SAFETY DEVICE FOR HYDRAULIC LIFT MECHANISM

摘要

PURPOSE:To prevent the damage of a hydraulic case or a transmission case, by switching a relief valve mechanism to a state of low-pressure relief when a passive arm is in a contact and stop state. CONSTITUTION:A relief valve mechanism is made to be actuated when a passive arm 13 is stopped by contacting with a hydraulic case or a part attached to a hydraulic case and is switched between a high-pressure relief state and a low-pressure relief state. When the passive arm is stopped by contacting with the above case, etc., the relief valve mechanism is automatically switched to the low-pressure relief state and when the passive arm is separated from the hydraulic case, the relief valve mechanism is switched to the high-pressure relief state.