JPH0416789U - - Google Patents

Description

[Brief explanation of the drawing]

1 to 3 show a telescopic boom implementing the telescopic device of the present invention, FIG. 1 is a longitudinal sectional view of the telescopic boom in an extended state, FIG. 2 is a plan view of the telescopic boom, and FIG. The figure is a longitudinal sectional view of the telescopic boom in a contracted state. FIG. 4 is an explanatory diagram of a work vehicle equipped with a conventional telescopic boom. 4...Telescopic boom, 4a...Base end boom section, 4b...Telescopic boom section, 6...Double acting cylinder, 6a...Cylinder part, 6b...Piston rod, 7...Moving pulley for extension drive, 7a, 7
b, 9a, 9b...Pulley, 8...Wire rope for extension, 9...Moving pulley for reduction drive, 10...Wire rope for reduction.

Claims (1)

[Claims for Utility Model Registration] A telescoping boom that is attached to the tip of a foundation boom so that it can be raised and lowered, particularly a long telescoping boom section that is telescopically inserted into a relatively short proximal boom section. A telescoping device used in a telescoping boom configured such that when the section is in a contracted state, a base end of the telescoping boom section protrudes from a base end of the proximal boom section, the cylinder portion of which is telescoping. A double-acting cylinder whose tip end of the piston rod is fixed to the tip of the base boom section so as to be located on the base end side of the boom, and is disposed between the base boom section and the telescopic boom section, and the most A double-acting cylinder in which the base end of the cylinder part is housed in the base boom section in the contracted state and the base end of the cylinder part protrudes from the base end of the base boom section in the fully extended state. A movable pulley for extension drive disposed at the distal end of the cylinder part, a position on the proximal boom section on the proximal end side of the movable pulley for extension drive in the most extended state of the double-acting cylinder, and a movable pulley for extension drive. and then pulled out from the extension drive movable pulley,
A wire rope for extension whose tip end on the drawer side is fixed to the base end of the telescopic boom section, a movable pulley for contraction drive attached to an appropriate position on the cylinder part of the double-acting cylinder, and the double-acting cylinder in its most contracted state. The movable pulley for reduction drive is suspended between a position on the proximal end boom section on the distal side of the movable pulley for reduction drive and the movable pulley for reduction drive, and is pulled out from the movable pulley for reduction drive, and is pulled out from the movable pulley for reduction drive, and is pulled out from the movable pulley for reduction drive; a retracting wire rope fixed to the tip of the telescopic boom section; the retractable boom extends when the double-acting cylinder is retracted; A telescoping device for a telescoping boom, characterized in that it is configured to.