Patent Publication Number: US-9851165-B2

Title: Firing pin assembly

Description:
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS 
     Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to firing pin assemblies and, in particular, includes a firing pin that permits a smoother and lighter trigger pull. 
     Description of the Related Art 
     Firing pins are formed in firearms to strike the primer of cartridges to cause the cartridges to fire. Firing pin assemblies are often spring loaded so as to be biased in a firing orientation. Typically, the firing pins are restrained from firing by components of a trigger assembly such as a trigger bar. When the trigger is pulled, the trigger bar is moved so as to permit the spring loaded firing pin to move forward and strike the primer of the cartridge. 
     The force of the spring that biases the firing pin can affect the amount of force needed to be exerted on the trigger to release the firing pin. The spring has to be sufficiently strong to permit the firing pin to fire the cartridge but should also not be so strong so as to cause the shooter to have to exert excessive force to fire the firearm as this may result in the firearm being jostled by the trigger pull thereby reducing the accuracy of the firearm. 
     Further, the engagement between the trigger assembly and the firing pin assembly may also result in inaccuracies. If the trigger assembly binds or is otherwise inhibited from disengaging with the firing pin assembly, this may retard the activation of the firing pin assembly which can induce malfunctions that negatively also affect the performance of the firearm. 
     Hence, there is a need for improved firing pin assemblies and, in particular, firing pin and trigger assemblies that permit easier trigger pulls and easier release of the firing pin by the trigger assembly. 
     SUMMARY OF THE INVENTION 
     The aforementioned needs are satisfied in one embodiment by a firearm comprising: a frame; a barrel positioned adjacent the frame; a receiver that houses a firing chamber and a firing pin assembly which includes a firing pin member having a vertically extending flange wherein the firing pin assembly is spring biased towards a firing position; a trigger assembly having a trigger and a trigger bar member that engages with the vertically extending flange of the firing pin member to inhibit the spring biased firing pin member from moving to the firing position and wherein activation of the trigger assembly disengages the trigger bar member from the flange resulting in the firing pin member moving into the firing position wherein an engagement surface of the flange that engages with the trigger bar member includes a channel to reduce the frictional engagement between the flange member and the trigger bar member. 
     The aforementioned needs are also satisfied in another embodiment by a firearm comprising: a frame; a barrel positioned adjacent the frame; a receiver that houses a firing chamber and a firing pin assembly which includes a firing pin member having a vertically extending flange wherein the firing pin assembly is spring biased towards a firing position wherein the vertical flange includes a rear surface that includes chamfer to reduce the weight of the firing pin member; a trigger assembly having a trigger and a trigger bar member that engages with the vertically extending flange of the firing pin member to inhibit the spring biased firing pin member from moving to the firing position and wherein activation of the trigger assembly disengages the trigger bar member from the flange resulting in the firing pin member moving into the firing position. 
     These and other objects and advantages will become more apparent from the following description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of a firearm having one embodiment of an improved firing pin assembly and trigger assembly; 
         FIGS. 2A and 2B  are front and top views of the firing pin assembly of  FIG. 1 ; and 
         FIGS. 2C-2F  are front, back, rear and detailed views of the firing pin assembly of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made to the drawings wherein like numerals refer to like parts throughout.  FIG. 1  illustrates an exemplary firearm  100  such as a semiautomatic pistol that incorporates an exemplary embodiment of an improved firing pin assembly  102 . As shown, the firearm  100  includes a trigger assembly  104  that includes a trigger that the user depresses to fire the firearm. As will be discussed in greater detail below, the firing pin assembly  102  includes a firing pin member  120  that is spring biased towards a firing chamber  112  of the firearm  100  by a spring  121 . The trigger assembly  104  engages with the firing pin assembly  102  such that depression of the trigger  114  induces the firing pin member  120  to be urged towards the firing chamber  112  thereby striking the primer of a cartridge positioned in the chamber  112  causing the cartridge to fire which results in the slug or bullet of the cartridge travelling down the barrel  114  and outward towards a target. 
     The firearm  100  in this embodiment, includes a frame  106  that has a slide  122  that houses the barrel  114 , the firing chamber  112  and the trigger assembly  104 . The frame  106  may also include a magazine  110  that houses additional cartridges. In operation, once the firearm  100  is fired, the firing pin assembly  112  returns to a cocked position and is held in place by the trigger assembly  104 . The slide  122  traverses backwards and the barrel pivots to receive an additional cartridge into the firing chamber  112 . The slide  122  then traverses forward into the position shown in  FIG. 1  when the firearm  100  is ready to fire an additional round. The firearm  100  may comprise a firearm that operates in the manner of a Glock™ type firearm that is known in the art. 
     As shown, the spring  121  buts up against a rear component  126  of the firing chamber and a flange  130  on the firing pin member  120 . The trigger assembly  104  includes the trigger  116  and an interconnecting piece  132  and a trigger bar  134 . The trigger bar  134  has a horizontally extending piece that engages with a front surface  142  of a flange  140  that extends downward from the firing pin member  120 . The trigger assembly  106  operates to depress the trigger bar  134  downwardly to disengage the trigger bar  134  from the flange  140  thereby inducing the spring  121  to propel the firing pin  120  forward to strike the primer of the cartridge in the firing chamber  112  firing the firearm  100 . 
     As discussed above, the strength of the spring  121  that biases the firing pin member  120  forward affects the amount of pressure that has to be exerted on the trigger  116  to discharge the firearm. A lower force spring allows for the trigger assembly  104  to fire the firearm with less pressure, however, the lower force of the spring results in less force being applied to the firing pin member  120  which can reduce the force with which the primer of the cartridge is struck. To address this, the Applicant has configured the firing pin member  120  to be lighter weight and has further configured a contact surface  124  to provide for greater deformation of the primer to facilitate firing of the firearm. 
       FIGS. 2A-2E  are views of the firing pin member  120  that has been adapted to facilitate the use of a lower spring constant spring and also to improve the engagement and disengagement between the trigger bar  134  and the firing pin member  120 . The firing pin member includes a central shaft  150  that has a front surface  152  and a rear surface  154 . The flange  140  is attached or formed onto the rear surface  154  and the contact surface  124  of the firing pin member  120  is positioned on the front surface  152 . The central shaft defines a spring mounting location where the spring  121  is positioned in the manner shown in  FIG. 1 . The central shaft  150  also includes a plurality of longitudinal indentations  160  that reduce the weight of the firing pin member  120 . In one implementation the rear longitudinal indentations  160  have a depth of 0.039 inches and extend 0.820 inches. The central shaft also includes a central section  162  that has a plurality of round indentations  164  that also reduce the weight of the member  120  that have a radius of 0.153 inches. In one embodiment, the firing pin member  120  is 2.185 inches long, the rear portion is 1.155 inches, the central portion is 0.477 inches and the front section is 0.432 inches and the member  120  has a general radius of 0.188 inches in the rear portion and 0.153 inches in the middle section. 
     The rear flange  140  has a rear or back surface  144  that, in one embodiment, has chamfers formed on the lower portions of the flange  140 . The chamfers  170  in one implementation are 0.250 inches long and 0.125 inches thick and are formed at a 45 degree angle with an outer depth of 0.045 inches. For further weight reduction, a channel  172  is formed between the chamfers  170  and the channel  172  extends the entire length of the flange  140 . The channel  172  can have a depth of 0.020 inches. 
     The chamfers  170 , the longitudinal indentations  160  and the round indentations or through holes  164  all contribute to a reduction of the weight of the firing pin member  120 . For example, a stock firing pin used in Glock™ pistols has a weight of approximately 7.4 grams, however, one specific embodiment of the Applicant&#39;s firing pin member can have a weight of 5.8 grams which is more than a 20% reduction. 
     The front surface  142  of the flange  140  also has a channel  176  formed therein. The channel  176  is formed so as to be centered and to extend approximately 0.193 of the 0.250 inches of the length of the flange  140 . The channel  176  is approximately a third of the width of the front surface of the flange  140  or 0.048 inches in one non-limiting embodiment. As a portion of the front surface  142  of the flange member  140  has been removed, the frictional engagement between the flange  140  and the trigger bar  134  is reduced. This reduction in frictional engagement allows for easier activation of the trigger assembly  104  which allows for smoother operation of the trigger assembly  104  and therefore more accuracy in shooting. 
     Further, the reduction in weight of the firing pin member  120  means that a softer firing pin spring  121  can be used. In typical Glock™ applications, the firing pin spring is a 5 pound spring, whereas the Applicant&#39;s design for a similar application can use a 2 pound spring which results in a lighter trigger pull and greater accuracy. 
     In order to ensure that the primers are fired with the firing pin assembly  102 , a firing pin end piece  180  is elongated and increased in depth as is shown in  FIGS. 2D and 2F . More specifically, the firing pin end piece  180  is one implementation, has a greater height than width as opposed to being a round firing pin. In one specific implementation, the firing pin is 0.033 inches wide but is 0.104 inches in height. The end of the firing pin end piece  180  forms a point having an approximately radius of 0.030 inches with an angle of approximately 73 degrees and extends outward 0.118 inches in the manner shown in  FIG. 2A  however, the elongate height of the firing pin results in greater deformation of the primer which provides greater assurance that the firing pin will detonate the primer by deforming a sufficient area of the primer outer wall to cause the primer to fire. 
     It will be appreciated that all of the dimensions given in this application and incorporated by reference from the parent provisional application are approximate and exemplary. It will further be appreciated that various changes, substitutions and modifications to the form, use and implementation of the embodiments described herein may be made by those skilled in the art without departing from the spirit or scope of the present invention. As such, the present invention should not be limited to the foregoing discussion but should be defined by the appended claims.