| 摘要 |
MOUNTING METHOD AND SUPPORT FOR A DOUBLE DRUM RAISING AND LOWERING SYSTEM A UNIQUE METHOD OF MOUNTING AND SUPPORT FOR TWO INDEPENDENT SINGLE DRUM WINCHES TO CONSTRUCT A SELFCONTAINED DOUBLE DRUM RAISING AND LOWERING DEVICE COMMONLY USED IN HIGH MOUNTED LIGHTING SYSTEMS TO BRING ILLUMINATION SYSTEMS OR LUMINAIRE ASSEMBLIES DOWN TO THE GROUND FOR MAINTENANCE. SUCH RAISING AND LOWERING DEVICES ARE GENERALLY MOUNTED INSIDE ON THE BOTTOM OF A HOLLOW POLE OR TOWER TO RAISE OR LOWER LUMINAIR ASSEMBLIES VERTICLE ALONG THE EXTERIOR BY USE OF STEEL CABLES CONFINED WITHIN THE HOLLOW OF SAID POLE OR TOWER.
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