US 6,318,990 B1Granted

Injection molding nozzle apparatus

AssigneeMold-Masters Limited

InventorsJobst Ulrich Gellert, Denis L. Babin, George T Olaru

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Abstract

Injection molding apparatus wherein a heated nozzle extends into an opening in a cooled mold. The nozzle has a locating and sealing ring made of a deformable material. After installation the locating and sealing ring contacts an inwardly tapered surface of the mold or an insert seated in the mold extending around the opening. When the nozzle is heated to the operating temperature, thermal expansion drives the locating and sealing ring forwardly into greater contact against the inwardly tapered surface. In one embodiment, the locating and sealing ring is near the front of the nozzle, and the nozzle also has a rear locating flange. During insertion of the nozzle into place in the opening and thermal expansion of the nozzle, the rear locating flange first comes into contact with an inwardly tapered shoulder extending around the opening which prealigns the nozzle. Then before the front locating and sealing ring comes into contact with the inwardly tapered surface and is partially deformed thereby which very accurately align the tip of the nozzle with the gate.

In an injection molding apparatus having at least one nozzle (18) extending into an opening (92) in a mold (26), the opening (92) having a rear end (106) and a surface (94) extending to at least one gate (22) leading to a cavity (24), the nozzle (18) having a rear end (108), a front end (78) and a melt bore (20) extending therethrough from the rear end (108) to the front end (78), the improvement wherein:

the surface (94) of the opening (92) in the mold (26) has a first locating shoulder (102) extending inwardly near the rear end (106) and a second locating shoulder (104) near the gate tapering inwardly toward the gate (22), the nozzle (18) has a rear locating flange (98) that extends outwardly into locating contact with the first inwardly extending locating shoulder (102) of the surface (94) of the opening (92) in the mold (26), and a front locating and sealing ring (90) is mounted around the heated nozzle (18) near the front end (78) of the heated nozzle (18) to provide locating contact with the second inwardly tapering locating shoulder (104) of the surface (94) of the opening (92) in the mold (26), the annular envelope defined by the outer annular surface of the locating and sealing ring (90) forming an acute angle with the inwardly tapering locating shoulder (104), the distance between the first inwardly extending locating shoulder (102) and the second inwardly tapering locating shoulder (104) being greater than the distance between the rear locating flange (98) and the front locating and sealing ring (90) whereby, during insertion of the nozzle (18) into the opening (92) in the mold (26) and thermal expansion of the nozzle (18), the rear locating flange (98) comes into locating contact with the first inwardly extending locating shoulder (102) of the surface (94) of the opening (92) in the mold (26) to prealign the nozzle (18) before the front locating and sealing ring (90) comes into locating and sealing contact with the second inwardly tapering locating shoulder (104) of the surface (94) of the opening (92) in the mold (26).

Facts

Application

09/610,009Filed 3 Jul 2000 · continuation in part

Priority

CA 225059816 Oct 1998

Granted

20 Nov 2001

Term ends

Not estimatedThe source records don’t support an estimate.

Classification5 codes

B29C 45/27
Moulds: sprue channels ; Runner channels or runner nozzles
B29C 2045/274
Heating or cooling means therefor: thermocouples or heat sensors
B29C 2045/2759
Sprue channels ; Runner channels or runner nozzles: nozzle centering or guiding means
B29C 2045/2761
Sprue channels ; Runner channels or runner nozzles: seals between nozzle and mould or gate

Abstract

Claims28