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US5439371A Expired / Lapsed US ⏱️ 0.0 years remaining

Locally pressurizing injection molding machine

Assignee: Sumitomo Heavy Industries Ltd
•
Filing: 1993-09-29
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Granted: 1995-08-08
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Expires: 2013-09-29
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Abstract

Abstract A locally pressurizing type injection molding machine includes a stationary die and a movable die, so that a molded product can be formed by charging a resin into a cavity defined between the dies. A pressurizing pin extends through the movable die and has its tip end facing at least one of a resin passage and the cavity. A pressurizing cylinder is disposed at the rear of the pressurizing pin to move the pressurizing pin through the pressurizing rod. Therefore, the resin charged in the cavity can be pressurized by advancing the pressurizing pin into a resin passage, for example, a gate, the cavity or the like and hence, it is possible not only to provide an extremely thin molded product, but also to prevent the generation of a sink mark. The area occupied by the movable platen can be reduced by disposing the pressurizing rod and ejector rod coaxially.

Inventors

  • 👤 Atsushi Sawaya

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 07:59
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/03; B29C45/17; B29C45/38; B29C45/40; B29C45/4005; B29C45/46; B29C45/57; B29C45/572

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 169 words
A locally pressurizing injection molding machine comprising: a stationary die; a movable die disposed for movement into and out of contact with said stationary die to define a cavity therebetween and a resin passage for injecting resin into said cavity; a pressurizing pin extending through said movable die to a distal end facing at least one of said resin passage and said cavity; a pressurizing cylinder for reciprocally driving said pressurizing pin and a pressurizing rod, said pressurizing rod transmitting a driving force of said pressurizing cylinder to said pressurizing pin; an ejector pin extending through said movable die to a distal end facing said cavity; and an ejecting cylinder for reciprocally driving said ejector pin and an ejector rod, said ejector rod being coaxial with said pressurizing rod transmitting a driving force of said ejecting cylinder to said ejector pin, said pressurizing rod being in the form of a hollow sleeve and said ejector rod extending through said hollow sleeve for sliding motion relative to said hollow sleeve.
Claim 2
Dependent Claim 169 words
A locally pressurizing injection molding machine comprising: a stationary die; a movable die disposed for movement into and out of contact with said stationary die to define a cavity therebetween and a resin passage for injecting resin into said cavity; a pressurizing pin extending through said movable die to a distal end facing at least one of said resin passage and said cavity; a pressurizing cylinder for reciprocally driving said pressurizing pin and a pressurizing rod, said pressurizing rod transmitting a driving force of said pressurizing cylinder to said pressurizing pin; an ejector pin extending through said movable die to a distal end facing said cavity; and an ejecting cylinder for reciprocally driving said ejector pin and an ejector rod, said ejector rod being coaxial with said pressurizing rod transmitting a driving force of said ejecting cylinder to said ejector pin, said pressurizing rod being in the form of a hollow sleeve and said ejector rod extending through said hollow sleeve for sliding motion relative to said hollow sleeve.
Claim 3
Dependent Claim 43 words
A locally pressurizing injection molding machine in accordance with claim 1 comprising a plurality of said pressurizing rods mounted on and extending from a single pressurizing plate for movement in synchronism therewith, said single pressurizing plate being reciprocally driven by said pressurizing cylinder.
Claim 4
Dependent Claim 37 words
A locally pressurizing injection molding machine in accordance with claim 2 further comprising a single ejector rod plate carrying a plurality of said ejector rods, said single ejector rod plate being reciprocally driven by said ejecting cylinder.
Claim 5
Dependent Claim 36 words
A locally pressurizing injection molding machine in accordance with claim 1 further comprising a single ejector rod plate carrying a plurality of said ejector rods, said ejector rod plate being reciprocally driven by said ejecting cylinder.
Claim 6
Dependent Claim 26 words
A locally pressurizing injection molding machine in accordance with claim 1 wherein said pressurizing pin is mounted on a plate reciprocally driven by said pressurizing rod.
Claim 7
Dependent Claim 26 words
A locally pressurizing injection molding machine in accordance with claim 1 wherein said ejector pin is mounted on a plate reciprocally driven by said ejecting rod.
Claim 8
Dependent Claim 26 words
A locally pressurizing injection molding machine in accordance with claim 5 wherein said ejector pin is mounted on a plate reciprocally driven by said ejecting rod.

References Cited (Backward Citations)

US2330369A Cited
GB1416870A Cited
DE8414995U1 Cited
US4710124A Cited
US5074779A Cited
JPH04369517A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-08-07 1999-02-06 1999-08-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-08-07 2003-02-06 2003-08-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-08-07 2007-02-06 2007-08-08 $7700.00 Window Closed / Lapsed

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