David Putnam

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Calhoun, LA, US

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Patents Grantslast 30 patents

Information Patent Grant
Traffic-compatible vented precipitation guarding manhole cover asse...
- Patent number 11,118,323
- Issue date Sep 14, 2021
- David Putnam
- E05 - LOCKS KEYS WINDOW OR DOOR FITTINGS SAFES
Information Patent Grant
Vented precipitation guarding manhole cover assemblies
- Patent number 9,605,403
- Issue date Mar 28, 2017
- David Putnam
- E02 - HYDRAULIC ENGINEERING FOUNDATIONS SOIL SHIFTING
Information Patent Grant
Manhole cover venting and precipitation guarding devices
- Patent number 8,851,791
- Issue date Oct 7, 2014
- David Putnam
- E02 - HYDRAULIC ENGINEERING FOUNDATIONS SOIL SHIFTING