Patent EP0742616A1 successfully refreshed from Google Patents.
US3607998A
Expired / Lapsed
US
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Method for producing hollow articles
Assignee: WALTER R GOODRIDGE
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Filing: 1969-04-07
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Granted: 1971-09-21
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Expires: 1989-04-07
Abstract
Abstract A generally hollow article is produced by coating a flexible bladder with material, integrating the material into a unitary structure, and thereafter removing the bladder therefrom. The apparatus includes coating means to form a fluidized mass of integrable particles, a flexible bladder which provides the form for the article, and means to cause adherence of the material to the bladder.
Inventors
- 👤 Walter R Goodridge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:05
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/42; B29C49/44; B29C33/00; B29C33/44; B29C33/48; B29C33/50; B29C33/505; B29C41/00; B29C41/006; B29C43/00; B29C43/02; B29C43/10; B29C43/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
127 words
In a method of producing a generally hollow article, the steps comprising: forming a cloud of electrically charged integrable particles; disposing in proximity to said cloud of charged particles a flexible bladder comprised of a material that is responsive to means acting thereon to promote adhesion of charged particles coming into contact therewith; acting upon said bladder to temporarily promote particle adhesion thereto and to induce attraction of particles thereto by steps including maintaining said bladder at an electrical potential charging it effectively opposite to said particles to induce said attraction; integrating said particles on said bladder into a cohesive, unitary, generally hollow article; terminating said action upon said bladder and at least partially collapsing said bladder to facilitate the release and removal thereof from said article.
Claim 2
Dependent Claim
127 words
In a method of producing a generally hollow article, the steps comprising: forming a cloud of electrically charged integrable particles; disposing in proximity to said cloud of charged particles a flexible bladder comprised of a material that is responsive to means acting thereon to promote adhesion of charged particles coming into contact therewith; acting upon said bladder to temporarily promote particle adhesion thereto and to induce attraction of particles thereto by steps including maintaining said bladder at an electrical potential charging it effectively opposite to said particles to induce said attraction; integrating said particles on said bladder into a cohesive, unitary, generally hollow article; terminating said action upon said bladder and at least partially collapsing said bladder to facilitate the release and removal thereof from said article.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein said particles are of a synthetic thermoplastic resin.
Claim 4
Dependent Claim
62 words
The method of claim 2 wherein said step of acting upon said bladder additionally includes preheating to an elevated temperature sufficient to at least partially fuse said particles and cause adherence thereof to said bladder upon contact therewith, said responsive material providing to said bladder a heat capacity sufficient to maintain said bladder at a relatively high temperature after said preheating step
Claim 5
Dependent Claim
38 words
The method of claim 1 wherein said method includes the steps of heating said particles on said bladder to a temperature sufficient to effect the integration thereof, and subsequently cooling said integrated particles into said cohesive, self-supporting article.
Claim 6
Dependent Claim
34 words
The method of claim 1 wherein said responsive material of said bladder is electrically conductive, and wherein said step of charging said bladder promotes adhesion as well as inducing attraction of said particles thereto.
Claim 7
Dependent Claim
25 words
The method of claim 5 wherein said responsive material is finely defined and is selected from the group consisting of electrically conductive metals and graphite.
Claim 8
Dependent Claim
47 words
The method of claim 1 wherein said method includes a step of masking a portion of the surface of said bladder to substantially avoid adherence of said particles on said bladder so that the article produced has an opening through which said bladder-removal step can be effected.
Claim 9
Dependent Claim
51 words
The method of claim 5 wherein a portion of the surface of said bladder is maintained at a potential different from the remainder thereof so as to reduce adherence of said particles on said portion and to provide an opening in said article through which said bladder removal step is effected.
Claim 10
Dependent Claim
23 words
The method of claim 1 wherein said bladder is inflatable and is maintained in an inflated condition during said disposing and integrating steps.
Claim 11
Dependent Claim
46 words
The method of claim 1 wherein said particles are of an orientable material and said bladder is inflatable, and wherein said method includes the step of inflating said bladder to increase the dimensions thereof after said article is formed, to orient the molecules of said material.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |