OBTURATOR-EXTRACTOR DEVICE FOR FIREARMS

• US 3,738,223 A
• Filed: 11/23/1971
• Issued: 06/12/1973
• Est. Priority Date: 11/23/1971
• Status: Expired due to Term

• Current Assignee: Frederick P. Reed, John S. Post
• Original Assignee: Frederick P. Reed, John S. Post
• Inventors: Post, John S., Reed, Frederick P.
• Primary Examiner(s): Borchelt, Benjamin A.
• Assistant Examiner(s): Tudor, H. J.
• Application Number:
  US05/201,523
• Time in Patent Office: 567 Days
• Field of Search: 89/26 42/16
• US Class Current: 89/26
• CPC Class Codes: F41A 15/14 the ejector being mounted on or within the bolt; Extractors per se
• CPC Class Codes: F41A 3/74 Obturating or packing devices for gas leak prevention in breech mechanisms

Abstract

An obturator-extractor provides safe firing of cartridges having cases made from lightweight materials, such as aluminum, plastics, or other non-metallic materials, in a firearm with a reciprocating bolt comprising a conoidal bolt head that is receivable by a mating chamber in the barrel breech when the bolt is in locked battery position. A single piece obturator-extractor device is mounted as a shell on the bolt head and is comprised of convexly formed surfaces which make sealing contact with the barrel chamber and a tubular section which is receivable by a recess formed in the head to receive the rear end of the case. An extractor of cantilever configuration is provided on the tubular section of the obturator for engagement with the extractor groove in the case. In an alternate embodiment, the obturator device includes a dish-shaped washer and a truncated conoidal sleeve which are mounted in the front end and circumferential wall of the barrel chamber, respectively, to make resilient, obturating contact with the bolt head and the barrel chamber when the bolt is in locked battery position. The extractor is a separate split tubular member which is mounted in the head recess and which is provided with a chordal claw of torsion bar configuration.

Claims

1. In a firearm for firing an ammunition round comprising a case having a base provided with an annular extractor groove, said firearm having a barrel with a chamber for receiving said round, the improvement wherein said firearm includes a longitudinally reciprocating bolt operatively disposed for feeding said round into said chamber for discharge responsive to movement of said bolt to a locked battery position, said bolt including a forwardly disposed head portion of conical configuration terminated by an annular front surface, said front surface having a centrally disposed recess extending rearwardly into said head portion for receiving at least a portion of said case base, said barrel chamber having a portion thereof of a configuration similar to that of said head portion for receiving said head portion responsive to movement of said bolt to a locked battery position, means on said bolt head portion for obturating the interspace between adjacent surfaces of said bolt head portion and said chamber portion incident to said bolt being disposed in a locked battery position, and extractor means disposed within said bolt head recess for engaging said cartridge case base.

2. The invention defined in claim 1 wherein said obturating means and said extractor means comprises a one-piece annular member, and includes fastening means for securing said annular member on said bolt head portion.

3. The invention as defined in claim 2 wherein said one-piece annular member comprises a front section conforming to said front surface of said head and convexly formed in cross-section so as to normally bow outwardly therefrom, a tapered section surrounding the outside circumference of said bolt head portion and convexly formed so as to normally bow outwardly therefrom, and a tubular section disposed for extension into said bolt head portion recess from said front section.

4. The invention as defined in claim 3 wherein said extractor means is an integral part of said tubular section and is disposed for angular extension inwardly from said tubular section to function as a cantilever.

5. The invention as defined in claim 1 wherein said barrel chamber defines an annular front end shoulder and a rear flange having an annular front face, and wherein said obturating means comprises a Belleville-type type washer disposed in said barrel chamber portion in contact with said front shoulder and a sleeve conforming substantially to the configuration of the walls of said barrel chamber portion between said front shoulder and said rear flange and formed convexly in longitudinal cross-section to bow outwardly respective to the walls of said chamber.

6. The invention as defined in claim 5 wherein said sleeve comprises a front edge having contact with said washer, a rear edge having contact with said front face of said flange and being responsive to movement of said bolt to the locked battery position to press said front edge against said washer and said rear edge against said front face thereby to effect sealing contacts at such contacted areas.

7. The invention as defined In claim 6 wherein said bolt head portion recess is expanded radially inwardly from said annular front surface to provide a front shoulder and said extractor means comprises a tubular body portion receivable by said expanded portion of said recess, and an integral claw provided on said tubular body portion disposed to function as a torsion bar.

8. The invention as defined in claim 7 wherein said extractor claw is of rectangular configuration in cross-section and comprises an inner surface which inclines inwardly and rearwardly terminating in a contact edge engageable with said cartridge responsive to movement of said bolt to the locked battery position, and a front edge having contact with said bolt head portion recess front shoulder to provide a fu crum for the angular displacement of said claw by said case and for forcing said contact edge inwardly responsive to rearward pressure applied thereagainst.

9. The invention as defined in claim 8 wherein said contact edge is sharply formed thereby to be capable of cutting a groove into said case responsive to rotation of said bolt to and from the locked battery position.