Patent Abstract:
A firearm comprising a frame, a barrel with a firing axis connected to the frame, a cylinder pivotally attached to the frame and positioned within an opening in the frame and having a plurality of firing chambers sized to receive a cartridge, and a firing mechanism including a trigger attached to the frame to actuate the firing mechanism, wherein the frame is substantially nonmetallic and includes at least one metal insert having a polymer over-molding. A cylinder retaining mechanism selectively retains the cylinder in a first position within a window in the frame and comprises a biasing pin operatively attached to a yoke and which is oriented in a direction substantially transverse to the bore axis when the cylinder is in the first position.

Full Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/141,715, filed on Dec. 31, 2008, which is herein incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to firearms and, more particularly, to a revolver having nonmetallic components, an improved barrel, drive mechanism and safety. 
       BACKGROUND OF THE INVENTION 
       [0003]    Revolvers have changed very little in their overall design and operation in over 100 years, and are generally comprised of a frame, a cylinder, a firing mechanism and a barrel. As is known in the art, revolvers begin as metal blanks that are forged into close approximations of these major parts. After annealing or heat-treating the parts, they undergo basic machining processes such as milling, drilling and tapping. This manufacturing and assembly process is often relatively costly and can require a great deal of hand fitting to orient and align the various metal components with one another so that smooth operation and firing is achieved. 
         [0004]    As alluded to above, a revolver is essentially comprised of four main components: a frame, a cylinder, a firing mechanism and a barrel. The frame generally includes one or more frame portions, often a main frame portion, a hand grip portion, and a trigger guard. The cylinder is mounted on the frame by a yoke and fits within a window in the frame. The cylinder has formed therein a plurality of chambers for receiving cartridges. As the trigger is pulled, the cylinder rotates in the frame to successively present the chambers to the barrel for firing. The cylinder also includes an ejector mechanism for removing cartridge casings subsequent to firing, and a cylinder retaining mechanism for holding the cylinder in place within the window in the frame during operation. Often, a cylinder release bar that can be moved via a thumb piece is provided to actuate the retaining mechanism and thereby allow the cylinder and yoke to be rotated away from the frame and into the cylinder-open position. 
         [0005]    The firing mechanism of a conventional revolver includes a trigger, a sear, a hammer, a main spring and a pawl that is sometimes referred to as a “hand.” When the revolver is in an operable mode, pulling the trigger causes the hand to move forward, reciprocate up and engage the ratchet, thereby rotating the ratchet and attached cylinder. However, this particular configuration requires that a slot be cut in the face of the frame in the breech face area to allow for the hand to move from the inner portion of the frame to engage the ratchet and turn the cylinder. Such a configuration results in increased manufacturing time and cost and requires that such components be hand fit precisely so that the revolver may operate smoothly. 
         [0006]    Pulling the trigger also causes the sear and hammer to rotate away from the cylinder. The rotation away from the cylinder is resisted by the main spring. After a predetermined amount of travel, the sear and hammer disengage from the trigger and allow the spring to force the hammer toward the cylinder. The hammer is aligned with one of the cylinder chambers and the cylinder chamber, in turn, is aligned with the barrel. A firing pin on the hammer is positioned to strike the cartridge disposed in the chamber. 
         [0007]    There is also an interest in designing firearms so that the inner parts of the revolver may be cleaned, serviced, repaired, etc. One solution to this problem is to provide a side plate on the side of the revolver that is pinned or otherwise secured to the frame of the revolver. The removal of the side plate allows access to the internal components of the revolver such as the hammer, sear, firing mechanism and hand. One drawback with the use of a side plate, however, is that the side plate can make the revolver less rigid and induces a series of a-symmetric stresses in the frame which can cause the frame to fatigue and ultimately fail over time. It is therefore a general object of the present invention to provide a revolver that is designed so as to allow access to the interior components while maintaining the structural rigidity of the frame. 
         [0008]    A retaining mechanism is necessary to retain the cylinder within the rectangular aperture, especially subsequent to firing. Many prior art revolvers lock the yoke directly into the frame via known means. Other revolvers use a ball detent to restrain the forward end of the cylinder. Often times, however, when a round is discharged, the forces which propel the round down the length of the barrel exert a corresponding force in the opposite direction, that is, towards the rear, handgrip portion of the revolver. Although the effect of this opposite force is marginal on the interconnected elements of the revolver, the manufacturing tolerances inherent in the revolver permit a minute amount of structural translation to occur as a result of this incident and opposite discharge force. The effect of the structural translation of certain elements in the revolver may cause the cylinder and yoke assembly to move slightly rearwards, causing, e.g., a ball detent to disengage, thus facilitating the unintended pivoting of the cylinder from its closed position to its open position. In such a situation, the revolver must then be clicked back into its cylinder-closed position before additional firing. It is therefore a general object of the present invention to provide an improved cylinder retaining mechanism that will retain the cylinder within the frame during firing. 
