| 摘要 |
PURPOSE:To cover an exposed valve with a simple method at low cost by combining a belt-like board formed with the proper number of foamed insulating boards connected in series and bonded with metal foil on both up and down sides, with a pair of split- molded side boards equally formed with foamed insulating boards bonded with metal foil on both sides. CONSTITUTION:On the upper surface of a belt-like sheet of metal foil 1a, the first formed insulating boards 2a that become the bottom when assembling, are positioned in the center, the second foamed insulating boards 2b that become the front and the back parts on the both sides of the first boards, and the third foamed insulating boards 2c that become the top surface are positioned further on the outside of the second boards, each bonded to the foil 1a. Square grooves 3 are provided at the connecting parts of the foamed insulating boards, which are then bonded with a sheet of metal foil respectively, and on the outer ends of the third foamed insulating boards are provided mutually mating projected and recessed tongues 4a and 4b. Grooves 5a and 5b are provided both on fore and back ends of each boards, while on both fore and back ends of the metal-foil sheet 1a are provided folding parts 6a and 6b. The belt-like cover board 7, thus formed, is assembled into a case, and a split-mold side boards are mounted on both right and left openings. |
