Patent Publication Number: US-11385010-B1

Title: Trigger energy absorption apparatus and method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and is a continuation-in-part of U.S. patent application Ser. No. 16/031,352, filed on Jul. 10, 2018 entitled TRIGGER ENERGY ABSORPTION APPARATUS AND METHOD which is hereby incorporated by reference in its entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     REFERENCE TO A MICROFICHE APPENDIX 
     Not Applicable. 
     RESERVATION OF RIGHTS 
     A portion of the disclosure of this patent document contains material which is subject to intellectual property rights such as but not limited to copyright, trademark, and/or trade dress protection. The owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent files or records but otherwise reserves all rights whatsoever. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to improvements in triggers and firing mechanisms for firearms. More particularly, the invention relates to improvements particularly suited for lightweight handguns. In one preferred embodiment, the present invention relates specifically to a force absorbing elastomer placed between the finger operated trigger mechanism and the frame assembly of the handgun to absorb the energy of the finger pull, especially after the trigger is releases the firing mechanism such as a sear. 
     2. Description of the Known Art 
     As will be appreciated by those skilled in the art, firearms are known in various forms. Patents disclosing information relevant to firearms include: U.S. Pat. No. 6,164,002, issued to Troncoso on Dec. 26, 2000 entitled Gun having a rapid fire trigger assembly and the assembly therefor; U.S. Pat. No. 9,644,913, issued to Dextraze\ on May 9, 2017 entitled Multi-stage trigger mechanism for rifle; U.S. Pat. No. 7,047,686, issued to Zimmermann on May 23, 2006, entitled Versatile M1911-style handgun and improved magazine for rifles and handguns; U.S. Pat. No. 5,060,555, issued to Sater, et al. on Oct. 29, 1991 entitled Slide decelerator for a firearm; U.S. Pat. No. 4,691,461, issued to Behlert on Sep. 8, 1987 entitled Adjustable gun trigger mechanism; U.S. Pat. No. 4,955,155, issued to Jones on Sep. 11, 1990 entitled Pivoting trigger group assembly; U.S. Pat. No. 7,698,845, issued to Hochstrate, et al. on Apr. 20, 2010 entitled Double action model 1911 pistol; U.S. Pat. No. 4,555,861, issued to Khoury on Dec. 3, 1985 entitled Firing pin locking device; U.S. Pat. No. 984,519, issued to Browning on Feb. 14, 1911 entitled Firearm; U.S. Pat. No. 6,260,301, issued to Aigner, et al. on Jul. 17, 2001 entitled Pistol, whose housing is composed of plastic; U.S. Pat. No. 5,060,555, issued to Sater, et al. on Oct. 29, 1991, entitled Slide decelerator for a firearm; U.S. Pat. No. 4,551,937, issued to Seehase on Nov. 12, 1985, entitled Recoil pad utilizing struts disposed at a compound angle and having adjustable energy-absorbing characteristics; and U.S. Pat. No. 4,539,889, issued to Glock on Sep. 10, 1985 entitled Automatic pistol with counteracting spring control mechanism. Each of these patents is hereby expressly incorporated by reference in their entirety. 
     From these prior references it may be seen that these prior art patents are very limited in their teaching and utilization, and an improved trigger energy absorption apparatus and method is needed to overcome these limitations. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an improved trigger energy absorption apparatus and method using a dampening energy absorbing element. In the process of firing a modern firearm, the trigger is typically designed to release a sear which is under spring tension. The users finger pressure against the trigger builds to the point at which the sear is released, which then releases the hammer or firing pin striker to fire the weapon. When a firearm trigger releases the sear, the constant pull of the user&#39;s finger on the trigger accelerates the trigger until it bluntly stops against the frame assembly causing a jarring impact load onto the frame assembly that changes the aim of the weapon before the bullet is fired/exits the barrel. In accordance with one exemplary embodiment of the present invention, a trigger energy absorption device is provided using a dampening elastomer to absorb trigger pull force and dampen trigger shock force transfer to the frame assembly. In its simplest form, the trigger energy absorption device uses a dampening energy absorbing element that fits between the back side of the firearm trigger and the trigger guard. The trigger energy absorption device can be adhesively mounted to a moving part of the trigger assembly or to an element of the frame assembly so that it absorbs the energy from the trigger moving element. In one embodiment, the trigger energy absorption device is precision cut so that it does not engage until after the movement required for the sear release. In this embodiment, the trigger energy absorption device is simply affixed to the trigger guard with a non-marring adhesive to form an inexpensive removable and easily replaceable device. In operation, the trigger is pulled and the rear of the trigger contacts the media and begins compressing it. The device can be sized so that compression can also be used before firing to slightly increase the trigger pull. In both the after firing release contact design and the before firing release contact designs, the after firing release trigger motion is absorbed by the media which prevents the shock load transfer of the destabilizing energy to the firearm frame assembly. The end result is a much more accurate and repeatable firearm action. 
     One advantage of the present invention is that it increases firearm accuracy by absorbing the kinetic energy of the trigger release preventing abrupt transfer of this energy to the firearm frame assembly which causes shake or instability during firing. The traditional approach to improving firearm accuracy has primarily focused on the aspect of lightening the trigger pull force of a weapon. However, it may be shown that reducing the trigger pull force has the undesirable effect of also reducing safety and causing potential accidental firing of the weapon. Thus, safety is sacrificed by lightening the trigger pull force. It is accepted in the firearm industry that a 4 lb trigger pull weapon may be accidentally fired more often that a 10 lb trigger pull weapon, of the same model, for obvious reasons. It may also be shown that the use of the trigger energy absorbing device, in lieu of lightening the trigger pull, can achieve the same or better accuracy improvement by effectively reducing the velocity component of the Kinetic Energy affecting the firearm, thus inflicting no degradation in safety of the weapon. It may be shown that the use of the Trigger Energy Absorbing Device is a preferred method of increasing firearm accuracy over the traditional approach of lightening the trigger pull, as it relates to the safety of the weapon 
     A further advantage of the present invention is an increase in shot repeatability by providing consistent dampening for a more consistent and repeatable action. 
     A still further advantage is an increase in trigger reset speed. Due to the fact that the released free trigger movement is limited in the absorption process, the reset distance is essentially shortened, providing improved function. 
     The invention is adaptable to all standard firearms currently in production that use traditional trigger/sear mechanisms for firing pin or hammer release thereby covering both striker and hammer technology. Examples of the styles of weapons include all varieties of automatic weapons, semiautomatic weapons, revolvers, bolt action pistols, rifles, and shotguns. The invention can also be used in other trigger devices such as air rifles, crossbows, paintball guns. 
     These and other objects and advantages of the present invention, along with features of novelty appurtenant thereto, will appear or become apparent by reviewing the following detailed description of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       In the following drawings, which form a part of the specification and which are to be construed in conjunction therewith, and in which like reference numerals have been employed throughout wherever possible to indicate like parts in the various views: 
         FIG. 1  is a schematic view of a crescent shaped embodiment of a trigger energy absorption device positioned in an uncompressed state between the trigger and the frame assembly of a gun. 
         FIG. 2  is a schematic view with the trigger moved to the firing release position. 
         FIG. 3  is a schematic view with the trigger moved past the firing release position and compressing the trigger energy absorption device. 
         FIG. 4  is a schematic view of a rectangular shaped trigger energy absorption device. 
         FIG. 5  is a schematic view of an ovate shaped trigger energy absorption device. 
         FIG. 6  is a schematic view of a pointed shape trigger energy absorption device. 
