Patent Publication Number: US-2002005005-A1

Title: Shotgun for competitive clay target shooting

Description:
CROSS REFERENCE TO RELATED APPLICATION  
     [0001] This application claims priority from U.S. Provisional Patent Application No. 60/217,711 filed Jul. 12, 2000 entitled Shotgun For Competitive Clay Target Shooting. 
    
    
     
       FIELD OF THE INVENTION  
       [0002] This invention relates to the field of sporting shotguns as opposed to those used primarily for hunting, and in particular to a sporting shotgun for competitive clay target shooting.  
       BACKGROUND OF THE INVENTION  
       [0003] In conventional clay target shooting competitions using for example Perazzi™ or Krieghoff™ sporting shotguns, a failure of a gun component while on the firing line will usually mean defaulting in that round of the competition because under the competition&#39;s rules, if a gun misfires, you have only 5 minutes in which to effect a repair.  
       [0004] In such instances it would be advantageous, and it is one object of the present invention to provide, a quickly interchangeable shotgun component which contains virtually all of the moving parts of a shotgun so that no matter which internal mechanism failed, the entire shotgun component may be removed and quickly replaced with a spare component otherwise referred to herein as a spare parts group.  
       [0005] Thus what is provided in the present invention is a modified stock which at the butt end is modified so that the user may select between a completely rigid stock or one having a recoil absorber, and which at its receiver end is modified to incorporate a quick release coupling for mating with the shotgun receiver. It is a further object to provide a modified shotgun receiver containing all of the moving parts which may be replaced by a spare parts group and which is further modified to allow selective release of the receiver from the shotgun barrel group by an actuator on the lower surface of the receiver forward of the trigger housing.  
       [0006] In the prior art, applicant is aware of hunting shotguns, for example those made by Browning and sold under the trade mark Citori. One example is shown partially cut-away in FIG. 1 a . As may be seen, in the Citori example, the shotgun stock is mounted to the receiver by means of a bolt inserted from the butt end along a bore in the stock so as to protrude from the receiver mating end of the stock. The bolt threads into a threaded hole or bore in the aft end of the receiver and is tightened, for example by means of a screwdriver, so as to draw the receiver snugly into mating with the stock. A cover plate is screwed into place to cover access to the bore in the stock.  
       SUMMARY  
       [0007] The shotgun of the present invention as defined herein is understood and intended to include the shotgun as an assembled whole, the shotgun as a partially or fully disassembled kit or system, and each separate novel part thereof. Consequently the shotgun of the present invention may be summarized as including a stock, a receiver and a barrel group. The stock has a butt end and an opposite second end. The receiver which is for containing a moving parts group, has a rear end and a forward end and is releasably mountable at the rear end by a releasable coupler to the second end of the stock. The barrel group has a discharge end and an opposite loading end. The loading end is releasably mountable by a pivotable coupler to the forward end of the receiver. The moving parts group, when mounted in the receiver, contain all of the moving parts between a trigger and a firing pin or pins in moving operation relative to the receiver required during firing of the shotgun. The releasable coupler includes a manually operable coupler release. The coupler release is manually actuable so that the releasable coupler mounts the receiver to, or demounts the receiver from, the stock upon tool-less, hand actuation by a user of the coupler release, that is, upon manual actuation by the user without the need to use a tool, such as a screwdriver, to assist in operating the coupler release. Consequently the receiver may be quickly removed by hand from the stock and quickly replaced with a spare receiver containing a spare moving parts group.  
       [0008] In one embodiment, the releasable coupler may comprise a rigid elongate member releasably mountable into a receiving socket. The rigid elongate member may threadably mount into the receiving socket. In particular, in one embodiment the receiving socket is a rigid tubular member mountable into a bore in the second end of the stock, and the rigid elongate member is mountable to the rear end of the receiver so as to cantilever the rigid elongate member from the rear end of the receiver into co-axial alignment with the tubular member when the tubular member is mounted to the stock and the stock is mounted to the receiver.  
       [0009] The rigid elongate member may be a bolt-like member threadably mountable to the tubular member. The bolt-like member may for example be a bolt having an interrupted thread. Such a bolt may have oppositely disposed parallel planar lands along thread-disengaging portions of a length of the bolt. The lands may extend contiguously between oppositely disposed threaded surfaces along thread-engaging portions of the length of the bolt. The tubular member may have an interrupted thread inner surface for threaded engagement with the thread-engaging portions of the bolt. The threaded walls of the tubular member may have apertures therein. The apertures are aligned and sized so that as the bolt is rotated relative to the tubular member while in threaded engagement with the tubular member, the thread-engaging portions are rotated out of thread engaging radial alignment with the threaded inner surface of the threaded walls and into radial alignment with the apertures in the threaded walls, thereby aligning the thread-disengaging portions of the bolt with the threaded inner surfaces of the threaded walls. The bolt is thereby disengaged from the tubular member and may be withdrawn therefrom.  
