EP0162438A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Injection molding nozzle probe and stack molding apparatus
Assignee: Individual
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Filing: 1985-05-20
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Granted: —
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Expires: 2005-05-20
Abstract
Abstract This invention relates to an improved heated nozzle probe for injection molding and an improved stack molding system in which it is used. Each nozzle probe has an inner helical shaped heating element which extends into the pointed tip, and a separate outer one which does not. In addition to providing more heat to the pointed tip, this has the advantage that a standard unit can be used for various applications. In the stack molding system, two heated nozzles are arranged in alignment to bridge the parting line and the pointed tip of only the downstream one is heated. Combined with tapering the aligned gates to gradually increase in diameter in a downstream direction, this has been found to considerable reduce stringing and drooling problems as the mold opens for ejection.
Inventors
- 👤 Jobst Ulrich Gellert
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-10 01:37
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/26; B29C45/32; B29C45/322; B29C45/27; B29C45/30; B29C45/2701; B29C2045/2724
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
230 words
An integral elongated heated nozzle probe to be seated in an injection molding system to convey melt towards a gate, comprising: (a) an elongated body having a melt receiving inlet at one end and a pointed tip at the other end to be aligned with the gate, the body having at least one melt passage which extends longitudinally from the inlet at said one end and becomes an outwardly open melt channel towards said other end; (b) a first electrically insulated heating element surrounded by a highly conductive material cast into the body, the first heating element extending from first external terminal means adjacent the inlet, along the melt passage and melt channel, and into the pointed tip; (c) a second electrically insulated heating element surrounded by a highly conductive material cast into the body, the second heating element extending from second external terminal means adjacent the inlet, along the melt passage and melt channel, and terminating short of the pointed tip; and (d) a source of electrical power with control means connected to the first and second terminal means, whereby for any particular application or location of the nozzle probe in the system either or both of the first and second heating elements can be activated, thereby providing more or less heat along the melt passage and melt channel and particularly to the pointed tip of the nozzle probe.
Claim 2
Dependent Claim
230 words
An integral elongated heated nozzle probe to be seated in an injection molding system to convey melt towards a gate, comprising: (a) an elongated body having a melt receiving inlet at one end and a pointed tip at the other end to be aligned with the gate, the body having at least one melt passage which extends longitudinally from the inlet at said one end and becomes an outwardly open melt channel towards said other end; (b) a first electrically insulated heating element surrounded by a highly conductive material cast into the body, the first heating element extending from first external terminal means adjacent the inlet, along the melt passage and melt channel, and into the pointed tip; (c) a second electrically insulated heating element surrounded by a highly conductive material cast into the body, the second heating element extending from second external terminal means adjacent the inlet, along the melt passage and melt channel, and terminating short of the pointed tip; and (d) a source of electrical power with control means connected to the first and second terminal means, whereby for any particular application or location of the nozzle probe in the system either or both of the first and second heating elements can be activated, thereby providing more or less heat along the melt passage and melt channel and particularly to the pointed tip of the nozzle probe.
Claim 3
Dependent Claim
51 words
A nozzle probe as claimed in claim 1 wherein the body has a plurality of melt passages which extend outwardly from a common central inlet at said one end around the first and second heating elements which are generally helical and extend coaxially around the central longitudinal axis of the body.
Claim 4
Dependent Claim
41 words
A nozzle probe as claimed in claim 2 wherein the first heating element has a first helical portion which is encircled by the second helical heating element, and a second portion which extends into the pointed tip of the nozzle probe.
Claim 5
Dependent Claim
41 words
A nozzle probe as claimed in claim 3 wherein said helical portion of the first heating element is located inside a longitudinally extending locating sleeve, and the coils of the second heating element extend around the outside of the locating sleeve.
Claim 6
Dependent Claim
35 words
A nozzle probe as claimed in claim 4 wherein the locating sleeve is formed of steel and the highly conductive material cast around the first and second heating elements providing an integral structure is copper.
Claim 7
Dependent Claim
204 words
Stack injection molding apparatus for conducting melt from a fixed platen to a movable platen which are actuated according to an operating cycle between open and closed positions, comprising: (a) a first heated elongated nozzle probe seated in the fixed platen having a pointed tip in alignment with a first gate extending through the fixed platen, the first nozzle probe having at least one melt passage extending to convey pressurized melt from an inlet to the first gate through the fixed platen; and (b) a second heated elongated nozzle probe seated in the movable platen having a pointed tip in alignment with a second gate extending through the movable platen, the first gate through the fixed platen connecting with the second gate through the movable platen in the closed position, the second nozzle probe having at least one melt passage extending to convey pressurized melt from the second gate to a melt duct in the movable platen; the second nozzle probe having heating means for heating the pointed tip of the second nozzle probe to a higher temperature than the pointed tip of the first nozzle probe, whereby stringing of the melt is reduced when the movable platen is actuated to the open position.
Claim 8
Dependent Claim
204 words
Stack injection molding apparatus for conducting melt from a fixed platen to a movable platen which are actuated according to an operating cycle between open and closed positions, comprising: (a) a first heated elongated nozzle probe seated in the fixed platen having a pointed tip in alignment with a first gate extending through the fixed platen, the first nozzle probe having at least one melt passage extending to convey pressurized melt from an inlet to the first gate through the fixed platen; and (b) a second heated elongated nozzle probe seated in the movable platen having a pointed tip in alignment with a second gate extending through the movable platen, the first gate through the fixed platen connecting with the second gate through the movable platen in the closed position, the second nozzle probe having at least one melt passage extending to convey pressurized melt from the second gate to a melt duct in the movable platen; the second nozzle probe having heating means for heating the pointed tip of the second nozzle probe to a higher temperature than the pointed tip of the first nozzle probe, whereby stringing of the melt is reduced when the movable platen is actuated to the open position.
Claim 9
Dependent Claim
90 words
Stack injection molding apparatus as claimed in claim 6 wherein the first and second nozzle probes each have first and second electrical heating elements extending longitudinally along the melt passage, the first heating element having a portion extending into the pointed tip of the respective nozzle probe and the second heating element terminating short of the pointed tip, including an electrical power source which is connected to energize only the second heating element in the first nozzle probe and at least the first heating element in the second nozzle probe.
Claim 10
Dependent Claim
34 words
Stack'injection molding apparatus as claimed in claim 7 wherein the second gate extending through the movable platen is tapered to gradually increase in - diameter towards the pointed tip of the second nozzle probe.
Claim 11
Dependent Claim
54 words
Stack injection molding apparatus as claimed in claim 8 wherein the first gate through the fixed platen is in alignment with the second gate through the movable platen, and both gates are tapered to form an opening in the closed position which gradually increases in diameter towards the pointed tip of the second nozzle.
References Cited (Backward Citations)
No citation records indexed.
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