Trigger Travel Stop Limit
A firearm trigger assembly has a trigger housing including a first opening and second opening through a surface of the trigger housing. A trigger assembly is disposed partially within the trigger housing. The trigger assembly has a trigger body with a trigger pull disposed within the trigger housing, disconnector in contact with the trigger body, and hammer body rotationally connected to the trigger body and latchable to the trigger body. A first limit stop, such as a first set screw, is disposed through the first opening and contacts the trigger body to stop movement of the trigger assembly in the first direction, and a second limit stop, such as a second set screw, is disposed through the second opening and contacts the trigger body to stop movement of the trigger assembly in the second direction. The trigger body has a concave surface adapted to receive a safety selector.
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The present application claims the benefit of U.S. Provisional Application No. 63/134,935, filed Jan. 7, 2021, which application is incorporated herein by reference.
FIELD OF THE INVENTIONThe present invention relates in general to firearms and, more particularly, to a firearm and method of limiting travel of the trigger assembly by using limit stops.
BACKGROUNDModern firearms are designed and manufactured to operate with multiple inter-operational components and often with modular construction. In one example, an AR-10 or AR-15 style sporting rifle 100 uses a modular construction with an upper receiver 102 and lower receiver 104, as shown in
The AR-10 and AR-15 platforms typically use a drop-in type trigger assembly. The trigger assembly includes a trigger housing, trigger body, disconnector, and hammer body. The trigger body includes an integral trigger pull and fits in and through the trigger housing. The disconnector is attached to the trigger body and inhibits automatic operation of the firearm. The trigger body engages a sear or notch in the hammer body to hold the trigger assembly in a cocked position, ready to fire. Upon applying pressure to the trigger pull, the trigger body releases or breaks from the hammer sear. The hammer body strikes the fire pin to discharge the weapon.
There is typically pre-travel or take-up, creep travel, and post-travel or over-travel in the trigger pull. In some contexts, creep travel is considered part of pre-travel, but in the interest of clarity, creep travel will be considered separately from pre-travel. Pre-travel is that movement for the trigger pull to bring the trigger body in pressure contact with the sear, up to the wall without releasing the hammer body. Creep travel is that movement of the trigger pull necessary to cause movement in the trigger body, breaking the wall and releasing the hammer to discharge the firearm. Post-travel is that movement of the trigger pull after discharge of the firearm. Pre-travel play and post-travel play can each be in the range of 0.15 to 0.32 centimeters (cm). With pre-travel and post-travel, the trigger pull and trigger body travel further than is actually necessary to release the hammer. The amount of pre-travel and post-travel is typically controlled using springs and generally follows the quality of the trigger assembly, i.e., high quality components tend to have less pre-travel and post-travel. Another method of reducing pre-travel is to reduce the trigger pull pressure, generally stated in terms of pounds of trigger pull, needed to break the wall and discharge the firearm. However, reducing trigger pressure tends to make the weapon susceptible to unintentional discharge, which is a major safety concern. Nonetheless, with pre-travel, the trigger pull travels further than necessary to reach creep travel. Pre-travel and post-travel cause undesired movement in the trigger and for the weapon as a whole. Shooting accuracy is reduced with excessive movement, as well as reliability in firing the weapon.
The following describes one or more embodiments with reference to the figures, in which like numerals represent the same or similar elements. While the figures are described in terms of the best mode for achieving certain objectives, the description is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the disclosure.
In
Pulling trigger pull 284 in the direction of arrow 328 causes a pressure contact between trigger body 294 and sear 334, i.e., hitting the wall, followed by releasing sear 334 from edge 344 of trigger body 294, i.e., breaking the wall. Once released, hammer body 318 rotates back in the direction of arrow 330 under tension of hammer spring 322 so that surface 332 of hammer body 318 strike the firing pin (not shown). Trigger limit set screw 340 and hammer limit set screw 342 limit the motion of trigger pull 284 and trigger body 280, as discussed infra.
In
Trigger limit set screw 340 and hammer limit set screw 342 are set to minimize the travel of trigger pull 284, and correspondingly the movement of trigger body 280. Upon trigger pull, trigger body 280 must exhibit some movement, i.e., creep travel, in order to pull edge 344 from sear 334 and release hammer body 318. Trigger limit set screw 340 sets the starting point of trigger pull 284 to reduce or eliminate pre-travel. Hammer limit set screw 342 limits the travel of trigger pull 284 in the direction of arrow 368 to reduce or eliminate post-travel. In one embodiment, trigger limit set screw 340 is adjusted first to set the screw as close to the wall of hammer release as possible. Again, trigger limit set screw is positioned to have a small positive movement of trigger pull 284, i.e., only creep travel, to reach the wall or release point of sear 334. On the other hand, trigger limit set screw should not be set too close to the wall for unintended discharge of the weapon. In one embodiment, the creep travel of trigger pull 284 to release hammer body 318 is 1.0 degrees with 3-6 pound trigger pull. Pre-trigger pull, trigger limit set screw 340 contacts surface 360 of trigger body 280, as shown in
Trigger limit set screw 340 and hammer limit set screw 342 operate as limit stops to physically stop undesired movement of trigger pull 284 and reduce or eliminate pre-travel and post-travel. The physical limit stop is achieved with the metal-to-metal contact between trigger limit set screw 340 and surface 360 of trigger body 280 and the metal-to-metal contact between hammer limit set screw 342 and surface 362 of trigger body 280. The stop position of trigger limit set screw 340 and hammer limit set screw 342 can be tuned by adjusting the height of the set screws extending from threaded openings 260 and 262 of trigger housing 230 to provide only creep travel for trigger pull 288 and eliminate pre-travel and post-travel, for any trigger poundage. Accordingly, pre-travel and post-travel can be eliminated without down-scaling trigger poundage, as used in the prior art.
