| 摘要 |
<p>A manual display board system for charts, and instant signs having a background board (10) bonded to a backing sheet of particle board (11) and of magnetically attractive steel sheet (12) with parallel, profiled grooved tracks (13) extending transversely across the board (10) and formed by laminating thin strips of steel (14) onto the board (10); magnetic display indicia carrier bars (16) of ferrite impregnated nylon have an indicia supporting ledge (19) in the lower edge of the flat front surface (17) and a groove-engaging rib (20) extending along the flat rear surface (18) of the carrier bar (16); the bars are magnetized with front to rear, or rear to front polarity and alternate bars have reversed front to rear, or rear to front polarity for synergistic magnetic adhesion to the board when used in close parallel proximity.</p> |
