US4098857A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making blow molded containers with high length to diameter ratio
Assignee: Farrell Patent Co
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Filing: 1976-01-28
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Granted: 1978-07-04
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Expires: 1996-01-28
Abstract
Abstract This invention increases the length-to-diameter ratio of plastic articles made on injection molding machines without using long and relatively thin core rods. This added length is obtained by having the first part of the blowing operation stretch the parison lengthwise before there is any substantial displacement of the parison in a radial direction. At the start of the blowing operation, a tube surrounds and confines radial expansion of the parison, but this tube is withdrawn progressively as the blowing operation continues.
Inventors
- 👤 John J. Farrell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:35
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/08; B29C49/16; B29C49/02; B29C49/06; B29C2049/023; B29C49/42; B29C49/48; B29C2049/4856; B29C2049/4858
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
129 words
A method for injection blow molding a container having a substantially greater length than diameter comprising; (a) injection molding a parison on a core rod; (b) providing a blow mold comprising a tube being formed with a substantially greater length longer than diameter cavity, said tube being disposed about the parison and core rod; (c) providing an air flow between the tube and the parison to maintain a clearance between the parison and the tube; (d) first blowing the parison to increase the length to diameter ratio of the parison so that said parison length approaches the length of the container being formed; and then (e) final blowing the parison while progressively withdrawing the tube with the progressive blowing of the parison to the final diameter of the container.
Claim 2
Independent Claim
129 words
A method for injection blow molding a container having a substantially greater length than diameter comprising; (a) injection molding a parison on a core rod; (b) providing a blow mold comprising a tube being formed with a substantially greater length longer than diameter cavity, said tube being disposed about the parison and core rod; (c) providing an air flow between the tube and the parison to maintain a clearance between the parison and the tube; (d) first blowing the parison to increase the length to diameter ratio of the parison so that said parison length approaches the length of the container being formed; and then (e) final blowing the parison while progressively withdrawing the tube with the progressive blowing of the parison to the final diameter of the container.
Claim 3
Dependent Claim
30 words
The method of claim 1, wherein the step of blowing the parison further comprises progressively blowing the diameter of the container from the top to the bottom of the container.
Claim 4
Dependent Claim
24 words
The method of claim 1, further comprising providing an air cushion between the inside surface of the tube and the outside of the parison.
Claim 5
Dependent Claim
25 words
The method of claim 3, further comprising controlling the pressure of the air in expanding the parison while controlling the pressure of the air cushion.
Claim 6
Independent Claim
145 words
A method for injection blow molding a container having a substantially greater length than diameter comprising; (a) injecting a parison having a neck and a body portion on a core rod in an injection mold; (b) transfering the parison and core rod from an injection mold to a blow mold comprising a tube; (c) inserting the parison and core rod into the tube within the blow mold, said tube being formed with a substantially greater length than diameter cavity; (d) increasing the length of the parison in the tube by first blowing the parison in the tube; while preventing contact between the inside of the tube and the outside of the parison; and then (e) progressively withdrawing the tube while blowing the parison body so as to progressively blow the diameter of the parison from below the neck to the bottom of the blown container.
Claim 7
Independent Claim
145 words
A method for injection blow molding a container having a substantially greater length than diameter comprising; (a) injecting a parison having a neck and a body portion on a core rod in an injection mold; (b) transfering the parison and core rod from an injection mold to a blow mold comprising a tube; (c) inserting the parison and core rod into the tube within the blow mold, said tube being formed with a substantially greater length than diameter cavity; (d) increasing the length of the parison in the tube by first blowing the parison in the tube; while preventing contact between the inside of the tube and the outside of the parison; and then (e) progressively withdrawing the tube while blowing the parison body so as to progressively blow the diameter of the parison from below the neck to the bottom of the blown container.
Claim 8
Dependent Claim
22 words
The method of claim 5, further comprising maintaining a clearance between the inside of the tube and the outside of the parison.
Claim 9
Dependent Claim
24 words
The method of claim 6, further comprising providing an air cushion between the inside surface of the tube and the outside of the parison.
Claim 10
Dependent Claim
44 words
The method of claim 5, further comprising terminating the withdrawal of the tube so that the end of the tube is at substantially the end of the blow mold cavity and being the end of the tube about flush with an a abutment surface.
Claim 11
Dependent Claim
23 words
The method of claim 8, further comprising timing the withdrawal of the tube in relation to completion of the blowing of the parison.
Claim 12
Dependent Claim
18 words
The method of claim 9, further comprising varying the speed of the tube withdrawal in said time relationship.
Claim 13
Dependent Claim
32 words
The method of claim 5, wherein the step of inserting the parison and core rod in the tube comprises aligning the parison and core rods to be substantially coaxial with the tube.
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) | 1981-07-03 | 1982-01-02 | 1982-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-03 | 1986-01-02 | 1986-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-03 | 1990-01-02 | 1990-07-04 | $7700.00 | Window Closed / Lapsed |