US3947204A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scrapless forming of plastic articles
Assignee: Dow Chemical Co
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Filing: 1974-01-14
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Granted: 1976-03-30
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Expires: 1994-01-14
Abstract
Abstract Apparatus for rapidly making thermoplastic containers wherein the resultant containers can, if desired, be multilayered for vapor or gas barrier or other reasons, or be oriented for toughness and improved stress crack resistance. The apparatus takes a measured amount of thermoplastic material which is lubricated, heated and forged into a desired shape preform with a predetermined lip configuration. The center portion of each said preform is maintained at a forming temperature while the peripheral portion thereof is clamped and rapidly brought below the softening point of the plastic resin. The preform can then be immediately thermoformed into a container having a desired shape and size, and cooled. If desired, the preform can be forged, cooled and recovered for a subsequent thermoforming operation or can be a finished article itself.
Inventors
- 👤 Ralph E. Ayres
- 👤 Kenneth J. Cleereman
- 👤 Walter J. Schrenk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:42
CPC Classifications
B; B65; B65D; B65D1/00; B65D1/22; B65D1/26; B29; B29C; B29C43/00; B29C43/32; B29C43/36; B29C43/361; B29C51/00; B29C51/02; B29C51/14; B29C51/26; B29C51/42; B29C51/428; B65D1/28; B29C2791/00; B29C2791/004; B29C2791/006; B29C2791/007; B29C2795/00; B29C2795/002; B29C2949/00; B29C2949/07; B29C2949/081; B29C2949/082; B29C43/02; B29C43/16; B29C49/00; B29C49/02; B29C49/0685; B29C51/30; B29C51/306; B29L; B29L2031/00; B29L2031/712; B29L2031/7158; B29L2031/716; Y; Y10; Y10S; Y10S220/00; Y10S220/12; Y10S220/14; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1386; Y10T428/1397; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31924; Y10T428/31931
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
233 words
An apparatus for scrapless forming of thermoplastic articles comprising a ring-like forming fixture adapted to receive a measured amount of thermoplastic material to be forged into a preform which can subsequently be thermoformed into an article, said forming fixture comprising an upper ring with a central oepning the lower extent of which defines a peripheral dimension about the same as that of said preform less its rim area, a lower ring including a central opening the upper extent of which defines a peripheral dimension about the same as that of said preform less its rim area, a lip opening contoured out of at least one of said rings around the entire extent thereof and presenting a face angled from the horizontal sufficient to resist the retraction stress of the thermoplastic material of the preform, the inner surfaces of said rings adjacent their respective central openings being spaced from one another a distance no greater than the thickness of said preform and presenting opposed shoulders which together with said face secure the peripheral rim area of said preform, including its lip, in clamped fashion within said fixture priior to and during subsequent thermoforming of the preform into a container, cooling channels extending through at least one of said rings adjacent the rim receiving portion thereof sufficient to cool rapidly the rim area while leaving the central portion of said proform at a thermoformable temperature.
Claim 2
Independent Claim
233 words
An apparatus for scrapless forming of thermoplastic articles comprising a ring-like forming fixture adapted to receive a measured amount of thermoplastic material to be forged into a preform which can subsequently be thermoformed into an article, said forming fixture comprising an upper ring with a central oepning the lower extent of which defines a peripheral dimension about the same as that of said preform less its rim area, a lower ring including a central opening the upper extent of which defines a peripheral dimension about the same as that of said preform less its rim area, a lip opening contoured out of at least one of said rings around the entire extent thereof and presenting a face angled from the horizontal sufficient to resist the retraction stress of the thermoplastic material of the preform, the inner surfaces of said rings adjacent their respective central openings being spaced from one another a distance no greater than the thickness of said preform and presenting opposed shoulders which together with said face secure the peripheral rim area of said preform, including its lip, in clamped fashion within said fixture priior to and during subsequent thermoforming of the preform into a container, cooling channels extending through at least one of said rings adjacent the rim receiving portion thereof sufficient to cool rapidly the rim area while leaving the central portion of said proform at a thermoformable temperature.
Claim 3
Dependent Claim
38 words
The apparatus of claim 1 wherein the peripheral edges of said central openings are chamfered outwardly from their inner extent to their outer extent, the inner extent of said central openings being in open communication with one another.
Claim 4
Dependent Claim
21 words
The apparatus of claim 2 wherein means is located within said central openings for forging said thermoplastic material into said preform.
Claim 5
Dependent Claim
43 words
The apparatus of claim 3 wherein said means comprises upper and lower platens adapted to fit within the chamfered openings within said upper and lower rings, respectively, and including means for driving said platens together to squeeze said thermoplastic material into said preform.
Claim 6
Dependent Claim
51 words
The apparatus of claim 4 wherein said upper and lower platens are located within said central openings for forging said thermoplastic material into said preform, the thermoplastic material engaging surfaces of said platens being contoured to distribute material in said preform for more uniform thermoforming of said preform into a container.
Claim 7
Dependent Claim
24 words
The apparatus of claim 2 wherein the rings have cooperating means to lock the same together for thermoforming of said preform into said container.
Claim 8
Dependent Claim
46 words
The apparatus of claim 2 wherein the upper ring has a plurality of notches cut out from the outer sides thereof, a spring detent carried within said lower ring mating with said notches to secure said rings together for thermoforming of said preform into said container.
Claim 9
Dependent Claim
55 words
The apparatus of claim 2 wherein the upper ring includes keyhold slots extending vertically through their periphery, the lower ring including headed lugs protruding through said slot with the heads of the lugs being locked with the narrow sections of the keyholes for securing said rings together for thermoforming of said preform into said container.
Claim 10
Independent Claim
274 words
An apparatus for scrapless forming of a thermoplastic article having a rim area with a finished molded lip, said apparatus comprising a ring-like forming fixture adapted to receive a measured amount of thermoplastic material to be forged into a preform which can subsequently be thermoformed into said article, said forming fixture comprising an upper ring with a central opening the lower extent of which defines a peripheral dimension about the same as that of said preform less its rim area, a lower ring including a central opening the upper extent of which defines a peripheral dimension about the same as that of said preform less its rim area, a lip opening contoured out of at least one of said rings at least partially about the extent thereof and presenting a lip opening angled from the horizontal to enable the preforms polymer when contained therein to resist the retraction stress of the thermoplastic material of the preform, the inner surfaces of said rings adjacent their respective central openings being spaced from one another a distance sufficiently close to the thickness of said preform to assist in resisting said retraction stress and presenting opposed shoulders which together with said lip secure the peripheral rim area of said preform in clamped fashion within said fixture prior to and during subsequent thermoforming of the preform in the event the preform is thermoformed into a container, at least one of said rings hving cooling means adjacent the rim receiving portion thereof sufficient to cool rapidly the rim area while leaving the central portion of said preform at a thermoformable temperature in the event subsequent thermoforming is desired without reheating.
Claim 11
Independent Claim
274 words
An apparatus for scrapless forming of a thermoplastic article having a rim area with a finished molded lip, said apparatus comprising a ring-like forming fixture adapted to receive a measured amount of thermoplastic material to be forged into a preform which can subsequently be thermoformed into said article, said forming fixture comprising an upper ring with a central opening the lower extent of which defines a peripheral dimension about the same as that of said preform less its rim area, a lower ring including a central opening the upper extent of which defines a peripheral dimension about the same as that of said preform less its rim area, a lip opening contoured out of at least one of said rings at least partially about the extent thereof and presenting a lip opening angled from the horizontal to enable the preforms polymer when contained therein to resist the retraction stress of the thermoplastic material of the preform, the inner surfaces of said rings adjacent their respective central openings being spaced from one another a distance sufficiently close to the thickness of said preform to assist in resisting said retraction stress and presenting opposed shoulders which together with said lip secure the peripheral rim area of said preform in clamped fashion within said fixture prior to and during subsequent thermoforming of the preform in the event the preform is thermoformed into a container, at least one of said rings hving cooling means adjacent the rim receiving portion thereof sufficient to cool rapidly the rim area while leaving the central portion of said preform at a thermoformable temperature in the event subsequent thermoforming is desired without reheating.
Claim 12
Dependent Claim
28 words
The apparatus of claim 9 wherein said lip opening is angled sufficiently to fully enable the preform polymer therein to remain in place during operation of the apparatus.
Claim 13
Dependent Claim
65 words
The apparatus of claim 9 wherein at least one of said rings includes at said lip opening a cut-out at a substantial angle to the inner surface of said ring to enable the thermoplastic material of the article located said cut-out together with the rest located in the lip opening to fully enable the thermoplastic material to remain in place during operation of the apparatus.
Claim 14
Dependent Claim
28 words
The apparatus of claim 11 wherein said cut-out presents a face substantially at a riight angle to the inner surface of the ring in which it is located.
Claim 15
Dependent Claim
31 words
The apparatus of claim 11 wherein said cut-out is of generally saw-tooth shape and extends in the same general direction from the inner surface of the ring as said lip opening.
Claim 16
Dependent Claim
20 words
The apparatus of claim 9 wherein said cooling means comprises cooling channels extending through at least one of said rings.
Claim 17
Independent Claim
203 words
An apparatus for scrapless forming of a thermoplastic article having a rim area with a finished molded lip, said apparatus comprising a forming fixture adapted to receive a measured amount of thermoplastic material to be forged into said article, said forming fixture comprisng a first clamp means with a centrral opening defining a peripheral dimension about the same as that of said article less its rim area, a second clamp means including a central opening defining a peripheral dimension about the same as that of said article less its rim area, a lip opening contoured out of at least one of said clamp means at least partially about the extent thereof, said lip opening including a cut-out presenting a face at an angle to the clamp means surface sufficient to enable the thermoplastic material of the article to resist the retraction stress of the thermoplastic material, inner surfaces of said clamp means adjacent their respective central openings being spaced form one another a distance sufficiently close to the thickness of said article to assist in resisting said retraction stress and presenting opposed shoulders which together with said lip opening secure the peripheral rim area of said article in clamped fashion within said fixture.
Claim 18
Independent Claim
203 words
An apparatus for scrapless forming of a thermoplastic article having a rim area with a finished molded lip, said apparatus comprising a forming fixture adapted to receive a measured amount of thermoplastic material to be forged into said article, said forming fixture comprisng a first clamp means with a centrral opening defining a peripheral dimension about the same as that of said article less its rim area, a second clamp means including a central opening defining a peripheral dimension about the same as that of said article less its rim area, a lip opening contoured out of at least one of said clamp means at least partially about the extent thereof, said lip opening including a cut-out presenting a face at an angle to the clamp means surface sufficient to enable the thermoplastic material of the article to resist the retraction stress of the thermoplastic material, inner surfaces of said clamp means adjacent their respective central openings being spaced form one another a distance sufficiently close to the thickness of said article to assist in resisting said retraction stress and presenting opposed shoulders which together with said lip opening secure the peripheral rim area of said article in clamped fashion within said fixture.
Claim 19
Dependent Claim
23 words
The apparatus of claim 15 wherein said first clamp means comprises an upper ring and said second clamp means comprises a lower ring.
Claim 20
Dependent Claim
34 words
The apparatus of claim 15 wherein said lip opening extends substantially laterally outwardly from the central opening and includes a plurality of said cut-outs extending into the inner surfaces of both said clamp means.
Claim 21
Dependent Claim
24 words
The apparatus of claim 17 wherein cooling means in the form of radiating fins extend outwardly from the outer periphery of said clamp means.
Claim 22
Dependent Claim
60 words
The apparatus of claim 15 wherein said article is a preform adpated to be subsequently thermoformed into a final article, at least one of said clamp means having cooling means adjacent the rim receiving portion thereof sufficient to cool rapidly the rim area while leaving the central portion of the preform at a thermoformable temperatue for subsequent thermoforming without reheating.
Claim 23
Dependent Claim
29 words
The apparatus of claim 15 wherein said cut-outs present a face substantially at a right angle to the inner surfaces of the clamp means in which they are located.
Claim 24
Dependent Claim
25 words
The apparatus of claim 20 wherein a cut-out on one clamp means is laterally disposed with respect to a cut-out in the other clamp means.
References Cited (Backward Citations)
US2541923A
Cited
US3324511A
Cited
US3271501A
Cited
US3551954A
Cited
US3488805A
Cited
US3695806A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |