US4070142A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Injection of plastic in molding machine
Assignee: Farrell Patent Co
•
Filing: 1977-01-26
•
Granted: 1978-01-24
•
Expires: 1997-01-26
Abstract
Abstract This invention reduces the time that a core rod must remain at an injection station of a plastic blow molding machine. The injection operation is usually performed by a plasticizer, and while the injection operation itself requires very little time, the plasticizer performs other roles that must be complete before the next injection. This invention uses two plasticizers alternately so that one can inject while the other recovers for its next injection operation. A plastic pump is used to relieve the plasticizers of some of the operations that they previously performed.
Inventors
- 👤 John J. Farrell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:47
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/46; B29C45/57; B29C45/03; B29C45/13
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
191 words
An injection blow molding apparatus comprising, an injection mold, a core rod disposed in the injection mold and onto which a thermoplastic parison is injection molded, a first plasticizer and a second plasticizer, a first passage and a second passage through which each of the plasticizers respectively communicate with the injection mold, pump means comprising a piston in common communication with said passages and said injection mold, first and second valve means disposed in said first and second passage means respectively for selectively shutting off communication of each respective plasticizer, control means to actuate the pump means in timed relationship with each of the valve means, so that said first plasticizer first charges the injection mold, said control means shuts off the first valve means and starts the piston to move thermoplastic material to the mold so as to compensate for any shrinkage of the thermoplastic in the mold, said first plasticizer then undergoing recovery, and wherein the control means actuates said second valve means so that said second plasticizer is in communication with the injection mold for the next parison formation prior to completion of recovery of the first plasticizer.
Claim 2
Dependent Claim
191 words
An injection blow molding apparatus comprising, an injection mold, a core rod disposed in the injection mold and onto which a thermoplastic parison is injection molded, a first plasticizer and a second plasticizer, a first passage and a second passage through which each of the plasticizers respectively communicate with the injection mold, pump means comprising a piston in common communication with said passages and said injection mold, first and second valve means disposed in said first and second passage means respectively for selectively shutting off communication of each respective plasticizer, control means to actuate the pump means in timed relationship with each of the valve means, so that said first plasticizer first charges the injection mold, said control means shuts off the first valve means and starts the piston to move thermoplastic material to the mold so as to compensate for any shrinkage of the thermoplastic in the mold, said first plasticizer then undergoing recovery, and wherein the control means actuates said second valve means so that said second plasticizer is in communication with the injection mold for the next parison formation prior to completion of recovery of the first plasticizer.
Claim 3
Dependent Claim
50 words
The injection blow molding apparatus of claim 1, said control means further reversing said piston after the injection molding of the parison is complete so as to draw back thermoplastic runner material at the injection mold; said control means closing said first and second valve means during said draw back.
Claim 4
Dependent Claim
72 words
The injection blow molding apparatus of claim 1, said core rod being mounted to an indexing head, and said injection mold being partible, so that said core and parison are removed from the injection mold, and a second core rod is positioned in the injection mold for the next injection, and wherein said control means then actuates said second valve means and second plasticizer to provide thermoplastic material to the injection mold.
References Cited (Backward Citations)
US3281899A
Cited
US3733156A
Cited
US3674401A
Cited
US3709644A
Cited
US3891372A
Cited
US3888612A
Cited
US3947175A
Cited
US3945784A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-23 | 1981-07-25 | 1982-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-23 | 1985-07-25 | 1986-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-23 | 1989-07-25 | 1990-01-24 | $7700.00 | Window Closed / Lapsed |