ELECTRIC CABLE REELING DRUM

摘要

1431277 Gable reels; taking up slack in flexible elements STRAWSON HYDRAULICS (CONSULTANTS) Ltd 28 Aug 1973 [13 Sept 1972] 42509/72 Headings B8M and B8B A cable drum comprises a main drum 12 with an auxiliary drum 28 mounted eccentrically within it, the auxiliary drum 28 carrying windings of a connecting wire for connecting an end of an electric cable 14 wound on the main drum 12 to fixed electrical apparatus 64, the connecting wire extending tangentially from the auxiliary drum to a fixed main bobbin 58 at the centre of the main drum, the arrangement being such that the connecting wire is wound on to or paid off the main bobbin 58 as the main drum 12 rotates. The main drum 12 and the auxiliary drum 28 are preferably provided with spring means 72 and 34 to take up slack in the cable 4 and the connecting wire respectively. The auxiliary drum 28 is preferably of hollow form with several turns of the connecting wire disposed with the auxiliary drum, the said several turns being wound on and off an auxiliary bobbin 30 fixed relative to the main drum 12. The main drum 12 is disposed within a casing 20 which is preferably fixed to an extensible boom crane. The cable 14 passes through an aperture in the surface of the drum 12 and the end thereof is electrically connected to the end of the connecting wire. The cable drum is preferably mounted on an extensible boom crane, the main drum 12 being provided with a steel tape 70 wound on its periphery and connected to the outermost section of the crane boom whereby the main drum is angularly displaced through a distance directly proportional to the length of the boom as the boom is extended or retracted. An electrical proportioning device is preferably provided for giving an electrical signal proportional to the overall length of the extensible crane boom in accordance with the angular displacement of the main drum.