Break open system having an adjustable, releasable forend stock

Abstract

A forend stock for a break open firearm having a housing lug, the housing lug being attached into the lower side of the barrel assembly. A coupler is secured onto the housing lug. At the coupler end opposite the housing lug rod, there is a cylindrical area, and between the two coupler ends, another finished area forming an extended flange. The extended flange has a larger diameter than the cylindrical ends of the coupler. A latch bolt is secured to the forend stock by a cover plate. The latch bolt is topped at one of its ends with a sharp bevel. At its other end, it has a cylindrical post to support a pressure spring, and is held in a longitudinal channel or recess, and arranged such that a user can access an actuator knob for manual handling of the latch bolt. The cover plate assembly has an aperture which the ledges of an extended protrusion of the latch bolt fit within, defining the forward and backward travel limits that the bolt can go in a direction parallel to the axial direction of the barrel.

Claims

1. A firearm having an adjustable, releasable forend stock comprising: a barrel assembly; a retainer mechanism including a housing lug, said housing lug being threadably attached on a first side to a lower side of said barrel assembly, said housing lug having a threaded rod projecting on a second side opposite said first side, towards said forend stock; a coupler threadably secured onto said housing lug threaded rod at a first end and having at a second end opposite said first end formed for insertion within a bushing fixed on said forend stock, said coupler including a cylindrical portion intermediate said coupler first and second ends, said cylindrical portion having an extended flange; and a latch bolt having a top surface and a beveled end, said latch bolt in slidable communication with said forend stock, and acted upon by a resilient component, such that said latch bolt secures said forend stock to said barrel assembly when in a locked position said latch bolt prohibits said coupler extended flange from movement.

2. The firearm of claim 1 wherein said housing lug includes a curved top surface for mating attachment to said barrel assembly.

3. The firearm of claim 1 including: a cover plate secured to said forend stock, said cover plate having an aperture; said latch bolt having a projection extending above said latch bolt top surface, and into said cover plate aperture, such that said cover plate aperture restricts slidable movement of said latch bolt.

4. The firearm of claim 1, wherein said cylindrical portion of said coupler includes a transition radius that decreases with axial length as said cylindrical portion extends towards said forend stock.

5. The firearm of claim 1, wherein said resilient component is at least partially contained by said latch bolt.

6. The firearm of claim 5, wherein said resilient component is a spring.

7. The firearm of claim 1, including an actuator knob connected at one end to said latch bolt, and extending at an opposite end from said forend stock underside, said actuator knob having a lower portion for promoting sliding action by a user.

8. The firearm of claim 7, wherein said actuator knob is attached to said latch bolt, such that upon sliding of said actuator knob towards said firearm breech end, said latch bolt is moved in a same direction, releasing said forend stock from said barrel assembly.

9. The firearm of claim 1, wherein said bushing includes a hollow end for receiving said coupler.

10. The firearm of claim 9, wherein said coupler includes a set screw for extending said coupler length and locking said coupler in place with respect to said housing lug.

11. The firearm of claim 10, wherein said set screw is receivable within said bushing hollow end.

12. The firearm of claim 1 wherein said latch bolt includes a back end shaped as a rod to serve as a guide to a compression spring that propels the latch bolt in a forward, muzzle end direction.

13. The firearm of claim 1 wherein said forend stock includes at a breech end a concave radial surface such that upon attachment with a complementary portion of a receiver end forms a rotational connection.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The features of the invention believed to be novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The figures are for illustration purposes only and are not drawn to scale. The invention itself, however, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which:

(2) FIGS. 1A-1B depict a bottom and side view, respectively, of a closed break action barrel gun;

(3) FIG. 1C depicts a side view of an open break action barrel gun in the loading and unloading position;

(4) FIG. 2 depicts a general exploded view of the firearm of FIG. 1 showing the different components which make up the present invention;

(5) FIG. 3 is an exploded view of FIG. 2, depicting the components of the present invention;

(6) FIG. 4 depicts a view of the forend stock identifying the housings arranged to house the components identified in FIG. 3;

(7) FIG. 5A is a cross-sectional, elevation view of the adjustment system of the present invention depicting a coupling part which can be raised and lowered by tightening or loosening so as to adapt it to a necessary measure to achieve a desired fit, and showing a gap between two threaded screws allowing for free movement of the parts;

(8) FIG. 5B depicts a cross-sectional view of FIG. 5A with the set screw 5 completely inserted within inner threaded area 4a.

(9) FIG. 6 depicts a cross-sectional view in the longitudinal direction (along the barrel axis) of the coupler attached to the barrel assembly at one end, and being rotationally moved relative to the forend stock away from the bushing, at the other end of the coupler;

(10) FIG. 7 depicts an attachment of the forend stock to the barrel assembly 2, showing the latch bolt under the resilient retraction force of a spring, forced against the coupler, and securing the extended disc portion of the coupler;

(11) FIG. 8 depicts a releasing action of the forend stock from the barrel assembly, showing a user's finger pushing the knob in the breech end direction, which in turn moves the latch bolt in the same direction to release the coupler from the latch bolt;

(12) FIG. 9 depicts an exploded view of a second embodiment of the present invention, presenting an alternative housing lug and coupler configuration;

(13) FIG. 10A depicts a perspective view of the second embodiment of the housing lug and coupler configuration;

(14) FIG. 10B depicts a perspective cross-sectional view of FIG. 10A.

(15) FIG. 11A depicts a cross-sectional view in the longitudinal direction (along the barrel axis) of the second embodiment of the housing lug and coupler configuration of FIG. 10A, attached to the barrel assembly; and

(16) FIG. 11B depicts a cross-sectional side view of the second embodiment of the housing lug and coupler configuration attached to the barrel assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

(17) In describing the preferred embodiment of the present invention, reference will be made herein to FIGS. 1-11 of the drawings in which like numerals refer to like features of the invention.

(18) The invention described herein is a simple and inexpensive system that enables the operation of disassembling the forend stock of a rifle or a shotgun, and which may be employed for a number of different firearms, including but not limited to, break action rifles, and especially break action muzzleloader rifles.

(19) Concerning the following descriptions, when reference is made to the assembled firearm, it is assumed that the firearm is horizontally directed and in shooting position, so that the fore part (forend stock) is on the barrel muzzle side of the firearm, the rear part is the side having the buttstock and receiver assembly, the lower portion or bottom portion is that portion directed towards the ground, and the upper portion or top portion is that portion directed towards the sky.

(20) FIGS. 1A-1B depict a bottom and side view, respectively, of a closed break action barrel firearm 100, having a buttstock 102, a forend stock 12, and a barrel assembly 2.

(21) FIG. 1C depicts a side view of the open break action barrel firearm 100 in the loading and unloading position, showing a cartridge 104 for insertion into the breech end of barrel 2.

(22) FIG. 2 depicts a general exploded view of the firearm of FIG. 1 showing the relative positions of the different components for the forend stock assembly.

(23) For assembly of a detached forend stock 12, utilizing the attachment scheme of the present invention, it is only necessary to position the forend stock 12 in its place, and press it to the barrel assembly 2 to secure it—advantageously, there is no need to employ additional operations.

(24) Referring to FIG. 3, an attachment scheme of the present invention features a housing lug 1 having a threaded rod 1b. Housing lug 1 is threadably attached into the lower side of the barrel assembly 2 shown using two screws 3; however, any number of screws, or other secure attachment schemes may suffice. In this preferred embodiment, screws 3 are designed to pass through via the holes 1a in housing lug 1, and secure to the lower portion of the barrel assembly 2, which has complementary receiving threaded apertures (not shown).

(25) A cylindrical coupling part or coupler 4 is threadably secured onto rod 1b, having an inner threaded area 4a which allows it to be coupled to the threaded portion of rod 1b. At the coupler end opposite threaded area 4a, there is a lower cylindrical, threaded area 4b, and between the two ends of coupler 4 is a finished area forming an extended disc portion 4c having an exposed edge. The extended disc portion 4c has a larger diameter than the cylindrical ends of coupler 4. In at least one embodiment, the extended disc portion 4c enjoys a transition radius 4d that decreases with axial length as the extended portion extends towards cylindrical, threaded area 4b.

(26) In order to ensure the fixing of coupler 4 to the threaded rod 1b and not allow the mating combination to loosen, a locking screw 5, which is suitably fitted in the cylindrical threaded area 4b of coupler 4, puts pressure on the end of the rod 1b straining the union of these parts and preventing them from coming loose.

(27) FIG. 4 depicts a top view of the forend stock 12 identifying the housing arrangement for housing the components identified in FIG. 3.

(28) The forend stock 12 is preferably made of synthetic material (plastic); however, the present invention does not limit the forend stock to any particular type of material. Referring to FIGS. 3 & 4, inside the forend stock, the housings and needed features for the assembly and operation of the system are shown as arranged.

(29) Viewing the inside of forend stock 12 is a dimensioned hole 12b, as depicted in FIG. 4, to hold the press-fit insertion of a bushing 11 (FIG. 3). Bushing 11 is designed to receive coupler 4.

(30) Bushing 11 is a hollow cylindrical lining or sleeve which may be fixed by press-fitting into the cavity 12b of the forend stock 12, for which it features a knurling finish 11a. As noted previously, bushing 11 receives coupler 4, and particularly prevents further extension of set screw 5.

(31) This hollow bushing is shaped so that coupler 4 may fit in the hollow portion, the cylindrical area 4b having a diameter that fits without noticeable clearances in the inner side of the bushing 11b. In order to facilitate access into this hole, the edge of the bushing 11c is rounded.

(32) Proximate bushing 11, assembled in the forend stock, is a slider channel for a slidable latch bolt 6, having a body shaped for sliding fore and aft the forend stock within the slider channel. Latch bolt 6 is slidably held in place by cover plate 9, which is fastened to the forend stock, shown in FIG. 3 fastened by three screws 10 which are fixed within complementary threaded holes of the forend stock 12, although other attachment schemes for cover plate 9 are not precluded by the design of the present invention. Cover plate 9 secures latch bolt 6 while allowing for a sliding action.

(33) Latch bolt 6 is fitted within the slider channel. The body portion of latch bolt 6 slides relative to the forend stock, resting on lower flat side 6c, and having two vertical curved guides 6a, which may preferably be semi-circular guides. Latch bolt 6 includes at one of its ends an angled portion or bevel 6b, similar to the end of a retainer cylinder of a door lock bolt. At its other end, latch bolt 6 features a cylindrical post 6d to support a pressure spring 8. Pressure spring 8 provides a resilient force to latch bolt 6 in the sliding direction.

(34) Crossing about the width of latch bolt 6 on its top side proximate its central area is a projection 6g having raised edges beyond the top side flat surface of latch bolt 6. The raised edges are available to mark the movement stoppers of latch bolt 6 within aperture 9b of cover plate 9. Preferably, projection 6g includes a straight-through orifice 6f preferably centering about the projection.

(35) An actuating knob 7 is exposed on the underside of forend stock 12 to facilitate user handling of latch bolt 6, and is designed to be pressed by finger touch, or slidable in a direction parallel to the barrel axis through finger motion. The aforementioned actuator knob preferably includes a cylindrical post 7b that is attachable within the straight-through orifice 6f of latch bolt 6, and may afterwards be riveted at a rivet end 7c for the attachment of both parts. A riveted attachment scheme is presented; however, other attachment schemes are clearly not precluded provided the actuator knob 7 is secured to, and capable of supporting itself to, latch bolt 6, and capable of moving latch bolt 6.

(36) Actuator knob 7 has a tapered end 7a adapted and formed in such a manner that lends itself to easy activation by a single finger, even if the user is wearing a glove. This area is accessible (once the gun is assembled) through the slot 12c (FIG. 4) at the bottom of forend stock 12. Slot 12c is a longitudinal channel or recess arranged such that a user can access the knob portion 7a of actuating knob 7 for manual handling of the latch bolt 6.

(37) Tapered end 7a of actuator knob 7 is shaped as cylindrical portion of reducing radius as it extends away from forend stock 12. This shape is amenable to single finger contact. Other shapes may be employed for single finger activation, and the present invention is not limited to any resultant exposed surface for actuator knob 7 provided the exposed surface facilitates capture by a user's finger.

(38) The assembly composed by latch bolt 6, the attached actuating knob 7, as well as compression spring 8, which after compression drives the latch bolt 6 forward towards the muzzle end of the firearm, is housed in the cavity installed in the forend 12a with the exception of the actuator knob finger grip 7a, which is exposed outside and underneath forend stock 12. Cover plate assembly 9 is fixed, preferably by the aforementioned three screws 10, which while penetrating through-holes 9a, tap in the forend stock into holes 12d.

(39) Cover plate assembly 9 includes a rectangular hole or aperture 9b sufficiently wide enough to receive the raised edges of projection 6g of latch bolt 6. The movement of latch bolt 6 relative to cover plate assembly 9 is prohibited at each end of aperture 9b by the raised edges of projection 6g. This restraint on movement defines the forward and backward travel limits that latch bolt 6 can traverse in a direction parallel to the axial direction of the barrel.

(40) At the rear or breech end of the forend stock is a dished, concave radial surface 12e that upon attachment of the forend stock 12 to the firearm is secured in proximity with the receiver end 13 of the firearm, which features an adjustment and complementary rotational protrusion 13a with approximately the same radius as concave radial area 12e but convex in curvature to form complementary adjoining surfaces. Essentially, the mating of receiver end 13 with the rear or breech end of the forend stock is configured for rotational attachment. This scheme facilitates a break-open action of the firearm, and ensures that the rotational motion during break-open is not restricted. The complementary mating surfaces work together to form a hinge to allow for the rotational opening and closing of the rifle action during loading and unloading.

(41) On this same end, the forend stock features two flanges 12f which are complementary to the firearm's receiver 13 and together improve the alignment and fastening of the forend stock to the receiver.

(42) FIG. 5A depicts a cross-sectional view of coupler 4 attached to barrel assembly 2. Set screw 5 is shown partially installed within inner threaded area 4a of coupler 4, exposing a gap “A” between the end of set screw 5 and the end of threaded rod 1b of housing lug 1. FIG. 5B depicts a cross-sectional view of FIG. 5A with the set screw 5 completely inserted within inner threaded area 4a.

(43) FIG. 6 depicts a cross-sectional view in the longitudinal direction (along the barrel axis) of coupler 4 attached to barrel assembly 2 at one end, and being rotationally moved relative to forend stock 12 away from bushing 11, at the other end of coupler 4. This action depicts the removal of forend stock 12 from barrel assembly 2. Arrow 20 depicts the relative motion of knob 7 towards the breech end of the firearm, which in turn slides latch bolt 6 in the same direction, releasing coupler 4 and allowing the forend stock to rotate away from barrel assembly 2.

(44) FIG. 7 depicts an attachment of forend stock 12 to barrel assembly 2. In this configuration, arrow 21 depicts the direction of latch bolt 6, under the resilient retraction force of spring 8, against coupler 4, securing extended disc portion 4c.

(45) FIG. 8 depicts a releasing action of the forend stock 12 from barrel assembly 2, showing a user's finger depressing knob 7 in the direction of arrow 22 (pushing knob 7 in the breech end direction), which in turn moves latch bolt 6 in the same direction to release coupler 4 from the latch bolt. Forend stock 12 is then able to rotate away from barrel assembly 2.

(46) FIGS. 9-11 depict a second embodiment for the housing lug. FIG. 9 depicts an exploded view of a second embodiment of the present invention, presenting an alternative housing lug. In this embodiment, housing lug 14 is configured with a base 14e for attachment to the underside of barrel assembly 2. Base 14e is curved on its top surface having a concave surface with a radius for mating attachment to the curved barrel assembly 2. Through-holes 14a in base 14e receive securing bolts 14f for attachment to barrel assembly 2. Barrel assembly 2 includes complementary receiving threaded apertures (not shown) to receive securing bolts 14f. Housing lug 14 includes coupler 14c attached thereto. In at least one embodiment, coupler 14c is formed integral with base 14e; however, other attachment schemes, such as threaded attachment, snap-fit, friction fit, to name a few, may be employed to secure coupler 14c to base 14e.

(47) Coupler 14c includes a threaded aperture 14b for receiving adjustment screw 15. Once installed within coupler 14c aperture, adjustment screw 15 is secured by set screw 16, which is inserted into a side wall of coupler base 14b.

(48) At the coupler end opposite barrel assembly 2, there is a lower cylindrical area 14g, and between the two ends of coupler 14 is a finished area forming an extended disc portion 14h having an exposed edge. The extended disc portion 14h has a larger diameter than the cylindrical ends of coupler 4. In at least one embodiment, the extended disc portion 14h enjoys a transition radius that decreases with axial length as the extended portion extends away from barrel assembly 2.

(49) Coupler 14 may be seated within bushing 17 in a similar manner as coupler 4 is seated within bushing 11.

(50) FIG. 10A depicts a perspective view of the second embodiment of the housing lug and coupler configuration, showing coupler 14. FIG. 10B depicts a perspective cross-sectional view of FIG. 10A.

(51) FIG. 11A depicts a cross-sectional view in the longitudinal direction (along the barrel axis) of coupler 14 attached to barrel assembly 2. FIG. 11B depicts a cross-sectional side view of coupler 14 attached to barrel assembly 2.

(52) A feature of the system described above allows for the forend stock 12 to be securely attached to the barrel assembly without the need of welded seams. Welds will typically generate strains and, in consequence, deformations and bending in the barrel itself, which ultimately could impact accuracy. To correct this bending and warping, expensive and time consuming straightening efforts are usually performed afterwards. Additionally, welds are contrary to clean processes and visually unattractive. Moreover, welds generally require further polishing.

(53) If a repair of a welded piece is required, this adds great difficulty to the removal and repair process since, if it is not done in the original factory, the necessary tools to carry out this replacement with appropriate guarantees are generally not available.

(54) In addition, having a forend stock being removably fixed instead of being welded, also includes the possibility of utilizing an adjustable coupler 4, 14 which is designed to vary in height. This feature, besides facilitating the assembly of the gun during its manufacturing process, ensures in the future that any user, who spots unwanted clearances caused by intensive use, should be able, by either loosening or tightening the coupler, to achieve a precise fit without clearances that may affect not only the accuracy but also the safety of the gun.

(55) It is preferably desired for all the component parts of the invention's system to be replaceable and adjustable with the assistance of a simple Allen wrench and a standard screwdriver.

(56) The forend stock recess 12c is shaped so that it can be easily operated on the actuator knob 7, even with gloves. In at least one embodiment, actuator knob 7 is exposed on the underside of forend stock 12 within the recess 12c so that the actuator knob 7 does not extend beyond the bottom surface of the forend stock. Apart from that, as it is inside this recess 12c, it becomes protected from unintended activations. As shown in FIG. 6, actuator knob 7 may include a curved portion 7a for seating a user's finger.

(57) Operation—Firearm Assembly

(58) Once the barrel is assembled on the rifle's receiver 13, the forend stock 12 is attached by fitting the concave radial area 12e in the complementary side of the receiver 13. The forend stock is then rotated until coupler 4, 14 is inserted into the housing's bushing 11, and more specifically, when the cylindrical adjustment area 4b and set screw 5 slide inside the bushing 11, or conversely, cylindrical area 14g and adjustment screw 15 slide inside bushing 11.

(59) At this point, two contacts occur. On the one hand, the locking screw 5 reaches the bottom of the recess 11b of bushing 11, which defines the adjustment endpoint, and, on the other hand, the latch bolt 6 starts moving backwards compressing spring 8 when acted upon by radius area 4d against the angled tip of the locking bolt 6b. In similar fashion, coupler 14 performs the same function against latch bolt 6 upon insertion of the barrel assembly 2 into the forend stock 12.

(60) At the end of this travel, extended disc portion 4c is below latch bolt 6 such that a resilient retraction force applied by spring 8 against latch bolt 6, pushes latch bolt 6 towards coupler 4, and a metallic click sound occurs that notifies the user that the part is fastened. Again, in a similar fashion, the embodiment of coupler 14 performs the same function.

(61) To disassemble the forend stock, the actuator knob 7 is pressed to slide towards the breech end of the firearm by means of the user's finger, and simultaneously with this pressing, latch bolt 6 is moved to the breach end against the tension of spring 8, compressing spring 8. This action releases coupler 4, 14. The forend stock 12 is then released from the barrel. The forend stock is thereby removable.

(62) Based on the implementation of the embodiments of the present invention, this sequence of operation is simple, natural, and essentially automated (finger motion on actuator knob 7 excepted); it needs no prior preparation or intervention of any mechanism and requires one or two seconds for its processing, both when assembling and disassembling.

(63) Attachment System

(64) One of the key aspects related with the accuracy of a rifle is the absence of clearances between its components and more precisely between the set of parts of the barrel, buttstock, forend stock, and action.

(65) The present invention effects the quick attachment of these elements in the three possible axes in a secure, effective, and adjustable manner.

(66) The movement of the forend stock in the direction parallel to the barrel axis (the forend lengthwise direction) is purposely limited as discussed below.

(67) Using the first embodiment as an exemplary embodiment, coupler 4, attached to housing lug 1 via threaded rod 1b, forms an integral part of the barrel assembly that extends below the barrel and fits into bushing 11. These components attach in a manner that provides for minimum clearance; that is, just enough for them to fit into each other. The forend stock upon attachment is thus prohibited from longitudinal movements in the axial direction of the barrel, both axially forward towards the muzzle end and axially backwards towards the breech end. The motion backwards towards the breech end of the firearm is supplemented by the predetermined radius of the receiver 13a with the predetermined radius of the forend 12e.

(68) In an alternative version, the housing lug having a threaded rod extending therefrom is replaced by a threaded rod secured directly to the barrel, either by threaded attachment or weld.

(69) Movement of the forend stock in a crosswise direction is limited by the two side flanges 12f of the forend stock 12 that fit in receiver 13. The aforementioned adjustment between coupler 4 and bushing 11 promotes keeping the forend stock from moving in a crosswise direction.

(70) When locking screw 5 reaches the bottom of bushing 11, there can be no further vertical movement, marking the maximum that these parts might be inserted one into the other, and thus forming the limit of the attachment of the forend stock against vertical movements towards the barrel. This configuration is adjustable by the user.

(71) In the other direction, the latch bolt 6 locks coupler 4, preventing the forend stock from getting loose and involuntarily pivoting away from the barrel.

(72) The attachment scheme of the present invention manages to secure the aforementioned parts against clearances and movements in any direction. For its assembly, one only needs to position the forend stock in place, and press it to lock in the fit. No further operation is necessary.

(73) While the present invention has been particularly described, in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention.