Semiautomatic firearm

• US 4,389,920 A
• Filed: 02/20/1981
• Issued: 06/28/1983
• Est. Priority Date: 02/20/1981
• Status: Expired due to Fees

• Current Assignee: Joseph H. Dufour Sr
• Original Assignee: Joseph H. Dufour Sr
• Inventors: Dufour, Joseph H. Sr.
• Primary Examiner(s): BENTLEY, STEPHEN
• Application Number:
  US06/236,493
• Time in Patent Office: 858 Days
• Field of Search: 89/190, 89/191 A
• US Class Current: 89/190
• CPC Class Codes: F41A 3/40 mounted on the bolt F41A3/42 takes precedence
• CPC Class Codes: F41A 5/18 gas-operated

Abstract

A gas operated system for use in semiautomatic firearms is disclosed. The gas operated system utilizes a gas powered assembly which is actuated by gas under pressure. The gas powered assembly is utilized to provide rearward motion to a drive assembly. The drive assembly has a rod associated therewith which engages unlocking structure so that this structure unlocks locking structure so that the bolt assembly can move rearwardly from the battery position. Movement of the bolt assembly rearwardly is accomplished principally due to expanding gas present in the barrel of the firearm which acts against the face of the bolt assembly.

Claims

1. In a semiautomatic firearm having (i) a receiver, (ii) a barrel mounted to said receiver, (iii) a magazine positioned adjacent to said barrel, (iv) a bolt assembly reciprocally mounted in said receiver, said bolt assembly having locking structure for locking said bolt assembly in the battery position, and unlocking structure for unlocking the lock achieved by said locking structure, the improvement which features a gas operated system which comprises:

a. gas powered means in association with said barrel and said magazine, said gas powered means being actuated by expanding gas to provide powered movement by at least a portion of said gas powered means towards said receiver;

b. at least one gas channel extending from the interior of said barrel to said gas powered means to communicate said expanding gas to said gas powered means when said firearm is fired;

c. drive means having its proximate end in association with said gas powered means whereby said powered movement by said at least portion of said gas powered means imparts movement to said drive means towards the receiver, said drive means having at its distal end a rod means adjacent but not connected to said unlocking structure, whereby said movement of said drive means operatingly engages said rod means with only said unlocking structure to unlock said lock structure so that said bolt assembly is free to move away from said battery position; and

d. return means in contact with said drive means for preventing impacting of said drive means with said receiver and for returning said drive means and said rod means to their original prior position so that said bolt assembly is free to return to the battery position and said locking structure can re-attain its locking of said bolt assembly.

2. The gas operated system of claim 1 wherein said at least portion of said gas powered means is a first annular piston means and wherein said gas powered means comprises:

a. a cylinder attached to said barrel and surrounding a portion of said magazine, the inside wall of said cylinder being radially spaced away from the outside wall of said magazine to provide an annular gas chamber; and

b. said annular piston means which is slidably mounted on said magazine within said gas chamber, said first annular piston being capable of achieving a gas sealing contact with said inside wall of said cylinder and the outside wall of said magazine.

3. The gas operated system of claim 1 wherein said gas channel is linear.

4. The gas operated system of claim 1 wherein said drive means is a cylindrical sleeve slidably mounted on said magazine.

5. The gas operated system of claim 1 wherein said rod means has a portion which fits interiorally of said receiver.

6. The gas operated system of claim 1 wherein said rod means is integral with said drive means.

7. The gas operated system of claim 4 wherein said rod means is integral with said drive means.

8. The gas operated system of claim 2 wherein said drive means is a cylindrical sleeve slidably mounted on said magazine, said rod means is integral with said drive means and wherein the proximate end of said cylindrical sleeve is drivingly engaged with said first annular piston means.

9. The gas operated system of claim 5 wherein said rod means is integral with said drive means.

10. The gas operated system of claim 9 wherein said drive means is a cylindrical sleeve slidably mounted on said magazine.

11. The gas operated system of claim 10 wherein said at least portion of said gas powered means is a first annular piston means and wherein said gas powered means comprises:

a. a cylinder attached to said barrel and surrounding a portion of said magazine, the inside wall of said cylinder being radially spaced away from the outside wall of said magazine to provide an annular gas chamber; and

b. said annular piston means which is slidably mounted on said magazine within said gas chamber said annular piston being capable of achieving a gas sealing contact with said inside wall of said cylinder and the outside wall of said magazine.

12. The gas operated system of claim 5 wherein said drive means is a cylindrical sleeve slidably mounted on said magazine.

13. The gas operated system of claim 12 wherein said at least portion of said gas powered means is a first annular piston means and wherein said gas powered means comprises:

a. a cylinder attached to said barrel and surrounding a portion of said magazine, the inside wall of said cylinder being faced away from the outside wall of said magazine to provide an annular gas chamber; and

b. said first annular piston means which is slidably mounted on said magazine within said gas chamber, said first annular piston being capable of achieving a gas sealing contact with said inside wall of said cylinder and the outside wall of said magazine.

14. The gas operated system of claim 1 wherein the return means is mounted on said magazine between said drive means and said receiver.

15. The gas operated system of claim 14 wherein said return means is a spring.

16. In a semiautomatic firearm having (i) a receiver, (ii) a barrel mounted to said receiver, (iii) a magazine positioned adjacent and parallel to said barrel, (iv) a bolt assembly reciprocally mounted in said receiver, said bolt assembly having a hollow chamber into which pivotally nests a locking block having an upstanding locking boss forward of its pivot point and connecting structure located below its pivot point for connection to a link which is forwardly spring biased and said bolt assembly additionally having a locking block latch to urge said locking block to maintain a locking relationship with other cooperating locking structure within said receiver, and having an operating handle slidably carried in a groove in said bolt assembly, said operating handle having adjacent its rearward end a boss which in in abutment on its forward face with said connecting structure and on its rearward face with a shoulder on said link, the improvement which features a gas operated system which comprises:

a. gas powered means in association with said barrel and said magazine, said gas powered means being actuated by expanding gas to provide powered movement by at least a portion of said gas powered means towards said receiver;

b. at least one gas channel extending from the interior of said barrel to said gas powered means to communicate said expanding gas to said powered means when said firearm is fired;

c. drive means having its proximate end in association with said gas powered means whereby said powered movement by said at least portion of said gas powered means imparts to said drive means movement towards said receiver, said drive means having at its distal end a rod means adjacent but not connected to the forward end of said operating handle whereby said movement of said drive means engages said rod means only with said operating handle to push said operating handle rearwardly thereby moving said link rearwardly against its forwardly spring bias, said movement of said link causing said locking block to rotate downwardly about its pivot point and against said urging of said locking block latch whereby said locking boss moves from locking cooperation with said cooperating locking structure; and

d. return means in contact with said drive means for preventing impacting of said drive means with said receiver and for returning said drive means and said rod means to their original prior position so that said bolt assembly is free to return to the battery position and said locking block can re-attain its locking cooperation with said other locking structure within said receiver.

17. The gas operated system of claim 16 wherein said at least portion of said gas powered means is a first annular piston means and wherein said gas powered means comprises:

a. a cylinder attached to said barrel and surrounding a portion of said magazine, the inside wall of said cylinder being radially spaced away from the outside wall of said magazine to provide an annular gas chamber; and

b. said annular piston means which is slidably mounted on said magazine within said gas chamber, said first annular piston being capable of achieving a gas sealing contact with said inside wall of said cylinder and the outside wall of said magazine.

18. The gas operated system of claim 16 wherein said drive means is a cylindrical sleeve slidably mounted on said magazine.

19. The gas operated system of claim 16 wherein said rod means has a portion which fits interiorally of said receiver.

20. The gas operated system of claim 16 wherein said rod means is integral with said drive means.

21. The gas operated system of claim 18 wherein said rod means is integral with said drive means.

22. The gas operated system of claim 17 wherein said drive means is a cylindrical sleeve slidably mounted on said magazine, said rod means is integral with said drive means and wherein the proximate end of said cylindrical sleeve is drivingly engaged with said annular piston means.

23. The gas operated system of claim 19 wherein said rod means is integral with the drive means.

24. The gas operated system of claim 23 wherein said drive means is a cylindrical sleeve slidably mounted on said magazine.

25. The gas operated system of claim 24 wherein said at least portion of said gas powered means is a first annular piston means and wherein said gas powered means comprises:

a. a cylinder attached to said barrel and surrounding a portion of said magazine, the inside wall of said cylinder being radially spaced away from the outside wall of said magazine to provide an annular gas chamber; and

b. said annular piston means which is slidably mounted on said magazine within said gas chamber, said first annular piston being capable of achieving a gas sealing contact with said inside wall of said cylinder and the outside wall of said magazine.

26. The gas operated system of claim 19 wherein said drive means is a cylindrical sleeve slidably mounted on said magazine.

27. The gas operated system of claim 25 wherein said at least portion of said gas powered means is a first annular piston means and wherein said gas powered means comprises:

a. a cylinder attached to said barrel and surrounding a portion of said magazine, the inside wall of said cylinder being radially spaced away from the outside wall of said magazine to provide an annular gas chamber; and

b. said annular piston means which is slidably mounted on said magazine within said gas chamber, said first annular piston being capable of achieving a gas sealing contact with said inside wall of said cylinder and the outside wall of said magazine.

28. The gas operated system of claim 16 wherein said return means is mounted on said magazine between said drive means and said receiver.

29. The gas operated system of claim 28 wherein said return means is a spring.