US4066725A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Injection molding control method
Assignee: Schneider Electric Buildings Americas Inc
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Filing: 1973-12-03
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Granted: 1978-01-03
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Expires: 1993-12-03
Abstract
Abstract The control cycle for an injection molding machine comprises successive fill, compaction, hold, cure and mold open times. The ram position and mold pressure are monitored at predetermined times respectively after the molding cycle has begun. If the ram position is out of tolerance, the fill pressure is adjusted to compensate for the deviation. If the mold pressure is out of tolerance, the compaction pressure is adjusted to compensate for the deviation in mold pressure.
Inventors
- 👤 Jon E. Boettner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:30
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/76
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
138 words
A method for control of a process for injecting into and curing in a mold cavity a plasticized material comprising the steps of sensing at a predetermined time after initiation of injection the position of a ram injecting said plasticized material into the cavity, determining the deviation of said sensed position from a predetermined setpoint position, adjusting a fill pressure in a manner to compensate for said position deviation, and compacting the plasticized material in said cavity under an independent compaction pressure, wherein said compacting step comprises sensing the mold pressure in said cavity at a second predetermined time after initiation of injection and after completion of filling of the cavity, determining the deviation of said sensed mold pressure from a predetermined setpoint pressure, and adjusting said compaction pressure in a manner to compensate for the pressure deviation.
Claim 2
Independent Claim
138 words
A method for control of a process for injecting into and curing in a mold cavity a plasticized material comprising the steps of sensing at a predetermined time after initiation of injection the position of a ram injecting said plasticized material into the cavity, determining the deviation of said sensed position from a predetermined setpoint position, adjusting a fill pressure in a manner to compensate for said position deviation, and compacting the plasticized material in said cavity under an independent compaction pressure, wherein said compacting step comprises sensing the mold pressure in said cavity at a second predetermined time after initiation of injection and after completion of filling of the cavity, determining the deviation of said sensed mold pressure from a predetermined setpoint pressure, and adjusting said compaction pressure in a manner to compensate for the pressure deviation.
Claim 3
Independent Claim
88 words
A method for control of a process for injecting into and curing in a mold cavity a plasticized material comprising the steps of filling the mold cavity with said plasticized material under a predetermined fill pressure, sensing the mold pressure in said cavity at a predetermined time after initiation of said filling and after completion of filling of the cavity, determining the deviation of said sensed mold pressure from a predetermined setpoint pressure, and adjusting a compaction pressure in an independent manner to compensate for said pressure deviation.
Claim 4
Independent Claim
88 words
A method for control of a process for injecting into and curing in a mold cavity a plasticized material comprising the steps of filling the mold cavity with said plasticized material under a predetermined fill pressure, sensing the mold pressure in said cavity at a predetermined time after initiation of said filling and after completion of filling of the cavity, determining the deviation of said sensed mold pressure from a predetermined setpoint pressure, and adjusting a compaction pressure in an independent manner to compensate for said pressure deviation.
Claim 5
Dependent Claim
23 words
A method according to claim 2 wherein said predetermined time is set to occur prior to substantial reduction of pressure in the mold.
Claim 6
Dependent Claim
22 words
A method according to claim 2 wherein said predetermined time is set to occur substantially at the maximum pressure in the mold.
Claim 7
Dependent Claim
20 words
A method according to claim 2 wherein said setpoint pressure is defined by an upper limit and a lower limit.
Claim 8
Dependent Claim
18 words
A method according to claim 2 wherein said compaction pressure is adjusted upwards and downwards in predetermined increments.
Claim 9
Dependent Claim
25 words
A method according to claim 2 further comprising employing said adjusted compaction pressure as the compaction pressure to be adjusted in a following control cycle.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-02 | 1981-07-04 | 1982-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-02 | 1985-07-04 | 1986-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-02 | 1989-07-04 | 1990-01-03 | $7700.00 | Window Closed / Lapsed |