Two stage flow through seal pin

Patent metadata

Field	Value
Publication number	US-10739883-B2
Application number	US-201314900018-A
Country	US
Kind code	B2
Filing date	Jun 28, 2013
Priority date	Jun 28, 2013
Publication date	Aug 11, 2020
Grant date	Aug 11, 2020

Abstract

A nozzle and system for hydraulic blow molding of a plastic container from a preform. The nozzle includes a nozzle body having a main bore extending therethrough and a seal pin received in the main bore and moveable between a closed position and an opened position. The seal pin include a central bore extending from an entrance orifice to an exit orifice, with the entrance orifice opening into the main bore of the nozzle body.

First claim

We claim:

1. A nozzle for hydraulic blow molding of a preform into a plastic container, the nozzle comprising:
a nozzle body having a main bore extending therethrough from an inlet to a outlet, portions of the main bore defining a valve seat;
a seal pin received in the main bore and moveable between a closed position and an opened position, the seal pin including portions defining a sealing surface and further having a central bore extending therethrough from a entrance orifice to a exit orifice, the entrance orifice opening into the main bore; and
a valve associated with the central bore, the valve being moveable between an open position and a closed position, in the closed position, the valve preventing the flow of a molding medium in liquid form through the central bore and into the preform.

2. The nozzle of claim 1 , wherein the central bore includes a central portion that is coaxial with the main bore and a plurality of lateral passageways, the lateral passageways extending laterally from the central portion and each defining a part of the entrance orifice and being located on an exterior surface of the seal pin.

3. The nozzle of claim 2 , wherein the lateral passageways extend obliquely from the exterior surface toward the central portion of the central bore.

4. The nozzle of claim 3 , wherein the lateral passageways converge in a direction toward the exit orifice.

5. The nozzle of claim 2 , wherein the lateral passageways extend perpendicularly from the exterior surface of the seal pin to the central portion of the central bore.

6. The nozzle of claim 2 , wherein the valve is a plug rod, the plug rod being axially moveable within a central portion of the central bore.

7. The nozzle of claim 6 , wherein the plug rod is axially moveable within the central portion of the central bore.

8. The nozzle of claim 7 , wherein the plug rod in one position extends over interfaces of the lateral passageways with the central portion of the central bore thereby sealing off the lateral passageways from the central portion and in another position does not extend over the interfaces allowing the lateral passageways to communicate with the central portion.

9. The nozzle of claim 2 , further comprising a flow straightener positioned within the central part of the central bore.

10. The nozzle of claim 9 , wherein the flow straightener is located adjacent to the interface of the lateral passageways with the central part.

11. The nozzle of claim 1 , wherein the valve is a plug rod, the plug rod being axially moveable within a portion of the central bore.

12. The nozzle of claim 1 , wherein the exit orifice defines a diameter that is smaller than a diameter of the outlet.

13. The nozzle of claim 1 , wherein the exit orifice is coaxial with the outlet.

14. The nozzle of claim 1 , wherein the exit orifice defines a spray angle of less than 5°.

15. The nozzle of claim 1 , wherein the exit orifice defines a spray angle of about 0°.

16. The nozzle of claim 1 , further comprising a flow straightener positioned within the central bore.

17. The nozzle of claim 16 , wherein the flow straightener is spaced apart from the exit orifice.

18. The nozzle of claim 17 , wherein the flow straightener defines a plurality of sub-passageways within the central bore.

19. The nozzle of claim 17 , wherein the sub-passageways are defined by at least one of a plurality of vanes oriented radially within the central bore, a baffle plate having an array of passageways therethrough and a plurality of tubes extending longitudinally within the central bore.

20. The nozzle of claim 1 incorporated into a hydraulic blow molding system and further comprising:
an actuator coupled to the seal pin and configured to move the seal pin between the closed position and the open position, in the closed position the sealing surface engaging the valve seat and closing off the main bore from the outlet, in the open position the sealing surface being spaced apart from the valve seat;
a source of the molding medium, the source being the coupled to the nozzle and the molding medium being provided to the nozzle in a pressurized state;
a mold having interior surfaces defining a mold cavity in the shape of the container, the mold being configured to receive the preform with a portion of the preform being positioned within the mold cavity; and
whereby during a first molding stage the seal pin is in the closed position and the molding medium is injected as a liquid vector into the preform through the central bore and the exit orifice with the central bore receiving the molding medium from the main bore, and thereafter the seal pin is moved to the open position, and during a second molding stage the molding medium is injected into the preform through the main bore and the outlet.

21. The nozzle of claim 20 incorporated into a hydraulic blow molding system and further comprising a centering rod, the centering rod being moveable between an extended position and a retracted position, in the extended position the centering rod extending into the mold cavity and in the retracted position the centering rod being retracted from the mold cavity.

22. The nozzle of claim 20 incorporated into a hydraulic blow molding system wherein an end of the centering rod is adapted to engage a closed end of the preform.

23. The nozzle of claim 20 incorporated into a hydraulic blow molding system and wherein the end of the centering rod is dished shaped.

24. The nozzle of claim 20 incorporated into a hydraulic blow molding system further and comprising a flow straightener positioned within the central bore, the flow straightener being spaced apart from the exit orifice and defining a plurality of sub-passageways within the central bore.

25. A method of hydraulic blow molding a container from a preform, the method comprising the steps of:
positioning a preform within a mold having interior surfaces defining a mold cavity in the shape of the container;
providing a molding medium to a main bore of a nozzle, the molding medium being liquid;
injecting the molding medium through a central bore of the nozzle into the preform during a first molding stage at a first flow rate, the first bore having an inlet opening in communication with the main bore and receiving the molding medium therethrough from the main bore;
axially stretching the preform in response to a force exerted on the preform by the injected molding medium during the first molding stage;
injecting the molding medium into the preform during a second molding stage and at a flow rate, during the second stage at least a portion of the molding medium not passing through the central bore and being injected into the preform directly from the main bore; and
radially expanding the preform into the shape of the container during the second molding stage.

26. The method of claim 25 , wherein the second flow rate is greater than the first flow rate.

27. The method of claim 25 , wherein the step of axially stretching the preform is solely initiated by the force exerted on the preform by the molding medium during the first molding stage.

28. The method of claim 25 , wherein all of the molding medium injected into the preform during the second molding stage is directly injected into the preform from the main bore.

29. The method of claim 25 , further comprising the step of passing

Assignees

• Discma Ag

Inventors

• Lisch G David
• Beuerle Frederick C
• Lee Darrell

Classifications

• B29C49/58

  Blowing means · CPC title

• B29C49/1208

  using additional means to clamp the preform bottom while stretching the preform · CPC title

• B29C2049/7832

  Blowing with two or more pressure levels · CPC title

• B29C2949/0715

  the preform having one end closed · CPC title

• B29C2049/7879

  Stretching, e.g. stretch rod · CPC title