APPARATUS AND METHODS FOR A DUAL DWELL WEIGHT FOR DIRECT GAS OPERATED FIREARMS

Abstract

An apparatus and methods are provided for a dual dwell weight for optimizing the operation of a direct gas operated firearm. The dual dwell weight comprises a forward weight and an aft weight with a centrally disposed spring. The weights slide within an undercut portion of a cylindrical interior of a bolt carrier of the firearm. The forward weight is a rear dwell enhancer while the aft weight is an unlock dwell enhancer and an anti-bounce weight. A longitudinal pin maintains alignment between the forward weight and the aft weight. A transverse pin maintains clocking of the first weight and the aft weight. The interior includes a keyway that enables installing the weights into the bolt carrier.

Claims

1. A bolt carrier for a direct gas operated firearm, comprising: a cylindrical member having a cylindrical interior; a bolt disposed at a distal end of the cylindrical member; and a dual biased dwell weight incorporated into a proximal end of the cylindrical interior.

2. The bolt carrier of claim 1, wherein the dual dwell weight comprises a forward weight and an aft weight with a centrally disposed spring.

3. The bolt carrier of claim 2, wherein the forward weight and the aft weight are configured to slide within the cylindrical interior of the bolt carrier.

4. The bolt carrier of claim 3, wherein the mass of the forward weight and the aft weight provides additional inertia to the bolt carrier.

5. The bolt carrier of claim 3, wherein the forward weight is configured to be a rear dwell enhancer while the aft weight is configured to serve as an unlock dwell enhancer and an anti-bounce weight.

6. The bolt carrier of claim 3, wherein stop wings are incorporated into the top and bottom of the forward weight and the aft weight.

7. The bolt carrier of claim 6, wherein the stop wings are configured to slide within an undercut portion of the interior of the bolt carrier.

8. The bolt carrier of claim 7, wherein the stop weights are configured to allow the first weight and the aft weight to move forward and rearward within the interior of the bolt carrier.

9. The bolt carrier of claim 7, wherein the interior includes a keyway that enables installing the forward weight and the aft weight into the bolt carrier.

10. The bolt carrier of claim 9, wherein the forward weight and the aft weight can be installed into the bolt carrier by inserting the stop wings through the keyway and then rotating the forward weight and the aft weight such that the stop wings move into the undercut portion.

11. The bolt carrier of claim 10, wherein a shaped recess is configured to facilitate rotating the forward weight and the aft weight within the interior.

12. The bolt carrier of claim 7, wherein the spring is disposed within a central hole of the forward weight and a central hole of the aft weight.

13. The bolt carrier of claim 12, wherein the spring biases the forward weight and the aft weight to opposite ends of the undercut portion, giving rise to a distance between the stop wings of the forward weight and the aft weight.

14. The bolt carrier of claim 2, wherein a longitudinal pin installed into a hole in the forward weight is received into a clearance hole disposed in the aft weight so as to maintain alignment between the forward weight and the aft weight.

15. The bolt carrier of claim 2, wherein clocking of the first weight and the aft weight is maintained by a transverse pin that slides within a recess disposed in the top of the forward weight.

16. The bolt carrier of claim 15, wherein the transverse pin is pressed into holes disposed in the bolt carrier such that the transverse pin extends across the recess.

17. A dual dwell weight for a bolt carrier, comprising: a forward weight and an aft weight with a centrally disposed spring; a longitudinal pin for maintaining alignment between the forward weight and the aft weight; and a transverse pin for maintaining clocking of the first weight and the aft weight.

18. The dual dwell weight of claim 17, wherein the forward weight and the aft weight are configured to slide within a cylindrical interior of the bolt carrier.

19. The dual dwell weight of claim 18, wherein the forward weight is configured to be a rear dwell enhancer while the aft weight is configured to serve as an unlock dwell enhancer and an anti-bounce weight.

20. The dual dwell weight of claim 19, wherein the interior includes a keyway that enables installing the forward weight and the aft weight into the bolt carrier.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings refer to embodiments of the present disclosure in which:

[0016] FIG. 1 illustrates a right-side elevation view of an exemplary embodiment of a firearm that utilizes direct gas impingement to operate a bolt carrier group comprising the firearm, in accordance with the present disclosure;

[0017] FIG. 2 illustrates a ghost-view of a bolt carrier that includes an exemplary embodiment of a dual dwell weight in accordance with the present disclosure;

[0018] FIG. 3 illustrates an exploded view of an exemplary embodiment of a dual dwell weight comprising a bolt carrier, according to the present disclosure;

[0019] FIG. 4 illustrates a midline cross-sectional view of the bolt carrier of FIG. 2, according to the present disclosure; and

[0020] FIG. 5 illustrates a close-up view of an exemplary embodiment of a dual dwell weight comprising a bolt carrier in accordance with the present disclosure.

