Ultrasonic cleaner

An ultrasonic cleaner for cleaning relatively small articles comprising:

• a metallic receptacle for containing a liquid in which articles to be cleaned are immersed, said receptable having an open top periphery;
• ultrasonic transducer means secured to the bottom of the receptacle and a power circuit including a relatively high power transducer driving circuit for the ultrasonic transducer means;
• a lower housing portion containing the power circuit and ultrasonic transducer means;
• an upper housing portion having a cross-sectional area less than that of the lower housing portion and joined to the lower housing portion by a peripherally extending shoulder, said upper housing portion extending above the lower housing portion to a height greater than the height of the receptacle, said upper housing portion containing the receptable therein and having a top rim which fits over the top periphery of the receptacle to define a top opening into the receptacle;
• a cover having an open end and a cross-sectional area greater than the upper housing portion and having a depth slightly less than the height of the upper housing portion, wherein the cover slides over the upper housing portion and substantially surrounds the upper housing portion when in place;
• means defining spaced projections disposed around said rim of said upper housing portion, wherein said means holds said cover in spaced relation with respect to said rim when the cover is in place over the upper housing portion;
• a magnet secured to the cover adjacent the open end thereof;
• and
• a low-power magnetic reed switch which is positioned adjacent said shoulder so that when said cover is in place over the upper housing portion, the magnet will close the magnetic reed switch and thereby allow said power circuit to energize said ultrasonic transducer means to operate the ultrasonic cleaner.