MANUFACTURING A SEAMLESS PRESSURE VESSEL

• US 3,651,559 A
• Filed: 04/13/1970
• Issued: 03/28/1972
• Est. Priority Date: 04/13/1970
• Status: Expired due to Term

• Current Assignee: Andrew W. Lawlor
• Original Assignee: Andrew W. Lawlor
• Inventors: Lawlor, Andrew W.
• Primary Examiner(s): Eager, Thomas H.
• Application Number:
  US05/027,785
• Time in Patent Office: 715 Days
• Field of Search: 29/422,400,4D,148.4B,DIG.11,DIG.47 72/349,364 220/3
• US Class Current: 29/422
• CPC Class Codes: B21K 1/762 Coupling members for conveying mechanical motion, e.g. universal joints
• CPC Class Codes: F16J 12/00 Pressure vessels in general covers therefor F16J13/00; for particular applications, see the relevant subclasses, e.g. B01J, F17C, G21C
• CPC Class Codes: Y10S 29/047 Extruding with other step
• CPC Class Codes: Y10T 29/49714 Hollow ball
• CPC Class Codes: Y10T 29/49808 Shaping container end to encapsulate material

Abstract

Improved method of manufacturing metallic seamless spherical pressure vessel wherein the vessel is controllably worked and heat treated during fabrication in such fashion that the final vessel has no localized weakened areas and full advantage is taken of the spherical shape of the vessel.

Claims

1. The method of forming a wrought mEtal sphere comprising the steps of impact extruding a metal blank to form a cylindrical shell having an integral hemispherical bottom of uninterrupted smooth walled configuration, thereafter without locking major portions of the shell to die elements progressively and incrementally compressing the cylindrical portion of the shell in order to complete the forming of the shell into a sphere, and all during said extruding and compressing of the shell exercising substantially full control over the metal by cold flowing the metal at any given time substantially uniformly in all directions so as to avoid excessive build-up of the metal in given parts of the shell structure and undesirable thinning of the metal in the shell structure.

2. The method of forming a wrought metal sphere comprising the steps of impact extruding a metal blank to form a cylindrical shell having an integral hemispherical bottom, thereafter progressively and incrementally compressing the cylindrical portion of the shell to complete the forming of the sphere, during said extruding and compressing of the shell exercising substantially full control over the cold flow of the metal so as to avoid excessive build-up of the metal in given parts of the shell structure and undesirable thinning of the metal in the shell structure, and annealing the shell after the extruding of the shell and prior to the compressing of the cylindrical portion of the shell.

3. The method of forming a wrought metal sphere comprising the steps of impact extruding a metal blank to form a cylindrical shell having an integral hemispherical bottom, thereafter progressively and incrementally compressing the cylindrical portion of the shell to complete the forming of the sphere and during said extruding and compressing of the shell exercising substantially full control over the cold flow of the metal so as to avoid excessive buildup of the metal in given parts of the shell structure and undesirable thinning of the metal in the shell structure and heat treating the shell after the full spherical formation thereof.

4. The method of claim 3 wherein the metal being formed into a sphere is aluminum and the heat treating step comprises a solution heat treating of the finished shell.

5. The method of claim 4 including the step of artificially aging the finished shell.

6. The method of forming a wrought metal sphere comprising the steps of impact extruding a metal blank to form a cylindrical shell having an integral hemispherical bottom, thereafter progressively and incrementally compressing the cylindrical portion of the shell to complete the forming of the sphere and during said extruding and compressing of the shell exercising substantially full control over the cold flow of the metal so as to avoid excessive buildup of the metal in given parts of the shell structure and undesirable thinning of the metal in the shell structure and said impact extruding being performed in multiple steps the last of which involves finally forming the hemispherical bottom of the vessel.

7. The method of forming a wrought metal sphere comprising the steps of impact extruding a metal blank to form a cylindrical shell having an integral hemispherical bottom, thereafter progressively and incrementally compressing the cylindrical portion of the shell to complete the forming of the sphere and during said extruding and compressing of the shell exercising substantially full control over the cold flow of the metal so as to avoid excessive buildup of the metal in given parts of the shell structure and undesirable thinning of the metal in the shell structure and the incremental compressing of the cylindrical shell portion being effected without disturbing the previously shaped hemispherical bottom.

8. The method of claim 5 including the step of solution heat treating the workpiece prior to the last extruding step and subsequently artificially aging the finally finished sphere.