         FIG. 7  is a schematic view of a triangular shaped trigger energy absorption device. 
         FIG. 8  is a schematic view of an elliptical shape trigger energy absorption device. 
         FIG. 9  is a schematic view of a cylindrical shape trigger energy absorption device mounted on a stud. 
         FIG. 10  is a schematic view of a cylindrical shaped trigger energy absorption device. 
         FIG. 11  is a schematic view of an internal L shaped trigger energy absorption device mounted on an internal frame assembly. 
         FIG. 12  is a schematic view of the internal L shaped trigger energy absorption device of  FIG. 11  compressed. 
         FIG. 13  is a schematic view of an elongated trigger energy absorption device inside a military and police style frame assembly. 
         FIG. 14  is a schematic view of the elongated trigger energy absorption device of  FIG. 13  compressed. 
         FIG. 15  is a schematic view of a trigger energy absorption device inside another frame assembly configuration. 
         FIG. 16  is a schematic view of the trigger energy absorption device of  FIG. 14  compressed. 
         FIG. 17  is a graph of an undampened trigger pull force, trigger velocity, and shock energy. 
         FIG. 18  is a graph of a dampened trigger pull force, dampened trigger velocity, and dampened shock energy when using a trigger energy absorption device. 
         FIG. 19  is a graph of an undampened trigger pull force. 
         FIG. 20  is a graph of a dampened trigger pull force when using a trigger energy absorption device. 
         FIG. 21  is a graph of an undampened trigger velocity. 
         FIG. 22  is a graph of a dampened trigger velocity when using a trigger energy absorption device. 
         FIG. 23  is a graph of an undampened shock energy. 
         FIG. 24  is a graph of a dampened shock energy when using a trigger energy absorption device. 
         FIG. 25  shows real world target results of absorption on weapon accuracy. 
         FIG. 26  shows proximeter measurement setup  FIG. 27  shows contrasting differences using the device in the proximeter setup. 
         FIG. 28  shows the inductive vibration measurement setup. 
         FIG. 29  shows contrasting differences using the device in the vibration setup. 
         FIG. 30  shows a measurement scale for a trigger application of an energy absorption device  100 . 
         FIG. 31  shows the contrasting relative positions of trigger travel with the device. 
         FIG. 32  shows a comparison end stop to reset measurement. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in  FIGS. 1-24  of the drawings one exemplary embodiment of the present invention is generally shown as a trigger energy absorption device  100  for use with a firearm  10 . The firearm  10  generally has a trigger assembly  20  with a trigger body  25  having trigger front  26 , trigger back  27 , and a movement connection  30  allowing a back pull release motion  22  to fire the bullet from the firearm  10  and a forward reset motion  21  to reset the firearm  10  for the next shot. 
     Thus, forward and backward are defined by the movement to fire the weapon. The trigger assembly  20  may also include trigger arm  36  moved by the trigger body  25  to release the sear  80 . 
     The movement connection  30  can be a simple trigger pivot  32  or trigger slide  34 . The firearm  10  has a gun body  40  with a body frame  42 . The body frame assembly  42  includes an upper frame assembly  43 , trigger guard  44 , and a grip handle  45 . The grip handle  45  includes a front strap  46 , back strap  48 , and side panel  50 . 
     The trigger energy absorption device  100  includes a main body  110  with a body shape  112 . The body shape  112  can be a front to back increasing height body shape  113 , front to back consistent height body shape  114 , front to back decreasing height body shape  115  or front to back varying height body shape  118 .  FIG. 7  shows a front to back increasing height body shape  113 .  FIG. 4  shows a front to back consistent height body shape  114 .  FIGS. 1-3  and  FIG. 9  show a front to back decreasing height body shape  115 .  FIGS. 5, 6, and 8  show a front to back varying height body shape  118 . Any body shape  113 ,  114 ,  115  can also be made as a hollow body shape  116  with the hole extending in any of the three dimensions.  