US3813026A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Accurately dimensioned smooth-surfaced multi-layer cardboard tubes and method of and apparatus for making the same
Assignee: Lhomme SA
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Filing: 1971-03-11
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Granted: 1974-05-28
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Expires: 1991-03-11
Abstract
Abstract In order to obtain helically wound multi-layer cardboard tubes of accurate diameter and very smooth external surface, the tubes are coated with a thermo-setting 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
- 👤 J Biancamaria
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:26
CPC Classifications
B; B31; B31C; B31C3/00; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1303; Y10T428/31504; Y10T428/31971; Y10T428/31975; Y10T428/31978; Y10T428/31982
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
74 words
A multi-layer, helically wound cardboard tube comprising, in combination: A. a basic tube; B. a compressed penultimate strip of low-density, compressible material helically wound about said basic tube, adjacent edges of consecutive turns of said strip disposed in a close, nonoverlapping relation; C. an outer strip of high-density material helically wound about and slightly glued to said penultimate strip; and D. an external polymerized thermosetting layer coherently covering the outside of said outer strip.
Claim 2
Dependent Claim
74 words
A multi-layer, helically wound cardboard tube comprising, in combination: A. a basic tube; B. a compressed penultimate strip of low-density, compressible material helically wound about said basic tube, adjacent edges of consecutive turns of said strip disposed in a close, nonoverlapping relation; C. an outer strip of high-density material helically wound about and slightly glued to said penultimate strip; and D. an external polymerized thermosetting layer coherently covering the outside of said outer strip.
Claim 3
Dependent Claim
21 words
A tube as defined in claim 1, wherein at least one edge of said outer strip is provided with a chamfer.
Claim 4
Dependent Claim
20 words
A tube as defined in claim 1, wherein the external face of said outer strip is provided with aligned fibers.
Claim 5
Dependent Claim
38 words
A tube as defined in claim 2, wherein both edges of said outer strip are provided with a chamfer said penultimate layer completely fills the space defined by the juxtaposed chamfers of adjacent edges of said outer strip.
Claim 6
Dependent Claim
36 words
A tube as defined in claim 4, wherein said penultimate strip and said outer strip are glued together by a polymerized adhesive thermosetting resin layer forming a seal at adjacent chamfered edges of said outer strip.
Claim 7
Dependent Claim
13 words
A tube as defined in claim 1, wherein said low-density material is fibrous.
Claim 8
Dependent Claim
18 words
A tube as defined in claim 1, wherein said high-density material is a dense material having long fibers.
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) | 1977-05-27 | 1977-11-26 | 1978-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-27 | 1981-11-26 | 1982-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-27 | 1985-11-26 | 1986-05-28 | $7700.00 | Window Closed / Lapsed |