Interlock control for hydraulic circuit valves - has arms formed as bell cranks with pivotal connections at corners and diagonal bar joining ends of shorter limbs

摘要

Two valves (14, 14') are installed in parallel pipes (10, 10') of a hydraulic circuit to control the flow to the common pipe (12). Each valve has an actuating lever (18, 18') with a ball handle (24, 24'). A bar (20, 20') extends from each ball at right angles to its lever. The ends of these bars are connected by a link (26). When the valve (14) is fully open the lever (18) has rotated through 90 deg. so that the cross link (28) and the bar (20') lie in a straight line. The lever (18') of the valve (14') is thus locked in its closed position and cannot be actuated. The same effect occurs if the other valve (14') is opened in that the first valve (14) is locked in the closed position.