Patent Application
20190041151
The present invention relates generally to firearms, and more specifically to firing mechanisms for a firearm.
Firearms use triggers to initiate the firing of a cartridge in the firing chamber of the weapon. This is accomplished by actuating a striking device (a striker) through a combination of spring and kinetic energy operating through a firing pin to strike and ignite the primer.
In semi-automatic pistols, rotation of a sear releases the striker, allowing the striker to contact the firing pin. The sear is in turn rotated by the rearward movement of the trigger. The trigger bar connects the trigger to the sear and translates the rearward movement of the trigger into the rotation of the sear that allows striker to be released, resulting in firing of the pistol.
The trigger is generally connected to the trigger bar via a trigger bar pin or boss which allows the trigger to move with the trigger bar and also allows the trigger bar to rotate around the pin/boss axis.
Trigger characteristics may include travel segments such as a pre-travel distance, an engagement distance, an over-travel distance, and a reset distance. The pre-travel distance, also called “take-up”, is generally the distance the trigger travels from its forward-most resting position (i.e. the position of the trigger in the absence of a rear-ward pull force) to an engagement point where the first element of the fire control system is engaged. The over-travel distance is the distance the trigger travels rearward between the instant the firing pin is released and the instant that the rearward movement of the trigger is arrested (typically by one or more mechanical stops).
Additionally, while a trigger is traveling these travel segments, trigger pull weights, or forces, are exerted in opposition to the general direction of travel of the trigger (except for a post-firing reset travel, wherein the force is generally in the direction of travel). Each travel segment may have a different trigger pull weight (i.e., level of force). This aids a user in determining by feel where a trigger is located within its general travel from a resting position through an engagement or firing position to a post-firing position, back to a reset point, and finally back to a resting position.
Users of firearms, and handguns in particular, often have differing preferences for the feel of a trigger. The feel can be affected by altering one, some, or all of the travel distances and/or altering one, some, or all of the pull weights associated with each travel segment. A trend exists towards a preference for a shorter pre-travel distance. A similar trend exists with respect to shorter over-travel and reset travel distances. These travel distances, alone or in combination, can affect how a user grips the firearm and how their grip can change throughout the travel of the trigger, which can ultimately affect accuracy.
Similarly, a trend exists toward a preference for lowered maximum trigger pull weights. Variations on factors affecting trigger pull weight are possible, but implementing certain variations can often affect other performance aspects of a firearm given current configurations.
Several embodiments of the invention advantageously address the needs above as well as other needs by providing a trigger bar for a firearm comprising: a generally longitudinal body having a front end and a rear end wherein the front end is configured to couple to a trigger of the firearm; an arm extending laterally outward from a portion of the body proximate to the rear end and including: a sear activation tab configured to engage a portion of a sear of the firearm; and a drop safety lifter tab configured to engage a portion of a drop safety lifter of the firearm, whereby the trigger bar is configured to engage the sear and a drop safety of the firearm when the trigger is pulled, whereby the firearm is fired, wherein the sear activation tab and the drop safety lifter tab are configured to result in a total rearward trigger travel distance of less than 0.14 inches prior to firing of the firearm.
The above and other aspects, features and advantages of several embodiments of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings.
Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention.
The following description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of exemplary embodiments. The scope of the invention should be determined with reference to the claims.
Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
Moreover, many references are made throughout this specification to approximate values and ranges. The terms “approximate” or “about” as used herein are meant simply to account for various tolerances and reasonable variances as may exist in manufacturing and testing procedures as are readily understood by those having skill in the art. For example, reference to an approximate value may inherently include a tolerance or variance of 0.10%, 1%, 5%, 10%, or anything in between, as would be deemed appropriate by one having skill in the relevant art with regard to the specific item or concept to which the value or range pertains.
In the context of this description, directions are oriented with respect to a direction along the firing axis towards the exit portion of a barrel of the firearm being defined as a “frontwards” or “forward” direction. “Rearwards” is understood to mean along the longitudinal axis towards a magazine or grip portion of the firearm. Left and right are defined with respect to looking in the forward direction.
Referring first to
By one approach, the firearm 100 is a semiautomatic handgun or pistol, though the teachings disclosed herein may be applied to any type of firearm 100. Shown are a frame 102, a slide 104, a barrel 106, a trigger 108, a longitudinal firing axis 110, and a cartridge 200. The barrel 106 is disposed at a front aperture of the slide 104 and is cooperatively linked therewith, and, together with the slide 104, defines the longitudinal firing axis 110. The barrel 106 has a rearward end adapted for receiving the cartridge 200 fed from a magazine. The trigger 108 is pivotally mounted to the frame 102 to actuate a firing mechanism to fire the firearm 100. A portion of the firing mechanism 300 is shown below in
The slide 104 is fitted to opposingly-positioned rails of the frame 102 to effect the reciprocal movement of the slide 104 along the longitudinal firing axis 110. The rails extend along the underside of the slide 104 in the longitudinal direction and are cooperative with the frame 102 to allow the cycling of the slide 104 between forward (battery) and rearward (retired) positions. The slide 104 further includes a breech, an ejection port 112, and an ejection mechanism that provides for the ejection of the cartridge 200 through the ejection port 112 upon firing the firearm 100 or upon manual cycling of the slide 104.
The cooperation of the frame 102, the slide 104, the barrel 106, and the firing mechanism during the loading, firing of a cartridge, and ejecting of the spent cartridge casing for the firearm 100 of the present type can be understood by referring to U.S. Pat. No. 7,617,628 (Curry) and U.S. Pat. No. 6,993,864 (O'Clair et al.), the entirety of which are incorporated herein by reference.
Referring next to
The firing mechanism frame 310 is mounted within the frame 102. The firing mechanism frame 310 provides a support framework for most of the components shown in
The drop safety 328 includes an interference tab that prohibits the striker from going forward. During the firing sequence of the firearm 100, the trigger bar 316 engages the sear 326 and the drop safety lifter 330, as described further below. The drop safety lifter 330 is rotated upwards and then engages the drop safety 328. Further movement of the trigger 108 caused the drop safety lifter 330 to lift the drop safety 328 out of the way, whereby the interference tab no longer prevents the striker from moving forward. As the trigger is moved further rearward the sear 326 is moved sufficiently that it releases the depending leg 306 of the striker 302 and the firearm 100 is fired.
Referring next to
As shown in
An over-travel pin (not shown) extends laterally inward from an inside face of the firing mechanism frame 310. The tubular over-travel stop 410 is configured to fit over the over-travel pin and is held in place by the firing mechanism frame 310. The over-travel stop 410 in one embodiment as an inside diameter for approximately 0.003″ larger than the over-travel pin. The over-travel stop 410 is stationary with respect to the firing mechanism frame 310 and is configured to stop the rearward movement of the trigger 108 after the trigger 108 has traveled a certain distance rearward after firing (the over-travel distance 916 as described in
The sear 326 rotates about and is supported by the sear pivot pin 322 in the sear pivot hole 402. The drop safety lifter 330 rotates about and is supported by the safety lever pin 320 in the safety lever hole 404.
The notch in the rear portion of the sear 326 restrains the striker 302 in the rearward (ready to fire) position. The arm 400 of the trigger bar 316 is configured to engage and move the drop safety lifter 330 and the sear 326 when the trigger is moved rearward.
In operation, before the firing procedure the trigger bar 316 may be biased forward in a rearward longitudinal direction by trigger bar spring 318 or the like. When the trigger 108 is pulled in a rearward direction, due to the trigger link 312 connection the trigger bar 316 is moved generally forward, whereby the arm 400 moves generally forward, engaging first the drop safety lifter 330 and then the sear 326. As the trigger 108 continues to be pulled, eventually the drop safety 328 and the sear 326 reach the position where the leg 306 of the striker 302 is released from the sear 326, whereby the firearm 100 is fired.
Referring next to
The trigger bar 316 comprises the longitudinal body 408 with a front end of the body 408 including the trigger bar hole 508 configured to couple to the trigger bar boss 406 as shown in
The arm 400 is generally rectangular, with a bottom surface aligned with a bottom surface of the body 408 at the location of the arm 400. The profile of an upper portion of the arm 400 varies, and is generally divided into three separate segments along the arm 400. Proximate to the body 408 is the cam portion 800, which includes the generally horizontal cam portion upper surface 510. The cam portion 800 includes a chamfer on a forward edge of the cam portion upper surface 510, which forms the angled cam surface 602. A front-to-back width of the cam portion 800, indicated by “A” in
A free end portion of the arm 400, i.e. the portion distal to the body 408, includes the sear activation tab 502. A height of the arm 400 at the sear activation tab 502, indicated by “D” in
Interposed between the cam portion 800 and the sear activation tab 502 is the drop safety lifter tab 500. The drop safety lifter tab 500 has a height between that of the cam portion 800 and the sear activation tab 502, as indicated by the dimension “E” shown in
The trigger bar 316 is configured to replace the factory trigger bar provided with the Sig Sauer P320 firearm and as such is configured to provide the required connections and operative characteristics of the original factory trigger bar. The geometry of the surfaces that interact with other elements of the firing mechanism 300, i.e. the cam surface 506, the drop safety lifter engagement surface 600, and the sear engagement surface 702 are configured to reduce a pre-engagement travel distance 912 and an over-travel travel distance 916, and condense an engagement travel distance 914, as described further below in
Referring next to
The trigger pull weight profile 902 shows the variation of the pull weight of the firearm 100 (as plotted with respect to the vertical pull weight axis 920) as the trigger 108 is pulled rearward (as plotted with respect to the horizontal trigger travel distance axis 918).
The trigger pull weight profile 902 starts at the trigger movement start point 934, which is at the origin of the graph 900, i.e. the trigger 108 has not moved rearward and no pull weight has been applied to the trigger 108.
As the user applies pressure to the trigger 108, moving the trigger bar 316 in the generally forward direction, the pull weight (along the pull weight axis 920) and the rearward travel distance (along the trigger travel distance axis 918) increase along a curve until the drop safety lifter engagement point 904 is reached after traveling the pre-engagement travel distance 912, which is approximately 0.045″ in the present embodiment. At the drop safety lifter engagement point 904 the trigger bar 316 first contacts the drop safety lifter 330. At the drop safety lifter engagement point 904 the total rearward trigger travel distance is the drop safety lifter engagement distance 928, and the required pull weight at the drop safety lifter engagement point 904 is the drop safety lifter engagement pull weight 922. In the present embodiment, the drop safety lifter pull weight 922 is approximately 1.015 pounds. After the trigger bar 316 engages the drop safety lifter 330, as the trigger bar 316 continues to move rearward it rotates the drop safety lifter 330 upward which in turn rotates the drop safety 328 upward to ultimately be in a position to allow for firing of the firearm 100.
As the trigger 108 is continued to be pulled rearward by the user, the travel distance and the pull weight continue to increase, until a short distance after the drop safety lifter engagement point 904, the trigger bar 316 engages the sear 326 at the sear engagement point 906. The total trigger rearward travel distance at the sear engagement point 906 is the sear engagement distance 936, and the required pull weight is the sear engagement pull weight 924. In the present embodiment, the sear engagement distance 936 is approximately 0.054 inches, and the sear engagement pull weight 924 is approximately 1.32 pounds.
After the engagement of the sear 326, the trigger pull weight increases sharply, then levels off until the sear release point 908. At the sear release point 908, the forward movement of the trigger bar 316 (as moved by the trigger 108) has rotated the drop safety 328 up and the sear 326 has been rotated in a clockwise direction until the depending leg 306 of the striker 302 loses contact with the sear 326, resulting in the firing of the firearm 100. The total trigger travel distance at the sear release point 908 is the sear release distance 930, and the trigger pull weight at the sear release point 908 is the sear release pull weight 926. In the present embodiment, the sear release distance 930 is approximately 0.13 inches, and the sear release pull weight 926, i.e. the maximum trigger pull weight prior to firing, is approximately 5.698 pounds. The rearward trigger travel distance between the first engagement of the trigger bar 316 with a portion of the firing assembly (i.e. the drop safety lifter engagement point 904), and the sear release point 908, is the engagement travel distance 914, which in the present embodiment is approximately 0.086 inches. In one embodiment, the trigger bar 316 of the present invention results in a total rearward movement before firing (i.e. the pre-engagement travel distance 912 plus the engagement travel distance 914) of less than 0.14 inches.
After release of the sear 326 and the firing of the firearm 100, the trigger continues to move rearward, and the trigger pull weight drops. At the trigger stop point 910 (corresponding to the trigger stop distance 932), the rearward movement of the trigger 108 is stopped, generally by contact with the over-travel stop 410. The rearward movement of the trigger 108 between the sear release point 908 and the trigger stop point 910 is the over-travel travel distance 916. In the present embodiment, the over-travel stop 410 is configured to interfere with the trigger 108 after firing, thereby stopping the rearward movement of the trigger 108 and limiting the over-travel travel distance 916 to less than 0.04 inches. In some embodiments the over-travel travel distance 916 is approximately 0.032 inches. A shorter over-travel travel distance 916 is advantageous as a shorter over-travel travel distance 916 lessens the distance the trigger 108 needs to travel to reset, resulting in less time between shots. A shorter over-travel travel distance 916 also prevents the firearm 100 from being disturbed while a bullet is still in the barrel 106.
Referring next to
As shown in
The arm 400 of the trigger bar 316 is also not yet in contact with the drop safety lifter 330, as the drop safety lifter engagement surface 600 of the arm 400 is not is separated from the trigger bar drop safety tab engagement surface 1102 of the drop safety lifter 330 by the drop safety lifter clearance distance 1106. In the present embodiment, the drop safety lifter tab 500 is configured such that at rest the drop safety lifter clearance distance 1106 is approximately 0.01 inches.
An angle between horizontal and a front face of the trigger link 312 forms the trigger bar boss angle 1000. Before the firing sequence, the angle 1000 is approximately 86.49 degrees, i.e. the trigger link 312 is rotated slightly rearward with respect to the trigger connection.
The positions shown in
Referring next to
The position of the portion of the firing mechanism corresponds to the drop safety lifter engagement point 904 of the trigger pull weight profile 902 of
Due to the geometry of the sear activation tab 502, there is still a gap between the trigger bar sear activation tab engagement surface 1100 and the sear engagement surface. In the present embodiment, at the drop safety lifter engagement point 904 the sear clearance distance 1104 is approximately 0.01″.
Referring next to
As shown in
Additionally, as the trigger bar 316 has moved forward, the continued contact between the trigger bar arm 400 and the drop safety lifter 330 has rotated the drop safety lifter 330 clockwise about the safety lever hole 404, as indicated by the directional arrow “J”. As the drop safety lifter 330 rotates upward the drop safety lifter 330 contacts drop safety 328 and pushes the drop safety 328 upwards, as indicated by the directional arrow “K”.
Also, as the trigger 108 continues to be moved rearward after the trigger bar 316 contacts the sear 326, the sear 326 is rotated clockwise about the sear pivot hole 402, as indicated by the directional arrow “L”. As the sear is rotated, the upper portion of the sear 326 contacting the depending leg 306 of the striker is moved downward away from the depending leg 306.
Referring next to
The position shown in
Referring next to
The rotation of the sear 326 has rotated a lower portion of the sear 326 including the trigger bar sear activation tab engagement surface 1100 so that an underside of the lower portion of the sear 326 rests against a top surface of the sear activation tab 502. When the trigger 108 is returned to a forward position, the trigger bar 316 will “reset” behind the sear 326, ready to fire the firearm 100 once again when the trigger 108 is pulled. Due to the short over-travel travel distance 916 and engagement travel distance 914, the distance to reset the trigger bar 316 is also short.
While the invention herein disclosed has been described by means of specific embodiments, examples and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.
