| 摘要 |
<p>Signaling and controlling members of planning boards of the wall type having modular elements, the members comprising coaxial elements 1, 3 having symbols, numbers, letters or colours, the inner element 1 of each member being freely rotatable while the other element 3 surrounds the inner element and is rotatable relatively thereto, the elements 1, 3 being independantly operable, and the outer element 3 having facets 4 in each of which is an opening 5 through which the inner element 1 can be seen, the said surface 7 of the inner element 1 being divided into bands of different colour or other signs.</p> |
