Telescoping boom assembly with longitudinally displaceable base boom

Abstract

Apparatus for providing additional effective length to the telescoping boom of a material handling apparatus is provided. A pivotable boom cradle is supported on an upper structure of the material handling apparatus. The boom cradle pivotally supports the base boom section by means of front and rear cradle arms. Front and rear straps are provided to attach the boom to the cradle arms. In addition, front stop blocks are provided intermediate the length of the base boom section while rear stop blocks are provided adjacent the trailing end thereof. In normal operation, bolts secure the front stop blocks to the front portion of the boom cradle. When it is desired to operate with an additional entended length of the boom, the material handling implement is imbedded in the ground, the bolts securing the front stop blocks to the boom cradle are removed and the bolts securing the front and rear straps to their respective cradle arms are loosened. The boom is then retracted which effectively causes the base section thereof to move forward toward the material handling implement while sliding on the front and rear cradle arms until the rear stop blocks engage the rear cradle arm. The bolts removed from the front stop blocks are secured between the rear stop blocks and the rear cradle arm and the bolts on the front and rear securing straps are tightened thereby readying the material handling apparatus for operation with an additional length of boom.