[0021] While the present disclosure is subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. The present disclosure should be understood to not be limited to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure.

DETAILED DESCRIPTION

[0022] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be apparent, however, to one of ordinary skill in the art that the dual dwell weight and methods disclosed herein may be practiced without these specific details. In other instances, specific numeric references such as first screw, may be made. However, the specific numeric reference should not be interpreted as a literal sequential order but rather interpreted that the first screw is different than a second screw. Thus, the specific details set forth are merely exemplary. The specific details may be varied from and still be contemplated to be within the spirit and scope of the present disclosure. The term coupled is defined as meaning connected either directly to the component or indirectly to the component through another component. Further, as used herein, the terms about, approximately, or substantially for any numerical values or ranges indicate a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein.

[0023] The AR15/M4/M16 family of firearms and their derivatives, including all direct gas operated versions, have been in use by the military and civilian population for many years. Given the popularity of the AR15/M4/M16 family of firearms and their derivatives, there is a continuing desire to improve and simplify the operation of such firearms. Embodiments presented herein provide an upper receiver for optimizing various aspects and increasing the longevity of a direct gas operated rifle.

[0024] FIG. 1 illustrates a right-side elevation view of an exemplary embodiment of a firearm 100 that utilizes direct gas impingement to cycle the action of a bolt carrier group comprising the firearm, as described herein. In general, the firearm 100 comprises a member of the AR15/M4/M16 family of firearms, and thus the firearm 100 includes an upper receiver 104 that houses the bolt carrier group (not shown) and a lower receiver 108 that receives a magazine 112 containing a multiplicity of ammunition cartridges. The lower receiver 108 positions the ammunition cartridges within the upper receiver 104 such that the bolt carrier group may strip cartridges into a battery position within a breech of a barrel 116. An ejection port 120 on a side of the upper receiver 104 enables the bolt carrier group to eject spent ammunition cartridges after each round is fired. A receiver extension 124 coupled with a rear of the upper receiver 104 provides a housing for longitudinal movement of the bolt carrier group during stripping and ejecting ammunition cartridges. A buttstock 128, handguards 132, and a grip 136 facilitate a practitioner holding and supporting the firearm 100 during operating the firearm 100 by way of a trigger 140. Further, a suppressor (not shown) may be coupled with a muzzle end of the barrel 116 to reduce noise and muzzle flash during operating the firearm 100.

[0025] As described herein, the bolt carrier group moves longitudinally within the upper receiver 104 during stripping ammunition cartridges from the magazine 112, chambering the cartridges in the breech, and ejecting spent cartridges. The energy to perform these functions is provided by way of hot, expanding gases from each fired cartridge that cause the bolt carrier to move rearward within the receiver extension 124 toward the buttstock 128. The expanding gases are directed to the bolt carrier group from a port at an end of the barrel 116 by way of a gas block 148 and a gas tube (not shown) disposed within the handguards 132. The expanding gases cause the bolt carrier group to move rearward within the receiver extension 124 and then are discharged through the ejection port 120. After discharge, a spring acting on the bolt carrier group moves the bolt carrier forward to an engaged position while at the same time stripping another ammunition cartridge from the magazine 112 and moving that cartridge into the battery position.

[0026] FIG. 2 illustrates a ghost-view of a bolt carrier 144 that includes an exemplary embodiment of a dual dwell weight 160 in accordance with the present disclosure. The bolt carrier 144 is a generally cylindrical member having a bolt 150 at a distal end 152 and the dual dwell weight 160 incorporated into a proximal end 156. As described hereinabove, the bolt carrier 144 is configured to move longitudinally within the upper receiver 104 during stripping ammunition cartridges from the magazine 112, chambering the cartridges in the breech, and ejecting spent cartridges.

[0027] In general, the dual dwell weight 160 is configured to put more inertia into the bolt carrier 144. As shown in FIGS. 2-3, the dual dwell weight 160 comprises a forward weight 164 and an aft weight 168 with a centrally disposed spring 172. The weights 164, 168 are configured to slide within a cylindrical interior 176 of the bolt carrier 144. The mass of the weights 164, 168 provides the inertia effect mentioned above. More specifically, the forward weight 164 is primarily a rear dwell enhancer while the aft weight 168 serves as an unlock dwell enhancer and an anti-bounce weight.

[0028] During operation, as the bolt carrier 144 accelerates rearward, both the bolt carrier 144 and the dual dwell weight 160 accumulate kinetic energy. Once the bolt carrier 144 and the dual dwell weight 160 both have achieved peak velocity and rearward momentum, the bolt carrier 144 begins to lose kinetic energy due to frictional losses from cartridge extraction as well as spring force resistance from the recoil spring and the hammer spring. However, the forward weight 164 continues rearward, unimpeded by these forces, and begins to transfer some of its kinetic energy back to the bolt carrier 144 through the spring 172 and/or directly to the bolt carrier 144 upon impact with the aft weight 168 at the proximal end 156 of the bolt carrier 144. This allows a more efficient use of kinetic energy in the bolt carrier 144 group for reliable extraction without increasing peak carrier group velocity, and thus prolonging overall cycle time. A longer overall cycle time benefits reliability in reducing mechanical wear and providing ample time for the magazine to present the next cartridge for feeding even in adverse environmental conditions.

[0029] As best shown FIGS. 4-5, stop wings 180 (see FIG. 1) incorporated into the top and bottom of the weights 164, 168 are configured to slide within an undercut portion 184 of the interior 176 of the bolt carrier 144. During assembly, the weights 164, 168 can be installed into the bolt carrier 144 by inserting the stop wings 180 through a keyway 188 (see FIG. 3) and then rotating the weights 164, 168 such that the stop wings 180 move into the undercut portion 184. A shaped recess 190 is configured to facilitate rotating the weights 164, 168. Thus, the stop weights 180 are configured to allow the weights 164, 168 to move forward and rearward within the interior 176 of the bolt carrier 144.

[0030] The spring 172 is disposed within a central hole 192 of the forward weight 164 and a central hole 196 of the aft weight 168. As best shown in FIG. 5, the spring 172 biases the weights 164, 168 to opposite ends of the undercut portion 184, giving rise to a distance 198 between the stop wings 180 of the weights 164, 168. The distance 198 is known to have a relationship with the amount of rear dwell (i.e., an increase in rebound time) imparted to the bolt carrier 144. As such, the distance 198, as well as the mass of the weights 164, 168 and the spring force of the spring 172, may be tuned to produce a desired rear dwell of the bolt carrier 144. Further, in some embodiments, the central hole 192 can include a narrow portion (not shown) configured to allow airflow in and out of the undercut portion 184. It is contemplated that such a narrow portion can prevent air pressure between the forward weight 164 and the aft weight 168 from hindering the longitudinal movement of the weights 164, 168.

[0031] With continuing reference to FIG. 5, a longitudinal pin 200 installed into a hole 202 (see FIG. 3) in the forward weight 164 is received into a clearance hole 204 disposed in the aft weight 168. The longitudinal pin 200 is configured to maintain alignment between the weights 164, 168. Further, clocking of the weights 164, 168 can be maintained by a transverse pin 208 that slides within a recess 212 disposed in the top of the forward weight 164. As best shown in FIG. 3, the transverse pin 208 can be pressed into holes 216 disposed in the bolt carrier 144 such that the pin 208 extends across the recess 212 as shown in FIG. 5.

[0032] As mentioned hereinabove, the dual dwell weight 160 provides an inertial effect when the bolt carrier 144 bottoms out at the end of its stroke, at which point the forward weight 164 continues on and thus introduces a pause before the bolt carrier 144 begins to move forward again. In some embodiments, the dual dwell weight 160 may slow down the very first part of unlocking the bolt 150, which has been observed to be beneficial, in some embodiments. Further, the aft weight 168 may be configured to prolong momentum transfer between dual dwell weight 160 and the bolt carrier 144, thereby staggering total momentum transfer between the carrier and a barrel extension comprising the firearm 100 and reducing overall restitution of the bolt carrier group upon impact with the barrel extension, commonly known as bolt bounce.

[0033] While the dual dwell weight and methods have been described in terms of particular variations and illustrative figures, those of ordinary skill in the art will recognize that the dual dwell weight is not limited to the variations or figures described. In addition, where methods and steps described above indicate certain events occurring in certain order, those of ordinary skill in the art will recognize that the ordering of certain steps may be modified and that such modifications are in accordance with the variations of the dual dwell weight. Additionally, certain of the steps may be performed concurrently in a parallel process, when possible, as well as performed sequentially as described above. To the extent there are variations of the dual dwell weight, which are within the spirit of the disclosure or equivalent to the dual dwell weight found in the claims, it is the intent that this patent will cover those variations as well. Therefore, the present disclosure is to be understood as not limited by the specific embodiments described herein, but only by scope of the appended claims.