| 摘要 |
Extendable support means comprises three steel bands (6, 7 ,8) each wound into a coil (3, 4, 5). The free ends of the three steel bands (6, 7, 8) are secured to a common support (16). The steel bands each have a row of slotted perforations adjacent one longitudinal edge and a row of punched out spigots adjacent the other longitudinal edge. As the bands are unwound and fed into the guide (15) by pairs of rollers (11, 12, 13), the punched out spigots of each band engage in the slotted perforations of an adjacent band to form a dimensionally stable triangular profile (14). The extendable support means may, as shown, support a television camera (17), measuring instruments, illuminating means or other tools in otherwise inaccessible areas. <IMAGE> |
