77466753
May 6, 2008
Trench shields made of metal and components thereof for use in providing static support for walls of excavated areas, and bedding boxes made of metal for holding bedding for use in excavated areas and trench shoring made of metal and components thereof for use in providing active support for walls of excavated areas
Metal GoodsDesign of trench shields and trench shoring for providing support for walls of excavated areas, and design of bedding boxes for holding bedding for use in excavated areas
Computer and Scientific