Patent ID: 8057197

Claim:
A pump for dry particulate material, comprising: a pump chamber defined in part by a gas permeable member; a manifold body having a bore, a first air passage, a second air passage, and a third air passage, said gas permeable member being disposed in said manifold body bore, said manifold body bore having at least one inlet in fluid communication with said first air passage; a transparent body comprising a bore and a transparent body air passage, said transparent body bore being in fluid communication with at least one of said second and third air passages of said manifold body through said transparent body air passage; a first pinch valve and a second pinch valve, wherein each said pinch valve comprises a member having an internal material passage that defines part of a flow path for particulate material through said pump, said flow passage passing through said pump chamber, wherein one of said first and second pinch valve members is disposed in said transparent body bore, and wherein said pinch valve members operate in response to external pressure applied thereto from said second and third air passages respectively to control the flow of material into and out of said pump chamber, and wherein during pump operation particulate material flows into said pump chamber under negative pressure applied to said manifold body bore through said at least one inlet and material flows out of said pump chamber under positive pressure applied to said manifold body bore.