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Publication numberUS2981155 A
Publication typeGrant
Publication dateApr 25, 1961
Filing dateMar 4, 1953
Priority dateMar 4, 1953
Publication numberUS 2981155 A, US 2981155A, US-A-2981155, US2981155 A, US2981155A
InventorsAuthony Parlanti Conrad
Original AssigneeAuthony Parlanti Conrad
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Composite gun barrels
US 2981155 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

m M RA A? ML N mm W m VP W W A A h 2 w \\/l 1 R K N I 0 c H V M 6 FIG. 3.

United States Patent COMPOSITE GUN BARRELS Conrad Anthony Parlanti, 34 W. Hill Road, Herne Bay, Kent, England Filed Mar. 4, 1953, Ser. No. 340,198

4 Claims. (Cl. 89-16) This invention relates to gun barrels and to methods of making the same.

It is known that the increasingly high muzzel velocities which are being used in modern guns produce greatly increased friction forces as the projectile travels through the gun barrel. This in turn results in the generation of increased heat, and in cases where rapid firing is required, the low thermal conductivity of steel frequently causes localized accumulations of heat which result in distortion of the barrel.

It is an object of the present invention to provide a gun barrel in which provision is made for rapid transfer and dissipation of heat.

It is a further object of the invention to provide methods of making such gun barrels.

Other objects and advantages of the invention will appear hereinafter. I

A preferred embodiment of the invention selected for purposes of illustration is shown in the accompanying drawings, in which,

Figure 1 is an elevation of a core suitable for use in casting a gun barrel shell embodying the invention.

Figure 2 is a longitudinal section through the core and cast shell. 1

Figure 3 is a longitudinal section through a completed barrel.

Referring to the drawings, the gun barrel illustrated in Figure 3 comprises a relatively thin shell 1 of steel and an outside casing 2 of aluminum or aluminum alloy containing at least 70% aluminum. The inside surface of the steel shell has rifle grooves 3 and lands 4 formed therein and the outside surface is surrounded by and in contact with a casing 2 throughout its entire length, or at least throughout a substantial portion of its length.

The outside of the casing 2 is provided with cooling fins 5 to aid the transfer of heat, and the outside surface of the casing, including the fins is treated to provide a thin outside layer of aluminum oxide, which, I have found, greatly increases the rate of heat transfer. If desired, the fins 5 may be machined down to heights indicated by broken line 6 to modify the rate of heat transfer at various points along the barrel as may be desired. The contour of the curve 6 for any type of gun may be determined by suitable firing tests.

' The preferred method of making a gun barrel as above described'is as follows. Referring to Figure 1, a core 11 of aluminum or aluminum alloy is first prepared, said core having a substantially cylindrical center section and enlarged end sections 13 provided with cooling fins 14. The outside surface of section 12 is provided with rifle grooves 15 andlands 16 which are the reverse (negative) of the grooves and lands of the rifling desired on the interior of the barrel.

The outside surface of the core including the end sections is then treated to provide a thin layer of aluminum oxide, preferably by one of the well known anodizing processes. This has a two fold effect in the subsequent ice 21 cylindrical cavity surrounding the center section 12 and a cylindrical steel shell 1A (Figure 2) is cast around the center section. The shell should be of substantial thickness, as for example, from 1" to 2". The shell may now be subjected to any desired heat treatment, and in the course of this treatment the core melts and runs out of the shell. Subsequently, the outside of the shell 1A is machined down to provide the shell 1 having a thickness (measured from the bottom of the rifle grooves) of approximately 0.1".

This shell is now placed in another casting mold in which it serves as a core around which the casing 2 is cast. Preferably, the mold is constructed and the casting operation is conducted in accordance with the invention disclosed 'in my prior application Serial No. 225,296, filed May 9, 1951, now Patent No. 2,759,231.

Subsequently, the exposed aluminum surfaces of the barrel are treated to provide a thin layer of aluminum oxide thereon for purposes previously described. This is preferably done. by one of the'well known anodizing processes, the ends of the barrel being sealed during the treatment to prevent the electrolyte from affecting the steel.

Thereafter, the barrel may be mounted on a lathe and the rifling may be accurately machined to the desired size. Also the cooling fins may be cut to any contour desired by the designer to provide proper cooling characteristics.

It will be understood that the drawings herein are merely representative and are not intended to portray any actual gun barrel in accurate proportions.

It will be understood that the invention may be variously modified and embodied within the scope of the subjoined claims.

I claim as my invention:

'1. A gun barrel comprising a relatively thin cylindrical shell of steel, the insidesurface of said shell having rifle grooves and lands formed therein, the inside diameter of said shell being greatly in excess of the wall thickness thereof, and an outside casing of metal containing not less than 70% 7 aluminum surrounding said shell and in direct, fixed contact therewith throughout substantially its entire length, said outside casing having a thickness substantially greater than the thickness of said shell of steel.

2. A gun barrel according to claim 1 in which the outside of said casing consists of a thin layer of aluminum oxide.

3.'A gun barrel according to claim 1 in which the outside of said case has been anodized.

4. A gun barrel according to claim 1 in which the thickness of said shell of steel is approximately 0.1".

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1553825 *Mar 28, 1925Sep 15, 1925Tracy C DicksonMethod of making guns and other hollow metal articles
US1986837 *May 10, 1933Jan 8, 1935Mccann George MGun
US2112144 *Jul 28, 1932Mar 22, 1938Secretary Of War Of The UnitedMeans for cooling gun barrels
US2137259 *Dec 14, 1935Nov 22, 1938Winchester Repeating Arms CoComposite firearm barrel
US2238670 *Nov 12, 1937Apr 15, 1941Commerciale Caproni CompGun barrel
US2287066 *Aug 21, 1940Jun 23, 1942Rogers George DHeat exchange unit
US2331477 *Sep 18, 1942Oct 12, 1943Keema Alexander WMethod of producing guns
US2375721 *Jun 5, 1940May 8, 1945Dryden KuserAutomatic rifle
US2736119 *Dec 18, 1951Feb 28, 1956 Firearm having chamber member
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3118243 *May 17, 1961Jan 21, 1964 Rifled barrel for firearms
US4641567 *May 31, 1983Feb 10, 1987Ga Technologies Inc.Barrel assembly for electromagnetic rail gun
US5448848 *Sep 15, 1993Sep 12, 1995Briley Manufacturing Co.Shotgun having light weight interchangeable barrel tubes
US6758004 *Dec 23, 2002Jul 6, 2004Michaels Of Oregon Co.Firearm barrel manufacturing methods and barrel assemblies
US7152357Mar 9, 2004Dec 26, 2006Michaels Of Oregon Co.Composite firearm barrel assemblies
US7735408 *Sep 21, 2005Jun 15, 2010The United States Of America As Represented By The Secretary Of The ArmyMortar tube with cooling fin
US7921590Jul 18, 2007Apr 12, 2011Strum, Ruger & Company, Inc.Composite firearm barrel reinforcement
US7934332May 3, 2011Sturm, Ruger & Company, Inc.Composite firearm barrel
US8291632 *Nov 3, 2008Oct 23, 2012Transmission Systems LimitedProjectile weapons
US8316568Mar 17, 2011Nov 27, 2012Sturm, Ruger & Company, Inc.Composite firearm barrel reinforcement
US9261316 *Dec 21, 2012Feb 16, 2016Gamo Outdoor, S.L.Method for the manufacture of a barrel for compressed air or CO2 rifles and barrel for compressed air or CO2 rifles obtained
US20040216350 *Mar 9, 2004Nov 4, 2004Michaels Of Oregon Co.Composite firearm barrel assemblies
US20070193102 *Feb 23, 2006Aug 23, 2007Briggs Vernon RComposite firearm barrel
US20100307045 *Nov 3, 2008Dec 9, 2010Transmission Systems LimitedProjectile Weapons
US20150000645 *Dec 21, 2012Jan 1, 2015Gamo Outdoors, S.L.Method for the manufacture of a barrel for compressed air or co2 rifles and barrel for compressed air or co2 rifles obtained
Classifications
U.S. Classification89/16, 42/78, 42/76.1, 42/76.2
International ClassificationB22D19/08, F41A21/02, F41A21/24, F41A21/00, F41A21/20
Cooperative ClassificationB22D19/08, F41A21/24, F41A21/02, F41A21/20
European ClassificationF41A21/20, F41A21/24, B22D19/08, F41A21/02