David T Field

US Patent:

7251976, Aug 7, 2007

Filed:

Mar 1, 2005

Appl. No.:

11/069173

Inventors:

David A. Field - Birmingham MI, US

Assignee:

GM Global Technology Operations, Inc. - Detroit MI

International Classification:

B21D 7/04

US Classification:

72149, 72146, 72157, 72369

Abstract:

A tube bending apparatus adapted for the noncircular bending of a tube includes a modified bend die, a modified wiper die, a translatable and pivotable element and an actuator. The bend die presents a noncircular bending profile having a linearly or nonlinearly increasing radius of curvature. The wiper die is configured to accommodate the maximum radius presented by the profile, and the element and actuator present an inclined rack and pinion configuration. The bend die presents an involute of a circle having a radius equal to the product of the radius of the pinion and the sine of the angle of inclination, so that the bend die engages the tube at a fixed point in space during bending.

US Patent:

7290421, Nov 6, 2007

Filed:

Jul 1, 2003

Appl. No.:

10/611842

Inventors:

David A. Field - Birmingham MI, US
William Hugh Frey - Grosse Pointe Farms MI, US

Assignee:

General Motors Corporation - Detroit MI

International Classification:

B21D 7/04

US Classification:

72149, 72146

Abstract:

A tube is bent having a curved portion with a variable radius extending between first and second ends. The curved portion includes a circular arc portion with a constant radius and a clothoid transition portion with a variable radius. The circular arc portion extends from the first end toward a point of integration. At the point of integration, the circular arc portion merges with the transition portion. The transition portion extends from the point of integration to the second end. As the transition portion extends from the point of integration, its radius of curvature increases over its arc length, thereby, improving the quality of the bent tube by gradually bending the tube over a longer distance, thereby reducing local stresses on the bent portion of the tube.

US Patent:

7475706, Jan 13, 2009

Filed:

May 30, 2007

Appl. No.:

11/807724

Inventors:

David A. Field - Birmingham MI, US
William Hugh Frey - Grosse Pointe Farms MI, US

Assignee:

GM Global Technology Operations, Inc. - Detroit MI

International Classification:

F16L 9/00

US Classification:

138177, 138178, 138DIG 11

Abstract:

A tube is bent having a curved portion with a variable radius extending between first and second ends. The curved portion includes a circular arc portion with a constant radius and a clothoid transition portion with a variable radius. The circular arc portion extends from the first end toward a point of integration. At the point of integration, the circular arc portion merges with the transition portion. The transition portion extends from the point of integration to the second end. As the transition portion extends from the point of integration, its radius of curvature increases over its arc length, thereby, improving the quality of the bent tube by gradually bending the tube over a longer distance, thereby reducing local stresses on the bent portion of the tube.

US Patent:

20080189236, Aug 7, 2008

Filed:

Feb 1, 2007

Appl. No.:

11/669978

Inventors:

Earnest J. Foster - Troy MI, US
Lynn T. Truss - Royal Oak MI, US
Jeffrey D. Tew - Rochester MI, US
David A. Field - Birmingham MI, US

Assignee:

GM Global Technology Operations, Inc. - Detroit MI

International Classification:

G06F 7/00

US Classification:

707 1

Abstract:

Methods, systems and computer program products for monitoring a delivery chain network. An exemplary method includes accessing a database of delivery records. Each delivery record includes delivery characteristics including delivery time data for an item transported along a route. A group of delivery records having one or more specified delivery characteristics is selected from the database. The selected group includes delivery records for items transported along at least two different routes. The delivery time data for the group of delivery records is averaged to calculate bundled chart data. The bundled chart data is then output.