Gun barrel
First Claim
1. A gun barrel for a gun, comprising:
- an elongated tube having a breech end and a muzzle end, and having an axial bore extending completely through said tube from said breech end to said muzzle end;
said axial bore through said tube having a contact surface for guiding a projectile toward a target and for containing propellant gasses behind said projectile;
said tube and said contact surface being made substantially entirely of Nitinol.
1 Assignment
0 Petitions
Accused Products
Abstract
A gun barrel for a gun has an elongated tube with an axial bore extending completely through the tube from the breech end to the muzzle end. The tube and the contact surface in the axial bore, which contains propellant gasses behind the projectile and engages the projectile while guiding it toward the target, are made of Nitinol having a transition temperature lower than the lowest ambient temperature at which a gun with the barrel is designed to be operated, or of a Nitinol formulation consisting essentially of 60% nickel and 40% titanium. A first sleeve may be mechanically coupled to the barrel tube by shape memory contraction thereon to prestress the barrel tube in compression. The first sleeve may be made of a Nitinol composition having a Martensite state and an Austenite state existing naturally on opposite sides of a transition temperature lower than the designed normal lower ambient temperature in which the gun operates, whereby the sleeve composition remains in the Austenite state during operation of the gun and provides substantial compressive preloading of the tube during operation. A second sleeve of a Nitinol composition having a transition temperature higher than the designed normal operating temperature of the gun is encased within the first sleeve, whereby the second sleeve composition remains in the Martensite state during normal operation of the gun and provides substantial damping of vibrations and whipping of the gun barrel in operation
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Citations
20 Claims
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1. A gun barrel for a gun, comprising:
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an elongated tube having a breech end and a muzzle end, and having an axial bore extending completely through said tube from said breech end to said muzzle end; said axial bore through said tube having a contact surface for guiding a projectile toward a target and for containing propellant gasses behind said projectile; said tube and said contact surface being made substantially entirely of Nitinol. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A gun barrel for a gun, comprising:
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an elongated tube having a breech end and a muzzle end, and having an axial bore extending completely through said tube from said breech end to said muzzle end; said axial bore through said tube having a contact surface for guiding a projectile toward a target and for containing propellant gasses behind said projectile; said tube and said contact surface being made of a nickel-titanium intermetallic compound; a first sleeve of a nickel-titanium composition having a Martensite state and an Austenite state existing naturally on opposite sides of a transition temperature, said sleeve surrounding said tube and pretensioned thereon to exert a compressive preload on said tube and couple said sleeve mechanically to said tube; said nickel-titanium composition of said first sleeve has a transition temperature lower than the designed normal lower temperature limit of said gun, whereby said sleeve composition remains in said Austenite state during normal operation of said gun and provides substantial compressive preloading of said tube during operation; said gun barrel further comprising a second sleeve of a nickel-titanium composition having a transition temperature higher than the designed normal operating temperature of said gun, whereby said second sleeve composition remains in its Martensite state during normal operation of said gun and provides substantial damping of vibrations and whipping of said gun barrel in operation.
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10. A process for making a composite gun barrel, comprising:
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cutting an axial bore longitudinally through an elongated gun barrel blank made of a first Nitinol composition to make a gun barrel liner having an outside diameter; making a sleeve substantially entirely of a second Nitinol composition having a low transition temperature with an Austenitic state and a low temperature Martensitic state on opposite sides of said transition temperature, said sleeve having an original form with an inside diameter smaller than said outside diameter of said liner; cooling said sleeve below said transition temperature; radially expanding said sleeve from said original size to an expanded form, increasing the diameter thereof to a dimension slightly exceeding said outside diameter of said liner; inserting said liner fully into said sleeve while the temperature of said sleeve is below said transition temperature and said sleeve is in said expanded form; allowing said sleeve to warm to a temperature above said transition temperature and revert to said Austenitic state; whereby said sleeve will shrink toward said original form and exert a strong compressive force on said liner to reinforce said liner against bursting pressures within said liner bore when a projectile is fired from said gun barrel. - View Dependent Claims (11, 12, 13)
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14. A process of propelling projectiles through a gun barrel bore of a gun, comprising:
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inserting said projectile into a bore of a breech structure of said gun, sealing said breech structure, and igniting a propellant in said breech structure behind said projectile; propelling said projectile into said bore of said gun barrel with gas pressure from said burning propellant; engaging a soft metal surface of said projectile with rifling in interior walls of said bore of said gun barrel and engraving grooves in said projectile with said rifling, said interior walls of said bore consisting essentially of a monolithic Nitinol composition; resisting corrosive attacks on said interior walls of said bore from said propellant gasses and particles of said projectile by chemical inertness of said Nitinol composition; retarding transfer of heat to said gun barrel by low friction between said interior walls of said gun barrel bore and said projectile, and retarding conduction of heat from said bore to radial outer regions of said gun barrel by a low coefficient of thermal conductivity of said Nitinol composition, thereby causing a slow rate of temperature increase of said gun barrel during firing. - View Dependent Claims (15, 16, 17, 18, 20)
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19. A gun barrel for a gun as defined in claim 19, wherein:
said contact surface of said bore is substantially entirely monolithic Type 60 Nitinol.
Specification