Patent US3567173A successfully refreshed from Google Patents.
US3567173A
Expired / Lapsed
US
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Core mandrel for making hollow plastic bodies
Assignee: Peterson Products of San Mateo Inc
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Filing: 1967-06-16
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Granted: 1971-03-02
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Expires: 1987-06-16
Abstract
Abstract A mandrel for use in making hollow reinforced plastic parts, which diametrically shrink during the curing cycle. The mandrel has an inner rigid core structure around which is laminated a thick layer of foam rubber to which is bonded sections of aluminum foil with their adjoining edges separated by longitudinal gaps to act as expansion joints and permit the metal sections to move closer together under influence of the diametral contraction of the plastic during its curing cycle.
Inventors
- 👤 Fred D Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:47
CPC Classifications
B; B29; B29C; B29C33/00; B29C33/44; B29C33/48; B29C33/50; B29C33/505; B29C37/00; B29C37/005
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
96 words
A core mandrel for making hollow bodies of plastic material of the type which shrink during their curing cycle, comprising: a rigid core, a layer of resilient material overlapping and bonded along the entire peripheral surface of said rigid core, a plurality of sections of nonresilient hard surface sheet material bonded to the outer surfaces of said resilient material, said plurality of sections separated by longitudinal expansion joints to allow said sections to move closer together against the outward biasing pressure of said resilient material and under influence of diametral contraction of plastic material applied thereto.
Claim 2
Dependent Claim
96 words
A core mandrel for making hollow bodies of plastic material of the type which shrink during their curing cycle, comprising: a rigid core, a layer of resilient material overlapping and bonded along the entire peripheral surface of said rigid core, a plurality of sections of nonresilient hard surface sheet material bonded to the outer surfaces of said resilient material, said plurality of sections separated by longitudinal expansion joints to allow said sections to move closer together against the outward biasing pressure of said resilient material and under influence of diametral contraction of plastic material applied thereto.
Claim 3
Dependent Claim
34 words
The combination of claim 1 and wherein each expansion joint constitutes a longitudinal space between adjacent edges of said adjoining sections and wherein each longitudinal space is covered by a strip of flexible tape.
Claim 4
Dependent Claim
14 words
The core mandrel of claim 1 wherein said bonding is accomplished with an adhesive.
Claim 5
Dependent Claim
22 words
The core mandrel of claim 1 wherein said expansion joints are spaced at about 90* intervals around the periphery of the mandrel.
References Cited (Backward Citations)
US2170188A
Cited
US3350049A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |