Patent US4407649A successfully refreshed from Google Patents.
US4407649A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Injection molding machine
Assignee: Shibaura Machine Co Ltd
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Filing: 1982-01-29
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Granted: 1983-10-04
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Expires: 2002-01-29
Abstract
Abstract An injection molding machine comprises an injection piston-cylinder mechanism including therein an injection piston and a booster piston. The booster piston is provided with a longitudinal through hole through which a pressurized fluid is supplied from an external source into the piston-cylinder mechansim so as to act on the injection piston to fill the mold cavity with molten bath. When the inner pressure of the cylinder chamber between both pistons reaches a predetermined value or the injection piston reaches a predetermined position, a valve assembly which is connected to the cylinder chamber through a conduit is operated so as to drain the pressurized fluid in the cylinder chamber in a controlled manner thereby to advance the booster piston.
Inventors
- 👤 Hiroji Saito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:14
CPC Classifications
B; B22; B22D; B22D17/00; B22D17/20; B22D17/32
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
150 words
An injection molding machine comprising an injection piston-cylinder mechanism including therein an injection piston and a booster piston located at a rear portion of said injection piston and provided with a central longitudinal through hole, first valve means connected to a pressurized fluid source and said injection piston-cylinder mechanism so that the pressurized fluids supplied into said injection piston-cylinder mechanism passes through said through hole of said booster piston and acts on said injection piston thereby to fill a mold cavity of a mold with molten bath, and a second valve means connected to said injection piston-cylinder mechanism which operates to discharge pressurized fluid in a cylinder chamber between said booster piston and said injection cylinder into a tank at a time when a fact that the molten bath injected into said molted cavity produces a predetermined condition is detected thereby to move said booster piston in a controlled manner.
Claim 2
Dependent Claim
150 words
An injection molding machine comprising an injection piston-cylinder mechanism including therein an injection piston and a booster piston located at a rear portion of said injection piston and provided with a central longitudinal through hole, first valve means connected to a pressurized fluid source and said injection piston-cylinder mechanism so that the pressurized fluids supplied into said injection piston-cylinder mechanism passes through said through hole of said booster piston and acts on said injection piston thereby to fill a mold cavity of a mold with molten bath, and a second valve means connected to said injection piston-cylinder mechanism which operates to discharge pressurized fluid in a cylinder chamber between said booster piston and said injection cylinder into a tank at a time when a fact that the molten bath injected into said molted cavity produces a predetermined condition is detected thereby to move said booster piston in a controlled manner.
Claim 3
Dependent Claim
89 words
The injection molding machine according to claim 1 wherein said first valve means is a direction changeover valve to change over the flow direction of the pressurized fluid and said second valve means comprises a sequence valve which operates so as to discharge the pressurized fluid in said cylinder chamber when an injection pressure reaches a predetermined value and a flow control valve connected in series with said changeover valve to a conduit connecting said cylinder chamber and said tank, whereby said booster piston advances in a controlled manner.
Claim 4
Dependent Claim
93 words
The injection molding machine according to claim 1 wherein said first valve means is a first direction change-over valve to change over the flow direction of the pressurized fluid and said second valve means comprises a second direction change-over valve which operates so as to discharge the pressurized fluid in said cylinder chamber when said injection piston reaches a predetermined position and a flow control valve connected in series with said second change-over valve to a conduit connecting said cylinder chamber and said tank, whereby said booster piston advances in a controlled manner.
Claim 5
Dependent Claim
67 words
The injection molding machine according to claim 3 wherein said booster piston comprises three cylindrical portions having different diameters and said second change-over valve is connected to a first cylinder chamber defined between said injection piston and said booster piston and a second cylinder chamber defined between the rear end portion of said booster piston and an end portion of a cylinder of said injection piston-cylinder mechanism.
Claim 6
Dependent Claim
30 words
The injection molding machine according to claim 1 wherein said injection piston-cylinder mechanism comprises an injection piston-cylinder assembly and a booster piston cylinder assembly which are interconnected through pipe means.
References Cited (Backward Citations)
US4274823A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-03 | 1987-04-04 | 1987-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-03 | 1991-04-04 | 1991-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-03 | 1995-04-04 | 1995-10-04 | $7700.00 | Window Closed / Lapsed |