Hot runner nozzle with a gate pressure equalizer
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 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 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.
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 moving between an open and a closed position, in the closed position melt is stopped from flowing out of a downstream end ( 216 , 316 ) of the primary melt channel ( 204 , 304 ), and in the open position melt is allowed to flow from the primary melt channel to the 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 claim 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 claim 4 , wherein the valve comprises a valve stem ( 212 , 312 ) slidably disposed in the primary melt channel ( 204 , 304 ).
6. The hot runner nozzle according to claim 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 ).