Phase adjustable metering pump, and method of adjusting the flow rate thereof

A method of adjusting the flow rate into or out of a valveless, positive displacement metering pump of the type including a housing, a cylindrical working chamber within said housing, a piston rotatably and slidably positioned within said working chamber, said piston including a duct defined by an outer surface portion of said piston, a first port extending into said housing and communicating with said working chamber at a first radial position, a second port extending into said housing and communicating with said working chamber at a second radial position, means for causing said piston to move in back and forth strokes along an axis within said working chamber, and means for rotating said piston within said working chamber as said piston moves back and forth within said working chamber such that said duct is in sequential communication with said first and second ports, respectively, comprising:

• changing the relative positions of said working chamber and said piston such that said duct communicates with each of said ports during different phases of the rotational and back and forth movements of said piston within said working chamber, the step of changing the relative positions of said working chamber and said piston including the step of rotating said housing from a first position to a second position with respect to said piston such that said duct communicates with each of said ports during different phases of said rotational and back and forth movements of said piston in said second position than in said first position.

A valveless, positive displacement metering pump comprising:

• a support;
• a drive cylinder rotatably mounted within said support, said drive cylinder including an axis of rotation;
• a housing secured to said support;
• a cylindrical working chamber defined within said housing, said working chamber including an axis;
• a piston positioned within said working chamber, said piston including a duct defined by a portion of an outer surface of said piston;
• means for pivotably connecting said piston to said drive cylinder;
• a first port extending within said housing and in fluid communication with said working chamber;
• a second port extending within said housing and in fluid communication with said working chamber;
• means for rotating said housing with respect to said support and about the axis of said working chamber;
• and
• means for securing said housing in a selected rotational position with respect to said support;
• said housing being secured to said support in a fixed, permanently immovable angular position with respct to said support such that the axis of said working chamber is at a fixed, permanently immovable angle with respect to the axis of rotation of said drive cylinder.