US5175032A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat shrinkable closure sheets and sleeve structures and methods employing the same
Assignee: Shawcor Ltd
•
Filing: 1991-05-02
•
Granted: 1992-12-29
•
Expires: 2011-05-02
Abstract
Abstract A longitudinally heat shrinkable closure sheet has a hold-down adhesive portion adjacent each longitudinal end for application on the exposed end portions a heat shrinkable wrap-around sleeve applied around a pipe or other article to be covered. Heat is applied to the closure sheet in order to weld the adhesive free portion of the underside of the closure sheet to the end portions of wrap-around sleeve. The initial shrinkage of the closure sheet between the hold-down adhesive portions draws it tightly into contact with the upper side of the end portions. Shearing forces are applied between the closure sheet and the end portions firstly as the closure sheet contracts relative to the end portions, and secondly, as the sleeve shrinks, develops hoop stress and stretches the closure sheet, and a high strength fusion bond is achieved between the closure sheet and sleeve.
Inventors
- 👤 Robert E. Steele
- 👤 Michael A. Romano
- 👤 Dilip K. Tailor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:44
CPC Classifications
B; B29; B29C; B29C65/00; B29C65/48; B29C65/50; B29C65/5042; B29C61/00; B29C61/06; B29C61/10; B29C65/02; B29C65/10; B29C65/106; B29C65/4805; B29C65/481; B29C65/4815; B29C66/00; B29C66/01; B29C66/05; B29C66/10; B29C66/11; B29C66/112; B29C66/1122; B29C66/40; B29C66/41; B29C66/43; B29C66/432; B29C66/4322; B29C66/70; B29C66/72; B29C66/723; B29C66/73; B29C66/737; B29C66/7371; B29C66/73711; B29C66/73712; B29C66/73715; B29C66/90; B29C66/91; B29C66/912; B29C66/9121; B29C66/91211; B29C66/91218; B29C66/91221; B29C61/0608; B29C61/0666; B29C2061/0683; B29C65/14; B29C65/1403; B29C65/1412; B29C65/1477; B29C65/4825; B29C65/483; B29C65/4835; B29C66/49; B29C66/50; B29C66/51; B29C66/53; B29C66/532; B29C66/5326; B29C66/71; B29C66/739; B29C66/7392; B29K; B29K2995/00; B29K2995/0037; B29K2995/0049; B29L; B29L2009/00; F; F16; F16L; F16L58/00; F16L58/18; F16L58/181; Y; Y10; Y10S; Y10S174/00; Y10S174/08; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/1352; Y10T428/139; Y10T428/19; Y10T428/24; Y10T428/24777; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826
Claims Analysis
Total Claims: 64
Claim 1
Independent Claim
144 words
A heat shrinkable closure for a dimensionally heat unstable wrap-around covering, said closure comprising s fusion bondable sheet of flexible material having longitudinally spaced end portions, the material having been stretched from an original heat stable form to a dimensionally heat unstable form capable of moving in the direction of its original form by the application of heat alone, said sheet having on one side to be applied to said covering a hold-down adhesive portion extending across a zone transverse to said direction of stretch and adjacent each said end portion, and an adhesive free zone between said hold down adhesive portions whereby said closure can be applied over adjoining end portions adhesively bonded to the end portions of wrap-around covering and whereby said one side of the closure can be fusion bonded to the upper sides of said end portions of said covering.
Claim 2
Dependent Claim
144 words
A heat shrinkable closure for a dimensionally heat unstable wrap-around covering, said closure comprising s fusion bondable sheet of flexible material having longitudinally spaced end portions, the material having been stretched from an original heat stable form to a dimensionally heat unstable form capable of moving in the direction of its original form by the application of heat alone, said sheet having on one side to be applied to said covering a hold-down adhesive portion extending across a zone transverse to said direction of stretch and adjacent each said end portion, and an adhesive free zone between said hold down adhesive portions whereby said closure can be applied over adjoining end portions adhesively bonded to the end portions of wrap-around covering and whereby said one side of the closure can be fusion bonded to the upper sides of said end portions of said covering.
Claim 3
Dependent Claim
36 words
A closure as claimed in claim 1 wherein each hold-down adhesive portion is spaced inwardly from the adjacent end edge of the closure sheet, whereby marginal portions of said sheet can be welded to the covering.
Claim 4
Dependent Claim
30 words
A closure as claimed in claim 1 wherein said closure sheet exhibits on heating a shrinkage of about 2% to about 50%, based on the length of the unshrunk sheet.
Claim 5
Dependent Claim
16 words
A closure as claimed in claim 3 wherein said shrinkage is about 2% to about 25%.
Claim 6
Dependent Claim
16 words
A closure as claimed in claim 4 wherein said shrinkage is about 5% to about 20%.
Claim 7
Dependent Claim
15 words
A closure as claimed in claim 1 wherein said closure sheet is translucent or transparent.
Claim 8
Dependent Claim
27 words
A closure as claimed in claim 6 having a thermochromic indicator on said one side of said sheet and visible through said sheet from an opposite side.
Claim 9
Dependent Claim
45 words
A closure as claimed in claim 1 wherein said closure sheet comprises a polyolefin, a blend of polyolefins, a blend of a polyolefin with an olefin copolymer or with an elastomer or with a mixture thereof, an elastomer, a thermoplastic elastomer, or a mixture thereof.
Claim 10
Dependent Claim
15 words
A closure as claimed in claim wherein said closure sheet is a weld efficient polymer.
Claim 11
Dependent Claim
22 words
A closure as claimed in claim wherein said closure sheet material is crosslinked to a degree of about 25% to about 85%.
Claim 12
Dependent Claim
23 words
A closure as claimed in claim 10 wherein said closure sheet material is crosslinked to a degree of about 45% to about 70%.
Claim 13
Dependent Claim
45 words
A closure as claimed in claim 2 wherein said closure sheet comprises a polyolefin, a blend of polyolefins, a blend of a polyolefin with an olefin copolymer or with an elastomer or with a mixture thereof, an elastomer, a thermoplastic elastomer, or a mixture thereof.
Claim 14
Dependent Claim
16 words
A closure as claimed in claim 2 wherein said closure sheet is a weld efficient polymer.
Claim 15
Dependent Claim
23 words
A closure as claimed in claim 2 wherein said closure sheet material is crosslinked to a degree of about 25% to about 85%.
Claim 16
Dependent Claim
23 words
A closure as claimed in claim 2 wherein said closure sheet material is crosslinked to a degree of about 45% to about 70%.
Claim 17
Dependent Claim
22 words
A closure as claimed in claim wherein the recovered thickness of said closure sheet is about 0.01 to about 0.2 inches thick.
Claim 18
Dependent Claim
18 words
A closure as claimed in claim 16 wherein said thickness is each about 0.02 to about 0.1 inches.
Claim 19
Dependent Claim
16 words
A closure as claimed in claim 1 wherein the hold-down adhesive is a pressure sensitive adhesive.
Claim 20
Dependent Claim
24 words
A closure as claimed in claim 18 wherein the hold-down adhesive is an isobutylene polymer, or a blend of isobutylene polymers, with a filler.
Claim 21
Dependent Claim
22 words
A closure as claimed in claim 9 wherein the hold-down adhesive is not pressure-sensitive at ambient temperature but develops pressure-sensitivity when heated.
Claim 22
Dependent Claim
21 words
A closure as claimed in claim 9 wherein the hold-down adhesive is constituted by a strip of double-sided adhesive transfer tape.
Claim 23
Dependent Claim
199 words
A sleeve structure comprising a wrap-around covering and a closure therefor, said covering comprising a sheet of dimensionally heat unstable flexible material having longitudinally spaced end portions capable of being juxtaposed when the covering sheet is applied to an article to be covered, said closure comprising a sheet of flexible material fusion bondable with said covering sheet and having longitudinally spaced end portions, the material of each of the closure sheet and the covering sheet having been stretched in the longitudinal direction from an original dimensionally heat stable form to a dimensionally heat unstable form capable of moving in the direction of its original form by the application of heat alone, said closure sheet having on a side to be applied to said covering a hold-down adhesive portion extending across a transverse zone adjacent each said end portions, and an adhesive free zone between said hold-down adhesive portions whereby said closure can be applied over adjoining end portions of said wrap-around covering with said hold-down adhesive portions adhesively bonded to the end portions of said wrap-around covering and whereby said side of the closure can be fusion bonded to the upper sides of said end portions of said covering.
Claim 24
Dependent Claim
199 words
A sleeve structure comprising a wrap-around covering and a closure therefor, said covering comprising a sheet of dimensionally heat unstable flexible material having longitudinally spaced end portions capable of being juxtaposed when the covering sheet is applied to an article to be covered, said closure comprising a sheet of flexible material fusion bondable with said covering sheet and having longitudinally spaced end portions, the material of each of the closure sheet and the covering sheet having been stretched in the longitudinal direction from an original dimensionally heat stable form to a dimensionally heat unstable form capable of moving in the direction of its original form by the application of heat alone, said closure sheet having on a side to be applied to said covering a hold-down adhesive portion extending across a transverse zone adjacent each said end portions, and an adhesive free zone between said hold-down adhesive portions whereby said closure can be applied over adjoining end portions of said wrap-around covering with said hold-down adhesive portions adhesively bonded to the end portions of said wrap-around covering and whereby said side of the closure can be fusion bonded to the upper sides of said end portions of said covering.
Claim 25
Dependent Claim
37 words
The structure as claimed in claim 22 wherein each hold-down adhesive portion is spaced inwardly from the adjacent end edge of the closure sheet, whereby longitudinally marginal portions of said sheet can be welded to the covering.
Claim 26
Dependent Claim
31 words
The structure as claimed in claim 22 wherein said covering sheet exhibits on heating a longitudinal shrinkage of about 20% to about 80% based on the length of the unshrunk sheet.
Claim 27
Dependent Claim
31 words
The structure as claimed in claim 22 wherein said closure sheet exhibits on heating a longitudinal shrinkage of about 2% to about 50%, based on the length of the unshrunk sheet.
Claim 28
Dependent Claim
16 words
The structure as claimed in claim 25 wherein said shrinkage is about 2% to about 25%.
Claim 29
Dependent Claim
16 words
The structure as claimed in claim 26 wherein said shrinkage is about 5% to about 20%.
Claim 30
Dependent Claim
21 words
The structure as claimed in claim 22 wherein said closure sheet commences shrinkage at a lower temperature than said covering sheet.
Claim 31
Dependent Claim
29 words
The structure as claimed in claim 28 wherein said closure sheet strip commences shrinkage at a temperature about 5° C. to about 15° C. lower than said covering sheet.
Claim 32
Dependent Claim
15 words
The structure as claimed in claim 22 wherein said closure sheet is translucent or transparent.
Claim 33
Dependent Claim
30 words
The structure as claimed in clain 30 having a thermochromic indicator on said one side of said sheet and visible through said translucent or transparent sheet from an opposite side.
Claim 34
Dependent Claim
23 words
The structure as claimed in claim 22 wherein said closure sheet contains a colorant different from a colorant contained in said covering sheet.
Claim 35
Dependent Claim
56 words
The structure as claimed in claim 22 wherein said closure sheet and said covering sheet are of different chemical composition and each is a polyolefin, a blend of polyolefins, a blend of a polyolefin with an olefin copolymer or with an elastomer or with a mixture thereof, an elastomer, a thermoplastic elastomer, or a mixture thereof.
Claim 36
Dependent Claim
54 words
The structure as claimed in claim 22 wherein said closure sheet is a weld efficient polymer and said covering sheet is a polyolefin, a blend of polyolefins, a blend of a polyolefin with an olefin copolymer or with an elastomer or with a mixture thereof, an elastomer, a thermoplastic elastomer, or a mixture thereof.
Claim 37
Dependent Claim
23 words
The structure as claimed in claim 22 wherein said covering sheet material is crosslinked to a degree of about 25% to about 85%.
Claim 38
Dependent Claim
21 words
The structure as claimed in claim 35 wherein said closure sheet is crosslinked to a degree lower than said covering sheet.
Claim 39
Dependent Claim
23 words
The structure as claimed in claim 35 wherein said covering sheet material is crosslinked to a degree of about 45% to about 70%.
Claim 40
Dependent Claim
21 words
The structure as claimed in claim 37 wherein said closure sheet is crosslinked to a degree lower than said covering sheet.
Claim 41
Dependent Claim
28 words
The structure as claimed in claim 22 wherein the recovered thickness of said covering sheet and said closure sheet are each about 0.05 to about 0.2 inches thick.
Claim 42
Dependent Claim
18 words
The structure as claimed in claim 39 wherein said thicknesses are each about 0.02 to about 0.1 inches.
Claim 43
Dependent Claim
20 words
The structure as claimed in claim 22 wherein said covering sheet material has a functional coating on its inner side.
Claim 44
Dependent Claim
18 words
The structure as claimed in claim 41 wherein said functional coating is a sealant or an adhesive material.
Claim 45
Dependent Claim
16 words
The structure as claimed in claim 22 wherein the hold-down adhesive is a pressure sensitive adhesive.
Claim 46
Dependent Claim
24 words
The structure as claimed in claim 43 wherein the hold-down adhesive is an isobutylene polymer, or a blend of isobutylene polymers, with a filler.
Claim 47
Dependent Claim
22 words
The structure as claimed in claim 22 wherein the hold-down adhesive is not pressure-sensitive at ambient temperature but develops pressure-sensitivity when heated.
Claim 48
Dependent Claim
21 words
The structure as claimed in claim 43 wherein the hold-down adhesive is constituted by a strip of double-sided adhesive transfer tape.
Claim 49
Dependent Claim
30 words
The structure as claimed in claim 39 wherein said closure sheet is about 10 to about 80% thinner than said covering sheet, based on the thickness of the covering sheet.
Claim 50
Dependent Claim
30 words
The structure as claimed in claim 39 wherein said closure sheet is about 30 to about 60% thinner than said covering sheet based on the thickness of the covering sheet.
Claim 51
Dependent Claim
30 words
The structure as claimed in claim 39 wherein said closure sheet is about 10 to about 80% thicker than said covering sheet, based on the thickness of the covering sheet.
Claim 52
Dependent Claim
31 words
The structure as claimed in claim 39 wherein said closure sheet is about 30 to bout 60% thicker than said covering sheet, based on the thickness of the covering sheet material.
Claim 53
Dependent Claim
30 words
The structure as claimed in claim 22 wherein said covering sheet has been crosslinked by a method different from a method by which said closure sheet has been cross linked.
Claim 54
Independent Claim
185 words
A method of applying a close fitting protective covering to an article to be covered, comprising providing a covering sheet and a closure sheet each having longitudinal end portions and each having been stretched in the longitudinal direction from an original heat stable form to a dimensionally heat unstable form capable of moving in the direction of its original form by the application of heat alone, said closure sheet having on one side a hold-down adhesive portion extending across a transverse zone adjacent each end portion and an adhesive free zone between the hold-down adhesive portions, wrapping the covering sheet around the article by laying the sheet against the article and juxtaposing its end portions, applying the closure sheet to said covering sheet with its adhesive free zone spanning said end portions and bonding the hold-down adhesive covered portions on said end portions, respectively, heating the closure sheet to effect a fusion bond between the adhesive free zone of the closure sheet and said end portions of the covering sheet, and heating the covering sheet to shrink it into close fitting relation to the article.
Claim 55
Independent Claim
185 words
A method of applying a close fitting protective covering to an article to be covered, comprising providing a covering sheet and a closure sheet each having longitudinal end portions and each having been stretched in the longitudinal direction from an original heat stable form to a dimensionally heat unstable form capable of moving in the direction of its original form by the application of heat alone, said closure sheet having on one side a hold-down adhesive portion extending across a transverse zone adjacent each end portion and an adhesive free zone between the hold-down adhesive portions, wrapping the covering sheet around the article by laying the sheet against the article and juxtaposing its end portions, applying the closure sheet to said covering sheet with its adhesive free zone spanning said end portions and bonding the hold-down adhesive covered portions on said end portions, respectively, heating the closure sheet to effect a fusion bond between the adhesive free zone of the closure sheet and said end portions of the covering sheet, and heating the covering sheet to shrink it into close fitting relation to the article.
Claim 56
Dependent Claim
24 words
A method as claimed in claim 52 wherein the end portions of the covering sheet are butted together on the article to be covered.
Claim 57
Dependent Claim
23 words
A method as claimed in claim 52 wherein the end portions of the covering sheet are overlapped on the article to be covered.
Claim 58
Dependent Claim
35 words
A method as claimed in claim 52 wherein the covering sheet is heated by applying heat locally at the region opposite the closure sheet and then progressively along the covering sheet toward the closure sheet.
Claim 59
Dependent Claim
20 words
The structure as claimed in claim 22 wherein said covering sheet has different dimensional heat stability from said closure sheet.
Claim 60
Dependent Claim
18 words
The structure as claimed in claim 22 wherein said covering sheet has different color from said closure sheet.
Claim 61
Dependent Claim
19 words
The structure as claimed in claim 22 wherein said covering sheet has different chemical composition from said closure sheet.
Claim 62
Dependent Claim
20 words
The structure as claimed in claim 22 wherein said covering sheet has different degree of crosslinking from said closure sheet.
Claim 63
Dependent Claim
18 words
The structure as claimed in claim 22 wherein said covering sheet has different thickness from said closure sheet.
Claim 64
Dependent Claim
44 words
The structure as claimed in claim 51 wherein said crosslinking methods are selected from the group consisting of exposure to ionizing radiation, blending with organic peroxides, and formation of a polymer containing pendant silane groups and exposure to moisture to crosslink said silane groups.
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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) | 1995-12-29 | 1996-06-29 | 1996-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-12-29 | 2000-06-29 | 2000-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-12-29 | 2004-06-29 | 2004-12-29 | $7700.00 | Window Closed / Lapsed |