Auto-loading firearm
View Patent ↗An auto-loading firearm has a frame defining a bolt passage, a bolt operable to reciprocate between a battery position and a retracted position, a barrel defining a gas aperture, an energy transmission facility having a first end communicating with the gas aperture and an opposed second end, the bolt having a bolt body and a bolt key movable with respect to the bolt body between a forward position and a rearward position, the bolt key operably engaging the second end of the energy transmission facility when the bolt is in the battery position, the bolt including a latch element operably engaged to the bolt key having a locked position to prevent reciprocation of the bolt, and an unlocked position in which reciprocation of the bolt is enabled, and the latch element being responsive to rearward motion of the bolt key to move from the locked position to the unlocked position.
1. An auto-loading firearm having a blowback operating system comprising;
a frame defining a bolt passage;
a bolt within the bolt passage and operable to reciprocate therein between a battery position and a retracted position along a bolt axis;
an elongated barrel connected to the frame;
the barrel defining a gas aperture at an intermediate position along the length of the barrel;
the barrel having a chamber adapted to receive a cartridge having a case;
a gas tube having a first end communicating with the gas aperture and an opposed second end;
the bolt having a bolt body and a bolt key movable with respect to the bolt body between a forward position and a rearward position;
the bolt key operably engaging the second end of the gas tube when the bolt is in the battery position;
the gas tube is open at the opposed second end allowing gas from the gas aperture to travel through the gas tube and directly impinge upon the bolt key;
the bolt including a latch element operably engaged to the bolt key;
the latch element having a locked position in which the latch element operably engages the frame to prevent reciprocation of the bolt, and an unlocked position in which the bolt is enabled to move rearward in response to blowback pressure from the cartridge case; and
the latch element being responsive to rearward motion of the bolt key to move from the locked position to the unlocked position.
2. The firearm of claim 1 wherein the latch element is a ball.
3. The firearm of claim 1 wherein the latch element includes two latch element portions that move in opposition.
4. The firearm of claim 1 wherein the frame defines a recess operable to engage the latch element when the bolt is in the battery position and the latch element is in the locked position.
5. The firearm of claim 1 wherein the bolt key is biased toward the forward position.
6. The firearm of claim 1 wherein the bolt key reciprocates along a bolt key axis parallel to the bolt axis, and wherein the latch element moves perpendicularly to the bolt axis.
7. The firearm of claim 6 wherein the bolt key includes a cam surface angularly offset from the bolt key axis and operable to laterally move the latch element as the bolt key moves forward and rearward.
8. The firearm of claim 7 wherein the bolt key includes a wedge, and the latch element includes two latch element portions, and where the wedge is positioned between the latch element portions to force the latch element portions apart from each other as the bolt key moves to the forward position.
9. The firearm of claim 1 wherein the bolt key includes a fitting operable to generate rearward motion of the bolt key in response to gas pressure in the gas tube.
10. The firearm of claim 1 wherein the latch element is in the locked position when the bolt is in the battery position when discharge energy is not being transmitted by the gas tube.
11. The firearm of claim 1 wherein the latch element being in the locked position when the bolt key is in the forward position, and in the unlocked position when the bolt key is in the rearward position.
12. The firearm of claim 7 wherein the cam surface is angularly offset at least 0° from the bolt key axis and is angularly offset no more than 20° from the bolt key axis.
13. The firearm of claim 1 wherein the bolt key is adapted to disengage from the gas tube when the bolt key is in the rearward position, such that moving the bolt key to the rearward position eliminates continued exertion of rearward force on the bolt key.
14. The firearm of claim 1 wherein a recess adapted to receive the latch element is formed in an insert received in the frame.
15. The firearm of claim 14 wherein the insert is externally threaded.
16. The firearm of claim 14 wherein the recess defines a polygonal aperture.
17. The firearm of claim 14 wherein the insert has a face recessed below an adjacent surface of the frame.
18. The firearm of claim 1 wherein a conical recess adapted to receive the latch element is formed in the frame.
19. The firearm of claim 18 wherein the conical recess comprises a linear surface contact portion adapted for contact by the latch, the linear surface contact portion is angled 45 degrees from the barrel.
20. An auto-loading firearm having a blowback operating system comprising;
a frame defining a bolt passage;
a bolt within the bolt passage and operable to reciprocate therein between a battery position and a retracted position along a bolt axis;
an elongated barrel connected to the frame;
the barrel defining a gas aperture at an intermediate position along the length of the barrel;
the barrel having a chamber adapted to receive a cartridge having a case;
a gas tube having a first end communicating with the gas aperture and an opposed second end;
the bolt having a bolt body and a bolt key movable with respect to the bolt body between a forward position and a rearward position;
the bolt key operably engaging the second end of the gas tube when the bolt is in the battery position;
the gas tube is open at the opposed second end allowing gas from the gas aperture to travel through the gas tube and directly impinge upon the bolt key;
the bolt including a latch element operably engaged to the bolt key;
the latch element having a locked position in which the latch element operably engages the frame to prevent reciprocation of the bolt, and an unlocked position in which the bolt is enabled to move rearward in response to blowback pressure from the cartridge case;
the latch element being responsive to rearward motion of the bolt key to move from the locked position to the unlocked position;
the frame defining a recess adapted to receive the latch element;
the recess having a contact surface portion adapted for contact by the latch and facing in a forward and medial angle direction;
the bolt key having a tapered latch contact surface angularly offset from the bolt axis and adapted to bias the latch against the contact surface portion; and
the bolt having a rearward-facing latch biasing surface operable to limit forward movement of the latch when the bolt is in the battery position and the latch is biased by the tapered latch contact surface, such that the latch element is positionally locked by the bolt, frame, and bolt key when the bolt is in the battery position, and wherein the bolt key is adapted to release the latch element to enable movement of the bolt only in response to energy transmitted from the gas tube.
21. The firearm of claim 20 further comprising a spring operably connected between the bolt and the latch to bias the latch in a forward direction.
22. The firearm of claim 21 wherein the spring is contained within the receiver.
23. The firearm of claim 20 wherein the spring is aft of a forward portion of the bolt.
24. The firearm of claim 20 wherein the spring is mounted to the bolt and reciprocates with the bolt.
25. An auto-loading firearm having a blowback operating system comprising;
a frame defining a bolt passage;
a bolt within the bolt passage and operable to reciprocate therein between a battery position and a retracted position along a bolt axis;
an elongated barrel connected to the frame;
the barrel defining a gas aperture at an intermediate position along the length of the barrel;
the barrel having a chamber adapted to receive a cartridge having a case;
a gas tube having a first end communicating with the gas aperture and an opposed second end;
the bolt having a bolt body and a bolt key movable with respect to the bolt body between a forward position and a rearward position;
a spring operably connected between the bolt and the latch to bias the latch in a forward direction;
the spring is contained within the receiver;
the bolt key operably engaging the second end of the gas tube when the bolt is in the battery position;
the gas tube is open at the opposed second end allowing gas from the gas aperture to travel through the gas tube and directly impinge upon the bolt key;
the bolt including a latch element operably engaged to the bolt key;
the latch element having a locked position in which the latch element operably engages the frame to prevent reciprocation of the bolt, and an unlocked position in which the bolt is enabled to move rearward in response to blowback pressure from the cartridge case; and
the latch element being responsive to rearward motion of the bolt key to move from the locked position to the unlocked position.
26. The firearm of claim 25 wherein the spring is aft of a forward portion of the bolt.
27. The firearm of claim 25 wherein the spring is contained within the bolt.
28. The firearm of claim 25 wherein the spring is positioned between a portion of the key and a portion of the bolt.
29. The firearm of claim 25 including a firing pin connected to the bolt and encompassed by the spring.