Liquid oscillator having control passages continuously communicating

Abstract

In a clothes washer, liquid pulses are delivered to a bucket or tank of water to create continuously recirculating flow therein in a vertical plane. The flow carries the clothes in a tumbling action and the pulses agitate the clothes passing the pulse source. Air is introduced into the water pulses and forms air bubbles in the tank which attract dirt particles and carry them to the surface where they are removed as part of a continuous surface overflow. In a preferred embodiment the liquid pulses are delivered by a novel fluidic oscillator of the feedback type in which air is continuously entrained by the power stream from each feedback passage in alternation. In one form, the oscillator utilizes scoop-type feedback passages between respective outlet passages and control ports, each feedback passage communicating with an air passage. Feedback liquid is aspirated by the power stream toward one control port at a relatively low flow rate via the active feedback passage; air is aspirated to the other control port via the inactive feedback passage at a substantially higher flow rate to thereby switch the oscillator power stream away from the latter control port. In a second form of oscillator the feedback passages are of the suction type which are aspirated by the liquid outflow through respective oscillator outlet passages. The air passages are in the form of standpipes extending to above the surface and connected to respective control ports from levels below the surface. The standpipe for the inactive outlet is filled with water to the surface level and blocks air flow to one control port; the standpipe for the active outlet is drained by aspiration through that outlet and unblocks air flow to the other control port. The differential pressure across the control ports, created by the different flow media, causes switching of the oscillator power stream and a reversal of standpipe conditions.