Liquid color injection pressure booster pump and pumping methods

• US 20070292290A1
• Filed: 06/16/2006
• Published: 12/20/2007
• Est. Priority Date: 06/16/2006
• Status: Active Grant

• Current Assignee: Stephen B. Maguire
• Original Assignee: Stephen B. Maguire
• Inventors: Maguire, Stephen B.
• Granted Patent: US 7,980,834 B2
• Time in Patent Office: Days
• US Class Current: 417/568
• CPC Class Codes: F04B 15/02 the fluids being viscous or non-homogeneous
• CPC Class Codes: F04B 53/14 Pistons, piston-rods or piston-rod connections
• CPC Class Codes: F04B 53/16 Casings; Cylinders; Cylinder liners or heads; Fluid connections
• CPC Class Codes: F04B 9/127 rectilinear movement of the pumping member in the working direction being obtained by a single-acting elastic-fluid motor, e.g. actuated in the other direction by gravity or a spring

Abstract

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.

Claims

1. A pump for boosting pressure of liquid color for injection into plastic resin in molding or extrusion apparatus, comprising:

a) a housing having an elongated 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 thereof, the first end of the first bore being blind;

b) an inlet check valve communicating with the second bore for permitting liquid flow through the second bore into the first bore but blocking liquid flow out of the first bore through the second bore;

c) an outlet check valve communicating with the third bore for permitting liquid flow out of the first bore through the third bore but blocking liquid flow into the first bore through the third bore; and

d) a pumping piston reciprocally movable within the first bore;

whereby when a source of liquid color is connected to the inlet check valve and liquid color flows through the second bore past the inlet check valve and into the first bore and the pumping piston advances, the liquid color is driven from the first bore through the third bore and past the outlet check valve into plastic resin in the molding or extrusion apparatus.

2. The pump of claim 1 wherein the inlet check valve is connected to the second bore.

3. The pump of claim 1 wherein the outlet check valve is connected to the third bore.

4. The pump of claim 1 wherein the check valves are within the housing.

5. The pump of claim 1 wherein the check valves are outside of the housing.

6. The pump of claim 1 wherein the pumping piston is pneumatically driven.

7. The pump of claim 1 wherein the pumping piston is mechanically driven.

8. The pump of claim 1 wherein the pumping piston is indirectly pneumatically driven.

9. The pump of claim 1 wherein the housing is a casting.

10. The pump of claim 1 further comprising an air cylinder/solenoid combination driving the pumping piston on the pumping stroke.

11. The pump of claim 1 further comprising an annular seal positioned about the pumping piston with the pumping piston being slidably movable therewithin, for sealing the first bore against liquid color leakage therefrom along the surface of the pumping piston.

12. A method for elevating pressure of liquid color to enable injection thereof directly into the barrel housing an extruder screw or an injection molding ram, comprising the steps of:

a) filling a chamber with liquid color flowing into the chamber under pressure through an inlet;

b) closing the inlet; and

c) advancing a piston into the liquid color in the chamber thereby reducing the volume of the chamber displacing the liquid color at such increased pressure out of the chamber via an outlet leading to the barrel housing the extruder screw or the molding ram.

13. The method of claim 12 wherein advancing the piston is performed pneumatically.

14. The method of claim 12 further comprising serially closing the outlet, opening the inlet and repeating steps (a), (b) and (c) in sequence for so long as liquid color at elevated pressure is required for direct injection into the barrel housing of an extruder screw or of an injection molding ram.

15. The method of claim 12 wherein the chamber has a cylindrical portion, the piston is cylindrical and slidably reciprocable within the cylindrical portion of the chamber towards and away from a blind chamber end, where the inlet and outlet to and from the chamber are at the chamber blind end.

16. The method of claim 12 wherein closing the inlet further comprises placing a first check valve in an inlet passageway emptying into the chamber at the inlet in a position permitting flow into the chamber but precluding flow out of the chamber via the inlet passageway.

17. The method of claim 12 wherein closing the outlet further comprises placing a second check valve in a discharge passageway exiting the chamber at the outlet in a position permitting flow from the chamber but precluding flow into the chamber via the discharge passageway.

18. The method of claim 16 wherein closing the outlet further comprises placing a second check valve in a discharge passageway exiting the chamber at the outlet in a position permitting flow from the chamber but precluding flow into the chamber via the discharge passageway.

19. Apparatus for boosting pressure of liquid color for injection into plastic resin in molding or extrusion apparatus, comprising:

a) a housing having an interior cavity and a pair of passageways extending through the housing and communicating with the cavity proximate one another;

b) means communicating the first passageway for permitting liquid flow through the first passageway into the cavity but blocking liquid flow out of the cavity through the first passageway;

c) means communicating with the second passageway for permitting liquid flow out of the cavity through the second passageway but blocking liquid flow into the cavity through the second passageway; and

d) a pumping member movable reciprocally in the cavity;

whereby when liquid color is connected to the means communicating with the first passageway and liquid color flows therepast and into the cavity through the first passageway and the pumping member advances against the liquid color in the cavity, the pressure of the liquid color increases, driving the liquid color from the cavity through the second passageway and past the liquid flow permitting/blocking means communicating therewith, into plastic resin in the molding or extrusion apparatus.

20. Apparatus of claim 19 wherein the means for permitting/blocking flow are connected to the housing.

21. Apparatus of claim 19 wherein the pumping member is pneumatically powered on the pumping stroke.

22. Apparatus for boosting pressure of liquid color prior to injection into plastic resin being processed in molding or extrusion apparatus, comprising:

a) a housing having an interior cavity with passageways through the housing and communicating with the cavity proximate one another;

b) means for permitting liquid flow through the first passageway only into the cavity;

c) means for permitting liquid flow only out of the cavity; and

d) a member slidably advancable into the cavity;

whereby when liquid color is connected with the first passageway and flows therethrough into the cavity and the member advances into the liquid color, liquid color pressure in the cavity increases, driving liquid color from the cavity through the second passageway to mix with plastic resin in the molding or extrusion apparatus.

23. A method for elevating pressure of liquid color to enable injection thereof directly into the barrel housing an extruder screw or an injection molding ram, comprising the steps of:

a) allowing a chamber to fill with liquid color entering into the chamber under pressure through an inlet;

b) closing the inlet; and

c) advancing a member into the liquid color in the chamber thereby displacing the liquid color at increased pressure out of the chamber via an outlet leading to the barrel housing the extruder screw or the molding ram.

24. The method of claim 23 wherein advancing the member is performed pneumatically.

25. The method of claim 23 further comprising repeating steps (a), (b) and (c) in sequence for so long as liquid color at elevated pressure is required for direct injection into the barrel housing of an extruder screw or of an injection molding ram.