Collapsible stock assembly
View Patent ↗A collapsible stock assembly for a firearm includes a stock body defining a buffer tube passage for slidably accommodating a firearm buffer tube therein. An adjustment slit communicates with the buffer tube passage along a forward portion thereof. A first adjustment mechanism canied by the stock body includes a buffer tube engagement element that can extend into the buffer tube passage and is selectively positionable by a first operating lever. A second operating mechanism includes a second operating lever that is operable to selectively compress the adjustment slit. Disengaging the first adjustment mechanism automatically disengages the second adjustment mechanism. Excessive force on the stock in several embodiments automatically disengages both adjustment mechanisms and minimizes damage to stock assembly and/or buffer tube.
1. A collapsible stock assembly for a firearm, the assembly comprising:
a stock body having a buffer tube passage defined therein extending in an axial direction, a buffer tube insertion opening being defined on a forward end of the stock body to allow insertion of a rear end of a firearm buffer tube therein in the axial direction, the buffer tube passage being dimensioned to slidably accommodate at least a portion of the buffer tube therein, the stock body also defining an adjustment slit extending axially rearwards from the buffer tube insertion opening and communicating with a forward portion of buffer tube passage and extending radially outward therefrom;
a first adjustment mechanism carried by the stock body, and including a buffer tube engagement element displaceable into the buffer tube passage and a first operating lever operable to selectively position the buffer tube engagement element; and
a second adjustment mechanism carried by the stock body, and including a second operating lever having a stock body engagement portion, the second operating lever operable to selectively engage the stock body with the stock body engagement portion to compress the adjustment slit.
2. The assembly of claim 1 , wherein the first adjustment mechanism further includes an engagement element biasing mechanism, the biasing mechanism biasing the buffer tube engagement element into the buffer tube passage, and the first operating lever being operable to urge the buffer tube engagement element out of the buffer tube passage.
3. The assembly of claim 2 , wherein the engagement element is a compression spring.
4. The assembly of claim 2 , wherein the stock body further defines an engagement element channel extending radially outward from the buffer tube passage, the engagement element biasing mechanism and the engagement element being arranged in the engagement element channel.
5. The assembly of claim 2 , wherein the first operating lever is pivotably mounted to the stock body between first operating lever first and second ends thereof, such that the first operating lever first end urges the engagement element out of the buffer tube passage when the first operating lever second end is urged toward the buffer tube passage.
6. The assembly of claim 5 , wherein the first and second operating lever are arranged on the stock body in proximity such that urging the first operating lever second end toward the buffer tube passage is operable to disengage the second operating lever from compressing the adjustment slit.
7. The assembly of claim 1 , wherein the first and second operating lever are arranged on the stock body in proximity such that the first operating lever is further operable to disengage the second operating lever from compressing the adjustment slit and the second operating lever being located forwardly of the first operating lever.
8. The assembly of claim 1 , wherein the stock body engagement portion of the second operating lever includes at least one engagement tooth extending toward the stock body.
9. The assembly of claim 8 , wherein at least one contoured engagement surface is defined on the stock body underlying the at least one engagement tooth, such that moving the at least one engagement tooth over the at least one contoured engagement surface will adjust compression of the adjustment slit.
10. The assembly of claim 9 , wherein the at least one contoured engagement surface includes at least one locking detent proximate an end thereof to releasably hold the at least one engagement tooth with the adjustment slit compressed.
11. The assembly of claim 1 , wherein the stock body includes a buffer tube accommodation portion in which the buffer tube passage is defined, an angled lower portion extending rearwardly and downwardly from a forward end of the buffer tube accommodation portion and a butt portion extending between rearward ends of the buffer tube accommodation portion and the angled lower portion, an operating lever opening being defined between the buffer tube accommodation portion and the angled lower portion and the butt portion, the first operating lever extending into the operating lever opening.
12. The assembly of claim 1 , wherein the buffer tube engagement element includes first and second engagement faces displaceable into the buffer tube passage, the first engagement face being angled rearwardly away from the buffer tube insertion opening, the second engagement face being angled rearwardly away from the buffer tube insertion opening at a steeper angle than the first engagement face, the first and second engagement faces sharing a common edge with the second engagement face displaceable further into the buffer tube passage than the first engagement face.
13. The assembly of claim 12 , wherein the second engagement face extends below a most forward detent of a plurality of spaced detents extending along the buffer tube wherein excessive forward force on the rear of the stock assembly unlocks the engagement element from a detent engaged therewith and all the detents of the buffer tube and the stock assembly moves to its most forward position on the buffer tube.
14. The assembly of claim 2 , wherein the buffer tube engagement element includes a forward engagement face displaceable into the buffer tube passage, the forward engagement face extends below a most forward detent of a plurality of spaced detents extending along the buffer tube, wherein excessive forward force on the rear of the stock assembly unlocks the engagement element from a detent engaged therewith and all the detents of the buffer tube and the stock assembly moves to its most forward position on the buffer tube.
15. The assembly of claim 2 , wherein the buffer tube engagement element includes a reduced upper portion displaceable into the buffer tube passage and a larger lower portion, the upper portion having a forward curved engagement face extending rearwardly and engageable with a selected detent of a plurality of spaced detents extending along the buffer tube, excessive forward force on the rear of the stock assembly causes the engagement element to move out of the buffer tube passage and unlocks the engagement element from the selected detent and from all detents except the most forward detent and the stock assembly moves forwardly until the larger lower portion engages in the most forward detent.
16. The assembly of claim 1 , further comprising a sizing shim releasably accommodated in the adjustment slit.
17. The assembly of claim 1 , further comprising a sizing pin extending along a sizing pin axis, the sizing pin having first and second sizing face, the second sizing face being farther from the sizing pin axis than the first sizing face; and wherein the stock body further defines a sizing passage partially intersecting and extending generally perpendicular to the axial direction of the buffer tube passage, the sizing pin being releasably arranged in the sizing passage with one of the first and second faces extending into the buffer tube passage.
18. A collapsible stock assembly for a firearm, the assembly comprising;
a stock body defining
a buffer tube passage extending in an axial direction therein, and a buffer tube insertion opening on a forward end of the stock body to allow insertion of a rear end of a firearm buffer tube therein in the axial direction, the buffer tube passage being dimensioned to slidably accommodate at least a portion of the buffer tube therein,
an engagement element channel extending radially outward from the buffer tube passage,
at least one contoured engagement surface, and
an adjustment slit extending axially rearwards from the buffer tube insertion opening, communicating with a forward portion of buffer tube passage and extending radially outward therefrom, and
a first adjustment mechanism including;
a buffer tube engagement element slidably arranged in the engagement element channel,
an engagement element biasing mechanism arranged in the engagement element channel and biasing the buffer tube engagement into the buffer tube passage, and
a first operating lever mounted to the stock body and operable to urge the buffer tube engagement element out of the buffer tube passage; and
a second adjustment mechanism including;
at least one engagement tooth slidably overlying the at least one contoured engagement surface, and
a second operating lever mounted to the stock body and carrying the at least one engagement tooth, the second operating lever being operable to move the at least one engagement tooth over the at least one contoured engagement surface to adjust compression of the adjustment slit.
19. The assembly of claim 18 , wherein the stock body includes a buffer tube accommodation portion in which the buffer tube passage is defined, an angled lower portion extending rearwardly and downwardly from a forward end of the buffer tube accommodation portion and a butt portion extending between rearward ends of the buffer tube accommodation portion and the angled lower portion, an operating lever opening being defined between the buffer tube accommodation portion, the angled lower portion and the butt portion, the first operating lever extending into the operating lever opening.
20. The assembly of claim 18 , wherein the first and second operating levers are pivotably mounted in proximity such that, with the second adjustment mechanism compressing the adjustment slit, operating the first operating lever to urge the buffer tube engagement element out of the buffer tube passage will automatically operate the second operating lever from compressing the adjustment slit the second operating lever being located forwardly of the first operating lever.