US3640662A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Injection molding machine with high-frequency dielectric heater
Assignee: Lester Engineering Co
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Filing: 1969-12-23
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Granted: 1972-02-08
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Expires: 1989-12-23
Abstract
Abstract A system for dielectrically heating primarily glass fiber filled polyester materials in an indexing-type injection molding machine. The machine is indexable between a shot-receiving and shot-ejecting position and several forms of dielectric apparatus are shown for heating the shot to achieve a partial cure in one or more of these positions, or in an advance-receiving arrangement. In at least one species of the invention correlation between position of the shot in the molding machine and operation of the dielectric heater is automatically effected to achieve a high efficiency of operation. A system for controlling the operational steps of the molding machine is disclosed, a portion of the sequencing being dependent upon a predetermined level of heating of the shot material.
Inventors
- 👤 William H Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:13
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/72
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
146 words
An injection molding machine of the shot type comprising an indexable member having a shot cylinder therein for receipt and discharge of a quantity of plastic material, said member being supported for rotation about an axis passing through said shot cylinder between a first shot-receiving position and a second shot-injecting position, a first electrode mounted adjacent said indexable member at one side of said shot cylinder, a second electrode mounted on said indexable member at the opposite side of said shot cylinder, said first and second electrodes defining a field for electric energy through said shot cylinder when brought into alignment with one another by rotation of said indexable member, and a radiofrequency generator operatively interconnected with said first and second electrodes for creating an electric field of heating energy therebetween to elevate the temperature of the plastic material for a partial cure prior to injection.
Claim 2
Dependent Claim
146 words
An injection molding machine of the shot type comprising an indexable member having a shot cylinder therein for receipt and discharge of a quantity of plastic material, said member being supported for rotation about an axis passing through said shot cylinder between a first shot-receiving position and a second shot-injecting position, a first electrode mounted adjacent said indexable member at one side of said shot cylinder, a second electrode mounted on said indexable member at the opposite side of said shot cylinder, said first and second electrodes defining a field for electric energy through said shot cylinder when brought into alignment with one another by rotation of said indexable member, and a radiofrequency generator operatively interconnected with said first and second electrodes for creating an electric field of heating energy therebetween to elevate the temperature of the plastic material for a partial cure prior to injection.
Claim 3
Dependent Claim
55 words
A machine as set forth in claim 1 wherein said first and second electrodes are plates of conductive material, having dimensions conforming substantially to those of said shot cylinder, and adapted to be parallel one another for defining an electric field through said shot cylinder only when said indexable member is in the shot-injecting position.
Claim 4
Dependent Claim
84 words
A machine as set forth in claim 1 wherein each of said first and second electrodes comprises a plurality of equally spaced conductive members, the members of said first electrode being alternately disposed in relation to the members of said second electrode and all said members being substantially equally disposed adjacent the shot cylinder to create multiple paths of heating energy through the shot cylinder, means for grounding the members of said second electrode, and means for interconnecting the members of said first electrode.
Claim 5
Dependent Claim
53 words
A machine as set forth in claim 3 wherein the members of said first electrode are linearly aligned at one side of the shot cylinder and the members of said second electrode are linearly aligned at the opposite side of the shot cylinder thereby to effect transverse electric fields through the shot cylinder.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |