James L Schroth

US Patent:

6810709, Nov 2, 2004

Filed:

Oct 11, 2002

Appl. No.:

10/269234

Inventors:

Richard Harry Hammar - Utica MI
James Gregory Schroth - Troy MI

Assignee:

General Motors Corporation - Detroit MI

International Classification:

B21D 3716

US Classification:

723427, 7234292, 72709, 219483

Abstract:

A heated metal forming tool including an un-heated mounting plate that is attached to a press. A tool detail is attached to the mounting plate. Insulation surrounds the tool detail to thermally isolate it from the mounting plate, and from the tool surroundings. The tool detail is heated internally by heaters disposed in zones within the tool detail. The temperature of various portions of the tool detail can be independently controlled by varying the temperature within any of the zones.

US Patent:

6825442, Nov 30, 2004

Filed:

Jan 6, 2003

Appl. No.:

10/337220

Inventors:

James G. Schroth - Troy MI
Paul E. Krajewski - Sterling Heights MI

Assignee:

General Motors Corporation - Detroit MI

International Classification:

B23K 900

US Classification:

219137WM, 219136

Abstract:

A tailor welded blank for use in a fluid-forming operation includes a first sheet element having a physical characteristic with a first value and a second sheet element having the physical characteristic with a second value different from the first value. The first and second sheet elements are welded together at at least one weld region to form at least a portion of a tailor welded blank. When the tailor welded blank is processed in a fluid forming process, the first and second values of the physical characteristic result in said first and second sheet elements having approximately equal effective strength values such that said first and second sheet elements deform at an approximately equal rate during the fluid forming process and local thinning and failure initiation is reduced at the at least one weld region and throughout the first and second sheet elements.

US Patent:

6880377, Apr 19, 2005

Filed:

Oct 17, 2002

Appl. No.:

10/274493

Inventors:

Chongmin Kim - Davisburg MI, US
Gary A. Kruger - Troy MI, US
Mark G. Konopnicki - Rochester MI, US
John Norman Johnson - Allenton MI, US
James Gregory Schroth - Troy MI, US
Michelle R. Goff - Grand Blanc MI, US

Assignee:

General Motors Corporation - Detroit MI

International Classification:

B21D026/02
B21D025/00

US Classification:

72 57

Abstract:

A method is disclosed for forming sheet metal articles, such as automotive body panels, having significant curvatures in front-to-back and side-to-side directions. Opposing, complementary, preforming and final shape forming tools are used in a single press. A sheet of superplastically or quick plastically formable sheet metal alloy, heated to a forming temperature, is first stretched against the preform tool using pressurized gas to form a preform that has experienced most of the metal stretching required for the final part shape. The preform is removed from the preform tool and formed against the opposing tool with pressurized gas to obtain the final sheet metal part shape.

US Patent:

6910358, Jun 28, 2005

Filed:

Aug 25, 2003

Appl. No.:

10/647401

Inventors:

James Gregory Schroth - Troy MI, US

Assignee:

General Motors Corporation - Detroit MI

International Classification:

B21D026/02
B21D025/00

US Classification:

72 57, 72297, 723427

Abstract:

A method is disclosed for two-stage stretch forming of a sheet metal blank workpiece between a preform tool with a concave cavity and an opposing finish-form punch tool. Both tools are independently heated to different forming temperatures with the preform tool being hotter. Gas pressure is first applied to one side of the workpiece in the first forming stage to balloon it into the cavity of the preform tool. Gas pressure is then applied to the other side of the preformed workpiece to stretch it against the finish-form surface. The hotter preform tool enables faster forming and gas venting in the first stage. The cooler finish-form tool enables the final shaping of the part and its undistorted removal from the punch surface.

US Patent:

7076981, Jul 18, 2006

Filed:

Mar 30, 2004

Appl. No.:

10/813580

Inventors:

John R. Bradley - Clarkston MI, US
James G. Schroth - Troy MI, US
Glenn S. Daehn - Columbus OH, US

International Classification:

B21D 26/14
B21J 5/04

US Classification:

72 56, 723792, 294192

Abstract:

A scheme for electromagnetic formation of fuel cell plates is provided. In accordance with one embodiment of the present invention, a method of forming a flow field plate is provided where an electromagnetic actuator is arranged opposite a profiled surface of a die portion. The profiled surface of the die portion is configured to at least partially define a network of flow field plate flow passages. The electromagnetic actuator is configured to generate a magnetic field upon activation and a sheet of material is positioned between the electromagnetic actuator and the profiled die surface. The sheet of material is characterized by an electrical conductivity sufficient to yield a repulsive electromagnetic force between the actuator and the sheet upon activation of the actuator. The passages are formed by driving the electromagnetic actuator such that the repulsive force is of sufficient intensity to deform the sheet against the profiled die surface.

US Patent:

7080535, Jul 25, 2006

Filed:

Apr 20, 2004

Appl. No.:

10/827721

Inventors:

Gary A. Kruger - Troy MI, US
James G. Schroth - Troy MI, US
Richard Harry Hammar - Utica MI, US

Assignee:

General Motors Corporation - Detroit MI

International Classification:

B21D 26/02

US Classification:

72 57, 72 60, 72340, 294211

Abstract:

A hot blow-forming apparatus includes opposed and complementary forming tools adapted for hot blow forming a surface of a heated sheet-metal workpiece against a forming surface of one of the tools. The tools are also adapted to close upon and grip a peripheral edge of the workpiece and perform work on a central portion of the workpiece to produce a formed panel. The tools incorporate an improved extraction apparatus, which includes a plurality of opposed and complementary spring-loaded extractor pads. Opposed extractor pads are spring-loaded to different levels so as to apply spring-load differentials therebetween and thereby apply different extraction forces in different locations of the resultant formed panel for distortion-free removal of the formed panel from the working surfaces of the tooling.

US Patent:

7112249, Sep 26, 2006

Filed:

Sep 30, 2003

Appl. No.:

10/674947

Inventors:

James Gregory Schroth - Troy MI, US
Mark W. Verbrugge - Troy MI, US
John Robert Bradley - Clarkston MI, US

Assignee:

General Motors Corporation - Detroit MI

International Classification:

C21D 11/00
C22F 1/04

US Classification:

148511, 72 57

Abstract:

A sheet material is gripped at its edges and hot blow formed by a pressurized working gas against a forming tool surface. The flow characteristics of the material are determined at increasing gas pressures over a range of temperature relevant to the forming operation. A predetermined pressure/time schedule is determined at a reference temperature for rapid shape formation of good parts on a continual basis. The process is then controlled as parts are thus formed by measuring the forming temperature of the parts and correcting the pressure time schedule, using the determined flow characteristics, for the actual temperature to achieve the desired shape evolution of the parts.

US Patent:

7159427, Jan 9, 2007

Filed:

Feb 27, 2004

Appl. No.:

10/788931

Inventors:

James Gregory Schroth - Troy MI, US
Richard Murray Kleber - Clarkston MI, US
Richard Harry Hammar - Utica MI, US
Edward W. Bennett - Clarkston MI, US

Assignee:

General Motors Corporation - Detroit MI

International Classification:

B21D 26/02

US Classification:

72 60, 7234292, 100326

Abstract:

Apparatus for hot gas blow-forming including opposed heated and insulated tool containers, each including a tool heater plate that is adapted for attachment to a platen of a press with one or more load bearing spacers interposed between the tool heater plate and the platen. Each tool container also includes an insulation enclosure having a base portion that is interposed between the tool heater plate and the platen and further having perimeter wall portion that surrounds the tool heater plate. A perimeter seal is preferably attached to at least one of the heated and insulated tool containers and is adapted for sealing engagement with the other of the heated and insulated tool containers.