HOT RUNNER NOZZLE WITH A GATE PRESSURE EQUALIZER

• US 20180015653A1
• Filed: 11/16/2015
• Published: 01/18/2018
• Est. Priority Date: 11/17/2014
• Status: Active Grant

• Current Assignee: Husky Injection Molding Systems Limited
• Original Assignee: Husky Injection Molding Systems Limited
• Inventors: JENKO, Edward Joseph
• Granted Patent: US 10,449,706 B2
• Time in Patent Office: Days
• CPC Class Codes: B29C 2045/2779 Nozzles with a plurality of outlets
• CPC Class Codes: B29C 2045/2886 closing at a distance from the gate
• CPC Class Codes: B29C 45/2735 for non-coaxial gates, e.g. for edge gates
• CPC Class Codes: B29C 45/2806 consisting of needle valve systems B29C45/2896 takes precedence

Abstract

A method and apparatus for equalizing gate pressure of a hot runner nozzle are disclosed. The nozzle includes a nozzle housing defining a primary melt channel, a first nozzle tip having a first secondary melt channel in fluid communication with the primary melt channel, a second nozzle tip having a second secondary melt channel in fluid communication 5 with the primary melt channel, and a valve disposed in the primary melt channel for selectively opening and closing a downstream end of the primary melt channel to control a flow of melt to the first and second secondary melt channels. In some embodiments, the valve is configured to selectively open when a pressure of the melt reaches a threshold peak pressure. In some embodiments, the 10 valve includes a valve stem that cooperates with the primary melt channel to block a flow of melt therefrom until the threshold peak pressure is established.

Claims

1. A hot runner nozzle (200, 300) for passing melt into a mold cavity (210, 310), the hot runner nozzle comprising:

a nozzle housing (202, 302) defining a primary melt channel (204, 304);

a first nozzle tip (208, 308), the first nozzle tip (208, 308) having a first secondary melt channel (206, 306) in fluid communication with the primary melt channel (204, 304);

a second nozzle tip (208, 308), the second nozzle tip (208, 308) having a second secondary melt channel (206, 306) in fluid communication with the primary melt channel (204, 304); and

a valve disposed in the primary melt channel (204, 304) for selectively opening and closing a downstream end (216, 316) of the primary melt channel (204, 304) to control a flow of melt to the first and second secondary melt channels (206, 306).

2. The hot runner nozzle according to claim 1, wherein the hot runner nozzle is a side gate nozzle.

3. The hot runner nozzle according to claim 1, wherein the hot runner nozzle is a multi-probe nozzle.

4. The hot runner nozzle according to any one of claims 1-3, wherein the valve is configured to selectively open when a pressure of the melt reaches a threshold peak pressure.

5. The hot runner nozzle according to any one of claim 1-4, wherein the valve comprises a valve stein (212, 312) slidably disposed in the primary melt channel (204, 304).

6. The hot runner nozzle according to any one of claim 1-4, wherein the valve is positioned in a downstream end (216, 316) of the primary melt channel (204, 304).

7. The hot runner nozzle according to claim 5, wherein a downstream end (214, 314) of the valve stem (212, 312) cooperates with a downstream end (216, 316) of the primary melt channel (204, 304).

8. A method of passing melt into mold cavities (210, 310), the method comprising:

selectively closing a valve disposed in a primary melt channel (204, 304) of a nozzle housing (202, 302) to stop melt from flowing from the primary melt channel (204, 304);

pressurizing the melt in the primary melt channel (204, 304) until the pressure of the melt reaches a threshold peak pressure; and

selectively opening the valve to allow the melt to flow from the primary melt channel (204, 304) to a first secondary melt channel (206, 306) defined in a first nozzle tip (208, 308) and a second secondary melt channel (206, 306) defined in a second nozzle tip (208, 308).

9. The method according to claim 8, further comprising filling first and second mold cavities (210, 310).

10. The method according to claim 9, further comprising selectively closing the valve after the first and second mold cavities (210, 310) have been filled.

11. The method according to claim 10, wherein selectively closing the valve comprises engaging a downstream end (214, 314) of a valve stem (212, 312) with a downstream end (216, 316) of the primary melt channel (204, 304) to block a flow of melt therefrom.