David L Willis

US Patent:

6967054, Nov 22, 2005

Filed:

Mar 6, 2003

Appl. No.:

10/382675

Inventors:

Jay Bernard Kirk - Plano TX, US
Zuhair Hilali - Dallas TX, US
Duy Phan - Garland TX, US
Darren S. Lee - Dallas TX, US
Duane E. Carter - Plano TX, US
Gary A. Evans - Plano TX, US
David Alan Willis - Dallas TX, US

Assignee:

Photodigm, Inc. - Richardson TX

International Classification:

B32B003/00
G02F001/00
G03C005/00

US Classification:

428156, 428120, 428167, 428172, 359321, 359566, 430322

Abstract:

A uniform coating is provided using surface features. Multiple ridges or other shapes are fabricated near an area of interest to allow for uniform coating in between the ridges. Areas at either ends of the ridges are left open to allow for excess pooling of photoresist liquid and to aid in obtaining uniform coating. The photoresist liquid or other coating fluid is applied to the sample and spun dry. A soft-bake process is performed to evaporate remaining solvents. An element, such as a diffractive, refractive, or reflective grating structure, is then formed in the area of interest using the uniform photoresist coating.

US Patent:

58903399, Apr 6, 1999

Filed:

Sep 10, 1996

Appl. No.:

8/711483

Inventors:

David R. Willis - Arlington TX

Assignee:

Alpine Engineered Products, Inc. - Pompano Beach FL

International Classification:

E04B 138
E04C 311
F16C 1100

US Classification:

52640

Abstract:

A pitch break connector is provided. The pitch break connector has an outside and inside rigid member. Each member has a first generally U-shaped channel defined by a spine member between first and second legs. Each member has a first and a second pivot end portion. A hinge pivotally connects the inside and outside members through the pivot end portions in a generally longitudinally opposing position. In this configuration, the first and second end portions of the inside member can be pivotally accepted into a cavity defined by the generally U-shaped channel of the outside member when the members are pivoted about the hinge.

US Patent:

58160124, Oct 6, 1998

Filed:

Mar 10, 1997

Appl. No.:

8/814781

Inventors:

David R. Willis - Arlington TX

Assignee:

Alpine Engineered Products, Inc. - Pompano Beach FL

International Classification:

E04C 302
F16B 2500

US Classification:

52696

Abstract:

An improved fastener securing framing members to metal studs is provided. The fastener has rigid shank, an integral head, a self-tapping or drilling tip, and a first and a second spaced apart buttress threads. The shank has a generally circular cross-section and a longitudinally extending axis. The head integrally extends a first end of the shank and has a top portion and an underside. The self-drilling tip is extends from a second end of the shank. The first buttress thread is formed in said shank and is adjacent the head and partially traverses the shank, terminating from the shank's second end. The second buttress thread is formed in the shank and sufficiently spaced apart from the first buttress thread such that the first thread does not continue to threadingly feed the shank through an aperture formed by the self-drilling tip, the second buttress thread terminating adjacent the tip.

US Patent:

20230131080, Apr 27, 2023

Filed:

Oct 27, 2022

Appl. No.:

17/975441

Inventors:

Paul S. Krueger - Plano TX, US
David A. Willis - Dallas TX, US
Haosen Tan - Dallas TX, US
Denise Cox - Dallas TX, US

International Classification:

B63B 1/38

Abstract:

A reduced drag surface involves a perforated or porous surface exposed to a flowing fluid and a slip interface disposed between the surface and the flowing fluid, wherein the slip interface is formed from an entrapped fluid trapped at the surface. A method for modifying a drag coefficient on a reduced drag surface involves the steps of supplying a fluid to a perforated or porous surface exposed to a flowing fluid, wherein the surface traps the fluid at the surface to form an entrapped fluid and forming a slip interface between the surface and the flowing fluid, wherein the slip interface is formed from the entrapped fluid. An apparatus for a reduced drag surface includes the reduced drag surface described above and a source of fluid fluidically coupled to the surface such that the source supplied fluid to the surface to form the entrapped fluid.