Charles R. Gray

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Coraopolis, PA, US

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Patents Grantslast 30 patents

Information Patent Grant
Method of making a profiled sheet metal building unit
- Patent number 5,056,348
- Issue date Oct 15, 1991
- Robertson-Ceco Corporation
- Raymond E. Albrecht
- E04 - BUILDING
Information Patent Grant
Profiled sheet metal building unit and method for making the same
- Patent number 4,962,622
- Issue date Oct 16, 1990
- H. H. Robertson Company
- Raymond E. Albrecht
- E04 - BUILDING
Information Patent Grant
Field-assembled raceway forming member
- Patent number 4,594,826
- Issue date Jun 17, 1986
- H. H. Robertson Company
- Charles R. Gray
- E04 - BUILDING
Information Patent Grant
Fire-resistant floor structure
- Patent number 4,324,078
- Issue date Apr 13, 1982
- H. H. Robertson Company
- Charles R. Gray
- H02 - GENERATION CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
Information Patent Grant
Electrical activating assembly and closure member therefor
- Patent number 4,289,921
- Issue date Sep 15, 1981
- H. H. Robertson Company
- Rodney W. Gartner
- H02 - GENERATION CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
Information Patent Grant
Fire-resistant electrical wiring distributing floor structure and m...
- Patent number 4,232,493
- Issue date Nov 11, 1980
- H. H. Robertson Company
- Charles R. Gray
- E04 - BUILDING