US3580146A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making accurately dimensioned smooth-surfaced multi-layer cardboard tubes
Assignee: Menasha Corp
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Filing: 1969-02-07
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Granted: 1971-05-25
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Expires: 1989-02-07
Abstract
Abstract In order to obtain helically wound multilayer cardboard tubes of accurate diameter and very smooth external surface, the tubes are coated with a thermosetting resin and forced through the bore of a heated jacket to cause (1) curing of the resin and (2) reduction of the tube diameter to the precise desired dimensions. This reduction is taken up by a radially compressible layer of the tube.
Inventors
- 👤 Joseph Biancamaria
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:07
CPC Classifications
B; B31; B31C; B31C3/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
109 words
A method of making a multilayer, helically wound cardboard tube of predetermined diameter, comprising the following steps: A. helically winding a compressible strip of low-density material on a basic tube; B. helically winding an outer or last strip over said compressible strip; C. providing a thermosetting coating on said last strip, said coating forming the outer face of said multilayer, helically wound cardboard tube; D. forcing said tube through a die for reducing the outer diameter of said tube by causing radial compression of said compressible strip; and E. simultaneously with step subjecting said tube to a heat treatment in said die to effect polymerization of said thermosetting resin.
Claim 2
Independent Claim
109 words
A method of making a multilayer, helically wound cardboard tube of predetermined diameter, comprising the following steps: A. helically winding a compressible strip of low-density material on a basic tube; B. helically winding an outer or last strip over said compressible strip; C. providing a thermosetting coating on said last strip, said coating forming the outer face of said multilayer, helically wound cardboard tube; D. forcing said tube through a die for reducing the outer diameter of said tube by causing radial compression of said compressible strip; and E. simultaneously with step subjecting said tube to a heat treatment in said die to effect polymerization of said thermosetting resin.
Claim 3
Dependent Claim
34 words
A method as defined in claim 1, including the step of gluing sad last strip to said compressible strip with a thermosetting resin layer simultaneously with step (B), and polymerizing said last-named resin layer.
Claim 4
Dependent Claim
61 words
A method according to claim 1, wherein one edge of said outer strip is chamfered; said step (B) is performed in such a manner that the other edge of said outer strip overlaps the chamfered edge; subsequent to step (B) but prior to step (D) said tube is submitted to an abrading step to eliminate helical protrusions caused by said overlap.
Claim 5
Dependent Claim
44 words
A method as defined in claim 1, wherein subsequent to step (C), but prior to step (D) said tube is submitted to a drying step at a temperature sufficient to cause evaporation of solvents in said thermosetting resin, but insufficient to cauSe polymerization thereof.
Claim 6
Dependent Claim
15 words
A method as defined in claim 1, wherein said thermosetting resin contains a polymerization catalyst.
Claim 7
Dependent Claim
24 words
A method as defined in claim 1, wherein said tube is cut into predetermined lengths subsequent to step (B), but prior to step (D).
Claim 8
Dependent Claim
71 words
A method as defined in claim 1, wherein said basic tube is made by helically winding a plurality of strips in a superposed relationship, the winding pitch of each strip, except said outer strip, is at least as large as the strip width to prevent overlapping of the edges of the same strip; each strip is wound in such a manner as to overlap adjacent turns of the immediately underlying strip.
Claim 9
Dependent Claim
21 words
A method as defined in claim 1, wherein said outer strip is slightly glued to said compressible strip during step (B).
Claim 10
Dependent Claim
35 words
A method as defined in claim 1, wherein both edges of said outer strip are chamfered; said step (B) is performed in such a manner that the chamfered edges are arranged in an adjoining relationship.
Claim 11
Dependent Claim
32 words
A method as defined in claim 9, wherein during the winding of said outer strip adjoining chamfers of immediately adjacent turns slope towards one another and towards the inside of the tube.
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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) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |