Fail Safe Valve for Air Cylinder Counter Balance Systems
Original Publication Date: 1987-Apr-01
Included in the Prior Art Database: 2005-Feb-01
This article describes a system utilizing a normally-closed (NC) air- pilot-operated valve between a self-venting regulator and the input port of an air cylinder which controls the decent of the Z-arm of a robot. Air cylinders are used as counter balance to support the Z arms of robots. An arm can approximate fifty pounds in weight. During unplanned air losses, an arm can fall rapidly causing severe damage to the end effector, the tooling and the product. This results in costly repairs and downtime. By installing a NC air-pilot-operated valve between the self-venting regulator and the input port of the air cylinder, the rapid decent of the Z-arm will be prevented. The system disclosed herein is shown in the drawing. The valve is installed in the cylinder air line.