Firearm having a dual cam, cock on close bolt action and a low creep sear and step trigger assembly
View Patent ↗A bolt action firearm that cocks the firing pin upon closing the bolt and includes a cam pin with dual heads for a high velocity rimfire cartridge. In one embodiment, actuating the main spring while closing the bolt, instead of while opening the bolt, more uniformly distributes the physical energy required by the user over the bolt actuation cycle. The dual heads of the cam pin provide symmetric reactive forces with dual cam slots, thereby preventing the cam pin from skewing or canting within the cam slots. A safety system is provided for the trigger mechanism and a robust connecting systems for the stock.
1. A firearm, comprising:
a receiver;
a barrel attached to said receiver;
a dual cam bolt adapted to engage with said receiver, said dual cam bolt including a firing mechanism having a main spring and firing pin;
a trigger assembly having a stop lever, said stop lever being selectively movable between a blocking position and a non-blocking position,
wherein said stop lever is finger actuated proximate to a finger portion of a trigger, and
wherein in the non-blocking position a sear is rotatable to release the main spring to discharge the firearm.
2. The firearm of claim 1 , further including a detachable magazine.
3. The firearm of claim 1 , wherein said firearm is a breech-loading firearm.
4. The firearm of claim 1 , wherein a breech end of the barrel includes an outer threaded portion for threaded engagement with an inner threaded portion of the receiver for removable attachment to the receiver.
5. The firearm of claim 4 , wherein the breech end of the barrel further includes an undercut portion for locking the barrel in place with a plurality of fasteners.
6. The firearm of claim 5 , wherein the plurality of fasteners includes a stud and locking set screws.
7. The firearm of claim 1 , comprising a removable trigger guard assembly that is attachable to said receiver without a tool and without fasteners.
8. The firearm of claim 7 , comprising a trigger pull adjustment for adjusting a pull force required to actuate said trigger, said trigger pull adjustment being accessible by removal of said removable trigger guard assembly.
9. The firearm of claim 8 , wherein said trigger pull adjustment includes a thumbwheel adjustment for adjustment of said pull force without need of an external tool.
10. The firearm of claim 9 , wherein said thumbwheel adjustment is accessible to a user with said trigger assembly in an installed configuration within said receiver.
11. The firearm of claim 1 , wherein, in said blocking position, said stop lever is engageable with a notch in said sear.
12. The firearm of claim 1 , wherein, in said blocking position, said sear contacts an upper face of said trigger.
13. The firearm of claim 12 , wherein said upper face cooperates with a lower face and an engagement face of said trigger to define a step portion, wherein in said blocking position said sear is engaged with said engagement face of said step portion.
14. The firearm of claim 13 , wherein said trigger is in an engaged position when said sear is in said blocking position with a lower surface of said trigger.
15. The firearm of claim 13 , wherein said trigger is in a disengaged position when said sear is in said non-blocking position.
16. A bolt action firearm, comprising:
a receiver;
a barrel attached to said receiver;
a trigger assembly having a stop lever, said stop lever being selectively movable between a blocking position and a non-blocking position,
a bolt assembly including a rimfire firing pin and a dual cam bolt adapted to engage with said receiver, said dual cam bolt including:
a main body defining central bore along a central axis and having a neck portion with a pair of elongate slots that pass through said neck portion, said elongate slots being diametrically opposed to each other;
a cam cylinder mounted to an external surface of said neck portion, said cam cylinder having diametrically opposed spiral-shaped slots, said spiral shaped slots being in mirrored symmetry about said central axis;
a spring retainer slidably engaged within said central bore at said neck portion, said spring retainer including a pin that passes laterally therethrough, said pin extending through said pair of elongate slots of said neck portion and through said diametrically opposed spiral-shaped slots of said cam cylinder; and
a main spring disposed distal to and in contact with said spring retainer,
wherein rotation of said bolt assembly from an open position to a closed position causes said cam to exert a force on said cam pin, which causes said cam pin and said spring retainer to move in a distal direction, applying a compressive force on said main spring,
wherein said stop lever is finger actuated proximate to a finger portion of a trigger, and
wherein in said non-blocking position a sear is rotatable to release said main spring to discharge said firearm.
17. The firearm of claim 1 , wherein said dual cam bolt is a bolt assembly, including:
a main body defining central bore along a central axis and a pair of elongate slots that pass through said main body, the elongate slots of said pair of elongate slots being diametrically opposed to each other;
a cam cylinder mounted to said main body, said cam cylinder defining diametrically opposed spiral-shaped slots that pass through said cam cylinder, said spiral shaped slots being in mirrored symmetry about said central axis; and
a cam pin that extends perpendicular to said central axis, through said pair of elongate slots of said main body, and through said diametrically opposed spiral-shaped slots of said cam cylinder,
wherein rotation of said bolt assembly about said central axis causes said spiral slots of said cam cylinder to rotate about and exert an axial force that is parallel to said central axis against said cam pin, which causes a translation of said cam pin within said elongate slots of said main body.
18. The firearm of claim 17 , comprising:
a spring retainer coupled to said cam pin and slidably engaged within said central bore, said main spring being disposed distal to and in contact with said spring retainer,
wherein rotation of said bolt assembly from an open position to a closed position causes said translation of said cam pin to exert a force on said spring retainer in a distal direction, which causes said spring retainer to move in said distal direction to apply a compressive force on said main spring.
19. The firearm of claim 17 , wherein said main body includes a neck portion that defines said pair of elongate slots.
20. The firearm of claim 19 , wherein said cam cylinder is mounted to an external surface of said neck portion.