Other types of limit stops, providing a similar function as trigger limit set screw 340 and hammer limit set screw 342, can be used to reduce or eliminate pre-travel and post-travel. For example, solid shafts or posts 367 and 369, as shown in
While one or more embodiments have been illustrated and described in detail, the skilled artisan will appreciate that modifications and adaptations to those embodiments may be made without departing from the scope of the present disclosure.
Claims
1. A firearm trigger assembly, comprising:
- a trigger housing including a first opening and second opening through a surface of the trigger housing;
- a trigger assembly disposed partially within the trigger housing;
- a first limit stop disposed through the first opening to limit movement of the trigger assembly in a first direction; and
- a second limit stop disposed through the second opening to limit movement of the trigger assembly in a second direction.
2. The firearm trigger assembly of claim 1, wherein the trigger assembly includes:
- a trigger body with a trigger pull disposed within the trigger housing;
- a disconnector in contact with the trigger body; and
- a hammer body rotationally connected to the trigger body and latchable to the trigger body.
3. The firearm trigger assembly of claim 1, wherein the trigger pull extends through a third opening in the trigger housing between the first opening and second opening.
4. The firearm trigger assembly of claim 1, wherein the first limit stop contacts a first portion of a surface of the trigger body to stop movement of the trigger assembly in the first direction and the second limit stop contacts a second portion of the surface of the trigger body to stop movement of the trigger assembly in the second direction.
5. The firearm trigger assembly of claim 1, wherein the first limit stop includes a first set screw threaded through the first opening and the second limit stop includes a second set screw threaded through the second opening.
6. The firearm trigger assembly of claim 1, wherein the trigger body includes a concave surface adapted to receive a safety selector.
7. A firearm trigger assembly, comprising:
- a trigger housing;
- a trigger assembly disposed partially within the trigger housing; and
- a first limit stop disposed through a first opening of the trigger housing to limit movement of the trigger assembly in a first direction.
8. The firearm trigger assembly of claim 7, further including a second limit stop disposed through a second opening in the trigger housing to limit movement of the trigger assembly in a second direction.
9. The firearm trigger assembly of claim 8, wherein the trigger assembly includes:
- a trigger body with a trigger pull disposed within the trigger housing;
- a disconnector in contact with the trigger body; and
- a hammer body rotationally connected to the trigger body and latchable to the trigger body.
10. The firearm trigger assembly of claim 9, wherein the trigger pull extends through a third opening in the trigger housing between the first opening and second opening.
11. The firearm trigger assembly of claim 9, wherein the trigger body includes a concave surface.
12. The firearm trigger assembly of claim 8, wherein the first limit stop contacts a first portion of a surface of the trigger body to stop movement of the trigger assembly in the first direction and the second limit stop contacts a second portion of the surface of the trigger body to stop movement of the trigger assembly in the second direction.
13. The firearm trigger assembly of claim 8, wherein the first limit stop includes a first set screw threaded through the first opening and the second limit stop includes a second set screw threaded through the second opening.
14. A method of making a firearm trigger assembly, comprising:
- providing a trigger housing;
- disposing a trigger assembly partially within the trigger housing; and
- disposing a first limit stop through a first opening of the trigger housing to limit movement of the trigger assembly in a first direction.
15. The method of claim 14, further including disposing a second limit stop through a second opening in the trigger housing to limit movement of the trigger assembly in a second direction.
16. The method of claim 15, wherein disposing the trigger assembly includes:
- disposing a trigger body with a trigger pull within the trigger housing;
- providing a disconnector in contact with the trigger body; and
- providing a hammer body rotationally connected to the trigger body and latchable to the trigger body.
17. The method of claim 16, wherein the trigger pull extends through a third opening in the trigger housing between the first opening and second opening.
18. The method of claim 16, wherein the trigger body includes a concave surface.
19. The method of claim 15, wherein the first limit stop contacts a first portion of a surface of the trigger body to stop movement of the trigger assembly in the first direction and the second limit stop contacts a second portion of the surface of the trigger body to stop movement of the trigger assembly in the second direction.
20. The method of claim 15, wherein the first limit stop includes a first set screw threaded through the first opening and the second limit stop includes a second set screw threaded through the second opening.
Type: Application
Filed: Apr 19, 2021
Publication Date: Jul 7, 2022
Applicant: 03312004 LLC (Chandler, AZ)
Inventor: Thomas Afshari (Gilbert, AZ)
Application Number: 17/233,866