Monolithic rail platform and bolt assemblies for a firearm

• US 20060236582A1
• Filed: 05/12/2003
• Published: 10/26/2006
• Est. Priority Date: 05/10/2002
• Status: Active Grant

• Current Assignee: Krl Holding Company Inc.
• Original Assignee: Karl R. Lewis
• Inventors: Schafer, Jacob A., Bargren, James Arend Seabold, Lewis, Karl R., Hohl, Neal David
• Granted Patent: US 8,234,808 B2
• Time in Patent Office: Days
• US Class Current: 42/73
• CPC Class Codes: F41A 11/00 Assembly or disassembly features; Modular concepts; Articulated or collapsible guns F41A3/64, F41A19/10 - F41A19/15, F41A21/48, F41A25/26 take precedence
• CPC Class Codes: F41A 21/00 Barrels; Gun tubes; Muzzle attachments; Barrel mounting means F41A25/00 takes precedence; barrel attachments for firing grenades or riot-control ammunition from smallarms F41C27/06
• CPC Class Codes: F41A 3/26 semi-automatically or automatically operated, e.g. having a slidable bolt-carrier and a rotatable bolt
• CPC Class Codes: F41A 3/36 Semi-rigid bolt locks, i.e. having locking elements movably mounted on the bolt or on the barrel or breech housing
• CPC Class Codes: F41A 3/64 Mounting of breech-blocks; Accessories for breech-blocks or breech-block mountings
• CPC Class Codes: F41A 3/66 Breech housings or frames; Receivers
• CPC Class Codes: F41C 23/16 Forestocks; Handgrips; Hand guards pump-action guns F41C7/02
• CPC Class Codes: F41C 27/00 Accessories; Details or attachments not otherwise provided for
• CPC Class Codes: F41G 11/003 Mountings with a dove tail element, e.g. "Picatinny rail systems"

Abstract

A firearm assembly for a firearm can include a monolithic rail platform with a handguard portion and an upper receiver portion. The barrel of the firearm can be positioned through the bandguard portion and secured with the upper receiver portion. A firearm assembly can also include a bolt assembly with a bolt carrier having minimized land area and a forward end sized for receipt in the barrel extension at the rearward end of the barrel.

Claims

1. A monolithic rail platform for a firearm, comprising:

a handguard portion adapted to receive at least a portion of a barrel assembly of the firearm therein; and

an upper receiver portion extending rearwardly from and integrally formed with said handguard portion, said upper receiver portion adapted to receive a bolt carrier therein.

2. The platform of claim 1, wherein said upper receiver portion includes a bore extending along a longitudinal axis thereof, said bolt carrier being movably received in said bore of said upper receiver portion along said longitudinal axis.

3. The platform of claim 1, further comprising a coupling portion at a forward end of said upper receiver portion and integral with said handguard portion, said coupling portion adapted to releasably clamp a rearward end of said barrel assembly extending through said handguard portion to said upper receiver portion.

4. The platform of claim 3, wherein said upper receiver portion includes a longitudinal axis and said coupling portion includes a slot extending in the direction of said longitudinal axis separating said coupling portion into first and second clamping portions positioned on respective sides of said slot.

5. The platform of claim 4, further comprising at least one fastener positionable through said coupling portion transversely to said longitudinal axis, said at least one fastener operable to bring said clamping portions toward one another to clamp said barrel assembly in said coupling portion.

6. The platform of claim 5, further comprising a pair of fasteners positionable through said coupling portion transversely to said longitudinal axis, one of said pair of fasteners positioned against a an enlarged portion of said barrel assembly to resist forward movement of said barrel assembly.

7. The platform of claim 1, wherein said handguard portion includes a number of rails extending therealong separated by recessed portions therebetween.

8. The platform of claim 7, wherein said number of rails includes an upper rail extending rearwardly along said upper receiver portion.

9. The platform of claim 8, wherein said upper rail includes a passage formed therealong for delivering gas from a forward end of said barrel.

10. The platform of claim 1, wherein said handguard portion extends along said barrel assembly to a position adjacent a forward end of said barrel assembly.

11. The platform of claim 1, wherein said upper receiver portion includes a first opening along a bottom side thereof adapted to receive a trigger assembly and a second opening along said bottom side thereof in communication with and forming a forward extension of said first opening, said second opening adapted to receive a magazine therein.

12. The platform of claim 1, wherein said barrel assembly is attachable to said upper receiver portion and extends through said handguard portion in a floating relationship therewith.

13. The platform of claim 1, wherein the monolithic rail platform comprises a portion of a bolt action rifle.

14. The platform of claim 1, wherein:

said barrel assembly includes a barrel extension at a rearward end thereof;

said upper receiver portion includes a longitudinal bore extending therethrough in communication with said barrel extension; and

said bolt carrier including a protrusion at a forward end thereof, said protrusion being sized for receipt in said barrel extension thereby increasing a stroke length of said bolt carrier in said longitudinal bore of upper receiver portion.

15. A firearm assembly, comprising:

a handguard portion;

a barrel assembly extending through said handguard portion, said barrel assembly including a barrel extension at a rearward end thereof;

an upper receiver portion extending from a rearward end of said handguard portion, said upper receiver portion including a longitudinal bore extending therethrough in communication with said barrel extension; and

a bolt assembly movably positioned in said longitudinal bore, said bolt assembly including a bolt carrier having a protrusion at a forward end thereof, said protrusion being sized for receipt in said barrel extension thereby increasing a stroke length of said bolt carrier in said longitudinal bore of said upper receiver portion.

16. The platform of claim 15, wherein said handguard portion is integrally formed with said upper receiver portion.

17. The assembly of claim 15, further comprising a coupling portion at a forward end of said upper receiver portion integral with said handguard portion, said coupling portion adapted to releasably clamp a rearward end of said barrel assembly extending through said handguard portion to said upper receiver portion.

18. The assembly of claim 17, wherein said upper receiver portion includes a longitudinal axis and said coupling portion includes a slot extending in the direction of said longitudinal axis separating said coupling portion into first and second clamping portions positioned on respective sides of said slot.

19. The assembly of claim 18, further comprising at least one fastener positionable through said coupling portion transversely to said longitudinal axis, said at least one fastener operable to bring said clamping portions toward one another to clamp said barrel assembly in said coupling portion.

20. The assembly of claim 15, wherein said handguard portion includes a number of rails extending therealong separated by recessed portions therebetween.

21. The assembly of claim 20, wherein said number of rails includes an upper rail extending rearwardly along said upper receiver portion.

22. The assembly of claim 15, wherein said handguard portion extends along said barrel assembly to a position adjacent a forward end of said barrel assembly.

23. The assembly of claim 15, wherein said barrel assembly is attachable to said upper receiver portion and said handguard portion extends around and is separated from said barrel assembly.

24. The assembly of claim 15, wherein said bolt carrier includes a forward end portion and a rearward end portion, said forward end portion including a number of lands extending therealong and spaced thereabout for contacting said upper receiver portion in said bore, said number of lands occupying from about 1% to about 12% of a surface area of said forward end portion along which said number lands extend.

25. The assembly of claim 15, wherein said protrusion extends into said barrel extension for a distance of one hundred thousandths of an inch when said bolt carrier is positioned completely forwardly in said upper receiver portion.

26. A firearm assembly, comprising:

a handguard portion;

a barrel assembly extending through said handguard portion;

an upper receiver portion extending from a rearward end of said handguard portion, said upper receiver portion including a longitudinal bore extending therethrough in communication with said barrel extension; and

a bolt assembly movably positioned in said longitudinal bore, said bolt assembly including a bolt carrier including a forward end portion and a rearward end portion, said forward end portion including a number of lands extending therealong and spaced thereabout, said number of lands occupying from about 1% to about 12% of a surface area of said forward end portion along which said number of lands extend.

27. The assembly of claim 26, wherein said number of lands occupy from about 1% to about 8% of said surface area of said forward end portion.

28. The assembly of claim 26, wherein said number of lands occupy from about 1% to about 4% of said surface area of said forward end portion.

29. The assembly of claim 26, wherein said number of lands occupy about 4% of said surface area of said forward end portion.

30. The assembly of claim 26, wherein said barrel assembly includes a barrel extension at a rearward end thereof.

31. The assembly of claim 26, wherein said bolt carrier includes a protrusion at a forward end thereof, said protrusion being sized for receipt in said barrel extension thereby increasing a stroke length of said bolt carrier in said longitudinal bore of said upper receiver portion.

32. The assembly of claim 26, wherein said handguard portion and said upper receiver portion are formed as an integral unit.

33. The assembly of claim 26, further comprising a coupling portion at a forward end of said upper receiver portion and integral with said handguard portion, said coupling portion adapted to releasably clamp a rearward end of said barrel assembly extending through said handguard portion to said upper receiver portion.

34. The assembly of claim 33, wherein said upper receiver portion includes a longitudinal axis and said coupling portion includes a slot extending in the direction of said longitudinal axis separating said coupling portion into first and second clamping portions positioned on respective sides of said slot.

35. The assembly of claim 26, wherein said handguard portion extends along said barrel assembly to a position adjacent a forward end of said barrel assembly.

36. The assembly of claim 26, wherein said barrel assembly is attachable to said upper receiver portion and extends through said handguard portion in a floating relationship therewith.