Robert L Shaffer

US Patent:

58360654, Nov 17, 1998

Filed:

Sep 26, 1996

Appl. No.:

8/721548

Inventors:

James R. Dehlinger - Ada MI
Roger A. Crawford - Muskegon MI
Wallace J. Poole - Fremont MI
Robert A. Shaffer - Comstock Park MI
Donald R. VandePolder - Grand Rapids MI

Assignee:

Benteler Automotive Corporation - Grand Rapids MI

International Classification:

B23P 2300
B21D 2602

US Classification:

29 33T

Abstract:

Hydroforming double wall tubular stock into an air gap tubular element comprising providing a plural wall tubular workpiece having at least an inner wall liner and an outer wall jacket having adjacent open axial ends, causing at least one of the jacket ends to extend axially beyond the adjacent liner end and to be flared outwardly, placing the workpiece into a first mold cavity of a size and configuration to result in the desired size and configuration of the liner, sealing the open ends of said liner, injecting hydroforming fluid into said liner to fill it and applying pressure thereto to expand the liner and jacket in the first mold cavity, releasing the pressure, placing the workpiece in a second mold cavity of a size and configuration desired for the jacket on a resulting air gap tubular element, providing hydroforming end closures to seal off the jacket ends, at least one of the end closures having an annular shoulder aligned with the flared extended jacket end radially outwardly offset from the adjacent liner end, pressing the annular shoulder directly against the flared jacket end to seal the flared jacket end between the shoulder and an anvil surface, injecting fluid into the workpiece to fill it and applying pressure to expand only the jacket.

US Patent:

56734700, Oct 7, 1997

Filed:

Aug 31, 1995

Appl. No.:

8/522172

Inventors:

James R. Dehlinger - Ada MI
Roger A. Crawford - Muskegon MI
Wallace J. Poole - Fremont MI
Robert A. Shaffer - Comstock Park MI
Donald R. VandePolder - Grand Rapids MI

Assignee:

Benteler Automotive Corporation - Grand Rapids MI

International Classification:

B21D 3904
B21D 2602

US Classification:

294211

Abstract:

Hydroforming double wall tubular stock into an air gap tubular element comprising providing a plural wall tubular workpiece having at least an inner wall liner and an outer wall jacket having adjacent open axial ends, causing at least one of the jacket ends to extend axially beyond the adjacent liner end and to be flared outwardly, placing the workpiece into a first mold cavity of a size and configuration to result in the desired size and configuration of the liner, sealing the open ends of said liner, injecting hydroforming fluid into said liner to fill it and applying pressure thereto to expand the liner and jacket in the first mold cavity, releasing the pressure, placing the workpiece in a second mold cavity of a size and configuration desired for the jacket on a resulting air gap tubular element, providing hydroforming end closures to seal off the jacket ends, at least one of the end closures having an annular shoulder aligned with the flared extended jacket end radially outwardly offset from the adjacent liner end, pressing the annular shoulder directly against the flared jacket end to seal the flared jacket end between the shoulder and an anvil surface, injecting fluid into the workpiece to fill it and applying pressure to expand only the jacket.