Telescopic crane jib with plastics bearings - is of angular cross=section at bottom and radiused at top

摘要

The telescopic crane jib incorporates plain bearings of plastics, and its lower part (6) which is subjected to the heavier compression loads is of angular cross-section, while the edges of the upper part (1) are radiused. The bearings (12,9,9') are shaped to fit against the edges on which they act. Internal plain bearings can be used for the top part, these each comprising a rocking member on a transverse axis, and in which a plastics bearing body fit loose, this being prevented from sliding in the lengthwise direction of the member, and shaped to fit against the edge (11) of the top part of the jib.