Patent ID: 7225946
Filing Date: 2007-06-05
Classification: B05B,B29B,F04B

Abstract:
1. A method of continuously and uniformly dispensing pressurized fluids, such as viscous fluids, from a common dispensing outlet fed from a dispensing system comprising a pair of alternately filling and emptying fluid-dispensing pumps, each connected to the dispensing outlet, that comprises, slowing the dispensing from the emptying pump while accelerating the dispensing from the filled pump to switchover thereto; refilling the emptied pump during the switched over dispensing of the other pump; and maintaining a constant system pressure during the switchover of the dispensing from one pump to the other to insure a predetermined constant dispensing rate at said outlet, wherein the dispensing pumps are positive displacement piston pumps driven by microprocessor-controlled respective step motors, each piston being driven independently by closed-loop step motor control to achieve accurate dispensing and verify performance, wherein said slowing and accelerating of the respective pump dispensing to said common outlet is effected by respective microprocessor-control of respective valves responsive to the continual sensing of pump fluid pressure and of fluid filling therein, and wherein said valves have multiple-way valving operation comprising a Fill position, wherein the refilling of the empty pump is started; a Dispense position wherein the emptying pump dispensing is decelerated by its step motor, while the filled pumps dispensing starts to accelerate under the action of its step motor; and a Partial position, wherein the filled pumps is first just exposed to the dispensing pressure and, if the same, then opens to the Dispense position.