US3749544A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preform reshaping means having web distortion control device
Assignee: PI ACQUISITION Inc
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Filing: 1971-08-20
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Granted: 1973-07-31
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Expires: 1991-08-20
Abstract
Abstract An apparatus for the forming of articles from a continuous web of plastic material is described. Certain of such materials are subject to longitudinal shrinkage, causing deformation of the finished articles, and means are provided for applying longitudinal tensions to the web to counteract the shrinkage effect. The tensioning means comprise a plurality of roller pairs spaced transversely across the path of the web, each pair adapted to frictionally engage the web. The roller speeds are adjusted to exert a constant tension on the web as it is incrementally or intermittently indexed through the forming apparatus and compensate for the deformation resulting from shrinkage.
Inventors
- 👤 F Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:16
CPC Classifications
B; B29; B29C; B29C51/00; B29C51/26; B29C51/261; B29C2795/00; B29C2795/002
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
125 words
In apparatus for producing hollow three dimensional articles from an elongated web of shrinkable material including pressure forming means adapted to shape one or more of the desired articles in said web at one time and means for feeding said web to said forming means and removing it therefrom after actuation of said forming means, said feeding means including transport means adapted to move along a path passing said forming means and firmly engaging said web along both edges thereof, the improvement comprising web distortion control tensioning means engaging said web at a location subsequent to said forming means for applying longitudinal tension to said web between the edges thereof as it moves through said apparatus to prevent said web from becoming distorted by shrinkage.
Claim 2
Dependent Claim
125 words
In apparatus for producing hollow three dimensional articles from an elongated web of shrinkable material including pressure forming means adapted to shape one or more of the desired articles in said web at one time and means for feeding said web to said forming means and removing it therefrom after actuation of said forming means, said feeding means including transport means adapted to move along a path passing said forming means and firmly engaging said web along both edges thereof, the improvement comprising web distortion control tensioning means engaging said web at a location subsequent to said forming means for applying longitudinal tension to said web between the edges thereof as it moves through said apparatus to prevent said web from becoming distorted by shrinkage.
Claim 3
Dependent Claim
34 words
Apparatus as set forth in claim 1 above for producing said articles from a web of biaxially oriented plastic material, further comprising means for heating said web prior to its reaching said forming means.
Claim 4
Dependent Claim
42 words
Apparatus as set forth in claim 1 wherein said tensioning means comprises a plurality of tensioning units disposed transversely of the path of said web, and means for individually controlling the tension applied to said web by each of said tensioning units.
Claim 5
Dependent Claim
108 words
Apparatus as set forth in claim 3 above wherein each of said tensioning units includes first and second rollers respectively disposed on opposite sides of said web as it moves through said apparatus, the peripheral surfaces of said rollers being arranged to frictionally engage the web therebetween, means for driving one of said rollers to rotate at a plurality of predetermined speeds in the direction of movement of said web, and means for urging the other of said rollers towards said one roller thereby to frictionally engage the web therebetween substantially without slippage between said rollers and said web and apply substantially constant tension forces to said web.
Claim 6
Dependent Claim
39 words
Apparatus as in claim 4 wherein said driven roller has a substantially unyielding, knurled peripheral surface and said other roller has a peripheral contact surface provided by an elastomeric O-ring retained in a circumferential groove in said other roller.
Claim 7
Dependent Claim
53 words
Apparatus as in claim 5 further comprising a common driving shaft for the driven rollers of all of said tensioning units, motor means for rotating said common shaft, and common support means for said other rollers of all of said units, each of said urging means for said other rollers being independently adjustable.
Claim 8
Dependent Claim
38 words
Apparatus as in claim 6 wherein each of said other rollers is mounted on said support means by means of a one-way clutch operable to enable said other roller to rotate only in the direction of web movement.
Claim 9
Dependent Claim
80 words
Apparatus as in claim 6 wherein said web feeding means is operative to move said web by successive incremental lengths to said forming means, said web being stationary during actuation of said forming means, said apparatus further comprising speed control means for said motor means, said speed control means being operative in synchronism with said web feeding means to increase the speed of said motor during movement of said web and decrease its speed during actuation of said forming means.
Claim 10
Dependent Claim
96 words
Apparatus as in claim 8 wherein said motor means comprises a compressed air actuated motor and said speed control means includes a source of compressed air, a plurality of pressure regulating valves coupled to said source, means coupling one of said valves to said motor and means including a solenoid actuated valve coupling the other of said valves to said motor, said solenoid opening its associated valve just prior to the feeding of the next incremental length of web to said forming means and permitting said associated valve to close when said forming means is actuated.
Claim 11
Dependent Claim
45 words
Apparatus as in claim 9 wherein said pressure regulating valve coupled to said motor through the solenoid actuated valve supplies air at a higher pressure than the other regulating valve, whereby the speed of said motor is higher during actuation of said solenoid actuated valve.
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) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |