Patent ID: 7837451

Claim:
A positive displacement capture device; comprising: a casing portion having a plurality of grooves formed on an inner surface of said casing portion; and a rotor portion having a plurality of lobes formed on an outer surface of said rotor portion, where said rotor portion is positioned adjacent to said inner surface of said casing portion such that said lobes interact with said grooves; wherein said interaction of said lobes with said grooves creates a plurality of contact points between said lobes and grooves which travel around a perimeter of; and along a length of, said rotor portion as said rotor portion rotates about an axis relative to said casing portion; and wherein said interaction captures a volume of material and moves said volume along a length of said device due to said relative rotation, and wherein there is no physical contact between said lobes and said grooves at said contact points and a portion of either of said lobes or said grooves has a plurality of depressions on a surface thereof where said contact points occur.