| 摘要 |
<p>The outer panels of the composite board enclose a reinforcement of laths set on edge and spaced by wood blocks at intervals. At the edges of the board, the reinforcement is covered by a solid wood edging. The outer panels may be composed of several thicknesses, esp. including, heat and a sound-insulating layers; pref. of glass wool, polystyrene foam, or cork. The reinforcement may include channel iron, and may be in two layers. Board may be bowed in mfr., so as to straighten under load. Two of the boards may be hinged together, and wood blocks attached to form a rigid structure.</p> |