       SUMMARY OF THE INVENTION 
       [0009]    In view of the foregoing, it is an object of the present invention to provide a revolver that includes a frame, a barrel, a cylinder, a hammer, a trigger, and a safety lock mechanism. 
         [0010]    It is another object of the present invention to provide a revolver that can be manufactured with a minimal or reduced amount of hand fitting of parts. 
         [0011]    It is another object of the present invention to provide a revolver that can be produced at a low cost. 
         [0012]    It is another object of the present invention to provide a revolver comprising a polymer frame. 
         [0013]    It is another object of the present invention to provide a revolver with modular subassemblies that may be quickly and easily inserted into a preformed frame and secured in place. 
         [0014]    It is another object of the present invention to provide a revolver with a removable trigger guard that allows for the customization of accessories. 
         [0015]    It is another object of the present invention to provide a revolver with an improved barrel, shroud and sight design. 
         [0016]    It is another object of the present invention to provide a revolver with an improved yoke lock that prevents the revolver from coming out of battery during operation. 
         [0017]    It is another object of the present invention to provide a revolver with an improved drive mechanism that obviates the need for a conventional hand mechanism to rotate the cylinder and obviates the need for a slot to be cut in the breech face to allow for the forward movement of the hand. 
         [0018]    It is another object of the present invention to provide a revolver with an improved retention drop safety. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below: 
           [0020]      FIG. 1  is a perspective view of a revolver according to one embodiment of the present invention; 
           [0021]      FIG. 2  is a perspective view of a lower frame portion and trigger guard of a revolver according to one embodiment of the present invention; 
           [0022]      FIG. 3  is a perspective view of an upper frame portion and barrel and shroud assembly of a revolver according to one embodiment of the present invention; 
           [0023]      FIG. 4  is a detailed perspective view of a barrel, shroud and sight assembly of a revolver according to one embodiment of the present invention; 
           [0024]      FIG. 5  is a detailed perspective view of a barrel and shroud assembly and a cylinder retaining mechanism of a revolver according to one embodiment of the present invention; 
           [0025]      FIG. 6  is a perspective view of a cylinder retaining mechanism of a revolver according to one embodiment of the present invention; 
           [0026]      FIG. 7  is a perspective view of a ratchet drive mechanism and breech face of a revolver according to one embodiment of the present invention; 
           [0027]      FIG. 8  is a perspective view of a cylinder and ratchet mechanism according to one embodiment of the present invention; 
           [0028]      FIG. 9  is a perspective view of a ratchet drive mechanism, trigger, hammer, firing pin and safety of a revolver according to one embodiment of the present invention; 
           [0029]      FIG. 10  is a perspective view of a ratchet drive mechanism, hand and latch of a revolver according to one embodiment of the present invention; 
           [0030]      FIG. 11  is a perspective view of a ratchet drive mechanism, hand and latch of a revolver according to one embodiment of the present invention; and 
           [0031]      FIG. 12  is a perspective view of a ratchet drive mechanism, hand, firing pin, safety and latch of a revolver according to one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0032]    Referring to  FIG. 1 , one exemplary embodiment of a firearm incorporating the present invention is shown generally at  10  and is hereinafter referred to a as “firearm  10 .” The firearm  10  is preferably a revolver (as described in U.S. Pat. Nos. 6,330,761 and 6,523,294, which are incorporated herein by reference) that includes a frame, a cylinder, a firing mechanism, and a barrel. A firing axis extends coaxially with the barrel. 
         [0033]    The frame is generally comprised of two main parts, an upper frame portion  20  and a lower frame portion  22 .  FIGS. 2 and 3  illustrate perspective views of the lower  22  frame portion and upper frame portion  20 , respectively. As shown in  FIG. 2 , the lower frame portion  22  contains the back strap, main spring housing  26  and the grip, as well as space for the internal firing mechanism. As shown in  FIG. 3 , the upper frame portion  20  houses the barrel  34 , cylinder  60  and internal firing mechanism, as described in detail below. A forward end  28  of the lower frame portion  22  is shaped so as to accept a corresponding rearward end  30  of the upper frame portion  20 . These upper and lower frame portions  20 ,  22  are joined together by pins to create a structurally rigid frame, although any other joining means known in the art may also be used. Importantly, there is no cut-out or accompanying side plate on either the upper or lower frame portions which is normally necessary to access the internal components of the revolver. Instead, due to the modular frame portions and the configuration thereof, the revolver may easily be broken down into its constituent frame parts and the internal components and mechanisms accessed in this manner. The absence of a side cut-out and side plate yields a more symmetrical, and therefore, stronger and more resilient frame. 
         [0034]    The firearm frame portions are preferably comprised of metal stampings or inserts having a polymer over-molding on top of the inserts. It will be readily appreciated, however, that other metallic and nonmetallic materials may be used in the construction of the frame portions without departing from the scope of the present invention. Indeed, any polymer known in the firearm art may be used to form the upper and lower frame portions provided that sufficient strength and rigidity of the frame components is achieved. The metal inserts can also be varied in material and thickness to achieve a desired strength and rigidity. 
         [0035]    As alluded to above, known methods of manufacturing firearms, and revolvers in particular, require the precision cutting, milling and fitting of many intricate parts. For example, known firearms require that a slot be cut in the breech face area to accommodate the hand which engages the ratchet on the cylinder to index the cylinder. Indeed, prior art revolvers must be bent and modified to ensure that the barrel, cylinder, firing and locking mechanisms all come into registration within prescribed tolerances so that the revolver operates properly. Importantly, such bending is not required with the polymer frame firearm of the present invention, as known polymer and other molding technologies may be employed to create all of the frame components so as to accommodate the barrel, cylinder, safety and firing mechanism without the need for any additional cutting, milling or modifying. 
         [0036]    Importantly, the molded polymer frame portions  20 , 22  are formed such that they generally define open receptacles preconfigured to receive component subassemblies. As will be readily appreciated, this obviates the need for the frame portions to be milled, cut, and bent to accommodate the individual component parts of the firearm. Instead, various subassemblies, such as the firing mechanism, trigger mechanism and barrel can be preassembled into subassemblies remote from the frame portions and simply “dropped” into the receptacles in the molded polymer frame portions  20 , 22  and pinned or otherwise secured in place. As a result of this configuration, the frame portions do not need to be substantially modified after the molding process to accommodate the component parts, thus cutting down on assembly and manufacturing time, as well cost. 
         [0037]    As shown in  FIG. 2 , the frame also includes a separate trigger guard  32  that is releasably attached to the frame via a notch and groove type configuration and which is secured in place by a pin. The fact that the trigger guard  32  is removable allows a user to customize the accessories that are used with the revolver, such as accessories that may be placed on the forward portion of the trigger guard, e.g., laser sights, etc. 
         [0038]    Referring now to FIGS.  1  and  3 - 5 , the barrel  34  comprises an axially elongated generally cylindrical sleeve which projects forwardly from the upper frame portion  20  and is received within a barrel shroud  36 . In one embodiment of the present invention, the barrel  34  may have a generally cylindrical rifled bore extending coaxially through it, the bore rifling being formed by conventional spiral rifling grooves cut in the wall of the bore, in a manner will known in the firearm and revolver art. 
         [0039]    A rear portion of the barrel  34  is externally threaded (not shown) for mating engagement with internal threads (not shown) in a bore on the upper frame portion  20  of the firearm frame. In a preferred embodiment, the barrel  34  is threaded at  36  threads per inch, although different thread sizes and thread counts may be used. There is also a second set of threads  38  on the distal or muzzle end of the barrel  34  that are enlarged in diameter and have substantially the same thread count as the rear portion of the barrel  34 . The barrel  34  may then be threaded through the shroud  36  and locked into place. Upon assembly of the firearm  10 , the cylindrical bore registers with the respective chambers of the cylinder and forms the longitudinal firing axis. 
         [0040]    The barrel shroud  36  includes a radially disposed and rearwardly facing abutment surface for complimentary engagement with the forwardly facing seating surface on the forward end of the upper frame portion  20  of the firearm frame. In one embodiment of the present invention, the upper surface  40  of the barrel shroud  36  is substantially flat and is provided with an axially elongated, upwardly open sight receiving groove  42  formed therein. The groove is adapted to receive a front sight  44  which is pinned or otherwise secured in fixed position to the shroud member  36 . 
         [0041]    The clearance between the forward-most surface of the cylinder and the rearward-most surface of the barrel is referred to as the barrel-cylinder (BC) gap. To set the barrel-cylinder gap, a crush washer  110  is used, with typical barrel-cylinder gap tolerances being in the range of 4,000ths to 10,000ths of an inch. In particular, to set the barrel-cylinder gap, there are a series of machine flats  48  provided on the outer circumference of the muzzle end of the barrel  34  in the approximate position where the front sight  44  is located. The barrel  34  is threaded through the shroud  36  and into the upper frame portion  20  against the metal frame insert until the threading crushes the metal washer  110 . Once the predetermined tolerance is reached, the barrel is cocked slightly further so that one of the machine flats  48  comes to the surface. A pin is then passed through the shroud  36  and rides across the top of the given flat  48  on the barrel  34 , locking the barrel  34  in place. 
         [0042]    Other sight configurations, such as a dove-tail sight, may also be used. In this embodiment, as shown in  FIGS. 3 and 4 , the barrel  34  is threaded through the shroud  36  and into the upper frame portion  20  against the metal frame insert until it crushes the metal washer  110 . Once the predetermined tolerance is reached, the barrel is cocked slightly further so that one of the machine flats  48  comes into alignment with the sight receiving groove  42 . A dove-tail front sight  44  may be placed into the sight receiving groove  42  and removably attached to the shroud  36  via a pin through the shroud  36  and sight  44 . The bottom tab  50  of the sight  44  is received in the machine flat  48  and held in place by the pin, locking the barrel  34  in place. 
         [0043]    Turning now to FIGS.  1  and  3 - 6 , a cylinder  60  and yoke  70  is shown. The cylinder  60  is pivotally mounted in the upper frame portion  20  and includes an ejector  62 , a ratchet  64 , and a plurality of chambers  66 . The chambers  66  are configured to receive and align cartridges  68  with the barrel  34 . The cylinder  60  is pivotally mounted on a yoke  70  that is attached to the frame via a yoke stud. A top strap  72  extends across a top portion of the frame from a forward portion to a rearward portion to define a generally rectangular aperture  74 . When the cylinder  60  is closed with respect to the yoke  70 , the cylinder  60  is positioned in the rectangular aperture  74  such that a chamber  66  of the cylinder  60  is longitudinally aligned with the barrel  34 . 
         [0044]    As will be readily appreciated, all known revolvers require a retaining mechanism to retain the cylinder within the rectangular aperture  74 , especially subsequent to firing. In one embodiment of the present invention, the cylinder retaining mechanism comprises an ejector rod  76  that is spring-biased forward and a ball detent mechanism  78 . The spring-biased ejector rod  76  contacts a portion of the frame adjacent the tip of the ejector rod, thereby holding the cylinder in place. To further ensure that the cylinder does not come out of battery during firing, ball detent mechanism  78  is also provided. 
         [0045]    The ball detent mechanism includes a vertical pin  80  with a substantially round head that is received within a corresponding shallow recess  82  on the underside of upper frame portion  20 . In the preferred embodiment, vertical pin  80  is biased by a coil spring, or the functional equivalent thereof, towards shallow recess  82  when the firearm is in the cylinder-closed position, although no biasing means need be employed. Vertical pin  80  is mounted in yoke  70  along an axis that is perpendicular to the bore-axis/firing axis and, importantly, perpendicular to the axis along which the majority of recoil forces are generated. This orientation of the ball detent mechanism  78  will not allow the yoke  70  to be released and the cylinder  60  to be urged open due to recoil forces associated with discharge of the firearm. Vertical pin  80  also has includes flat  84  that is in registration with the ejector rod  76  and is axially movable along an axis perpendicular to the firing axis of the firearm  10 . Both the spring-biased ejector rod  76  and the ball detent mechanism  78  prevent the yoke  70  from releasing during the firing of the gun. This design is advantageous because it allows for a simpler design and therefore the use of fewer parts than prior art retaining mechanisms. 
         [0046]      FIGS. 7-12  illustrate the drive mechanism of the firearm  10 . As known in the art, the drive mechanism functions to rotate the cylinder  60  upon the pulling of the trigger  12  to place a new cartridge  68  into alignment with the hammer  14  and firing pin  16 . According to one embodiment of the present invention, a complimentary set of star-shaped configurations are used to rotate/index the cylinder  60 . This star-shaped configuration replaces the commonly-used ratchet mechanism. As shown in  FIG. 8 , the cylinder is provided with a star-shaped socket  64  on its rearward-facing surface. As shown in  FIG. 7 , a rotatable shaft mounted within the frame and having a complimentary star-shaped hub/head  86  extends through the breech face area  18  below the firing pin  16  and is configured to engage the star-shaped ratchet mechanism  64  on the cylinder  60 . It will be readily appreciated, however, that the cylinder may have a male head configuration and the portion of the drive mechanism that extends through the breech face may comprise the corresponding female socket. 
         [0047]    As best shown in  FIGS. 9-12 , there is internal to the frame a supplemental ratchet surface  88  on the rearwardly extending portion of the hub/head  86  whose geometry is such that it is configured to receive on the lower surface a top portion of the newly designed hand  90 . It is this interior mounted ratchet surface  88  that receives the hand  90 . The hand  90  reciprocates up and down in a vertical fashion, and does not need any lateral forward motion or backward motion to rotate the hub  86 . Simple vertical reciprocal motion of the hand  90  upon pressing of the trigger  12  then causes the pin to be pushed upward to index the cylinder  60 . The hand  90  is then is reciprocated downward at the end of the firing stroke. 
         [0048]    As alluded to above, prior art drive mechanisms necessitated that a slot be cut in the frame in the breech face area to allow the hand to be urged from the interior portion of the gun to a ratcheting mechanism on the center portion of the cylinder to rotate the cylinder. As will be readily appreciated, this hand, ratchet and slot design was costly to manufacture and was very time consuming to align the parts with the needed precision. The present invention therefore benefits from the improved hub/head and interior hand and ratchet mechanism in that no slot need be cut in the breech face area of the frame because the hand does not move laterally out of the interior of the firearm, but instead reciprocates vertically, as described below. 
         [0049]    With the cylinder indexing mechanism of the present invention, however, there is also a need to disengage the hub  86  from the cylinder  60  so that the cylinder  60  and yoke  70  can be rotated out of the frame, such as when an operator wishes to eject spent cartridges  68  and reload. As shown in  FIGS. 7 ,  10 ,  11  and  12  a latch mechanism  92  reciprocates the hub  86  in a direction substantially parallel to the firing axis of the firearm  10 . This reciprocal movement causes the hub  86  to be placed into and out of engagement with the star-shaped ratchet mechanism  64  on the cylinder  60 . If an operator desires to place the firearm  10  in the cylinder-open position, the latch  92  is actuated, which retracts the star-shaped hub  86  back behind the breach face area  18  and out of engagement with the star-shaped ratchet  86  on the cylinder  60 . This retracted position is best shown in  FIG. 12 . Upon releasing the latch  92 , the star-shaped hub  86  extends back through the breech face area  18  to engage the corresponding star-shaped ratchet mechanism  64  on the cylinder  60 . 
         [0050]    The present invention also contemplates using either or both of a hammer block and a firing pin block as a safety feature to prevent the unintended discharge of the firearm. In the preferred embodiment, there is a firing pin block, as is shown in  FIGS. 9-12 . According to one embodiment of the present invention, the firing pin block comprises a generally cylindrical blocking member  94  with a flat surface or relieved portion  96  provided thereon. When the trigger  12  is in a non-depressed position, the flat surface or relieved portion  96  on the blocking member  94  is not in registration with the corresponding relieved portion  100  on the underside of the firing pin  16 . As relieved portions  100 ,  96  of the firing pin and blocking member are not in registration with one another, no clearance is provided for the firing pin, as the full diameter portion of the blocking member  94  contacts the firing pin  96 . This prevents the firing pin  16  from striking a chambered cartridge unless the trigger is pulled, even if the hammer is released due to a faulty components or the pin is struck by another object. 
         [0051]    When the trigger  12  is pulled, however, hand  90  reciprocates up and contacts a lever arm  98  fixedly attached to blocking member  94 . As hand  90  goes through its full stroke, it pushes against lever arm  98 , causing blocking member  94  to rotate so that relieved portion  96  is in registration with relieved portion  100  on the underside of the firing pin  16 . When in registration with one another, the relieved portions  96 , 100  provide a clearance that allows the firing pin  16  to release and strike a cartridge. At rest, the pin  94  is urged back into action such that it comes forward and engages the firing pin  16 , holding it in place. 
         [0052]    Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those of skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above detailed description, but that the invention will include all embodiments falling within the scope of this disclosure.

Technology Classification (CPC): 5