Control system for valveless metering pump

A method of controlling the rotational speed of the piston of a metering pump, comprising the steps of:

• a. generating an enabling signal operative for rotating a piston;
• b. after a preselected time delay, producing a first control signal in response to the presence of the enabling signal, said first control signal operative for rotating the piston at a first controlled speed;
• and
• c. producing a second control signal in response to a preselected angular position of rotation of the piston, said second control signal operative for rotating the piston at a second controlled speed.

A control system for controlling the speed of rotation of a rotating piston in a pump as the piston cycles sequentially from an inlet port to a first outlet port and a second outlet port and to the inlet port, comprising:

• a. means for monitoring the angular rotational position of the piston and operative for producing a signal when said piston is at a preselected angle of rotation;
• b. means associated with the pump and operative for driving the piston at a first controlled speed of rotation when it is in a first preselected angular position;
• and
• c. means for driving the piston at a second controlled speed of rotation when it is in a second preselected angular position.

A control system for controlling the speed of rotation of the rotating piston of a metering pump as the piston cycles sequentially from an inlet port of the pump to a first outlet port and a second outlet port and back to the inlet port, in sequence, comprising:

• a. monitoring means associated with the piston for monitoring the position of angular rotation of the piston and adapted for producing a signal in response to movement of the piston to a preselected angle of rotation;
• b. means for generating an enabling signal adapted for activating the pump cycle;
• c. drive means responsive to the presence of an enabling signal for driving and rotating the piston of the pump in a first direction at a first controlled speed;
• and
• d. speed control means responsive to the monitoring signal for producing a second control signal for altering the speed of rotation of the piston to a second controlled speed.