FIG. 9  shows a decreasing body shape  115  as a hollow body shape  116  with body threads  117  formed within the hollow body shape  116  for connection to a mounting structure  170 , shown here as a rod mount  172  with mating mounting threads  174  mounted off of the back  27  of the trigger  25 . The hollow body shape  116  can have the aperture extend all of the way through the body or can just be a partial depth aperture. The aperture extending all of the way through the body provides the most adjustment range but can expose the end of the rod mount  172 . In contrast, a partial hole ensures that a minimum thickness of material is always dampening the trigger. The trigger energy absorption device  100  includes a body front  120 , body back  130 , body top  140 , body bottom  142 , left side  144 , and right side  146 . The main body  110  is made from a dampening body material  150 . 
     The body front  120  can have a body front concave shape  122 ; body front convex shape  124 ; body front pointed shape  126 ; or body front flat shape  128 . The body back  130  can have a body back concave shape (not shown); body back convex shape  134 ; body back pointed shape (not shown); or body back flat shape  138 . 
     The top to bottom height and whether or not a hollow is used in the body shape  112 , the shape of the body front  120  and the shape of the body back  130  in relation to the frame  42  affect the amount of elastomer being compressed at any point during the trigger  20  travel. Each of the profiles presented have been proven to work to provide the necessary dampening with different characteristics preferred by the individual user&#39;s preferences. The external embodiment shown in  FIGS. 1-3  and the internal embodiments in  FIGS. 11-16  have provided solid performance in keeping the sight alignment on target. 
     The dampening body material  150  is preferably an elastomer chosen to quickly return to the starting shape after being compressed by the pull of the trigger  20 . This return time is preferably less than the time for firing another round from the firearm  10 . The dampening body material  150  may be selected as a softer material for more travel or a harder material to limit the trigger  25  travel for a given force and shape. Embodiments have been successfully made from two part moldable silicon, and both cross-linked and non-crosslinked polyethylene foam. The preferred embodiment is a four pound crosslinked polyethylene with successful tests run with foam density between two and six pound density (lb/cubic ft). Another preferred product for the body material is TPE (thermo plastic elastomer) constructed in a solid, lattice or honeycomb pattern to provide absorption characteristics via compression of the structure. The embodiment of which may be injection molded or 3D printed. Yet another product is SORBOTHANE (trademark) which is the brand name of a synthetic viscoelastic urethane polymer used as a shock absorber and vibration damper. It is manufactured by Sorbothane, Incorporated, 2144 State Route 59, Kent, Ohio 44240. Appropriate absorbing bladder designs may also be used. 
     The dampening body material  150  should also be chosen based on the expected temperature range to be encountered in relation to the material properties, the depth of travel for the mounting location, the shock absorbing nature of the material including the material dampening characteristics, the light weight of the material, and the microfine air bubble properties of the material. Note that it is preferred that the material would have good oil resistance properties and also have a closed cell construction to minimize contaminants. For example, an open cell polyurethane that is subject to oil penetration can be used, but the service life is negatively impacted by the undesirable characteristics of collecting contamination in the open cell structure. Thus, one might choose a crescent shaped of material based on a summer day with a temperature range between 60 and 90 degrees Fahrenheit, for three eighths of an inch travel after the trigger release, with a ten pound absorption rate within 2 milliseconds of contact or through a 1-3 mm of compression, in an oil resistant closed cell foam. 
     The trigger energy absorption device  100  may be manufactured from various materials that exhibit shock absorbing characteristics, with the most common and available being medium density closed cell foam. Layered manufacture of the absorbing dampening body material  150  is possible with the most desirable construction using a high density base layer contacting the gun body  40 , followed by medium density, and finally low density which will be in contact with the back  27  of the trigger  25 . Precision cutting of the material is best performed by a three dimensional layout via computer aided drafting, then water-jet cut. Three dimensional printing is also an option for manufacture. Die cutting of 4# cross linked polyethylene sheet material of ⅜″ thickness is the expected manufacture for the external device, while TPE or silicon rubber injection molding is the expected manufacture of the internal device. 
     The trigger energy absorption device  100  can be held in place by being friction fit to the gun mechanism as shown in  FIGS. 9, and 12-16  or a body adhesive  160  may be used to mount the trigger energy absorption device  100  to the trigger  25 ,  FIG. 1-3 , or the gun body  40 ,  FIGS. 4-8 , specifically, the back of the trigger guard  44  at the top front of the grip handle  45 . 
       FIGS. 1-9  show the trigger energy absorption device  100  in an external frame assembly mounting  104  and  FIGS. 11-16  show an internal frame assembly mounting  102 . Basically,  FIG. 11  shows the mounting in a SIG P320 (trademark) and  FIG. 12  shows the compression of the device  100 ,  FIG. 13  shows the mounting in a SMITH &amp; WESSON M&amp;P9MM (trademark) and  FIG. 14  shows the compression of the device  100 , and  FIG. 15  shows the mounting in a GLOCK 19 (trademark) and similar and  FIG. 16  shows the compression of the device  100 . In this manner, both internal and external mountings may be understood. 
     Operation and Absorption 
     To understand operation of the invention, the following details are provided with a simplified example of handgun operation so that one may understand the invention. The invention originated from an observation during dry fire practice, aka non-live practice, with a lightweight handgun firearm  10  that the front sight  60  to rear sight  70  alignment of the firearm  10  tended to move a slight amount at what seemed to be the exact moment of firing pin release. Realizing that this movement is detrimental to firearm  10  accuracy and repeatability, efforts were taken to improve the user&#39;s grip skill. While improving the grip helped with both dry fire and live fire operation of the handgun firearm  10 , there was still an annoying movement in the front sight  60  as noted above and the accuracy of the firearm  10  was still subpar. The next approach was to take the traditional route of improving the trigger assembly  20  release by installing a match competition grade trigger spring, with the supposed benefit of increasing accuracy via reducing the trigger pull required to fire the firearm  10 . The effect did seem to slightly improve accuracy, but the reduced trigger assembly  20  force meant that the firearm  10  was easier to fire both intentionally and unintentionally. Also, the front sight still moved an excessive amount during live fire and dry fire practice. Again, the accuracy was less than satisfactory. 
     When considering where this front sight movement was originating, consideration went to a visualize of the action of the firearm at a sub-second timing level. It became clear that while trigger assembly  20  to sear  80  release tension is important, the energy in motion from the trigger assembly  20  after sear  80  release has a profound impact on the accuracy of the firearm  10 . As the humorous adage goes, ‘it&#39;s not the fall that kills you: it&#39;s the sudden stop at the end!’ This thought applies to firearm trigger assembly  20  release. It&#39;s not the trigger assembly  20  release that kills firearm  10  accuracy, it&#39;s the sudden stop of the trigger assembly  20  against the rest of the frame assembly  42 . Here, the trigger assembly  20  is defined as the mechanism moved by the user&#39;s finger in relation to the frame assembly  42 . The potential energy built up on the trigger assembly  20  by the finger is suddenly released which causes an acceleration of the trigger assembly  20  all the way to the sudden stop in movement of the trigger assembly  20  where the energy of the trigger velocity is transferred to the frame assembly  42 . 
