This alternate circuit for actuating a double-acting cylinder, replaces the pressure regulator with an air-piloted 3-port toggle valve.
An alternate circuit uses an air piloted, normally open 3-way valve, D, instead of the regulator. When valve A is actuated, air flows through the check valve and fills the volume tank. Pressurized air also flows through the pilot line to close valve D. This opens the rod-end port of the cylinder to atmosphere. At the same time, air flows into the cap end of the cylinder, extending the piston and raising the owl.
Toggling valve A closed allows air in the cylinder’s cap end to exhaust to atmosphere. This action also terminates pilot pressure to valve D, so it opens the air in the volume tank to the rod end of the cylinder. As a result, the piston retracts, lowering the owl.
Boutell mentioned that to keep the pigeons away, the valve is periodically toggled open and closed throughout the workday. “Eventually, we’d like to install a motion detector and timer on the roof. That way, whenever a pigeon landed on the roof, the motion sensor would send a signal to a solenoid valve, which would pop up the owl. After a while, the timer would toggle the valve back closed, and the owl would again disappear into the pipe. But the problem seems to be solved, so if we go the higher-tech route, it’ll be mainly for our own satisfaction.”
For more information on Clippard's valves, cylinders, and other components, call (513) 521-4261, or visit www.clippard.com.