Dust collector

A cyclone dust collector comprising:

• an airtight shell;
• a horizontal dividing plate mounted in said shell and dividing the interior of said shell into upper and lower dust chambers;
• suction means communicating with said upper dust chamber;
• a communicating duct extending downward into said lower chamber from said dividing plate and comprising means for providing air flow communication between said upper and lower chambers;
• tangential air inlet means in said lower chamber, whereby said suction means can cause dust laden air to enter said lower chamber through said air inlet means and form a cyclone flow therein;
• a cyclone drum in said lower chamber and having a circumferential surface, an unrestricted open top end and a closed bottom end;
• means for supporting said cyclone drum in said lower chamber such that an air gap is formed between said plate and an edge of said circumferential surface at said open top end, said air gap being dimensioned such that swirling air entering said cyclone drum therethrough is accelerated at said air gap, and such that a bottom of said communicating duct extends into said cyclone drum;
• and
• a horizontal disc supported in said cyclone drum between said bottom of said communicating duct and said bottom end of said cyclone drum, whereby said cyclone drum is vertically divided into two chambers, a lower one of which is isolated from swirling air in an upper one thereof.