     A greatly simplified trigger assembly  20  and release of an internal sear  80  in a frame assembly  42  is shown in  FIGS. 1 through 3 .  FIG. 1  shows the sear  80  engaged with the trigger assembly  20  note how there is an air gap separating the trigger energy absorption device  100 .  FIG. 2  shows the sear  80  releasing from the trigger assembly  20  and how the air gap has been closed.  FIG. 3  shows the trigger energy absorption device  100  absorbing the energy via compression and transferring it to the frame assembly  42 , specifically transferring the energy to the grip handle  45 . In this manner, the main body  110  is compressed after the release motion has been initiated Thus, one may understand the trigger assembly  20  movement the transfer of energy to the frame assembly  42  and the absorption of energy after the sear  80  release. In application, one may consider this concept applied to modern firearm  10  design. Typical modern handgun firearm  10  design is currently migrating toward a striker fired mechanism for the firing pin. Striker fired weapons utilize a spring coiled pin that must be held in tension and released by a sear  80  which is controlled by a trigger assembly  20 . The sear  80  release for the firing pin can be of significant load depending on manufacturer. This load, which must be overcome by the shooter with the force of the trigger assembly  20  finger, is usually around six to seven pounds of pulling force. Once the required pulling force for sear  80  release is achieved, the firing pin is released to make impact on the ammunition primer and fire the weapon. However, simultaneous to this, the trigger assembly  20 , now released of the resistance load of the sear  80 , travels with an increasing velocity all the way to its end stop. Due to the fact that the released trigger assembly  20  motion is not normally absorbed or halted until this end stop, the finger and trigger assembly  20  quickly gain velocity and kinetic energy. Kinetic Energy is defined by KE=½ mass times velocity squared. Once the trigger assembly  20  reaches the abrupt end stop, this kinetic energy is then transferred to the firearm frame assembly  42  which is transferred to the user&#39;s grip which causes shock load instability in the frame assembly  42 . This occurs at the same general time that the ammunition is being ignited and propelled down the barrel. Due to the fact that modern polymer handguns are so light, with typical mass for a sub-compact pistol being around 24 oz., the imparted energy to weight ratio becomes significant. A six-pound trigger pull is 96 oz, which his 4 times the weight of the handgun firearm  10  itself! This results in a weapon that has a tendency to shake or shift due to imparted kinetic energy. Therefore, the most accurate guns in production generally happen to be amongst the heaviest, and this is also why the light weight polymer frame weapons generally exhibit relatively poor accuracy. These characteristics noted are also prevalent in hammer fired or other percussion style firearms. 
       FIGS. 17-24  show graphs with the base line trigger pull force  1702 , base line trigger velocity  1704  of movement, and the base line kinetic energy transfer  1706  to the frame assembly  42  compared against the dampened trigger pull force  1802 , dampened trigger velocity  1804  of movement, and the dampened kinetic energy transfer  1806 . Using the simple formula of Force=Mass*Acceleration, one can understand that the trigger assembly  20  and finger mass remain the same. However, the acceleration greatly increases after the trigger assembly  20  release, in FIGS.  17 - 24  look at time T 1  for the start of the pull, time T 2  for the start of the trigger assembly  20  release of the sear  80 , and T 2  to T 3  for the difference in dampened versus undampened. Simply understood from  FIG. 1 , the force provided by the finger that is used to overcome the internal friction and move the trigger assembly  20  to the release point continues to be applied by the finger such that the prior art open gap behind the trigger back  27  that extends to the hard stop allows the trigger assembly  20  to increase in acceleration at times T 2  to T 3  until the trigger contacts the hard stop of the frame assembly  42  at time T 3 . On solid or sliding trigger  20  designs, this hard stop may be internal to the frame assembly  42  such as those shown in  FIGS. 11-16 . At this point, the kinetic energy=0.5*mass*velocity*velocity. Because the acceleration has resulted in a finger and trigger assembly  20  velocity across the prior art air gap, a large jarring force is generated and transferred to the frame assembly  42  pulls the sights  60 ,  70  out of alignment. Thus, as acceleration increases, so does the jarring force generated for a given mass. Now look at the contrast between  FIG. 17  and  FIG. 18  and note that in contrast to the large open air gap of the prior art, the present invention uses the trigger energy absorption device  100  to