Prior to the present invention there have existed various devices which are operated by pressurized fluid-flow streams such as fluid-streams driven motors and such as pest-control jet resonators, merely as typical examples, in which excessive pressure accidentally may injure the motor by bringing about excessive uncontrolled speeds as well as the blowing of gaskets or the like, which also possibly injuring other equipement or persons for which the fluid-driven motor is utilized in that particular instance. Similarly, the excess fluid pressure even momentarily in a jet resonator can exceed tolerances of the equipement, but more importantly with ultrasonic jet resonators utilized in pest control, air or other fluid pressure exceeding 60 pounds can cause ultrasonic sound detrimental to the human ear and even can be fatal to human being in bringing about death while being in a pitch beyond the detection by the human ear in so far as the human being being conscious of the presence of the sound, thereby increasing the potential danger of such resonators to human beings. Additionally, within normal operation of jet resonators for producing ultrasonic sound for pest control, there have existed certain problems.
One problem with regard to the effectiveness of such pest control systems arises from the fact that the control effected in pests such as in rodent control--typically of rats, is that the effectiveness is intended to result from the sound being irritating and bothersome to the rats, which rats thereby, it is hoped, abandon their abode for more pleasant surroundings. As a matter of fact, however, it has been found that the rats are very adaptable to such nuisance sound, adjusting themselve to tolerate and continue to thrive in the presence of such sound.
Also, in order for a jet resonator to produce harmonics, the input air flow must be pulsating. The air source used on typical first jet resonators for a single system was a diaphragm or a piston type compressor. The output of the above-type of compressors were fed directly into the input of the jet resonator without an air reserve tank. The output pressure of these compressors were between 12 and 20 pounds per square inch; for multiple installations it was necessary to use a much larger air compressor to produce a higher air pressure into a reserve tank. The purpose of this was so that many jet resonators could be fed by one central system, each jet resonator being tapped off of a main air line at 100 pound per square inch pressure with a regulator to cut the pressure down to between 12 to 20 p.s.i. pressure. It was noted that the sign wave output of the jet resonator at 20 KHZ was not producing enough harmonics to be effective for the application. While using a single compressor feeding the jet resonator without an air reserve tank, the pulsating of the piston or diaphragm was felt in the resonant cavity of the jet resonator producing a steady air flow, cutting down the amount of harmonics generated.
A typical prior art jet resonator of the type to which the present invention is adaptable, or utilizable with, is disclosed in the U.S. Pat. No. 3,188,999 patented June 15, 1965 to Baxter. However, the present invention is not limited to that particularly disclosed system, as shall be apparent from the preceding and following disclosure.