| 摘要 |
<p>A truck mounted crane has a three-part, extensible boom in which telescopic motion is accomplished by a pair of extension cylinders contained within the boom. Frictional forces between the slidably mounted boom sections are minimized by improved pad assemblies positioned at selected bearing points. Support members in the form of rollers are positioned within the boom immediately above the lower extension cylinder to not only prevent the extension cylinder from buckling under full load conditions, but to support the outer boom section when it is retracted inward. The result is a reduction in the size and weight of the extension cylinders and a consequent reduction in boom weight.</p> |