absorb the trigger pull force after the trigger assembly  20  release. As shown by  FIGS. 18, 20, 22, and 24 , through the absorption of this unneeded pull force, the after release acceleration of the trigger assembly  20  is greatly reduced such that very little jarring force is transferred to the frame assembly  42 . By comparing the prior art open air gap graph of  FIG. 17  to the trigger energy absorption device  100  filled gap graph of  FIG. 18 , one can see that the velocity  1704 ,  1804  is reduced because the trigger assembly  20  does not have as significant of an acceleration because the energy  1706 ,  1806  is absorbed and released by the elastomer dampening body material  150  in a cushioned manner instead of a shock load. 
       FIG. 25  shows the end result of this absorption on weapon accuracy using a SIG SAUER P320 (trademark) at a distance of 20 yards with twelve rounds per target. Figure A shows the result without the absorption device with a 27.4 square inch group area. Contrast Figure A against Figure B and Figure C, where Figure B with a 6.05 square inch area shows the result of an external device and Figure C with a 4.53 square inch area shows the results of an internal device. The external device provides a 78% improvement in group area and the internal device provides an 84% improvement. 
       FIG. 26 through 29  show how the vibration of the pistol is reduced as measured by two different sensor types.  FIG. 26  shows the proximeter measurement setup with  FIG. 27  contrasting the differences between the no device measurements  2701  and the with device measurements  2704 .  FIG. 28  shows the inductive vibration measurement setup with  FIG. 29  contrasting the differences between the no device measurements  2701  and the with device measurements  2704 . Note the amplitude reduction in the signal comparison that corresponds with the real world target results presented in  FIG. 25 . 
       FIGS. 30-32  show an added benefit of the trigger energy absorption device  100  in the reduction in over travel of the trigger assembly  20  to reduce the total Trigger Reset Travel. For this description, we can look at an external mount and measure the movement of the trigger back, but one should understand that this applies to internal devices as well. As noted by  FIG. 30 , the diagrams are based on 10 mm measurement scale using a HECKLER &amp; KOCH VP9 (trademark) and a closed cell polyethylene foam of four pound density affixed as an external trigger energy absorption device  100 . Note that the schematic drawings are drawn for illustrative purposes and are not actually to scale. Similar measurement results have been shown with various other weapons, with both internal and external embodiments. 
       FIG. 31  shows the schematic positions of trigger travel from the at rest position  3101 , through the sear release position  3102 , to the no absorber end stop position  3103  and back to the trigger reset position  3104 . The trigger energy absorption device  100  changes the end stop position to an absorber end stop position  3105 , but otherwise the trigger positions remain the same.  FIG. 31  shows the difference between the no absorber end stop to reset measurement  3111  of 3.7 mm and the reduction in the with absorber end stop to reset measurement  3112  of 1.8 mm. 
       FIG. 32  shows a comparison of the no absorber end stop to reset measurement  3111  of 3.7 mm and the reduction in the with absorber end stop to reset measurement  3112  of 1.8 mm. Note the corresponding reduction in overtravel which represents an improvement of greater than fifty percent. 
     In final summary, it may be noted that the traditional approach to mitigate the shock of trigger release into the firearm has been to lighten the trigger pull. Standard trigger pull weights being anywhere from 6# up to 14#. While this positively affects the performance, this approach has focused on the “mass” parameter of the kinetic energy equation, which has a multiplier of 0.5. The velocity of trigger movement, after release, is of much more relevance because it has a squared component in the equation. Therefore, velocity dampening is the primary purpose and key feature of this device, although other positive attributes become realized with it&#39;s application. Absorption may be accomplished via internal or external embodiment. 
     Reference numerals used throughout the detailed description and the drawings correspond to the following elements: 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
             
            
               
                   
                   
                 firearm 10 
                   
               
               
                   
                   
                  Trigger assembly 20 
                   
               
               
                   
                   
                    Reset motion 21 
                   
               
               
                   
                   
                    Release motion 22 
                   
               
               
                   
                   
                   Trigger body 25 
                   
               
               
                   
                   
                    Trigger front 26 
                   
               
               
                   
                   
                    Trigger back 27 
                   
               
               
                   
                   
                   Movement connection 30 
                   
               
               
                   
                   
                    Trigger pivot 32 
                   
               
               
                   
                   
                    Trigger slide 34 
                   
               
               
                   
                   
                   Trigger arm 36 
                   
               
               
                   
                   
                  Gun body 40 
                   
               
               
                   
                   
                   Frame assembly 42 
                   
               
               
                   
                   
                    Upper frame assembly 43 
                   
               
               
                   
                   
                    Trigger guard 44 
                   
               
               
                   
                   
                    grip handle 45 
                   
               
               
                   
                   
                     Front strap 46 
                   
               
               
                   
                   
                     Back strap 48 
                   
               
               
                   
                   
                     Side panel 50 
                   
               
               
                   
                   
                    Front sight 60 
                   
               
               
                   
                   
                    Rear sight 70 
                   
               
               
                   
                   
                    Sear 80 
                   
               
               
                   
                   
                 Trigger energy absorption device 100 
                   
               
               
                   
                   
                  internal frame assembly mounting 102 
                   
               
               
                   
                   
                  external frame assembly mounting 104 
                   
               
               
                   
                   
                  Main body 110 
                   
               
               
                   
                   
                   Body shape 112 
                   
               
               
                   
                   
                    Increasing body shape 113 
                   
               
               
                   
                   
                    Consistent body shape 114 
                   
               
               
                   
                   
                    Decreasing body shape 115 
                   
               
               
                   
                   
                    Hollow body shape 116 
                   
               
               
                   
                   
                     Body threads 117 
                   
               
               
                   
                   
                    Varying body shape 118 
                   
               
               
                   
                   
                   body front 120 
                   
               
               
                   
                   
                    body front concave shape 122 
                   
               
               
                   
                   
                    body front convex shape 124 
                   
               
               
                   
                   
                    body front pointed shape 126 
                   
               
               
                   
                   
                    body front flat shape 128 
                   
               
               
                   
                   
                   body back 130 
                   
               
               
                   
                   
                    body back concave shape (not shown) 
                   
               
               
                   
                   
                    body back convex shape 134 
                   
               
               
                   
                   
                    body back pointed shape (not shown) 
                   
               
               
                   
                   
                    body back flat shape 138 
                   
               
               
                   
                   
                   Body top 140 
                   
               
               
                   
                   
                   Body bottom 142 
                   
               
               
                   
                   
                   Left side 144 
                   
               
               
                   
                   
                   Right side 146 
                   
               
               
                   
                   
                  Dampening body material 150 
                   
               
               
                   
                   
                  Body adhesive 160 
                   
               
               
                   
                   
                  Mounting structure 170 
                   
               
               
                   
                   
                   Rod mount 172 
                   
               
               
                   
                   
                   Mounting threads 174 
                   
               
               
                   
                   
                  trigger pull force 1702 
                   
               
               
                   
                   
                  velocity of movement 1704 
                   
               
               
                   
                   
                  energy transfer to the frame assembly 1706 
               
               
                   
                   
               
            
           
         
       
     
     From the foregoing, it will be seen that this invention well adapted to obtain all the ends and objects herein set forth, together with other advantages which are inherent to the structure. It will also be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. Many possible embodiments may be made of the invention without departing from the scope thereof. Therefore, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. 
     When interpreting the claims of this application, method claims may be recognized by the explicit use of the word ‘method’ in the preamble of the claims and the use of the ‘ing’ tense of the active word. Method claims should not be interpreted to have particular steps in a particular order unless the claim element specifically refers to a previous element, a previous action, or the result of a previous action. Apparatus claims may be recognized by the use of the word ‘apparatus’ in the preamble of the claim and should not be interpreted to have ‘means plus function language’ unless the word ‘means’ is specifically used in the claim element. The words ‘defining,’ having,′ or ‘including’ should be interpreted as open ended claim language that allows additional elements or structures. Finally, where the claims recite “a” or “a first” element of the equivalent thereof, such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements.