Adjustable length bi-directional folding stock for firearm
View Patent ↗A stock for a firearm. In some embodiments, the stock is configured for bi-directional folding to either side of a receiver of the firearm. In some embodiments, the stock is configured for length adjustment. A biasing element is provided for the length adjustment that biases a proximal (butt) subassembly of the stock against the shoulder of the user. The user can adjust the length of the stock by moving his or her shoulder fore and aft against the butt of the stock. The bi-directional folding and the shoulder length adjustment aspects may be incorporated into a single embodiment.
1. A folding stock for a firearm, comprising:
a stock assembly including:
a butt end and a receiver end portion and defining a stock axis that extends from said butt end through said receiver end portion, said stock assembly including a first side that faces away from said stock axis and a second side that faces away from said stock axis in a direction opposite said first side of said stock assembly, said stock assembly including a first pivot assembly disposed on said first side and defining a first pivot axis that extends substantially parallel to said first side and in a direction that is substantially perpendicular to said stock axis, said stock assembly including a second pivot assembly disposed on said second side and defining a second pivot axis that extends substantially parallel to said second side and in a direction that is substantially perpendicular to said stock axis, each of said first pivot assembly and said second pivot assembly being configured to pivot said folding stock about a selected one of said first pivot axis and said second pivot axis;
an adaptor coupled to said receiver end portion of said stock assembly and for mounting to a receiver of the firearm, said adaptor defining a mounting axis that is parallel to a barrel axis of said firearm, said adaptor including a first side that faces away from said mounting axis and a second side that faces away from said mounting axis in a direction opposite said first side of said adaptor, wherein said adaptor includes a first pin receiving structure that defines a first receiving axis and a second pin receiving structure that defines a second receiving axis, said first pin receiving structure being disposed on said first side of said adaptor, said second pin receiving structure being disposed on said second side of said adaptor, said first pin receiving structure being configured to pivotally couple with said first pivot assembly, said second pin receiving structure being configured to pivotally couple with said second pivot assembly; and
a bow spring mounted to said adaptor, said bow spring including a first free end and a second free end, wherein said first free end clips into a first notch defined on said first side of said stock assembly when in said first folded configuration to secure the folding stock assembly in said first folded configuration, and said second free end clips into a second notch defined on said second side of said stock assembly when in said second folded configuration to secure the folding stock in said second folded configuration,
wherein:
in a battery configuration, said stock axis of said stock assembly is substantially parallel with said mounting axis of said adaptor, said first pivot axis is aligned with said first receiving axis, and said second pivot axis is aligned with said second receiving axis, said adaptor being coupled to said stock assembly with a first mounting pin disposed in said first pin receiving structure, and with a second mounting pin disposed in said second pin receiving structure;
in a first folded configuration, said first side of said stock assembly is adjacent said first side of said adaptor and said first pivot axis is aligned with said first receiving axis, said adaptor being coupled to said stock assembly with said first mounting pin disposed in said first pin receiving structure; and
in a second folded configuration, said second side of said stock assembly is adjacent said second side of said adaptor and said second pivot axis is aligned with said second receiving axis, said adaptor being coupled to said stock assembly with said second mounting pin disposed in said second pin receiving structure.
2. The folding stock of claim 1 , wherein said first pivot assembly includes structure defining a first eye centered about said first pivot axis and said second pivot assembly includes structure defining a second eye centered about said second pivot axis.
3. The folding stock of claim 1 , wherein said first pin receiving structure defines a third eye concentric about said first receiving axis and said second pin receiving structure defines a fourth eye concentric about said second receiving axis.
4. The folding stock of claim 1 , wherein said first pin receiving structure includes a trunnion structure concentric about said first receiving axis and said second pin receiving structure includes a trunnion structure concentric about said second receiving axis.
5. The folding stock of claim 1 , wherein said first pivot axis and said second pivot axis are parallel to each other to define a stock mounting plane that passes through said receiver end portion of said stock assembly, and said first receiving axis and said second receiving axis are parallel to each other to define an adaptor mounting plane that passes through said adaptor.
6. The folding stock of claim 5 , wherein said stock mounting plane is substantially perpendicular to said stock axis, and said adaptor mounting plane is perpendicular to said mounting axis.
7. The folding stock of claim 1 , wherein said mounting axis is parallel to said stock axis when in at least one of said first folded configuration and said second folded configuration.
8. The folding stock of claim 1 , wherein an adaptor mounting plane that passes through said adaptor is co-planar with a stock mounting plane that passes through said receiver end portion of said stock assembly when in at least one of said first folded configuration and said second folded configuration.
9. The folding stock of claim 1 , wherein said first notch is distal to first eye axis and said second notch is distal to said second eye axis.
10. The folding stock of claim 1 , wherein said receiver end portion includes a mounting piece fastened to said stock assembly, said mounting piece defining said first pivot axis and said second pivot axis.
11. A folding stock for a firearm, comprising a stock assembly including a butt end and a receiver end portion and defining a stock axis that extends from said butt end through said receiver end portion, said stock assembly including a first side that faces away from said stock axis and a second side that faces away from said stock axis in a direction opposite said first side of said stock assembly, said stock assembly including a first pivot assembly disposed on said first side and defining a first pivot axis that extends substantially parallel to said first side and in a direction that is substantially perpendicular to said stock axis, said stock assembly including a second pivot assembly disposed on said second side and defining a second pivot axis that extends substantially parallel to said second side and in a direction that is substantially perpendicular to said stock axis, each of said first pivot assembly and said second pivot assembly being configured to pivot said folding stock about a selected one of said first pivot axis and said second pivot axis, wherein said stock assembly includes:
a proximal stock subassembly including said butt end and a proximal stock housing, an adjustment tube fixedly attached to said proximal stock housing, said adjustment tube defining an adjustment axis that extends distally from said proximal stock subassembly, said adjustment tube defining a plurality of apertures, each aperture facing in a direction perpendicular to said adjustment axis;
a distal stock subassembly, including a distal stock housing that defines an internal passageway, said adjustment tube being slidably engaged within said internal passageway, and a retractable set pin coupled to said distal stock housing and arranged for selectively engaging any one of said plurality of apertures of said adjustment tube to releasably secure said proximal stock subassembly in a fixed relationship with said distal stock subassembly; and
a biasing spring disposed between said proximal stock subassembly and said distal stock subassembly, said biasing spring exerting a biasing force parallel to said adjustment axis in a proximal direction on said proximal stock subassembly.
12. The folding stock of claim 11 , wherein said adjustment tube includes a cylindrical portion.
13. The folding stock of claim 12 , wherein said adjustment tube includes a rail portion, said plurality of apertures being defined in said rail portion.
14. The folding stock of claim 11 , comprising a lever pivotally mounted to said distal stock housing and coupled to said retractable set pin for selectively engaging and disengaging said retractable set pin from said any one of said plurality of apertures.