Patent ID: 8419340
Filing Date: 2013-04-16
Classification: E02F

Abstract:
1. A working machine comprising: a frame; a drive section mounted to the frame for contacting a ground surface, rotation of a portion of the drive section enabling forward and rearward movement of the frame relative to the ground surface; a body section mounted to the frame for pivotal movement generally about a vertical axis which extends generally vertically, the body section at least including a prime mover for powering the drive section; a boom unit having a plurality of booms telescopically extendable from and retractable to one another; a support arm mounted to the body section for pivotal movement about a first horizontal axis which extends generally horizontally, an end of the support arm being coupled with a basal boom which is one of the booms, the basal boom being pivotable relative to the support arm about a second horizontal axis which extends generally horizontally; a first hydraulically operable device having a piston rod connected to the basal boom for pivoting the basal boom relative to the support arm about the second horizontal axis; a guide rail fixed to the basal boom and extending along the longitudinal axis of the boom unit; a bracket movably received in the guide rail and extending along a longitudinal axis of the boom unit; and wherein the bracket has a first pin through which the basal boom is coupled to the support arm for pivotal movement about the second horizontal axis; and wherein the bracket is movable along the guide rail and fixable at a rear location and at a front location such that the basal boom projects further forward relative to the body section when the bracket is located in the rear location than when the bracket is located in the front location.