       [0010] The shotgun receiver may further comprise a low-locking barrel group release latch mounted to a low side of the receiver. The low side of the receiver is defined as corresponding to a trigger side of the receiver. The release latch cooperates with a locking mechanism on the barrel group for releasable locking of the barrel group on the pivotable coupler. When the release latch is locked onto the barrel locking mechanism a round in the barrel is aligned for firing engagement with the firing pin or pins in receiver.  
       [0011] The release latch may have a latch actuating trigger mounted to the low side of the receiver so as to extend therefrom for manual actuation by a user. The latch actuating trigger may be mounted adjacent a trigger guard of the receiver. The latch actuating trigger may be slidably mounted to the low side of the receiver.  
       [0012] The butt end of the stock may have a slide channel formed therein in generally co-planar alignment with a longitudinal axis of a barrel of the barrel group. The stock may then further include a recoil absorbing slide resiliently slidably mounted in the slide channel. The slide may have a shoulder pad mounted at an exposed end of the slide, that is, the exposed end protruding from the butt end of the stock. The slide may have an upper portion extending from the slide channel along an upper surface of the stock, for example generally opposite a handgrip of the stock. A slide cover member may be mounted to the slide and may extend generally the length of the stock and along the upper surface of the stock. The slide cover slides over the upper surface of the stock as the slide slides in the slide channel so as to absorb recoil upon firing of the shotgun. The slide cover may be conformally shaped so as to smoothly conform to the contours of the stock. A rigid insert may be provided which is slidable over an exposed portion of the exposed end of the slide when the slide is fully extended from the butt end of the stock so as to disable operation of the slide.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0013]FIG. 1 is a partially exploded perspective view of the shotgun of the present invention,  
     [0014]FIG. 1 a  is an exploded, partially cut-away perspective view of a prior art shotgun.  
     [0015]FIG. 2 is a side elevation of the butt stock of FIG. 1 showing the recoil mechanism in operation,  
     [0016]FIG. 3 is, in partially exploded view, the butt stock of FIG. 2 with the recoil mechanism disabled,  
     [0017]FIG. 3 a  is, in elevation view, the recoil disabling mechanism of FIG. 3,  
     [0018]FIG. 4 is an exploded isometric view illustrating the coupling mechanism between forestock and trigger housing of the shotgun of FIG. 1,  
     [0019]FIG. 5 is a cross-sectional view along line  5 - 5  in FIG. 4,  
     [0020]FIG. 6 is a partially exploded isometric view illustrating the trigger housing and the coupling bolt and male coupler of FIG. 4,  
     [0021]FIGS. 7 and 7 a  are isometric views of the break-open mechanism in the forestock.  
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION  
     [0022] As seen in FIG. 1, the improved shotgun  10  of the present invention has a stock  12 , a receiver  14  and a barrel group  16 .  
     [0023] As illustrated in FIGS. 2 and 3, stock  12  may have at its butt end a shoulder pad  18  mounted to a rigid base plate  20 . Base plate  20  is rigidly and orthogonally mounted to internal slide arm  22 . Slide arm  22  slides within a channel in stock body  24  along a plane generally vertically bisecting stock  12  so as to cooperate with a resilient shock absorber such as conventionally known in the art housed within stock body  24 . Slide body  26  is also rigidly orthogonally mounted to base plate  20  so as to extend co-extensively along an upper surface of stock body  24 . Slide body  26  slides over interface  27  relative to stock body  24  when stock body  24  recoils in direction A due to recoil following firing of the shotgun. Slide body  26  is shaped conformally with stock body  24  so that with slide arm  22  in its normally extended non-compressed position, other than a hairline at interface  27 , slide body  26  and stock body  24  appear as a unitary whole in the shape of a conventional rigid shotgun stock.  
