Firearm safety feature

Abstract

A novel firearm safety feature includes arresting surfaces for preventing the fall of a hammer in the event of a spontaneous failure of other firearm parts. In a particular embodiment a safety lug has an arresting surface and the hammer has a complementary arresting surface. In the event of a spontaneous failure, the arresting surface and the complementary arresting surface create a positive engagement and prevent the hammer from falling. In another embodiment, a grip safety includes an arresting surface and the hammer includes a complementary arresting surface. In the event of a spontaneous failure, the arresting surface and the complementary arresting surface create a positive engagement and prevent the hammer from falling.

Claims

1. A firearm safety feature, comprising: a firing pin; a hammer spring; a hammer biased by said hammer spring to rotate in a first direction to impact said firing pin, said hammer including an arresting surface; a sear operative to engage said hammer such that said hammer is prevented from rotating toward said firing pin; a trigger operative to disengage said sear from said hammer, allowing said hammer to rotate in said first direction toward said firing pin; a safety switchable between a safe position and a firing position, a portion of said safety positioned to prevent said sear from disengaging said hammer when said trigger is depressed; and wherein said safety includes a complementary arresting surface; and said arresting surface and said complementary arresting surface become positively engaged under influence of said hammer spring when said safety is in said safe position and said hammer rotates in said first direction, preventing said hammer from impacting said firing pin.

2. The firearm safety feature of claim 1, wherein: said arresting surface is defined by a first angled cut in said hammer; said complementary arresting surface is defined by a second angled cut in said portion of said safety; and said first angled cut and said second angled cut are equiangular.

3. The firearm safety feature of claim 1, wherein at least one of said arresting surface and said complementary arresting surface are modified to increase the coefficient of friction between said arresting surface and said complementary arresting surface.

4. The firearm safety feature of claim 3, wherein at least one of said arresting surface and said complementary arresting surface are textured.

5. The firearm safety feature of claim 3, wherein at least one of said arresting surface and said complementary arresting surface include a coating that increases said coefficient of friction.

6. The firearm safety feature of claim 1, wherein said arresting surface and said complementary arresting surface become positively engaged between one third and half-way between a cocked position and a fully forward position of said hammer.

7. The firearm safety feature of claim 1, wherein said engagement of said arresting surface and said complementary arresting surface results in a force on said safety in a direction toward said hammer.

8. A firearm safety feature, comprising: a firing pin; a hammer spring; a hammer biased by said hammer spring to rotate in a first direction to impact said firing pin, said hammer including an arresting surface; a sear operative to engage said hammer to prevent rotation of said hammer in said first direction and said hammer impacting said firing pin; a trigger operative to engage said sear such that when said trigger is depressed said sear disengages from said hammer, allowing said hammer to rotate in said first direction and impact said firing pin; and a grip safety configured to prevent said trigger from engaging said sear absent a firing grip on said firearm and comprising a complementary arresting surface adjacent said hammer when said hammer is in a cocked position; and wherein said arresting surface and said complementary arresting surface become positively engaged when said grip safety is in a safe position and said hammer rotates in said first direction, thereby preventing said hammer from impacting said firing pin.

9. The firearm safety feature of claim 8, wherein: said hammer defines a travel path before impacting said firing pin; said travel path passes through said complementary arresting surface when said grip safety is in a safe position; and said arresting surface and said complementary arresting surface are parallel when said hammer contacts said grip safety along said travel path.

10. The firearm safety feature of claim 8, wherein: said grip safety includes a lever pivotally coupled to said firearm; said lever includes a lower arm extending downward from said pivotal coupling behind a rear surface of a grip of said firearm; said lever includes an upper arm extending rearward, said upper arm including a distal end defining a hook; and said complementary arresting surface is disposed on said hook.

11. The firearm safety feature of claim 10, wherein: said grip safety additionally includes a biasing member; said biasing member urges said lever into a safe position, wherein said complementary arresting surface is in a path of said arresting surface when said hammer from rotates in said first direction from a cocked position; and urging said lower arm of said lever against a rear surface of said grip rotates said lever, thereby moving said complementary arresting surface out of said path.

12. The firearm safety feature of claim 10, wherein: said hammer includes a distal tip that defines a raised hook; and said arresting surface is disposed on said raised hook.

13. A firearm comprising: a firing pin; a hammer spring; a hammer biased by said hammer spring to rotate in a first direction to impact said firing pin, said hammer including a first arresting surface and a second arresting surface; a sear operative to engage said hammer such that said hammer is prevented from rotating in said first direction toward said firing pin; a trigger operative to disengage said sear from said hammer, allowing said hammer to rotate in said first direction toward said firing pin; a thumb safety switchable between a safe position and a firing position, a portion of said thumb safety positioned to prevent said sear from disengaging said hammer when said trigger is depressed, said thumb safety including a first complementary arresting surface; and a grip safety configured to prevent said trigger from engaging said sear absent a firing grip on said firearm, said grip safety including a second complementary arresting surface adjacent said hammer when said hammer is in a cocked position; and wherein said first arresting surface and said first complementary arresting surface engage one another when said safety is in said safe position and said hammer rotates in said first direction, preventing said hammer from impacting said firing pin; or said second arresting surface and said second complementary arresting surface engage one another when said grip safety is in a safe position and said hammer rotates in said first direction, preventing said hammer from impacting said firing pin.

14. The firearm of claim 13, wherein at least one of said first arresting surface and said first complementary arresting surface are modified to increase the coefficient of friction between said first arresting surface and said first complementary arresting surface.

15. The firearm of claim 14, wherein at least one of said first arresting surface and said first complementary arresting surface are textured.

16. The firearm of claim 14, wherein at least one of said first arresting surface and said first complementary arresting surface include a coating that increases said coefficient of friction.

17. The firearm of claim 13, wherein: said grip safety includes a lever pivotally coupled to said firearm; said lever includes a lower arm extending downward from said pivotal coupling behind a rear surface of a grip of said firearm; said lever includes an upper arm extending rearward, said upper arm including a distal end defining a hook; and said second complementary arresting surface is disposed on said hook.

18. The firearm of claim 17, wherein: said grip safety additionally includes a biasing member; said biasing member urges said lever into said safe position, wherein said second complementary arresting surface is in a path of said second arresting surface when said hammer from rotates in said first direction from a cocked position; and urging said lower arm of said lever against a rear surface of said grip rotates said lever, thereby moving said second complementary arresting surface out of said path.

19. The firearm of claim 13, wherein: said hammer includes a distal tip that defines a raised hook; and said second arresting surface is disposed on said raised hook.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention is described with reference to the following drawings, wherein like reference numbers denote substantially similar elements:

(2) FIG. 1 is a cutaway drawing of an example prior art firearm;

(3) FIG. 2 is cutaway drawing of the firearm of FIG. 1;

(4) FIG. 3 is a diagram showing various parts of the firing mechanism and thumb safety of the firearm of FIG. 1;

(5) FIG. 4 is a photograph of an example prior art cutaway firearm showing the thumb safety in an engaged configuration;

(6) FIG. 5 is a photograph of the firearm of FIG. 4 showing the thumb safety in an unengaged configuration;

(7) FIG. 6A is a diagram showing various parts of an example firearm including a thumb safety according to the present invention;

(8) FIG. 6B is a diagram showing various parts of the firearm of FIG. 6A after failure of a sear;

(9) FIG. 7A is a diagram showing various parts of an example firearm including a grip safety according to the prior art in an engaged configuration;

(10) FIG. 7B is a diagram showing the firearm of FIG. 7A showing the grip safety in an unengaged configuration;

(11) FIG. 8A is a diagram showing various parts of an example firearm including a grip safety according to the present invention in an engaged configuration; and

(12) FIG. 8B is a diagram showing various parts of the firearm of FIG. 8A after failure of a sear.

DETAILED DESCRIPTION

(13) FIG. 1 is a cutaway drawing of an example firearm 100. Firearm 100 is a typical handgun, particularly a US M1911 pistol. While the M1911 pistol is used as an example, the present invention is not limited only to pistols of this type. Indeed, the designs can be adapted for use in any applicable firearm.

(14) FIG. 2 is a cutaway drawing of firearm 100 in an alternate configuration, particularly in an unloaded and unlocked condition with the slide held open.

(15) FIG. 3 is a diagram showing various parts of the firing mechanism and thumb safety of firearm 100. Applying the safety blocks a sear 302. When pulling a trigger 308 on the 1911, trigger 308 acts upon the bottom of sear 302, causing the bottom of sear 302 to move rearward. As sear 302 is mounted via a pivot pin 310 that is roughly vertically central to its body, when the bottom of sear 302 moves rearward, the top of sear 302 moves forward, disengaging from a sear notch 304 in a hammer 306, allowing hammer 306 to fall and contact a firing pin 322, which then impacts the cartridge and causes the cartridge to fire. When pulling trigger 308 with the safety on, the bottom of sear 302 is blocked from any rearward movement by a lug 314 integral to the safety, so the pistol will not fire.

(16) Note that when the safety is engaged, it pivots or swings up, presenting integral lug 314 that protrudes inward, which blocks sear 302 as described above. This safety can only be engaged when hammer 306 is cocked. Hammer 306, pivoting on its own pin 312, comprises an upper portion, containing the part that actually contacts firing pin 322 and has serrations to increase friction for thumb-cocking, and the lower portion, which contains sear notch 304, which, in concert with the tip of sear 302, acts to hold hammer 306 in the cocked position. The safety can only be engaged with hammer 306 in a cocked position, because, in the cocked position, a radial clearance cut in the bottom portion of hammer 306 provides space for safety lug 314 to occupy when the safety is pivoted up into the safe position. In this safe position, lug 314 does appear to be in the way of hammer 306 falling, should a spontaneous failure of sear 302, sear pin 310, or sear notch 304 of hammer 306 occur. However, the relationship between cocked hammer 306 and safety lug 314 is such that if hammer 306 should fall, it will simply cam safety lug 314 out of the way and continue to fall onto firing pin 322. The safety's on and off positions are detented by a spring plunger, and the effort to move the safety up and down varies greatly from pistol to pistol and can be tuned to be heavy or light. In a pistol with heavy detents, this detent action, making downward movement of the safety require greater effort, could constitute enough resistance to the safety's movement to retard the fall of hammer 306 enough to prevent firing. However, in many pistols it will not, and, in any event, the safety detent effort is not and should not be relied upon as a safety feature.

(17) FIG. 4 is a photograph of an example prior art cutaway firearm 400 showing the thumb safety in an engaged configuration.

(18) FIG. 5 is a photograph of firearm 400 showing the thumb safety in an unengaged configuration.

(19) FIG. 6A is a diagram showing various parts of an example firearm 600 including a thumb safety according to the present invention. The present invention includes alterations to the previously discussed safety system. Particularly, it includes differently shaped hammer 606 and safety lug 614. Even more particularly, hammer 606 includes an arresting surface 624 and safety lug 614 includes a complementary arresting surface 626. When contacting each other, these arresting surfaces create a positive engagement, preventing hammer 606 from falling.

(20) In a traditional M1911, such as firearm 100, when the safety is engaged, it rotates upward and, subsequently, the safety lug rotates upward as well. When the hammer falls due to a failure of the sear, sear pin, or sear notch of the hammer, the hammer applies a rotational force on the safety lug, which rotates downward, and the safety disengages.

(21) The present design prevents this by orienting the arresting surfaces in a way that eliminates the rotational force on safety lug 614. When the arresting surfaces come into contact, the resulting force on safety lug 614 is predominately radial, as opposed to tangential or rotational. Indeed, the rotation of hammer 606 acts to lift safety lug 614 toward hammer 606 as opposed to rotating it down and out of place. While a particular embodiment of the present invention is detailed below, it should be noted that alternate features can be used without departing from the scope of the present invention.

(22) In the example design the radial cut in the bottom of hammer 606, provided to give safety lug 614 clearance, includes a right-angle cut or notch defined partially by arresting surface 624. Safety lug 614 also includes a right-angle cut defined partially by complementary arresting surface 626, so, should hammer 606 fall with the safety on, it is not possible for hammer 606 to simply bump or cam the safety to the off position and continue falling. Indeed, the hammer 606 and safety lug 614 will become hooked together, and due to the positive angles of the engagement surfaces, this engagement is very secure. Optionally, the engaging surfaces can be textured, coated, and/or otherwise adapted to increase the coefficient of friction between the surfaces, which makes the engagement even more secure. Under the influence of a hammer spring 620 on hammer 606, pushing it forward, hammer 606 and safety lug 614 tend to pull themselves into this positive engagement. This positive arresting of the fall of hammer 606 occurs about a third to half-way between the cocked and fully-forward positions of hammer 606.

(23) FIG. 6B is a diagram showing various parts of the firearm of FIG. 6A after failure of a sear. Arresting surface 624 and complementary arresting surface 626 are positively engaged, preventing hammer 606 from falling and striking a firing pin 622.

(24) FIG. 7A is a diagram showing various parts of an example firearm 700 including a grip safety according to the prior art in an engaged configuration. Absent a firing grasp on the pistol, a grip safety 702, under the influence of a flat spring (not shown) inside the pistol's handle portion, pivots to the rear (about a pivot shaft 704 of the thumb safety). When pivoted to this position, a horizontal, forward-reaching arm 706 integral to the grip safety is pivoted downward and blocks the rearward movement of a trigger 708. While grip safety 702 prevents rearward movement of the trigger from disengaging a sear 710 from a hammer 712, and, thus, prevents unintended firing of firearm, someone skilled in the art will realize that grip safety 702 will not prevent unintended firing in the event of a failure of sear 710.

(25) FIG. 7B is a diagram showing the firearm of FIG. 7A showing the grip safety in an unengaged configuration. When a firing grasp is applied to the handle of firearm 700, grip safety 702 pivots forward, and forward reaching arm 706 is raised up and out of the path of trigger 708. In this position, trigger 708 can move rearward, rotating sear 710 about a sear pin 714 (assuming a safety lug 716 is in the firing position), thereby causing the pistol to fire. There is nothing about grip safety 702 that acts upon hammer 712 or blocks its path in any way.

(26) FIG. 8A is a diagram showing various parts of an example firearm 900 including a grip safety 902 according to the present invention in an engaged configuration. Grip safety 902 includes alterations from the traditional grip safety. Particularly grip safety 902 includes a hook 904, which introduces a relationship between grip safety 902 and a hammer 906. In the example embodiment, hook 904 is fashioned into the beavertail type. In alternate embodiments hook 904 can be altered or substituted for specific applications. Hook 904 includes an arresting surface 908, and hammer 906 includes a complementary arresting surface 910. When these surfaces contact each other, they create a positive engagement, preventing hammer 906 from falling. The positive engagement arrests the forward movement of hammer 906 in the event of a spontaneous failure of a sear 912, a sear pin 914, or a sear notch 916 of hammer 906.

(27) Absent a firing grasp on firearm 900, as stated above, a forward-protruding horizontal arm (not shown) of grip safety 902 blocks movement of a trigger 918. In the example design, grip safety 902 has an added portion 920 that presents a roughly vertical surface 922 behind cocked hammer 906. This added portion envelops hammer 906 at its rear, and vertical surface 922 has a horizontal cut 924 in it. Hammer 906 includes a raised hook 926 at the very rear of the spur or serrated thumb-cocking surface. When grip safety 902 is at rest in its out or engaged position, that is, when there is nothing pushing it inward, not only is trigger 918 blocked as per the original design, but the newly introduced rear vertical surface 922 with horizontal cut 924, in this at-rest position, is pivoted slightly upward and forward, so that raised hook 926, at the rear of the spur of hammer 906, is in an interference relationship with horizontal cut 924 in vertical surface 922. In other words, the arc described by raised hook 926, in the event of hammer 906 falling due to a spontaneous failure of sear 912, sear pin 914, or sear notch 916 on hammer 906, interferes with horizontal cut 924 in vertical surface 922 of grip safety 902, effecting a positive engagement of the two parts. This engagement positively arrests the forward fall of hammer 906, preventing an unintentional discharge.

(28) Example grip safety 902, in that it by necessity envelops hammer 906 more than previous designs, also affords hammer 906 more protection against an unintentional blow, which could cause the engagement between hammer 906 and sear 912 to fail. Further, as it closes the gap that is normally present between a typical hammer and grip safety, the likelihood of getting an article of clothing snagged in the gap, interfering with the drawing of the pistol, is greatly reduced.

(29) FIG. 8B is a diagram showing various parts of the firearm of FIG. 8A after failure of a sear. Horizontal cut 924 and raised hook 926 are positively engaged, preventing hammer 906 from falling and striking a firing pin 928.