David M Larson

US Patent:

6874925, Apr 5, 2005

Filed:

Mar 6, 2003

Appl. No.:

10/382379

Inventors:

David J. Page - Painesville OH, US
David B. Larson - Huntington Beach CA, US
Joseph Lee Diamond - Rancho Santa Margarita CA, US

Assignee:

Lumitex, Inc. - Strongsville OH

International Classification:

F21V007/04
G02B006/04

US Classification:

362554, 362556

Abstract:

Fiber optic light panel assemblies include a panel member having one or more layers of individual optical fibers arranged in close proximity to each other. One or more of the optical fibers may be completely severed adjacent the light receiving end of the panel member to prevent any light entering the light receiving end from being transmitted through the severed optical fibers. At least some of the severed optical fibers may extend along one or more side edges of the panel member and/or intermediate the side edges. A slot may extend through an unlighted end of the panel member toward the light receiving end intermediate the side edges that sever a number of the optical fibers at the innermost end of the slot. The panel member may also be cut into a plurality of smaller width panel sections to provide gaps between the panel sections. One or both ends of the panel member (including any smaller width panel sections) and/or any severed ends of the optical fibers may be masked with a light absorbent material to absorb any light emitted therefrom.

US Patent:

42365686, Dec 2, 1980

Filed:

Dec 4, 1978

Appl. No.:

5/966070

Inventors:

David L. Larson - Chagrin Falls OH

Assignee:

Sherwood Refractories, Inc. - Cleveland OH

International Classification:

B22C 100

US Classification:

164 41

Abstract:

Partially devitrified silica cores with exceptional high temperature strength are disclosed for foundry use in sand casting of ferrous alloys. Precision cored holes of small size and long length, which heretofore could not be cast accurately or had to be machined because of limitations in existing core technology, are formed using accurately machined extruded porous silica cores fired to eliminate combustibles and partially devitrified (e. g. , 15 to 30%) to develop a strong crystalline phase bond that resists viscous flow at a temperature of 1500. degree. C. and to increase the refractoriness of the vitreous silica grains, whereby the permeability and thermal shock resistance are such that the core can be heated very rapidly by molten steel to above 1500. degree. C. without spalling, cracking, sagging, breaking, or loss of integrity and without gas holes, scabs, fissures or other serious casting defects. The cores are made from an extrudable composition containing vitreous silica, a mineralizer, an organic binder, and a plasticizer and/or tempering fluid.

US Patent:

43523900, Oct 5, 1982

Filed:

Sep 12, 1980

Appl. No.:

6/186415

Inventors:

David L. Larson - Chagrin Falls OH

Assignee:

Sherwood Refractories, Inc. - Cleveland OH

International Classification:

B22C 100

US Classification:

164351

Abstract:

Partially devitrified silica cores with exceptional high temperature strength are disclosed for foundry use in sand casting of ferrous alloys. Precision cored holes of small size and long length, which heretofore could not be cast accurately or had to be machined because of limitations in existing core technology, are formed using accurately machined extruded porous silica cores fired to eliminate combustibles and partially devitrified (e. g. , 15 to 30%) to develop a strong crystalline phase bond that resists viscous flow at a temperature of 1500. degree. C. and to increase the refractoriness of the vitreous silica grains, whereby the permeability and thermal shock resistance are such that the core can be heated very rapidly by molten steel to above 1500. degree. C. without spalling, cracking, sagging, breaking, or loss of integrity and without gas holes, scabs, fissures or other serious casting defects. The cores are made from an extrudable composition containing vitreous silica, a mineralizer, an organic binder, and a plasticizer and/or tempering fluid.