Telescopic boom device

Abstract

A telescopic boom device is constructed of a first boom section 1, a second boom section 2 telescopically received in the first boom section 1, and an extension/retraction cylinder. The boom sections 1,2 are constructed of main parts 1a,2a, boss brackets 1c,2c arranged integrally on ends of the main parts 1a,2a via partitions 1b,2b, slide pad brackets 1e,2e arranged integrally on opposite ends of the main parts 1a,2a via partitions 1d,2d, respectively, bosses 1f,2f arranged on the boss brackets 1c,2c, and slide pads 1g,2g arranged on the slide pad brackets 1e,2e, respectively. The plural slide pads 1g are attached on an inner wall of the slide pad bracket 1e formed larger in the width dimension and height dimension than the main part 1a, and the plural slide pads 2g are attached on an outer wall of the slide pad bracket 2e formed smaller in the width dimension and height dimension than the main part 2a. The telescopic boom device can avoid increases in the dimensions of the cross-sectional contour despite the arrangement of the slide pads 1g, 2g.

Dependencies are inferred from the claim text.