Magnetic pulse welder pressure canister
AssigneeFuel Cell Components and Integrators, Inc.
InventorsRichard A. Bennett, Robert L. Benoit, Bernard I. Rachowitz, Anthony Mascolo
Life of this patent
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Abstract
A pressure vessel or pressurizable canister has a hollow, thin-walled, cylindrical metal shell or tube. Two end caps are hermetically sealed to the respective distal ends of the metal shell by the process of magnetic pulse welding that requires no external heat. The two end caps are made of a metallic alloy such as aluminum. The end caps are each cylindrically shaped and have at least one circumferential recess to accommodate the metal of the shell tube as it deforms about the end caps and forms an intermolecular bond. The canister can hold a pressure of at least 1,800 psi.
Claims17
A pressure vessel, comprising a pressurizable canister, said canister comprising:
- a) a hollow, thin-walled, lightweight, cylindrical metal shell, said metal shell having an inside diameter;
- b) two distally disposed, substantially cylindrical, metallic alloy end caps comprising a top end cap and a bottom end cap, respectively, each of said end caps comprising a first portion having a first diameter slightly larger than said inside diameter of said cylindrical metal shell, said first diameter being selected to provide an interference fit with said inside diameter when said first portion of said end cap is inserted into said metal shell, and a concentric second portion having a second diameter smaller than said first diameter, said second diameter being selected so as to leave a predetermined, uniform gap between a circumferential surface of said second portion and an inside surface of said wall of said cylindrical metal shell when said second portion is substantially completely inserted thereinto;
- said metal shell being hermetically sealed to each respective, end cap by a process of magnetic-pulse welding.
A pressure vessel, comprising a pressurizable canister, said canister comprising a hollow, thin-walled, lightweight, cylindrical metal shell having an inside diameter, and a top end cap and a bottom end cap, each of said top end cap and said bottom end cap being substantially cylindrical and comprising a first portion having a first diameter slightly larger than said inside diameter of said cylindrical metal shell, said first diameter being selected to provide an interference fit with said inside diameter when said first portion of said end cap is inserted into said metallic metal shell, and a concentric second portion having a second diameter smaller than said first diameter, said second diameter being selected so as to leave a predetermined, uniform gap between a circumferential surface of said second portion and an inside surface of said wall of said cylindrical metal shell when said second portion is substantially completely inserted thereinto, said circumferential surface of said second portion and an inside surface being disposed substantially parallel to one another, said metal shell being formed so as to create an intermolecular bond at the interface between said shell and said respective second portions of said top end cap and said bottom end cap, respectively;
- said metal shell being hermetically sealed to each of said respective second portions of said end caps by a process of magnetic pulse welding, said respective end caps comprising a high-strength, lightweight, metallic alloy that withstands the magnetic pulse welding process and allows for an intergranular fusion of shell and end cap materials in the absence of applied heat, whereby a permanent bond is established between said metal shell and said respective second portions of said end caps wherein the material of said shell and said end caps becomes integrally and directly bonded to one another with no intervening material therebetween.
A method for forming a light-weight pressure vessel, the steps comprising:
- a) providing a light-weight, cylindrical metal alloy shell having proximal and distal ends and a predetermined inside diameter;
- b) providing two substantially cylindrical metal end caps, each comprising a first portion having a first diameter slightly larger than said predetermined inside diameter of said cylindrical metal alloy shell, said first diameter being selected to provide an interference fit with an inside of a wall of said cylindrical metal alloy shell when said first portion of said end cap is inserted therein, and a concentric second portion having a second diameter smaller than said first diameter, said second diameter being selected so as to leave a predetermined, uniform gap between said second portion and an inside of said inside of said wall of said cylindrical metal alloy shell when said second portion is inserted therein;
- c) inserting a first of said two end caps completely into one of said distal and said proximal ends of said cylindrical metal alloy shell, said first portion being inserted first, said first portion substantially centering said end cap within said cylindrical metal alloy shell, thereby leaving a substantially uniform gap between a circumferential surface of said second portion and said inside of said cylindrical metal alloy shell, said circumferential surface of said second portion and said inside of said cylindrical metal alloy shell being disposed substantially parallel one another when said end cap is substantially completely inserted in said shell;
- d) electro-pulse welding said cylindrical metal alloy shell to said inserted end cap, a weld being formed substantially only between said circumferential surface of said second portion of said end cap and said inside surface of said shell;
- and
- e) repeating steps (c) and (d) by inserting a second one of said end caps into a remaining, unsealed one of said distal and said proximal ends of said cylindrical metal alloy shell;
- whereby a pressure-tight, hermetic seal is formed by intergranular fusion of said cylindrical metal alloy shell and each of said two end caps in the absence of applied heat.
A pressure vessel, having a pressurizable canister, said canister comprising:
- a) a hollow, thin-walled, cylindrical aluminum shell, said aluminum shell having an inside diameter;
- b) two distally disposed, substantially cylindrical, aluminum end caps, each of said end caps comprising a first portion having a first diameter slightly larger than said inside diameter of said cylindrical metal shell, said first diameter being selected to provide an interference fit with said inside diameter when said first portion of said end caps is inserted into said metal shell, and a concentric second portion having a second diameter smaller than said first diameter, said second diameter being selected so as to leave a predetermined, uniform gap between a circumferential surface of said second portion and an inside surface of said wall of said cylindrical aluminum shell when said second portion is substantially completely inserted thereinto, said circumferential surface of said second portion and said inside surface of said wall of said cylindrical aluminum shell being disposed substantially parallel to one another when a respective one of said ends caps is inserted substantially completely into said aluminum shell;
- said aluminum-shell being hermetically sealed to each of said second portions of said end caps by a process of magnetic pulse welding.
Dependencies are inferred from the claim text.