WEAPON CONVERSION BOLT ASSEMBLY DEVICE

• US 3,776,095 A
• Filed: 11/05/1971
• Issued: 12/04/1973
• Est. Priority Date: 11/05/1971
• Status: Expired due to Term

• Current Assignee: Maxwell G. Atchisson
• Original Assignee: Maxwell G. Atchisson
• Inventors: Atchisson, Maxwell G.
• Primary Examiner(s): Bentley, Stephen C.
• Application Number:
  US05/196,087
• Time in Patent Office: 760 Days
• Field of Search: 89/128,149,194,197,199 42/75B,77
• US Class Current: 89/128
• CPC Class Codes: F41A 11/02 Modular concepts, e.g. weapon-family concepts

Abstract

A conversion bolt assembly for a hand carried weapon having automatic and semi-automatic or semi-automatic only modes of operation. The bolt assembly includes a tube having a fixed back plate on one end and longitudinally extending slots to permit spreading of the other end of the tube for assembly of the internal components. The internal components include a bolt having a firing pin and ejector assembled thereon, a recoil mechanism, an extractor affixed to the tube, and a trip for automatic operation actuable by the bolt. An external gas deflector is affixed to the bolt on a guiding projection extending through one of the slots in the tube. A removable cartridge barrel is provided at the other end of the tube.

Claims

1. A bolt assembly for converting a firearm for firing cartridges of a first caliber to the firing of cartridges of a second caliber by merely replacing the bolt of the firearm, wherein the firearm is of the type having a receiver, said assembly comprising a tube of resilient material having a flattened side and being insertable in the receiver, a first longitudinal slot in said flattened side extending substantially the length of said tube, the edges of said slot forming a bolt guide, a bolt slidably positioned in said tube and having a projection extending through said slot, plate means on said projection external of said tube, said bolt and plate means forming a pair of opposed slots guided by said bolt guide, a second longitudinal slot in the side of said tube opposite said flattened side and extending substantially the length of said tube, a back plate affixed in one end of said tube, whereby said tube forms a U-shaped spring, a chamber barrel member, means for releasably holding said chamber barrel member in the other end Of said tube, said chamber barrel comprising means for receiving cartridges of the second caliber, said assembly being adapted for fitting into the receiver of the firearm.

2. The bolt assembly of claim 1 in which said tube has a plurality of transverse holes in the other end thereof, and said releasable holding means for said chamber barrel member comprises a plurality of lug means on said chamber barrel member positioned to engage said apertures, whereby said chamber barrel member may be assembled and disassembled by spreading apart the sides of said tube.

3. The bolt assembly of claim 1 wherein said bolt has a longitudinally extending firing pin slot aligned with said first slot in said tube, and said plate means covers the external side of said firing pin slot.

4. The bolt assembly of claim 1 wherein said bolt has a longitudinally extending ejector slot in a side thereof opposite said first longitudinal slot of said tube, said tube having a transverse slot adjacent said second longitudinal slot therein, and wherein said bolt assembly further comprises an ejector mounted in said transverse slot and having an ejector blade slidably extending into said ejector slot.

5. The bolt assembly of claim 4 wherein the edges of said transverse slot form knife edges, and the sides of said ejector are shaped to conform to said knife edges for holding said ejector rigidly in said tube, whereby said ejector may be assembled and disassembled in said tube by the spreading of said other end of said tube.

6. The bolt assembly of claim 1 further comprising a trip slidably positioned in said tube between one surface of said bolt and the inside surface of said tube adjacent said second longitudinal slot, said trip having a central aperture, said bolt having a projection extending into said central aperture for engaging one edge of said aperture upon movement of said bolt toward said chamber barrel member at a predetermined position.

7. The bolt assembly of claim 1 wherein said bolt has a longitudinally extending bore, and said assembly further comprises recoil spring means extending from said back plate into said bore, said bore having a shoulder engaging said spring for urging said bolt toward said chamber barrel member.

8. The bolt assembly of claim 1 wherein said plate means further comprises a transversely extending gas deflecting projection.

9. A bolt assembly for converting a firearm fireable in automatic and semi-automatic modes for firing cartridges of a first caliber to the firing of cartridges of a second caliber by merely replacing the bolt of the firearm, wherein the firearm is of the type having a receiver, said assembly comprising an elongated tube of resilient material having a pair of opposed slots longitudinally extending substantially the entire length of said tube, back plate means at one end of said tube, whereby said tube forms a U-shaped spring the other end of which may be sprung apart, a chamber barrel member, means releasable upon the spreading apart of said other end of said tube for releasably holding said chamber barrel member in said other end of said tube, and bolt means slidably mounted within said tube, said chamber barrel comprising means for receiving cartridges of the second caliber, said assembly being adapted for fitting into the receiver of the firearm.

10. The bolt assembly of claim 9 wherein said elongated tube has a plurality of apertures in the other end thereof, and said means releasably holding said chamber barrel member comprises lug means on said chamber barrel member positioned to engage said apertures.

11. The bolt assembly of claim 9 wherein the end of said chamber barrel member extending from said tube has the shape of a cartridge casing of a first caliber, and said chamber barrel member has an inner bore shaped to conform to a cartridge of a second caliber.

12. The bolt assembly of claim 9 wherein said bolt means has two generally D-shaped side portions engaging the inside of said tube, a bridge member joiniNg said side portions and having an extension extending through one of said longitudinally extending slots in said tube, a longitudinally extending firing pin slot in said bridge member extending through said projection, and gas deflecting plate means externally of said tube and covering said firing pin slot, whereby said gas deflector and bolt means form a pair of opposed slots guided by the sides of said one slot of said tube, and a firing pin in said firing pin slot.

13. The bolt assembly of claim 12 wherein said D-shaped sides of said bolt means extend further in the direction away from said chamber barrel than said bridge, and wherein said firing pin is mounted to permit movement into the space between said D-shaphed sides beyond said bridge to permit engagement therein with a hammer.

14. The bolt assembly of claim 12 wherein said bolt means further has a longitudinally extending ejector slot on the side thereof toward the other longitudinally extending slot of said tube, said tube further having a transverse slot adjacent said other slot therein, and said bolt assembly further comprises an ejector member releasably clamped between the edges of said transverse slot and having an ejector blade slidably extending into said ejector slot of said bolt means.

15. The bolt assembly of claim 12 further comprising a recoil spring bore longitudinally extending in one of said D-shaped sides of said bolt means, and wherein said bolt assembly further comprises a recoil spring assembly extending from said back plate and into said bore for urging said bolt means toward said chamber barrel.

16. The bolt assembly of claim 12 further comprising a trip member slidably positioned in said tube between said bolt means and the inside of said tube adjacent to the other of said longitudinally extending slots in said tube, said trip means having a central aperture, a projection on said bolt means extending into said aperture in said trip means for engaging one edge thereof upon movement of said bolt to a position at a predetermined distance from said chamber barrel.

17. The bolt assembly of claim 16 further comprising an ejector slot in said bolt means, and ejector means fixedly mounted to said tube and having ejector blade means extending slidably into said ejector slot, said ejector being positioned to form a stop for said trip means in the direction toward said chamber barrel.

18. A bolt assembly for a firearm comprising a tubular member having a pair of opposed longitudinally extending slots and plate means closing one end of said tubular member, said tubular member being of a resilient material whereby said tubular member forms a U-shaped spring, bolt means slidably mounted within said tubular member, a transverse slot in said tubular member at one of said longitudinal slots, the edges of said transverse slot having knife edges, and an ejector member mounted in said transverse slot and having recesses that mate with said knife edges for holding said ejector in said transverse slot, said ejector having an ejector blade means extending into said tubular member and positioned in cooperative relationship with said bolt for the ejection of cartridge cases from said tubular member.

19. A bolt assembly for converting a firearm for firing cartridges of a first caliber to the firing of cartridges of a second caliber by merely replacing the bolt of the firearm, wherein the firearm is of the type having an automatic sear, said bolt assembly comprising a tubular member having a longitudinal slot extending substantially the entire length of said member, a bolt slidably mounted within said tubular member, a trip member slidably mounted in said tubular member adjacent said slot, said trip member having a rectangular recess adjacent said slot with one end of said recess forming automatic sear engaging means, said bolt having a projection extending into said rectangular recess for engaging the other end of said recess at a predetermined position of said bolt, said assembly being adapted for fitting into the receiver of the firearm.

20. A bolt assembly for converting a firearm for firing cartridges of a first caliber to the firing of cartridges of a second caliber by merely replacing the bolt of the firearm, wherein the firearm is of the type having a receiver, an automatic sear extending into said receiver and operatively coupled to a hammer, and a charging handle extending in said receiver and having a bolt engaging projection, said bolt assembly comprising a tube having a first longitudinal slot extending substantially the entire length of said tube and forming an opening into which the automatic sear and hammer may operatively extend, a second opposed longitudinal slot in said tube extending substantially the entire length of said tube, means connecting one end of said tube to constitute the same as a U-shaped spring, said second longitudinal slot in said tube forming a bolt guide, a bolt slidably positioned in said tube and having a projection extending through said second slot, and plate means on said projection outside of said tube and positioned to operatively engage the bolt engaging projection of the charging handle, said assembly being adapted for fitting into the receiver of the firearm.

