US3873661A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of blow molding and exhausting a blown article through the same blow needle
Assignee: OI Glass Inc
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Filing: 1973-05-11
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Granted: 1975-03-25
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Expires: 1993-05-11
Abstract
Abstract One mold half of a blow molding machine carries a slidably mounted hollow blow needle which is driven by air pressure to penetrate the extruded plastic tube after the molds have closed, following which blowing air is supplied through the needle bore to inflate the tube to the shape of the mold cavity. After blowing, the blowing air is exhausted from the blown shape and the blow needle is withdrawn. The valve which controls the supply of needle-positioning and tube blowing pressure is also carried by the mold half, to minimize time lag and pressure drop.
Inventors
- 👤 Robert F Kontz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:19
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/42; B29C49/58; B29C49/60; B29C49/48; B29C2049/6072
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
242 words
In a method of blow molding, comprising the steps of: simultaneously (1) forming a blowable shape by closing a pair of blow mold halves defining a blow mold cavity onto a plastic tubular parison and (2) gripping the tubular parison in a piercing region with a pair of gripping surfaces carried by respective blow mold halves to define a cylindrical passage communicating with the blowable shape and having a radial wall; introducing pressurized air against a rear flanged region of a blow needle having an axial bore, initially preventing the pressurized air from flowing through the needle axial bore, and advancing the needle relative to the blow mold cavity toward the blowable shape to pierce said radial wall and to project through said passage toward said blowable shape; injecting the pressurized air through the needle bore for flow into said shape immediately after but only after said needle has pierced said radial wall to blow the shape to the configuration of a blown article conforming to the size and shape of the blow mold cavity; maintaining full blow pressure within the blow mold cavity for a time interval to (a) fully inflate the blowable shape to the configuration of the mold cavity, (b) maintain the plastic material in firm contact with the mold cavity walls, and (c) enhance the cooling the blown article; and simultaneously retracting said blow needle and rapidly exhausting blow air from the blown shape through the needle bore.
Claim 2
Dependent Claim
242 words
In a method of blow molding, comprising the steps of: simultaneously (1) forming a blowable shape by closing a pair of blow mold halves defining a blow mold cavity onto a plastic tubular parison and (2) gripping the tubular parison in a piercing region with a pair of gripping surfaces carried by respective blow mold halves to define a cylindrical passage communicating with the blowable shape and having a radial wall; introducing pressurized air against a rear flanged region of a blow needle having an axial bore, initially preventing the pressurized air from flowing through the needle axial bore, and advancing the needle relative to the blow mold cavity toward the blowable shape to pierce said radial wall and to project through said passage toward said blowable shape; injecting the pressurized air through the needle bore for flow into said shape immediately after but only after said needle has pierced said radial wall to blow the shape to the configuration of a blown article conforming to the size and shape of the blow mold cavity; maintaining full blow pressure within the blow mold cavity for a time interval to (a) fully inflate the blowable shape to the configuration of the mold cavity, (b) maintain the plastic material in firm contact with the mold cavity walls, and (c) enhance the cooling the blown article; and simultaneously retracting said blow needle and rapidly exhausting blow air from the blown shape through the needle bore.
Claim 3
Dependent Claim
36 words
The method as defined in claim 1, further including venting the exhausting air from the needle to atmosphere initially through two exhaust ports and then, after the needle has partially retracted, through a single exhaust port.
Claim 4
Dependent Claim
209 words
In a method of blow molding a plastic article, the steps of: simultaneously (1) forming a blowable shape by closing a pair of blow mold halves defining a blow mold cavity having the shape of the article onto a plastic tubular parison and (2) pinching shut a portion of the parison immediately adjacent said cavity to define a cylindrical passage communicating with the blowable shape and having a radial wall; advancing a blow needle having an axial bore toward said blowable shape (1) to pierce said radial wall and (2) to project through said passage toward said blowable shape; injecting pressurized air through the needle bore for flow into said shape immediately after but only after said piercing step to blow the shape of the configuration of a blown article conforming to the size and shape of the blow mold cavity; maintaining full blow pressure within the blow mold cavity for a time interval to (a) fully inflate the blowable shape to the configuration of the mold cavity, (b) maintain the plastic material in firm contact with the mold cavity walls, and (c) enhance the cooling of the blown article; and simultaneously retracting said blow needle and rapidly exhausting blow air from the blown shape through the needle bore.
Claim 5
Dependent Claim
209 words
In a method of blow molding a plastic article, the steps of: simultaneously (1) forming a blowable shape by closing a pair of blow mold halves defining a blow mold cavity having the shape of the article onto a plastic tubular parison and (2) pinching shut a portion of the parison immediately adjacent said cavity to define a cylindrical passage communicating with the blowable shape and having a radial wall; advancing a blow needle having an axial bore toward said blowable shape (1) to pierce said radial wall and (2) to project through said passage toward said blowable shape; injecting pressurized air through the needle bore for flow into said shape immediately after but only after said piercing step to blow the shape of the configuration of a blown article conforming to the size and shape of the blow mold cavity; maintaining full blow pressure within the blow mold cavity for a time interval to (a) fully inflate the blowable shape to the configuration of the mold cavity, (b) maintain the plastic material in firm contact with the mold cavity walls, and (c) enhance the cooling of the blown article; and simultaneously retracting said blow needle and rapidly exhausting blow air from the blown shape through the needle bore.
Claim 6
Dependent Claim
23 words
The method as defined in claim 3, characterized by utilizing a single source of air pressure to effect the advancing and injecting steps.
Claim 7
Dependent Claim
35 words
The method defined in claim 3, further including venting the exhausting air from the needle to atmosphere initially through two exhaust ports and then, after the needle has partially retracted, through a single exhaust port.
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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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |