초록 ▼

A pump for boosting pressure of liquid color for injection into plastic resin in molding or extrusion apparatus includes a housing having a first bore extending in a first direction and second and third bores extending through the housing and communicating with the first bore proximate a first end o

A pump for boosting pressure of liquid color for injection into plastic resin in molding or extrusion apparatus includes a housing having a first bore extending in a first direction and second and third bores extending through the housing and communicating with the first bore proximate a first end of the first bore with the first end of the first bore being blind. The pump further includes an inlet check valve connectable to the second bore for permitting liquid flow through the second bore into the first bore. Further included is an outlet check valve connective to the third bore for permitting liquid flow out of the first bore through the third bore. A member is reciprocally axially movable within the first bore. A solenoid applies air pulses to the end of the first member facing oppositely from the blind end of the first bore.

대표청구항 ▼

The invention claimed is: 1. A method for furnishing liquid color at elevated pressure for injection thereof directly into the barrel housing of an extruder screw or an injection molding ram, comprising:a) allowing a chamber to fill with liquid color entering the chamber at a first pressure through

The invention claimed is: 1. A method for furnishing liquid color at elevated pressure for injection thereof directly into the barrel housing of an extruder screw or an injection molding ram, comprising:a) allowing a chamber to fill with liquid color entering the chamber at a first pressure through an inlet;b) closing the inlet;c) energizing a solenoid to move a piston of an air cylinder-piston combination in a direction to contact and advance a free-floating pumping piston along a cylindrical part of the chamber into liquid color occupying the chamber thereby displacing the liquid color at pressure increased from the first pressure out of the chamber via an outlet leading to a barrel housing of an extruder screw or an injection molding ram;d) de-energizing the solenoid so as to permit spring bias to withdraw the piston of the air cylinder-piston combination away from the free-floating pumping piston and thereby permit new liquid color entering the chamber to urge the free-floating pumping piston away from the liquid color displacement position and towards the piston of the air cylinder-piston combination.