초록 ▼

A locked breach, gas operated long action firearm capable of firing heavy caliber shotgun or rifle shells with substantially reduced recoil. The gas piston and bolt carrier assembly are supported for recoil movement along a single guide rod which extends the entire length of the gun, permitting a lo

A locked breach, gas operated long action firearm capable of firing heavy caliber shotgun or rifle shells with substantially reduced recoil. The gas piston and bolt carrier assembly are supported for recoil movement along a single guide rod which extends the entire length of the gun, permitting a longer recoil path resulting in reduced impulse due to recoil. The guide rod has a noncircular or radially-assymmetrical cross-section mating with a corresponding opening in the gas piston, so that the bolt carrier assembly remains in alignment over the entire recoil path. Separate close-bolt and open-bolt embodiments are disclosed, and the open-bolt embodiment is selectively capable of firing either semi-automatic or full-automatic while permitting reliable cartridge feeding from a box or drum magazine.

대표청구항 ▼

1. A gas operated firearm comprising: means defining a buttplate at the rear of the firearm for resting against the shoulder of a shooter; a barrel; means defining a gas cylinder affixed to said barrel so as to receive the reaction force of firing, and in gas flow communication with the barrel;

1. A gas operated firearm comprising: means defining a buttplate at the rear of the firearm for resting against the shoulder of a shooter; a barrel; means defining a gas cylinder affixed to said barrel so as to receive the reaction force of firing, and in gas flow communication with the barrel; guide rod means connected at a rear end to said buttplate so that longitudinal forces applied to the guide rod means are transferred to the buttplate; said guide rod means extending from said buttplate and rigidly connected to said gas cylinder so that the reaction force received by the gas cylinder is imparted to the guide rod means; means providing a gas piston supported on said guide rod means for reciprocal movement therealong so that the guide rod means extends through said gas piston, whereby the reaction force exerted on the gas cylinder is transferred from the gas cylinder to the buttplate by the guide rod means to reduce the recoil of the firearm; and action spring means operative to urge said gas piston forwardly along said guide rod means, whereby said gas piston can compress the action spring means and travel rearwardly on said guide rod means toward said buttplate in response to gas from said barrel entering said gas cylinder. 2. A firearm as in claim 1, wherein: said gas piston means is capable of rearward travel sufficient to strike said buttplate; and said buttplate comprises a resilient material to absorb impact of said gas piston means. 3. A firearm as in claim 1, wherein: said guide rod means supporting said gas piston is a single elongate guide rod having a nonuniform cross-section; and said gas piston has a hole of complementary nonuniform shape to receive and slidably travel along said single guide rod, so that the angular position of said gas piston relative to said guide rod is fixed by the complementary sliding engagement of said nonuniform gas piston hole and said single nonuniform guide rod. 4. A firearm as in claim 3, wherein said guide rod means has a rectangular cross-section. 5. A firearm as in claim 3, further comprising bolt carrier means rigidly attached to said gas piston for reciprocation therewith, so that the gas piston and the bolt carrier means are supported by said single guide rod and the angular position of said bolt carrier means is located by said angularly fixed location of said gas piston means. 6. A firearm as in claim 1, wherein: said guide rod means is a single guide rod having a noncircular cross-section, and said gas piston slides on the guide rod means through an opening of complementary noncircular shape operative to fix the angular position of the gas piston on the guide rod means; bolt carrier means operatively associated with said gas piston for reciprocable movement therewith; means defining a receiver section including a pair of spaced apart surfaces flanking said bolt carrier means when the gas piston is in a forward position on said guide rod means; said guide rod means extending far enough behind said receiver sections means so that said bolt carrier means travels outside said spaced apart surfaces during said rearward travel of said gas piston; and said noncircular guide rod means and complementary noncircular opening maintaining said gas piston and associated bolt carrier means in predetermined angular alignment relative to said spaced apart surfaces of said receiver section means as the bolt carrier means travels outside said spaced apart surfaces, so that said bolt carrier means can travel forwardly to re-enter said receiver section in response to said action spring means without becoming angularly misaligned and hitting said receiver section surfaces. 7. A firearm as in claim 6, wherein: said flanking surfaces of said receiver section means slidingly engage said bolt carrier means, therby guiding the sliding movement of the bolt carrier means when traveling within the receiver section. 8. A firearm as in claim 1, wherein said action spring means in expansion extends from said buttplate to said gas piston. 9. A firearm as in claim 1, further comprising: a hollow piston rod extending rearwardly from said gas piston and terminating at an open rear end; said guide rod means passing through said piston rod; and said action spring means surrounds said guide rod means and extends forwardly from said buttplate into said hollow piston rod to terminate in operative engagement at the forward end of the piston rod, so that said action spring means in expansion extends substantially from said buttplate to said gas piston means. 10. A firearm as in claim 1, wherein: said guide rod means extends into said gas cylinder through an opening in the base of the gas cylinder to terminate at a forward end; tip means secured to said forward end of the guide rod means; and said tip means having a portion of reduced area immediately in front of the base of said gas cylinder to receive a retaining means, and having a portion of relatively enlarged area in front of said reduced area to engage said retaining means when the guide rod is urged rearwardly by said action spring means to bring said retaining means into contact with said gas cylinder. 11. A firearm as in claim 10, wherein: at least a forward portion of said guide rod means is hollow; said reduced area portion of said tip means is secured within the hollow forward end of said guide rod means, with said enlarged portion being spaced apart from said forward end to define a necked region for receiving the retaining means. 12. A gas operated firearm comprising: a gas cylinder operative to receive gas when the firearm is fired; gas piston means normally received in said gas cylinder and operative to move along a movement path including movement outside of the gas cylinder, in response to gas pressure; an action spring urging said gas piston means to return to said gas cylinder; a single guide rod having a noncircular cross-section and extending along the entire movement path of said gas piston means; and said gas piston means has a noncircular opening complementary to the noncircular cross-section of said single guide rod and is slidably mounted on said single guide rod, so that the gas piston means is slidably and nonrotatably supported on the guide rod, the complementary noncircular opening of the gas piston means coacting with the noncircular single guide rod to maintain the gas piston means in fixed angular alignment on the guide rod, and the gas piston means, guide rod, and action spring are substantially concentric along the movement path of the gas piston, whereby the single noncircular guide rod and the complementary noncircular opening cooperate to maintain said gas piston means in fixed angular position while moving along the entire movement path. 13. A firearm as in claim 12, further comprising: bolt carrier means connected to said gas piston means and movable therewith along said movement path between forward and rearward positions in response to movement of the gas piston means; receiver means including a pair of laterally spaced-apart surfaces between which said bolt carrier means slides when in the forward position; and said single guide rod extends behind said receiver means to allow the bolt carrier means to move outside said spaced-apart surfaces during rearward movement of the bolt carrier means; so that the angular position of the bolt carrier means while outside the receiver surfaces is maintained by the fixed angular alignment of said gas piston means on said guide rod. 14. A firearm as in claim 12, wherein said single guide rod is disposed within said action spring. 15. A firearm comprising: a receiver section; guide rod means having a back end portion in spaced apart relation behind the receiver section, and also having a forward end portion; a buttplate attached to the back end portion of said guide rod means and held by the guide rod means in spaced apart relation in back of the receiver section; a barrel in fixed relation to said receiver section; mounting means affixed to said barrel in juxtaposition with said forward end portion of said guide rod means; said forward end portion of said guide rod means being longitudinally movable with respect to said mounting means and selectably engaging said mounting means at a certain fixed longitudinal position relative to the mounting means when said firearm is in assembly, thereby keeping the mounting means at a predetermined maximum distance from said buttplate so as to keep said firearm in assembly; and stock means engaging said buttplate and rigidly extending forwardly from said buttplate in laterally spaced relation to said receiver section to engage said mounting means at said predetermined longitudinal position relative to the buttplate and thereby prevent the guide rod means and affixed buttplate from moving forwardly relative to said mounting means, whereby said stock means maintains said barrel and mounting means in assembly relative to said buttplate and guide rod means, so that the stock means must be removed to permit relative movement and disassembly thereof. 16. A firearm as in claim 15, wherein said mounting means defines an opening through which said guide rod means extends, with the forward end portion of the guide rod means protruding in front of the mounting means; means forming a transverse channel across said protruding portion of the guide rod means spaced inwardly of said forward end; retaining means engaging said guide rod means along said transverse channel so as to abut said mounting means and thereby limit rearward movement of the guide rod means when in assembly; and said retaining means having a portion which engages said guide rod means when the retaining means abuts the mounting means, thereby preventing withdrawing the retaining means from the guide rod, so that the firearm thereby is maintained in assembly when said stock means is in place preventing the mounting means from moving rearwardly relative to said buttplate means and said guide rod means. 17. A firearm as in claim 16, wherein said forward end of said guide rod means is pyramid-shaped so as to guide the insertion of the guide rod means sequentially through said action spring means, said gas piston, and the opening in said mounting means. 18. The firearm as in claim 15, wherein: the forward end portion of said guide rod means slidably extends through said mounting means; and further comprising retaining means selectably engaging said guide rod means and said mounting means to prevent said sliding movement beyond said certain position, so that said firearm is held in assembly by said retaining means and by said stock means; and said retaining means selectably operative to disengage said guide rod means only when said stock means is disengaged from said retaining means and longitudinally displaced relative to said retaining means, whereby said mounting means and said barrel can thereafter be withdrawn from said guide rod means. 19. The firearm as in claim 15, further comprising: means defining a gas cylinder affixed to said barrel in gas flow communication therewith; means defining a gas piston supported on said guide rod means for reciprocal movement therealong, so that said guide rod means extends through said gas piston; and action spring means operative to urge said gas piston forwardly along said guide rod means to enter said gas cylinder. 20. A gas operated firearm comprising: means defining a buttplate at the rear of the firearm for resting against the shoulder of a shooter; a barrel; means defining a gas cylinder affixed to said barrel and in gas flow communication with the barrel; guide rod means extending from said buttplate to said gas cylinder; means providing a gas piston reciprocably carried on said guide rod means so that the guide rod means extends through said gas piston; action spring means operative to urge said gas piston forwardly along said guide rod means, whereby said gas piston can travel rearwardly on said guide rod means toward said buttplate in response to gas from said barrel entering said gas cylinder; said guide rod means extending into said gas cylinder through an opening in the base of the gas cylinder to terminate at a forward end; tip means secured to said forward end of the guide rod means; said tip means having a portion of reduced area immediately in front of the base of said gas cylinder to receive a retaining means, and having a portion of relatively enlarged area in front of said reduced area to engage said retaining means when the guide rod is urged rearwardly by said action spring means to bring said retaining means into contact with said gas cylinder; at least a forward portion of said guide rod means being hollow; said reduced area portion of said tip means being secured within the hollow forward end of said guide rod means, with said enlarged portion being spaced apart from said forward end to define a necked region for receiving the retaining means; the portion of said tip means within the hollow forward end of the guide rod means being solid and extending into a portion of the guide rod within said gas cylinder; and means defining a gas flow passageway transversely extending through said guide rod means and the tip means within, at a gas receiving location in the gas cylinder, so that the gas can flow through said passageway to act more uniformly on said gas piston means carrier on the guide rod means. 21. A firearm comprising: a single elongate guide rod means having noncircular cross-section and extending longitudinally of the firearm; bolt carrier means supported by said single guide rod means for reciprocal movement along the single guide rod means between a forward position and a rearward position; said bolt carrier means including means defining a longitudinal opening of noncircular cross-section complementary to the noncircular cross-section of the guide rod means and providing a complementary sliding fit on said single guide rod, so that the sliding fit of said complementary noncircular guide rod means within said noncircular opening maintains the guide rod means fixed at a certain angular position on the guide rod means during reciprocal movement; means defining a receiver section including a pair of spaced apart surfaces flanking said bolt carrier means when in a forward position along said guide rod means; said guide rod means extending behind said receiver section to permit the bolt carrier means to travel behind said spaced apart surfaces during rearward movement of the bolt carrier means; extractor means movable with said bolt carrier means to travel behind said receiver section during said rearward movement of the bolt carrier means; said extractor means including a pair of mutually spaced apart arms slidably extending longitudinally within said spaced apart surfaces when said extractor means is within said receiver section; and said extractor arms having forward ends bowed inwardly to help guide said bolt carrier means for returning between said spaced apart surfaces as the bolt carrier means moves forwardly from said rearward position behind the spaced apart surfaces. 22. The firearm as in claim 21, further comprising: alignment means operatively associated with said guide rod means and said bolt carrier means to maintain the bolt carrier means in fixed angular alignment with said receiver section while the bolt carrier means travels rearwardly outside said receiver section. 23. The firearm as in claim 22, wherein: said guide rod means is a single elongate guide rod having a noncircular cross-section; and said alignment means comprises a member having a noncircular opening providing a complementary sliding fit on said noncircular guide rod, so that said member remains in a fixed angular position during sliding movement along said guide rod; and said member being connected to said bolt carrier means so as to maintain the bolt carrier means in alignment with said spaced apart receiver surfaces while outside said receiver section. 24. The firearm as in claim 21, wherein said single guide rod means is located symmetrically across the longitudinal axis of the firearm. 25. A firearm comprising: means defining a buttplate at the rear of the firearm for resting against the shoulder of a shooter; a barrel; means defining a gas cylinder affixed to said barrel and in gas flow communication with the barrel; guide rod means secured to said buttplate and extending forwardly from said buttplate into rigid engagement with said gas cylinder means and operative to maintain the gas cylinder means at a predetermined maximum longitudinal spacing from the buttplate; means providing a gas piston supported on said guide rod means for reciprocal movement therealong so that the guide rod means extends through said gas piston whereby reaction force is mechanically coupled from the gas cylinder to the buttplate by the guide rod means; action spring means operative to urge said gas piston forwardly along said guide rod means, whereby said gas piston can travel rearwardly on said guide rod means toward said buttplate in response to gas from said barrel entering said gas cylinder; securement means releasably securing the guide rod means to the buttplate; stock means having a back portion removably engaging said buttplate; and said stock means extending rigidly forward from said back portion and selectably operatively engaging said gas cylinder means to maintain said predetermined longitudinal spacing from said buttplate, so that the stock means prevents the gas cylinder means from moving rearwardly on the guide rod means toward the buttplate, whereby the firearm normally is held in assembly by rigid engagement of the guide rod means with the gas cylinder means and by the stock means rigidly extending between the buttplate and the gas cylinder means, and whereby the gas cylinder means can move rearwardly on the guide rod means for disassembling the firearm only when the rigid stock means is removed from engagement with the buttplate and the gas cylinder means. 26. A firearm comprising: a single elongate guide rod means having noncircular cross-section and extending longitudinally of the firearm; bolt carrier means supported by said single guide rod means for reciprocal movement along the single guide rod means between a forward position and a rearward position; said bolt carrier means including means defining a longitudinal opening of noncircular cross-section complementary to the noncircular cross-section of the guide rod means and providing a complementary sliding fit on said single guide rod, so that the sliding fit of said complementary noncircular guide rod means within said noncircular opening maintains the guide rod means fixed at a certain angular position on the guide rod means during reciprocal movement; means defining a receiver section including a pair of spaced apart surfaces flanking said bolt carrier means when in a forward position along said guide rod means; and said guide rod means extends behind said receiver section to permit the bolt carrier means to travel behind said spaced apart surfaces during rearward movement of the bolt carrier means, so that the single noncircular guide rod means and the complementary noncircular opening in the bolt carrier means cooperate to maintain the bolt carrier means in fixed angular alignment on the single guide rod means while the bolt carrier means is behind the receiver section surfaces.