Patent US3755862A successfully refreshed from Google Patents.
US3755862A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Machine for simultaneous biaxial stretching of a web of thermoplastic sheeting
Assignee: Erwin Kampf GmbH and Co Maschinenfabrik
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Filing: 1971-11-26
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Granted: 1973-09-04
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Expires: 1991-11-26
Abstract
Abstract A web stretching machine has serially arranged gripper driving screws extending at angles relative to each other. Helical coil springs are secured to adjacent ends of adjacent screws to define flexible gripper advancing helixes for the continuous driving of grippers from screw to screw.
Inventors
- 👤 U Molz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:17
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/02; B29C55/10; B29C55/12; B29C55/16; B29C55/165; D; D06; D06C; D06C3/00; D06C3/02; D06C3/021
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
149 words
In a machine for simultaneous biaxial stretching of a web of thermoplastic sheet material and having a preliminary treatment zone, a stretching zone, an after treatment zone, guide rails for guiding grippers through said zones sequentially and return from the end of said after treatment zone to the start of said preliminary treatment zone, adjustably angularly related rigid driving screws, having helical grooves therein, arranged to advance grippers through said zones sequentially, and drive means for rotating said screws and for returning said grippers to said start, the improvement comprising: adjacent ends of angularly related screws being axially spaced apart and at least one resiliently flexible helical spring freely spanning the space between said ends and secured to said screws, said spring having a surface defining an uninterrupted smooth continuation of the gripper driving surface of the guide grooves of said screws and being of substantially the same diameter.
Claim 2
Dependent Claim
149 words
In a machine for simultaneous biaxial stretching of a web of thermoplastic sheet material and having a preliminary treatment zone, a stretching zone, an after treatment zone, guide rails for guiding grippers through said zones sequentially and return from the end of said after treatment zone to the start of said preliminary treatment zone, adjustably angularly related rigid driving screws, having helical grooves therein, arranged to advance grippers through said zones sequentially, and drive means for rotating said screws and for returning said grippers to said start, the improvement comprising: adjacent ends of angularly related screws being axially spaced apart and at least one resiliently flexible helical spring freely spanning the space between said ends and secured to said screws, said spring having a surface defining an uninterrupted smooth continuation of the gripper driving surface of the guide grooves of said screws and being of substantially the same diameter.
Claim 3
Dependent Claim
33 words
A machine as defined in claim 1 wherein each end of said spring is received and secured in a cut-away portion of the corresponding screw at one side of the guide groove thereof.
Claim 4
Dependent Claim
45 words
A machine as defined in claim 2 wherein two of said helical springs are provided between said screws, said springs being spaced apart a distance substantially equal to the width of said guide grooves and respectively defining continuations of the respective sides of said grooves.
References Cited (Backward Citations)
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US3148765A
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US3178012A
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US3445887A
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US3590985A
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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) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |