Abstract:
Disclosed is a multi-material firearm trigger having an upper portion configured to interact with at least one other component of a fire control mechanism and a finger lever portion attachable to the upper portion. The upper portion is formed by injection molding and the finger lever portion is formed from metal by material removal machining processes.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to a firearm trigger. In particular, it relates to a trigger member made from at least two distinct materials. 
       BACKGROUND OF THE INVENTION 
       [0002]    The Ruger® (Sturm, Ruger &amp; Co., Inc. of Southport, Conn.) Model 10/22® is a semi-automatic rimfired rifle chambered in 0.22 Long Rifle. Since its introduction in 1964, it has remained a very popular firearm known for its easy handling characteristics, negligible recoil, and inexpensive ammunition, making it ideal for youth or inexperienced shooters, as well as small-game hunters and those who want an inexpensive rifle firing inexpensive ammunition for target and plinking use. 
         [0003]    In late 2007, Ruger introduced the 0.22 Charger pistol, based on the 10/22 action. Other than the stock and the length of the barrel, this pistol is mechanically identical to the 10/22® in operation and also shares interchangeable parts. 
         [0004]    The popularity of the 10/22 led to the availability of many after-market modifications to improve performance or augment the rifle&#39;s looks. Consequently, it has become one of the most customizable firearms made. Custom manufacturers also make “clones” of the 10/22® platform, which share interchangeability of most parts, but may be built to higher specifications or for specialized purposes. As used herein, reference to the 10/22® platform or 10/22® action is intended to be inclusive of both a rifle and a pistol configuration, and to include “clones” made by other manufacturers intended to have interchangeability of parts. 
         [0005]    The standard 10/22 barrel uses a unique v-block system to attach the barrel to the receiver, making removal and replacement of the barrel (which would require a gun smith&#39;s work with most other rifles) very easy. Combined with a simple construction of the remainder of the components, this allows the average person to easily replace any part in the firearm with nothing more than a screw driver, a hex key and simple punches. The wide availability of interchangeable custom parts in a wide variety of anodized colors makes the 10/22® platform popular and accessible for assembly and customization by the owner without the needing to hire a gun smith. 
         [0006]    The 10/22® platform receiver and fire control group (trigger mechanism) are often made of an aluminum alloy that may be anodized to a wide variety of colors and finishes. 
         [0007]    In 2014, Ruger introduced a redesigned fire control mechanism (trigger assembly), known as the BX-TRIGGER™, which provids an improved trigger feel that may be retrofitted as a “drop-in” assembly into any model of the 10/22® platform. The BX-TRIGGER™ changed the “standard” design of several internal fire control mechanism parts, some of which are molded from a high-strength polymer material. One of these parts is the trigger member, itself. This design, shown in  FIG. 1 , includes geometry that is extremely difficult (or at least very expensive) to manufacture by conventional material removal machining methods from solid material. While the polymer used to mold this part may be available in a variety of colors, the color and finish of a polymer trigger will not match the color and finish of the anodized aluminum receiver (or other custom color parts). 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides a multi-material firearm trigger member, including an upper portion configured to interact with at least one other component of a fire control mechanism and a finger lever portion attachable to the upper portion. The upper portion is formed by injection molding and the finger lever portion is formed from metal by material removal machining processes. This allows the upper portion to me economically manufactured with complex geometry that is difficult to machine by conventional machining methods and the finger lever portion to be made of metal that can match the color and finish of other custom metal parts of the firearm. 
         [0009]    In one example, the upper portion may be formed by metal injection molding (MIM) processes. Steel material may be preferred for the upper portion in the MIM process. The finger lever portion may be attached to the upper portion with a threaded fastener. Additionally, the upper portion and finger lever portion can include engageable interface surfaces that, when attached, provide mechanical transfer of shear forces between the portions. One example of interlocking interface surfaces would include a dovetail tenon and mortise. 
         [0010]    Other features, objectives, and benefits of the present invention may be apparent from a review of the various figures of the drawing, the detailed description of a exemplary embodiment, and claims, all of which comprise disclosure of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Like reference numerals are used to indicate like parts throughout the various figures of the drawing, wherein: 
           [0012]      FIG. 1  is an isometric view of a prior art trigger member molded from a polymer material; 
           [0013]      FIG. 2  is an isometric view of a multi-material trigger with an interchangeable finger lever according to one embodiment of the present invention; 
           [0014]      FIG. 3  is a sectional view thereof taken substantially along line  3 - 3  in  FIG. 2 ; 
           [0015]      FIG. 4  is a side elevation view thereof; 
           [0016]      FIG. 5  is a side sectional view thereof taken substantially along line  3 - 3  in  FIG. 2 ; 
           [0017]      FIG. 6  is a first isometric exploded view thereof; and 
           [0018]      FIG. 7  is a second isometric exploded view thereof. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    The original trigger member for the 10/22® platform (not shown) was a design that could be readily manufactured from a billet of steel or aluminum alloy material by conventional material removal machining processes. Made from these materials, the trigger member could be anodized to a color and finish that would exactly match that of other custom metallic parts in a rifle build, such as the receiver, charging handle, trigger guard/housing, magazine release lever, and extended magazine body. The trigger member  10  of the Ruger® BX-TRIGGER™, shown in  FIG. 1 , includes internal geometry that would be extremely difficult (or at least very costly) to machine from a billet of solid material. Instead, the trigger member  10  was designed to be manufactured by molding, typically using a fiber-reinforced polymer material. However, the trigger member  10  cannot be manufactured from a polymer material and have a color and finish to match that of other customized, metal parts of the firearm. 
         [0020]    The present invention provides a replacement, custom trigger member  12  formed from at least two distinct materials by different manufacturing processes, joined together. This allows an upper portion  14  to be formed by a molding process and the exposed finger lever portion  16  to be CNC milled (or otherwise formed by material removal machining processes) from a billet of material, such as an aluminum alloy, that may be anodized to a color and finish exactly matching that of other customized parts of the firearm. For example, the upper portion  14  may be molded from a high-strength polymer material or made by metal injection molding (MIM), a well-known process by which finely-powdered metal is mixed with a binder material and formed by injection molding. Following proper post-molding treatment, the end-product MIM metal part will have mechanical and physical properties comparable with parts made using classic metal working methods. Forming the upper portion  14  using steel MIM can produce a part appreciably stronger than that of the prior art polymer material. The molded upper portion  14  and machined finger lever portion  16  may be permanently joined together or may be removably attached. Triggers  12  may be economically manufactured using one mold to produce an upper portion  14  for a selected firearm to be joined with a variety of different finger lever portions having different shapes, colors, and/or finishes. 
         [0021]    Like the prior art trigger  10  shown in  FIG. 1 , the upper portion  14  of the trigger member  12  includes a longitudinally oriented slot or trough  18  bounded on each side by opposite, upwardly extending flanges  20 ,  22 . Transversely aligned openings  24 ,  26  of appropriate size are provided in the flanges  20 ,  22  at appropriate locations to receive transverse pivot pins (not shown) for mounting the trigger member  12  in a trigger housing (not shown) and for interaction with other parts of the trigger assembly (e.g., sear and disconnector, not shown). As described above, complex geometry, such as the particularly shaped recesses on inner surfaces of the flanges  20 ,  22  (necessary for fit and conformance with the Ruger® BX-TRIGGER® design), make the manufacture of this portion by conventional material removal machining processes nearly impossible, or at least unacceptably expensive. Thus, according to one aspect of the present invention, the upper portion  14  is manufactured by an injection molding process. While the upper portion  14  may be molded from a polymer material, a metal injection molding (MIM) process using sintered steel or other metal can be used to produce a significantly stronger part while maintaining a low manufacturing cost. 
         [0022]    The finger lever portion  16  may be machined using conventional material removal (CNC) machining methods from a billet of material matching other customized metallic parts of the firearm. For example, the finger lever  16  can be machined from an aluminum alloy or steel, selected so that its surface may be finished, such as by anodizing, to match the look of the receiver, trigger guard, or other customized parts. 
         [0023]    The upper portion  14  and finger lever portion  16  may be joined together after separate manufacture by any suitable means, such as a threaded fastener  28  inserted through an opening  30  in the upper portion  14  and into a threaded socket  32  in the finger lever portion  16  (or vice-versa). Alternatively, the upper portion  14  and finger lever portion  16  may be joined together by a more permanent means, if desired, such as by fusing, adhesive bonding, or a non-removable fastener. 
         [0024]    As best seen in  FIGS. 5-7 , the interface between the upper portion  14  and finger lever portion  16  may be provided with mating or interlocking surfaces to increase the surface area of the interface and provide a mechanical connection with increased shear strength in lateral and longitudinal directions. This can include a stepped protrusion on one of the components with a complementary-shaped socket  36  in the other. A stepped profile allows maximum engagement with the deeply curved profile of the finger lever portion  16 . If desired, the interface may include an interlocking dovetail shape mortise/tenon or keyway, so that the upper portion  14  and finger lever portion  16  are assembled by sliding the two portions together. 
         [0025]    While one embodiment of the present invention has been described in detail, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. Therefore, the foregoing is intended only to be illustrative of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not intended to limit the invention to the exact construction and operation shown and described. Accordingly, all suitable modifications and equivalents may be included and considered to fall within the scope of the invention.