     [0024] As better seen in FIG. 3 a , U-shaped insert  28  may be slid in direction B into the cavity between base plate  20  and the adjacent end of plate  30  mounted to stock body  24 . Channel  32  in U-shaped insert  28  slides snugly over slide arm  22  until the upper ends of U-shaped insert  28  abut the lower surface of slide body  26  so as to completely cover slide arm  22 . With U-shaped insert  28  so mounted, the operation of slide arm  22 , that is, the operation of the resilient recoil absorber, is disabled so that stock  12  performs as a conventional rigid stock. The outer surface of U-shaped insert  28  is shaped so as to conform to the lateral cross-sectional shape of stock body  24  and base plate  20 . U-shaped insert  28  may be releasably locked into place between base plate  20  and end plate  30  by means of a friction fit assisted by, for example, a spring-loaded ball bearing latch mechanism wherein ball bearing  34  resiliently mounted in end plate  30  releasably engages a corresponding cup or aperture  36  in U-shaped insert  28 .  
     [0025] As seen in FIG. 4, at the opposite end of stock body  24  opposite to plate  30 , a female receiver coupler  38  is mounted into forestock  12   a . Forestock  12   a  is longitudinally bored so as to snugly receive sleeve  40  of coupler  38  journalled into and along the bore. Sleeve  40  is itself hollow having a pair of oppositely disposed cutouts  42  along its length defining therebetween an opposed facing pair of threaded lands  44 . Sleeve  40  is rigidly mounted to annular collar  46  so as to extend perpendicularly therefrom. Annular collar  46  is shaped and sized so that its outer perimeter is conformal to the end surface of forestock  12   a  when sleeve  40  is mounted within the longitudinal bore of forestock  12   a.    
     [0026] In the illustrated embodiment, not intended to be limiting, the alignment of sleeve  40  within the bore of forestock  12   a  is assisted and maintained by fiberglassing the sleeve into the bore, assisted by the fiberglass engaging longitudinal grooves  40   a  in sleeve  40 .  
     [0027] The cylindrical aperture  46   a  of collar  46  is coaxial with, and of corresponding diameter to, the internal cylindrical cavity of sleeve  40  so as to receive therethrough male coupling shaft  48  when inserted in direction C into sleeve  40  along axis D.  
     [0028] Male coupling shaft  48  is in the shape of a two sided cant, that is, when viewed in cross-section in a plane perpendicular to axis D, shaft  48  is obround with the two parallel sides of the obround corresponding to a pair of parallel planar faces  50  and the oppositely disposed curved ends of the obround corresponding to a pair of threaded uniformly curved surfaces  52 . A base  54  is mounted to the non-threaded end of shaft  48 .  
     [0029] Male coupling shaft  48  may be inserted or removed from sleeve  40  when shaft  48  is rotated about axis D, so that threaded surfaces  52  are aligned with, so as to be exposed through, cutouts  42 . The result is that the threads on threaded surfaces  52  are disengaged from the threads on threaded lands  44 . Thus, shaft  48  is inserted in direction C into sleeve  40  by aligning planar faces  50  so as to slide over threaded lands  44  until shaft  48  is completely journalled within sleeve  40 . Shaft  48  may then be rotated in direction E about axis D by 90 degrees so as to mate the threads on surfaces  52  with the threads on lands  44 . With the threads so engaged, the receiver coupler pair, which mates male coupling shaft  48  to female receiver coupler  38 , are releasably locked together.  
     [0030] In one embodiment, a pin  53  or like protrusion seen in FIG. 5 on base  54  engages, so as to slide along, arcuate groove  55  on collar  46  as base  54  is mated against collar  46 . The end  55   a  of groove  55  arrests rotation of base  54  relative to collar  46  by engaging pin  53 . End  55   a  acts as a stop to prevent over-tightening and to ensure and ease correct alignment of the receiver coupler pair once mated so that locking  56  aligns with locking aperture  58 .  
     [0031] Spring loaded locking pin  56  in collar  46  releasably engages corresponding locking aperture  58  on base  54  when the threads on the pair of curved surfaces  52  and the pair of threaded lands  44  are uniformly aligned. To release locking pin  56  from engagement from locking aperture  58 , locking pin  56  is retracted in direction F by a user pulling back on thumb operated button  60 , mounted adjacent the upper surface of annular collar  46 , against the return biasing force of resilient spring  51  housed within a spring housing  62 . It is understood that, although spring housing  62  is shown as being exposed on the upper surface of forestock  12   a , that spring housing  62  may also be recessed into a corresponding cavity in forestock  12   a  so that for aesthetic purposes, only thumb operated button  60  is exposed on the upper surface of forestock  12   a.    
     [0032] As seen in FIGS. 6 and 7, receiver  14  is a housing comprising base  54 , left side wall  64 , right side wall  66 , the trigger housing  68 , and the internal firing mechanism between trigger  70  and the firing pins  71 . Except as set out herein, the internal firing mechanism may have parts from a conventional receiver assembly such as sold by Browning™ under the trademark Citori as would be well known to, and well understood by, a person skilled in the art. A Browning Citori shotgun is shown in exploded view in FIG. 1 a  with the firing mechanism partially cut-away. On each of the left and right side walls, a circular recess  72  may be provided with provides no function other than to receive an embossed coin bearing the applicant&#39;s trademark.  
     [0033] Male coupling shaft  48  is itself hollow so as to receive journalled therethrough a threaded bolt  74 . Bolt  74  is journalled through borehole  48   a  in shaft  48  so as to protrude through aperture  54   a  in base  54 . The threaded end of bolt  74  protruding through aperture  54   a  mounts the internal firing mechanism rigidly between the side walls and rearwardly against base  54 . In one embodiment, side walls  64  and  66  are rigidly mounted to base  54  by bolting corresponding side walls to the corresponding flanges of base  54  using bolt holes  54   b.    
     [0034] Barrel group  16  is quickly dismountable from between sidewalls  73  on receiver  14  by the operation of a barrel release trigger  76 . As better seen in FIG. 8 a , trigger  76  is slidably mounted on pin  76   a . Pin  76   a  is immediately forward of trigger housing  68 . Release trigger  76  has an elongated aperture  76   b  through each of two bifurcated sides  78 . Aperture  76   b  permits slidable movement of release trigger  76  in direction rearwardly past trigger guard  68 . Trigger  76  is resiliently urged forwardly, by a spring or other similar well known means (not shown). Nylon inserts  76   c  are mounted on the forward upper surface  76   d  of trigger  76 . Inserts  76   c  provide frictionless bearing surfaces between surface  76   d  and the lower surface of base  86  so that trigger  76  translates smoothly parallel to base  86 .  
     [0035] An elongated locking block  80 , which is generally tee-shaped, has an elongated slide portion  80   a  and a transverse portion  80   b . A recess  82  on the underside of transverse portion  80   b  engages projections  84  on the upper surface of release trigger  76 . Elongated slide portion  80   a  extends rearwardly into the Citori component housing between side walls  64  by sliding over the base of the housing above trigger guard  68 . Sliding movement of trigger  76  also slides block  80 .  
     [0036] Receiver  14  has a lower planar base  86  between side wall extensions  64 ′ and  66 ′. Side wall extension  64 ′ and  66 ′ extend forwardly of side walls  64  and  66  respectively and are coplanar therewith. They support at their forward end a hinge pin  88 .  
     [0037] Symmetrically positioned beneath the breech end  16   a  of the barrel  16  is locking lug  90 , which has formed at its forward end a hinge-pin recess  90   a . Positioned rearwardly of lug  90  are a pair of transversally spaced apart locking arms  92  which depend from the breech end  16   a  and which have a rearwardly facing locking notch  92   a  formed therein.  
     [0038] Disassembly of the barrels  16  from the receiver  14  requires that the operator slidably move release trigger  76  rearwardly toward trigger guard  68 . Engagement of projections  84  on the upper surface of trigger  76  with recess  82  on the underside of transverse portion  80   b  of locking block  80  co-operatively also moves block  80  toward trigger guard  68 . This movement withdraws the forward edge  94  of transverse portion  80   b  from engagement with locking notch  92   a  formed in locking arms  92  as forward edge  94  is withdrawn into slot  75 . As hinge-pin recess  90   a  of locking lug  90  is still in engagement with hinge pin  88 , barrels  16  may be rotated in a downwardly arcuate direction, in direction H, to free locking arms  92  from base  86  of receiver  14 . Once locking arms  92  are freed, the barrels  16  may then be drawn rearwardly in a slightly upward direction to release recess  90   a  in locking lug  90  from engagement with hinge pin  88 .  
     [0039] A cocking wing  100  is pivotally mounted about pin  76   a  within elongate aperture  80   c  of block  80  and between sides  78  of release trigger  76 . Pin  76   a  is journalled through a laterally extending hole  102  in cocking wing  100 . Upper end  100   a  of cocking wing  100  extends upwardly into the Citori™ component housing between side walls  64  in the manner of a conventional Citori™ cocking wing. The lower forwardly extending end  100   b  of cocking wing  100  extends through channel  75   a  below slot  75  so as to be engaged, in the manner of a conventional Citori™ cocking wing, by the end of barrel group  16  as the barrels are pivoted about pin  88  into the closed position. Cocking wing  100  is pivoted about pin  76   a  as the barrels are closed, that is, as the barrels engage end  100   b  of cocking wing  100 .  
     [0040] As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof.