All-pneumatic oscillating valves for applications such as shaking, wiping, feeding, hammering, plunging, scraping, winding, raking, diverting, spraying, cleaning and dipping are now available from Hoerbiger-Origa. Pneumatic logic elements are mounted at each end of the main body of the valves and configured to provide constant switching of the air supply to create the oscillating effect. Two adjustable flow controls adjust the piston’s speed. Stroke is set by the cylinder’s length or by adjustable physical stops. At maximum stroke the back pressure will decay and the logic elements will switch the valve to reverse stroke. Based on a 5/2 spool valve, in use the outlet ports (4 and 2) of the oscillating valve are alternately supplied with air from the inlet port.
The valve is biased to one position, so that if the air is switched off mid-cycle (with air-off it can not complete its cycle) when restarted the valve will initially travel to i’s “home” or “biased” position. Because they do not use a solenoid or other electrical devices, there is no possibility of sparking during operation. This makes the valves particularly suited to explosive atmospheres and remote locations where there is no electricity supply.