US3751208A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum forming machine
Assignee: Upchurch H and Co Ltd
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Filing: 1971-06-21
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Granted: 1973-08-07
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Expires: 1991-06-21
Abstract
Abstract A machine for vacuum forming plastics sheets has a perforated mould platform above a vacuum reservoir. A valve is operable to place the holes in the platform in communication with the reservoir. Heating means are located above the platform. A carrier frame is movable up and down between the heating means and the mould platform. This frame carries at its underside a clamping frame to receive a plastics sheet. The clamping frame, which is at least partially separable from the carrier frame, is clampable to the latter by adjustable toggle clamps. The carrier frame is movable by a handle first upwards to present a sheet to the heating means and then downwards to clamp the clamping frame in an airtight manner upon the platform with the softened sheet drawn in an airtight manner over a mould.
Inventors
- 👤 P Hepworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:31
CPC Classifications
B; B29; B29C; B29C51/00; B29C51/18; B29C51/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
414 words
Apparatus for vacuum-forming a sheet of heat-softenable plastic material to the shape of a mould on a support comprising, in combination: a perforated mould-platform for supporting mould means upon which a sheet of plastic material will be shaped; vacuum-reservoir means operatively connected to said mouldplatform; means for selectively communicating said vacuum-reservoir means to said mould-platform to supply a forming-vacuum thereat to shape a conditioned sheet juxtaposed thereover; pump means operatively connected to said vacuum-reservoir means for maintaining a vacuum therein; fixed support means extending above said mould-platform; heating means connected to said support means and overlying said mould-platform in fixed relation thereto for conditioning a sheet of softenable plastic material exposed thereto; carrier-frame means displacable supported on said support means for traversing the space between said heating means and said mould-platform; clamping-frame means releasably supported on said carrier-frame means and including means for removably supporting a sheet of plastic in exposed relation when traversed between said heating means and mould-platform; and means for moving said carrier-frame and clamping-frame means through the space between said heating means and mould-platform for sequentially subjecting the sheet of plastic material to conditioning heat and a forming vacuum, said mould-platform including peripheral seal means confronting said carrier-frame and clamping-frame means for engagement thereby for substantially sealing the sheet of conditioned plastic material over said mould-platform and trapping a forming-vacuum thereat whereby the sheet of conditioned material is shaped according to said mould means; the improvement in which said support means comprises vertically extending guide pillars betwen said mould-platform and said heating means, said carrier-frame means including collars including bearing means telescopically received on said pillars for free vertical movement therealong in the space between said heating means and said mould-platform, handle means on said carrier frame for effecting the sequentional conditioning and forming operations for clampingly engaging the clamping-frame and carrier-frame means onto said peripheral seal means, said handle means including lever portions pivotally connected to fixed pivot portions above said collers for effecting a mechanical advantage as said handle means is urged downwardly, toggle links pivotally connected between intermediate portions of said lever portions and said collars for forcibly urging said carrier-frame clamping-frame means onto said mould-platform, said carrier-frame means including load-distributing end frame portions connected to said collars for insuring that downward force applied by said toggle links will be distributed onto corresponding portions of said mould platform of said peripheral seal means onto which the carrier-frame and clamping-frame means are forcibly urged by said handle means.
Claim 2
Dependent Claim
414 words
Apparatus for vacuum-forming a sheet of heat-softenable plastic material to the shape of a mould on a support comprising, in combination: a perforated mould-platform for supporting mould means upon which a sheet of plastic material will be shaped; vacuum-reservoir means operatively connected to said mouldplatform; means for selectively communicating said vacuum-reservoir means to said mould-platform to supply a forming-vacuum thereat to shape a conditioned sheet juxtaposed thereover; pump means operatively connected to said vacuum-reservoir means for maintaining a vacuum therein; fixed support means extending above said mould-platform; heating means connected to said support means and overlying said mould-platform in fixed relation thereto for conditioning a sheet of softenable plastic material exposed thereto; carrier-frame means displacable supported on said support means for traversing the space between said heating means and said mould-platform; clamping-frame means releasably supported on said carrier-frame means and including means for removably supporting a sheet of plastic in exposed relation when traversed between said heating means and mould-platform; and means for moving said carrier-frame and clamping-frame means through the space between said heating means and mould-platform for sequentially subjecting the sheet of plastic material to conditioning heat and a forming vacuum, said mould-platform including peripheral seal means confronting said carrier-frame and clamping-frame means for engagement thereby for substantially sealing the sheet of conditioned plastic material over said mould-platform and trapping a forming-vacuum thereat whereby the sheet of conditioned material is shaped according to said mould means; the improvement in which said support means comprises vertically extending guide pillars betwen said mould-platform and said heating means, said carrier-frame means including collars including bearing means telescopically received on said pillars for free vertical movement therealong in the space between said heating means and said mould-platform, handle means on said carrier frame for effecting the sequentional conditioning and forming operations for clampingly engaging the clamping-frame and carrier-frame means onto said peripheral seal means, said handle means including lever portions pivotally connected to fixed pivot portions above said collers for effecting a mechanical advantage as said handle means is urged downwardly, toggle links pivotally connected between intermediate portions of said lever portions and said collars for forcibly urging said carrier-frame clamping-frame means onto said mould-platform, said carrier-frame means including load-distributing end frame portions connected to said collars for insuring that downward force applied by said toggle links will be distributed onto corresponding portions of said mould platform of said peripheral seal means onto which the carrier-frame and clamping-frame means are forcibly urged by said handle means.
Claim 3
Dependent Claim
53 words
Apparatus as claimed in claim 1 in which said mould-Platform, carrier-frame and clamping-frame means are all rectangular in shape and of substantially the same peripheral size, said vertical guide pillars being disposed medially of the opposed ends of said mould platform and said vacuum-reservoir means, said vacuum-reservoir means being disposed beneath said mould-platform.
Claim 4
Dependent Claim
70 words
A vacuum forming machine according to claim 2, wherein the heating means comprise an electrical heating element which is encased within a casing open at the bottom and having a closed top surmounted by a protective heat-insulating cover, the said casing providing a heat-reflecting shroud for the heating element and being supported within a fixed mounting frame carried by and at the upper ends of the two vertical guide pillars.
Claim 5
Dependent Claim
76 words
Apparatus according to claim 2, wherein the clamping-frame means is hingedly connected along one side to the corresponding side of the carrier-frame means and is thus adapted to be turned upwardly at its other side to fit flat against the underside of the carrier-frame means, with a plastics sheet held betwen the two means, and adjustable toggle clamps are provided to secure these means together in readiness for upward and downward movements thereof as a unit.
Claim 6
Dependent Claim
37 words
A vacuum forming machine according to claim 3, wherein the casing of the electrical heating element has mounted therein an electrically driven paddle fan arranged to distribute the heated air and thereby even out the heating effect.
Claim 7
Dependent Claim
73 words
A vacuum forming machine according to claim 1, wherein spring means are provided for urging the vertically movable carrier-frame means upwards, said spring means comprising at least one spring reel of tape carried by a fixed part at the upper ends of one vertical guide pillar, the free ends of the tape being connected to one collar and the reel tending to wind up suchwise as to exert upward pulls on the collar.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |