Firearm having a dual cam, cock on close bolt action
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 bolt action firearm, comprising:
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;
a handle portion coupled to said cam cylinder; 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 with said handle portion 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.
2. The bolt action firearm of claim 1 , comprising:
a spring retainer coupled to said cam pin and slidably engaged within said central bore; 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 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.
3. The bolt action firearm of claim 1 , wherein said body portion includes a neck portion that defines said pair of elongate slots.
4. The bolt action firearm of claim 3 , wherein said cam cylinder is mounted to an external surface of said neck portion.
5. The bolt action firearm of claim 1 , comprising:
a trigger assembly; and
a barrel operatively coupled with said trigger assembly,
wherein said bolt assembly is operatively coupled to said trigger assembly and said barrel.
6. The bolt action firearm of claim 5 , wherein said barrel includes a cartridge chamber.
7. The bolt action firearm of claim 6 , wherein said cartridge chamber is configured to accept one of a .17 caliber cartridge, a .17 WSM cartridge, and a .17 HMR cartridge.
8. The bolt action firearm of claim 5 , comprising a housing attached to a proximal end of said barrel, said housing defining an actuation axis, said bolt assembly being disposed within said housing so that said central axis of said bolt assembly is substantially concentric with said actuation axis, said bolt assembly being translatable along said actuation axis.
9. The bolt action firearm of claim 8 , wherein:
said housing includes a plurality of inwardly extending retaining tab portions disposed at a proximal end thereof, each of said inwardly extending retaining tab portions including a distal face; and
said cam cylinder of said bolt assembly includes a plurality of outwardly extending tab portions, each of said outwardly extending tab portions including a proximal face,
wherein rotation of said bolt assembly from an open position to a closed position causes each proximal face of said plurality of outwardly extending tab portions to rotate into contact with said distal face of a corresponding one said plurality of inwardly extending retaining tab portions of said housing to secure said bolt assembly within said housing.
10. The bolt action firearm of claim 9 , wherein said plurality of inwardly extending retaining tab portions include lead-in surfaces.
11. The bolt action firearm of claim 9 , wherein said plurality of outwardly extending tab portions include lead-in surfaces.
12. A cock-on-close bolt action firearm, comprising:
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;
a spring retainer coupled to said cam pin and slidably engaged within said central bore, said spring retainer including 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; and
a main spring disposed distal to and in contact with said spring retainer,
wherein rotation of said bolt assembly about said central axis from an open position to a closed position causes said cam to exert a force on said cam pin in a distal direction, which causes said cam pin and said spring retainer to move in said distal direction to apply a compressive force on said main spring.
13. The cock-on-close bolt action firearm of claim 12 , wherein said body portion includes a neck portion that defines said pair of elongate slots.
14. The bolt action firearm of claim 13 , wherein said cam cylinder is mounted to an external surface of said neck portion.
15. The bolt action firearm of claim 12 , comprising:
a trigger assembly; and
a barrel operatively coupled with said trigger assembly,
wherein said bolt assembly is operatively coupled to said trigger assembly and said barrel.
16. The bolt action firearm of claim 15 , wherein said barrel includes a cartridge chamber.
17. The bolt action firearm of claim 16 , wherein said cartridge chamber is configured to accept one of a .17 caliber cartridge, a .17 WSM cartridge, and a .17 HMR cartridge.