21. The bolt assembly of claim 20 further comprising a back plate in one end of said tube, said bolt having a longitudinally extending bore, and recoil spring means in said tube extending from said back plate into said recoil spring bore for urging said bolt toward the other end of said tube.

22. The bolt assembly of claim 21 wherein said back plate includes a projection extending beyond said tube for aligning said bolt assembly in said receiver.

23. The bolt assembly of claim 21 further comprising chamber barrel means, and means for releasably holding said chamber barrel means in the other end of said tube.

24. The bolt assembly of claim 23 wherein said tube is formed of a resilient material whereby the sides of the other end on opposite sides of said longitudinal slots may be sprung apart to permit assembly and disassembly of said bolt and chamber barrel through said other end.

25. The bolt assembly of claim 24 in which said tube has a plurality of transverse apertures in said other end, and said means for releasably holding said chamber barrel therein comprises lug means on said chamber barrel for engaging said apertures.

26. The bolt assembly of claim 24 in which said bolt has a pair of generally D-shaped side portions engaging the insides of said tube and the end of said bolt toward said chamber barrel being connected by a bridge, thereby providing a space between the other ends of said D-shaped sides into which said hammer operatively extends, said bridge having a longitudinally extending firing pin slot extending into said projection of said bolt and being covered by said plate means.

27. The bolt assembly of claim 26 wherein the side of said bolt facing said first slot of said tube is flat, further comprising a trip member slidably positioned in said tube between said flat side of said bolt and the inside surfaces of said tube, said trip having a rectangular recess with one edge thereof being positioned to engage said automatic sear, said bolt further having a projection extendinG into said rectangular recess for engaging an opposite edge of said recess at a predetermined point in the movement of said bolt toward said chamber barrel.

28. The bolt assembly of claim 27 wherein said bolt comprises a longitudinally extending ejector slot, and further comprising an ejector member fixedly mounted with respect to said tube and having an ejector blade slidably extending into said ejector slot.

29. The bolt assembly of claim 26 in which said tube has an ejection port, and said bolt has an extractor slot longitudinally extending therein, further comprising an extractor lever pivoted in said extractor slot for engaging the rim of a cartridge case for ejection through said port.

30. A bolt assembly for converting a fiRearm firable in automatic and semi-automatic modes for firing cartridges of a first caliber to the firing of cartridges of a second caliber by merely replacing the bolt and magazine of the firearm, wherein the firearm is of the type having a receiver, an automatic sear extending into said receiver and operatively coupled to a hammer, a charging handle extending into the receiver and having a bolt engaging projection, and a gas tube extending into the receiver for automatic and semi-automatic operation of the bolt, and wherein said firearm further includes a recoil spring and buffer at the rear of the receiver;

said bolt assembly comprising a tube insertable in said receiver and having a fixed back plate for engaging the buffer and recoil spring assembly of the firearm, a cartridge barrel held in the other end of said tube and having an outer end portion in the shape of a cartridge of said first caliber and an inner bore of the shape of a cartridge of said second caliber, whereby the buffer and recoil spring assembly of said firearm urge said bolt assembly into the breach of said firearm, said tube having an upper slot and a lower slot, a bolt slidable within said tube and having a projection extending through said upper slot, gas deflector plate means externally of said tube and affixed to said projection for effecting the movement of said bolt away from said chamber barrel in response to firing gases ejected into said receiver from said gas tube, a recoil spring assembly in said tube for urging said bolt toward said chamber barrel, a trip slidably mounted in said tube under said bolt, said trip having a rectangular recess with one edge thereof positioned to engage said automatic sear, a projection on said bolt for engaging an opposite edge of said recess at a predetermined position in the movement of said bolt toward said chamber barrel, a slot in the end of said bolt away from said chamber barrel, whereby said hammer can move into said slot in said bolt, a firing pin slot extending longitudinally in said bolt, and a firing pin positioned therein and adapted to extend into said space.

31. The bolt assembly of claim 30 wherein said tube is of a resilient material and forms a U-shaped spring thereby permitting assembly of the internal components of said bolt assembly in said other end of said tube.