arms <NUM> may each comprise an inwardly projecting pivot protuberance <NUM> to better engage slots <NUM>. The forward end of slots <NUM> may include outwardly open cylindrical mounting receptacles <NUM>-<NUM> to better engage the pivot protuberances <NUM> of the release button arms <NUM> (best shown in <FIG>). Pivot protuberances define a pivot axis P3 of the release button <NUM> and concomitantly the bolt release mechanism <NUM>.

When release button <NUM> is in the downward unactuated position, the mounting arms <NUM> of actuating portion <NUM> are fully engaged with longitudinal slots and oriented substantially parallel to longitudinal axis LA of firearm <NUM>. When release button <NUM> is in the upward actuated position, mounting arms <NUM> leave the slots except for the retention protuberances <NUM> thereby maintaining engagement with the slots. In this position, arms <NUM> are obliquely oriented to longitudinal axis LA. The actuating portion <NUM> of the release button essentially pivots about the protuberances as release button <NUM> moves between the unactuated and actuated positions.

To provide a compact bolt release mechanism which is accessible to the user without their trigger hand substantially leaving the firearm, the actuating portion <NUM> of release button <NUM> is preferably axially aligned with the longitudinal axis LA of the firearm adjacent to the rear end <NUM> of receiver <NUM> as shown. Actuating portion <NUM> of the release button extends rearward from the rear end wall <NUM> of the receiver. As best shown in <FIG>, the right and left lateral sides <NUM> of release button actuating portion <NUM> preferably do not project laterally outwards beyond the laterally widest parts of the receiver defines by the right and left lateral sides <NUM> of the receiver <NUM> (side designations from shooter's vantage looking forward while holding the firearm). This advantageously maintains the compact design of the bolt release mechanism and avoids interference with carrying and storage of the firearm. Moreover, the user can maintain their hand easily in substantial axial alignment with the firearm without an undue lateral or twisting motion to actuate the bolt release. This results in a more natural hand action. In total, the present design thus facilitates rapid firing of the firearm even with an interrupted action firing system.

In one embodiment, referring particularly to <FIG>, <FIG>, and <FIG>, the receiver rear end wall <NUM> may be angled obliquely to the longitudinal axis LA sloping downwardly and rearwardly, and front wall <NUM> of the release button actuating portion <NUM> has a complementary angle. This creates an angled but slideable operating interface and abutment therebetween. In one embodiment, receiver rear end wall <NUM> and release button front wall <NUM> may be arcuately curved from side to side (best shown in <FIG>). When release button <NUM> is actuated, the front wall <NUM> of actuating portion <NUM> slideably engages and rides upwards along the rear end wall <NUM> of receiver <NUM>. The end wall <NUM> thus advantageously provides guided and supported motion of the actuating portion which creates smooth operation of the release button.

The coupling portion <NUM> of release button <NUM> comprises a rear vertical section <NUM>-<NUM> and a generally downwardly angled front section <NUM>-<NUM>. Disconnect lever <NUM> may be pinned to the rear section in one embodiment. A reset spring <NUM> arranged and acting between the underside of the receiver <NUM> and the front section <NUM>-<NUM> serves to automatically return the release button <NUM> from the upward actuated position to the downward unactuated position when the button is released. Spring <NUM> may be a coil compression spring in one embodiment; however, other type springs may be used. Coupling portion <NUM> further defines a longitudinally-extending channel <NUM> between its right and left sidewalls <NUM> which receives rear mounting leg <NUM> of disconnect lever <NUM> therein for connection to pivot pin <NUM>.

The rear wall <NUM> of the release button actuating portion <NUM> defines an actuation surface <NUM>-<NUM> may be textured in some embodiments to facilitate engagement with the user's thumb for actuating the bolt release. This proves helpful especially in wet and/or cold firing conditions.

Bolt release mechanism <NUM> further includes an operating spring <NUM> arranged and acting between the release button coupling portion <NUM> and disconnect lever <NUM>. Spring <NUM> may be a coil compression spring in one embodiment; however, other type springs may be used. Disconnect lever <NUM> includes a downwardly open bore <NUM> which receives spring <NUM>. The top end of spring <NUM> acts inside the bore on the lever <NUM> and bottom end of the spring acts on the front end of front section <NUM>-<NUM> of the coupling portion <NUM> of the release button <NUM>. This biases the lever upwards to its upward position, and concomitantly biases the coupling portion <NUM> of release button <NUM> and disconnect lever <NUM> apart in a spring-loaded scissor type action. Disconnect lever <NUM> may include a laterally projecting travel stop <NUM> which abuttingly engages against a bottom surface of the receiver <NUM> to limit the upward position of the disconnect lever. In the upward position, the uppermost portion of the disconnect lever projects at least partially into the longitudinal cavity <NUM> (i.e. rear section <NUM>-<NUM>) to engage the bolt <NUM>, as further described herein.

The disconnect lever <NUM> will now be described in greater detail. Lever <NUM> may have a generally S-shaped body comprising a vertically elongated upright central portion <NUM>, elongated rear mounting leg <NUM> extending rearwardly from the central portion, and a front working protrusion <NUM> extending forwardly from the central portion. Spring bore <NUM> may be formed in the central portion in one embodiment. The rear terminal end of rear mounting leg <NUM> is pinned to coupling portion <NUM> of release button <NUM>. The front working protrusion <NUM> may be generally wedge-shaped in one embodiment and terminates in a narrowed front contact tip <NUM> arranged to selectively engage the top surface of the hammer <NUM>, as further described herein. Tip <NUM> may preferably be slightly rounded for smooth engagement with the hammer. The top of disconnect lever <NUM> defines an upward facing cam surface <NUM> extending along the entire central portion to the front contact tip <NUM>. The upward facing cam surface <NUM> is arranged to be engaged by the cam <NUM> of the bolt <NUM> when in its axial rearward position. In one embodiment, the cam surface may be slightly arcuately curved to facilitate smooth engagement with the cam <NUM> of bolt <NUM>.

The release button <NUM> and disconnect lever <NUM> may each be monolithic unitary structures which include their respective constituent parts previously described herein. The release button and disconnect lever may be formed of a metallic or non-metallic material. In one non-limiting embodiment, release button <NUM> may be formed of a suitable polymer such as nylon reinforced plastic and disconnect lever <NUM> may be formed of metal such as steel or aluminum as some non-limiting examples.

The bolt release mechanism <NUM> has a unique operational feature which relies on interaction of bolt <NUM> with the mechanism. As previously described herein, the disconnect lever <NUM> has a rear "mounted" pivot axis or point P1 where its rear end is pinned to the release button <NUM> via transverse pivot pin123. This physical connection thus forms a fixed or permanent primary rear pivot axis or point of the disconnect lever. The disconnect lever <NUM> however further has a secondary transient forward pivot axis or point P2 (not associated with the rear pinned connection) whose formation depends on whether the bolt is in the forward or rearward position. As previously described herein, operating spring <NUM> acting between the release button <NUM> and disconnect lever <NUM> biases the lever upwards into its upward position (limited only by travel stop <NUM>). When the bolt is in battery (i.e. forward closed breech position), there is no element of the firearm in contact with the top cam surface <NUM> of the disconnect lever <NUM> which remains in its upward position. Accordingly, movement of release button <NUM> from its downward unactuated position to its upper actuated position does not appreciably move the front contact tip <NUM> of the disconnect lever <NUM> either upward or downwards because there is no physical element against which the cam surface <NUM> may be braced to rotate front contact tip <NUM> of disconnect lever <NUM> downwards to counter the foregoing upward biasing action of operating spring <NUM>.

Conversely, when the bolt <NUM> is locked in its rearward open breech position to the rear of receiver <NUM>, the cam <NUM> formed on the bottom of the bolt engages top cam surface <NUM> of disconnect lever <NUM> thereby forming a fulcrum at the contact point which defines a secondary transient forward pivot axis or point P2 which exists only as long as bolt <NUM> remains in its rearward position. With release button <NUM> still in its downward unactuated position, bolt cam <NUM> now pushes the disconnect lever <NUM> downwards contacting its front contact tip <NUM> against the top actuating surface <NUM>-<NUM> of hammer <NUM> which is holding the bolt <NUM> in its rearward axial position. The contact is not sufficient to displace the hammer <NUM> downwards and disengage it from bolt <NUM> while release button <NUM> remains in the unactuated position. In this downward position of the disconnect lever <NUM>, upwards movement of release button <NUM> to its actuated position now rotates the front contact tip <NUM> of the lever working protrusion <NUM> farther downwards (clockwise in <FIG>) about the fulcrum formed at the cam-cam surface interface (transient forward pivot axis/point P2) against the upward biasing action of operating spring <NUM>. This additional movement of the disconnect lever front contact tip <NUM> is sufficient to force the hammer farther downwards/rearwards removing catch protrusion <NUM> of the hammer out of retention notch <NUM> on the bottom of the bolt <NUM>. The bolt <NUM> is released and returns forward under the biasing action of the slide spring <NUM> associated with slide <NUM> to its forward closed breech position back in battery with the barrel. The transient forward pivot axis/point P2 no longer exists.

The foregoing unique aspects of the present bolt release mechanism will become further apparent upon describing the operation of the mechanism below.

A method for operating a firearm with the interrupted action according to the present disclosure will now be described with reference to <FIG>. These figures depict sequential views in the operation of the action. General reference is made however to <FIG> as applicable.

<FIG> shows the provided firearm <NUM> with bolt release mechanism <NUM> each in the ready-to-fire position. Trigger <NUM> is in its forward unpulled condition albeit with finger grip portion <NUM>-<NUM> obliquely angled to vertical trigger axis Va of the trigger defined as extending through trigger pivot pin <NUM>-<NUM>. In other possible constructions, grip portion <NUM>-<NUM> may be parallel to trigger axis Va. Bolt release mechanism <NUM> is unactuated. Bolt <NUM> is in its forward closed breech position in battery with barrel <NUM> at its rear breech end <NUM> adjacent chamber <NUM> which contains a cartridge C (not shown in this particular figure). In addition, bolt <NUM> is positioned in the front section <NUM>-<NUM> of the receiver cavity <NUM> and parallel to longitudinal axis LA. Hammer <NUM> is held in the cocked rearward position (obliquely angled to vertical trigger axis Va) by sear protrusion <NUM>-<NUM>. Disconnect lever <NUM> is in its upward position with forward working protrusion <NUM> substantially horizontal such that top cam surface <NUM> of the lever is positioned in rear section <NUM>-<NUM> of receiver longitudinal cavity <NUM>.

As further seen in <FIG>, the trigger interlock safety is in the deactivated state. Accordingly, trigger block protrusion <NUM> on blocking leg <NUM>-<NUM> of the trigger <NUM> is retracted from locking recess <NUM> of the release button <NUM>, thereby allowing the trigger to be pulled without interference from the interlock created with the bolt release mechanism so long as the bolt release mechanism remains unactuated.

Next, <FIG> shows firearm immediately after the trigger <NUM> has been pulled rearward (force F) to release the hammer <NUM> from the trigger sear protrusion <NUM>-<NUM> and discharge the firearm. Hammer <NUM> rotates to its upright forward fire position (substantially parallel to vertical trigger axis Va) striking the firing pin <NUM>, which in turn drives the firing pin forward to strike the percussion cap in the rear base of the cartridge. This detonates the round which launches the projectile down the barrel bore <NUM>. Note that the cam surface <NUM> of disconnect lever <NUM> remains in the upright position partially entering the rear section <NUM>-<NUM> of receiver longitudinal cavity <NUM> for eventual contact by the bolt cam <NUM> during its rearward motion, as further described during the firing sequence below.

Notably in <FIG>, the trigger interlock safety has been activated such that trigger block protrusion <NUM> has moved upwards via the trigger pull to now engage locking recess <NUM> of the disconnect lever <NUM> as the rear blocking leg <NUM>-<NUM> of the trigger rotates upwards with the rearward pull of the trigger. When the interlock safety has been activated, the release button <NUM> of bolt release mechanism <NUM> cannot be actuated (i.e. moved upwards). This prevents the firearm from automatically firing unintentionally if the bolt were released while the trigger was still pulled. The safety remains activated until the user releases the trigger.

<FIG> shows firearm <NUM> after being fired causing the action to begin to cycle. Here, bolt <NUM> has started moving axially rearward to the point which opens the breech as the combustion gases traveling forward from the fired cartridge creates an opposite rearward recoil thrust against the breech face of the bolt. The rear end <NUM> of bolt <NUM> has entered the downward sloping rear section <NUM>-<NUM> of receiver cavity <NUM>, which causes the bolt to assume a tilted position obliquely angled to longitudinal axis LA (note bolt axis BA in comparison). The bolt has also has moved far enough back to engage and rotate the hammer <NUM> back rearward and just past the front contact tip <NUM> of disconnect lever <NUM>. Rotation of the hammer breaks engagement with the sear protrusion <NUM>-<NUM> of trigger <NUM> as shown. Hammer <NUM> is now momentarily held in its rearward position via engagement by the bolt.

<FIG> shows the bolt <NUM> traveling farther rearward into rear section <NUM>-<NUM> of receiver cavity <NUM> as it bottom surface slideably continues to hold hammer <NUM> downwards. Bolt <NUM> has finished traveling rearward and is now in its rearward-most position. Cam <NUM> defined on the underside of bolt <NUM> now engages cam surface <NUM> on disconnect lever <NUM> of the bolt release mechanism <NUM> and pushes/displaces the disconnect lever <NUM> downwards, thereby partially rotating the front contact tip <NUM> of the lever into contact with the top actuating surface <NUM>-<NUM> of the hammer <NUM>. Importantly, for purposes of forming the present interrupted action, the catch protrusion <NUM> of the hammer <NUM> has engaged retention notch <NUM> on the bottom of the bolt <NUM> thereby arresting its forward travel under the biasing action of the recoil spring. Bolt <NUM> may be simultaneously engaged with both disconnect lever <NUM> and hammer <NUM> as shown. It bears noting that the foregoing displacement of disconnect lever <NUM> by the bolt is not sufficient however to displace the hammer sufficiently to break contact between the hammer and bolt, but merely takes up slack in the linkage by closing the gap between the disconnect lever and hammer in preparation for releasing the bolt. This advantageously improves the responsiveness of release button <NUM> for releasing the bolt to reclose the breech, as further described below. At this stage in the firing cycle, the hammer <NUM> continues to hold the bold <NUM> rearward with the breech open.

The action shown in <FIG> and <FIG> is currently in the locked rear position. In order to release the bolt <NUM> forward back into battery with the barrel to reclose the breech for firing the next round, the user must both: (<NUM>) release the trigger <NUM> to deactivate the trigger safety interlock to break engagement between trigger block protrusion <NUM> on the trigger with locking recess <NUM> of the bolt release mechanism <NUM>; and then (<NUM>) manually actuate the bolt release mechanism <NUM>.

<FIG> shows that the user has now released the trigger <NUM>. This deactivates the trigger interlock safety such that trigger block protrusion <NUM> is now disengaged from locking recess <NUM> of the disconnect lever <NUM>, thereby achieving step (<NUM>) above in the bolt release process. The also user starts to apply an upward applied force F via the thumb or finger on release button <NUM> which begins to move slightly upward as depicted in this figure. In the present application, force F designates any manually applied force by the user.

In <FIG>, the user now fully actuates the bolt release mechanism <NUM> by pushing release button <NUM> at the rear end of the receiver <NUM> farther upwards as shown by applied force F. This achieves step (<NUM>) above in the bolt release process. The user pushes the release button upwards until the front contact tip <NUM> of disconnect lever <NUM> rotates downward sufficiently to disengage the hammer <NUM> from bolt <NUM>. Bolt catch protrusion <NUM> on hammer <NUM> disengages retention notch <NUM> on the bolt which frees and releases the bolt.

<FIG> shows the released bolt <NUM> beginning to travel forward under the biasing action of spring-biased slide <NUM> to reclose the breech. The bolt will strip and chamber a fresh new cartridge from the magazine <NUM> during it return motion. The disconnect lever <NUM> begins to move back upwards under the biasing action of operating spring <NUM> and releases the hammer <NUM> to rotate upward and slideably engage the portion of bolt <NUM> behind the retention notch <NUM>. Hammer <NUM> is now held downward/rearward by slideable engagement with the underside of bolt <NUM> alone (noting that the sear protrusion <NUM>-<NUM> of trigger <NUM> is not yet re-engaged with the hammer and disconnect lever <NUM> is completely disengaged from the hammer).

In <FIG>, the bolt <NUM> continues to travel forward to reclose the breech. The hammer <NUM> disengages the bolt and is therefore no longer held down so that the hammer can rotate upwards back into engagement with the primary sear protrusion <NUM>-<NUM> of the trigger <NUM>. Notably, assuming that the user has not yet released the release button <NUM> which is therefore still in in the upward actuated position, a second aspect of the trigger interlock safety is now activated. Downward facing blocking surface <NUM> on release button <NUM> is now vertically aligned with and positioned over to engage trigger block protrusion <NUM> of trigger <NUM> as shown if an attempt is made to pull the trigger (still in its forward unpulled state). The trigger <NUM> thus cannot be actuated until the release button is released, which will then reposition the blocking surface <NUM> forward of the trigger block protrusion <NUM> and vertically realign (but not engage) the trigger block protrusion with the locking recess <NUM> (see, e.g. <FIG>). Once the user releases the release button <NUM> which is returned to its downward unactuated position under the biasing action of reset spring <NUM>, the trigger may be pulled to fire the firearm and repeat the foregoing interrupted firing cycle starting with <FIG> again and a closed breech.

Claim 1:
A firearm (<NUM>) with interrupted action comprising:
a longitudinal axis (LA);
a receiver (<NUM>) defining a longitudinally-extending cavity (<NUM>);
a barrel (<NUM>) supported by the receiver (<NUM>);
a trigger (<NUM>) movably mounted to the receiver (<NUM>);
a bolt (<NUM>) slideably mounted in the cavity (<NUM>) of the receiver (<NUM>) for movement between a forward position in battery with the barrel (<NUM>) and a rearward position;
a cockable hammer (<NUM>) operably interacting with the trigger (<NUM>), the hammer pivotably movable about a pivot axis between a rear cocked position and a forward fire position via pulling the trigger;
the hammer (<NUM>) configured and operable to retain the bolt (<NUM>) in the rearward position after a trigger (<NUM>) pull to fire the firearm (<NUM>); and
a bolt release mechanism (<NUM>) operably interacting with the bolt (<NUM>),
characterized in that
the bolt release mechanism comprising a user-actuated release button (<NUM>) and a spring-biased disconnect lever (<NUM>) coupled to the release button and engageable with the hammer (<NUM>);
the release button (<NUM>) when actuated being configured and operable to move the disconnect lever (<NUM>) which disengages the hammer (<NUM>) from the bolt (<NUM>) to release the bolt from the rearward position.