US3594868A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Forming unit for use with apparatus for forming and cutting three-dimensional plastic articles
Assignee: Solo Cup Operating Corp
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Filing: 1969-10-13
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Granted: 1971-07-27
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Expires: 1989-10-13
Abstract
Abstract A forming unit for use in an integrated system which continuously extrudes a strip of foamed thermoplastic material, forms articles from the advancing strip, and cuts the formed articles therefrom. The unit consists of a rotatable forming wheel carrying a series of peripheral vacuum molds designed to form trays and other three-dimensional articles and sequentially connected to a source of vacuum. A vacuum chamber in each mold is connected with the cavity of the mold to form the articles and is also connected to a vacuum sheet sealing groove in the top surface of the upper edge of the mold, which, when vacuum is applied, secures the edges of the overlying strip of plastic material in place of the mold during the forming operation. Valve means are provided to control the application of vacuum to the molds and to the respective vacuum grooves.
Inventors
- 👤 Thomas W Winstead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:32
CPC Classifications
B; B29; B29C; B29C51/00; B29C51/26; B29C51/44; B29C51/445; B26; B26D; B26D7/00; B26D7/01; B26D7/018; B26F; B26F1/00; B26F1/38; B26F1/384; B29C44/00; B29C44/34; B29C44/36; B29C44/46; B29C44/50; B29C44/505; B29C48/00; B29C48/25; B29C48/30; B29C48/305; B29C51/18; B29C51/20; B29C51/22; B29C51/225; B29C48/03; B29C48/07; B29C48/08; B29C51/10; B29L; B29L2007/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
170 words
A forming wheel for manufacturing trays or the like from a sheet of thermoplastic material, comprising a rotatable body having a series of vacuum molds located successively about its periphery, each of said molds having a mold cavity bounded by upstanding walls, having at least one vacuum conduit, having at least one suction port connecting said conduit to said cavity, and having a vacuum sheet-sealing groove connected to said conduit and extending at least partially around the upper edge of said upstanding cavity walls, a source of vacuum, valve means operable upon the rotation of said wheel for controlling the application of vacuum to said vacuum conduits as said molds successively reach a predetermined location upon rotation of said wheel, and means for causing each sheet-sealing groove to be substantially evacuated for holding the sheet upon the associated mold before the mold cavity is substantially evacuated, the last said means comprising means for controlling the flow of gas from said cavity relative to the flow of gas from said groove.
Claim 2
Dependent Claim
170 words
A forming wheel for manufacturing trays or the like from a sheet of thermoplastic material, comprising a rotatable body having a series of vacuum molds located successively about its periphery, each of said molds having a mold cavity bounded by upstanding walls, having at least one vacuum conduit, having at least one suction port connecting said conduit to said cavity, and having a vacuum sheet-sealing groove connected to said conduit and extending at least partially around the upper edge of said upstanding cavity walls, a source of vacuum, valve means operable upon the rotation of said wheel for controlling the application of vacuum to said vacuum conduits as said molds successively reach a predetermined location upon rotation of said wheel, and means for causing each sheet-sealing groove to be substantially evacuated for holding the sheet upon the associated mold before the mold cavity is substantially evacuated, the last said means comprising means for controlling the flow of gas from said cavity relative to the flow of gas from said groove.
Claim 3
Dependent Claim
23 words
Apparatus as claimed in claim 1, wherein said vacuum molds are independently mounted on said rotatable body and are respectively radially adJustable thereon.
Claim 4
Dependent Claim
24 words
Apparatus as claimed in claim 1, including means admitting atmospheric pressure to said molds for ejecting said articles from respective mold cavities after forming.
Claim 5
Dependent Claim
33 words
Apparatus as claimed in claim 1, wherein the last-mentioned means comprises means for restricting the flow connection of said cavity to said conduit relative to the connection of said groove to said conduit.
Claim 6
Dependent Claim
51 words
Apparatus in accordance with claim 1, wherein each mold comprises a base from which said walls project and in which said conduit is located, said conduit having an endless channel loop with a cross-channel connecting opposite sides of said loop, the upper edges of said walls being located in a plane.
References Cited (Backward Citations)
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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) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |