To enable the lowering speed of a suspended cargo to be safely and reliably controlled without paying attention to the amount of depressing operation of a brake pedal.
In a winch drum 2, a brake unit 5 is stored which includes an inner disc 17 and an outer disc 18 to abut on each other with a planetary reduction mechanism 4 and a resilient body 24 to be driven by a hydraulic motor 3. A hydraulic cylinder 6 is provided for attaching/detaching the inner disc 17 and the outer disc 18 of the brake unit 5 to/from each other, and chambers 20, 21 are formed on both axial sides of a piston 22 of the hydraulic cylinder 6 to supply pressure oil. A brake valve 28 is provided on the way of a hydraulic duct 29 which supplies the pressure oil to the chamber 21. A position holding bolt 46 is provided on the brake pedal 30 which operates the brake valve 28, so that the brake pedal 30 holds a half-braking condition during the half-braking of the brake unit 5.
NAKAJIMA TAKASHI
ONO HIROYUKI
ENOMOTO YUTAKA
| JPH11130381A | 1999-05-18 | |||
| JP2003238079A | 2003-08-27 |