US3914101A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for forming corrugated tubing
Assignee: Norbalt Rubber Corp
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Filing: 1974-06-03
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Granted: 1975-10-21
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Expires: 1994-06-03
Abstract
Abstract A method and apparatus for forming corrugated tubing is disclosed. The corrugated tubing is formed from a cylindrical uncured tube of plastically deformable material. Such tube is inflated in a separable mold to an intermediate shape in which shallow extended corrugations are provided. The intermediate tube is subsequently placed on a curing mandrel in the final shape required and is cured. The apparatus for forming the intermediate tube includes separable mold halves each consisting of a plurality of separate corrugation forming sections and two end forming sections. The initial tube is positioned over an inflatable mandrel having spaced elastic sleeves and is enclosed within the mold halves. The sleeves extend to deform the ends of the initial tube and form a seal therewith. Subsequently, air under pressure is admitted to the interior of the tube to complete its inflation. The number of corrugations formed in the tube can be changed by removing or inserting corrugation forming sections in the active portion of the mold halves. Similarly, the type of end formed on the tube can be changed by changing the end forming sections in the mold halves.
Inventors
- 👤 Joseph Anthony Stefanka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:01
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/42; B29C49/48; B29C33/00; B29C33/30; B29C33/301; B29C33/302; B29C33/44; B29C33/48; B29C33/50; B29C33/505; B29C49/44; B29C2049/4879; B29C2049/4881; B29C43/00; B29C43/02; B29C43/10; B29C43/12; B29C53/00; B29C53/22; B29L; B29L2023/00; B29L2023/18; Y; Y10; Y10S; Y10S425/00; Y10S425/044
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
113 words
An apparatus for forming corrugated tubing comprising a separable mold which can be opened and closed, said mold when closed providing an interior mold surface having spaced portions shaped to form the ends of such tube and an intermediate portion shaped to form extended corrugations, an inflation mandrel providing a radially expandable member enclosed within said mold when said mold is closed operable when pressurized to radially expand from its deflated position to radially deform an initial cylindrical tube of plastically deformable material into mating engagement with said mold thereby forming an uncured intermediate tube, said mold when opened and said mandrel is deflated permitting removal of said intermediate tube without substantial distortion.
Claim 2
Independent Claim
113 words
An apparatus for forming corrugated tubing comprising a separable mold which can be opened and closed, said mold when closed providing an interior mold surface having spaced portions shaped to form the ends of such tube and an intermediate portion shaped to form extended corrugations, an inflation mandrel providing a radially expandable member enclosed within said mold when said mold is closed operable when pressurized to radially expand from its deflated position to radially deform an initial cylindrical tube of plastically deformable material into mating engagement with said mold thereby forming an uncured intermediate tube, said mold when opened and said mandrel is deflated permitting removal of said intermediate tube without substantial distortion.
Claim 3
Dependent Claim
23 words
An apparatus as set forth in claim 1 wherein said mold includes separate end forming sections which may be separately removed and replaced.
Claim 4
Dependent Claim
27 words
An apparatus as set forth in claim 1 wherein said mold includes a plurality of similar and separate corrugation forming sections cooperating to provide said intermediate portion.
Claim 5
Dependent Claim
33 words
An apparatus as set forth in claim 3 wherein said corrugation forming sections can be removed or inserted in said intermediate portion to change the number of corrugations formed in said intermediate tube.
Claim 6
Dependent Claim
60 words
An apparatus as set forth in claim 4 wherein said mold includes two separable assemblies each of which provides two separate end forming sections and a plurality of corrugation forming sections, and releasable mounting means to secure said assemblies together, release of said mounting means permitting changing of the number of corrugation forming sections between the associated end forming sections.
Claim 7
Dependent Claim
54 words
An apparatus as set forth in claim 5 wherein said assemblies each include corrugation forming sections on the side of at least one end forming section remote from said intermediate portion, and said one end forming section being removable to allow movement of selected corrugation forming sections into and out of said intermediate portion.
Claim 8
Dependent Claim
36 words
An apparatus as set forth in claim 1 wherein said inflation mandrel includes inflatable elastic means operable upon inflation to engage and laterally deform at least part of said initial tube into engagement with said mold.
Claim 9
Dependent Claim
32 words
An apparatus as set forth in claim 7 wherein said elastic means forms a fluid-tight joint with at least one end of said initial tube and allows pressUrization of said initial tube.
Claim 10
Dependent Claim
34 words
An apparatus as set forth in claim 7 wherein said elastic means forms a fluid-tight joint with both ends of said initial tube and allows pressurization of the intermediate portion of said initial tube.
Claim 11
Dependent Claim
30 words
An apparatus as set forth in claim 8 wherein said mandrel includes flow control means operable to cause inflation of said elastic means before substantial pressurization of said initial tube.
Claim 12
Dependent Claim
25 words
An apparatus as set forth in claim 10 wherein said flow control means includes at least two flow restriction means having different resistances to flow.
Claim 13
Dependent Claim
87 words
An apparatus as set forth in claim 1 wherein said mandrel includes a hollow rod the interior of which can be pressurized and exhausted, an elastic sleeve around said rod cooperating therewith to form an expansible chamber, said rod being formed with first passage means connecting the interior of said rod with said chamber and second passage means connecting the interior of said rod with the interior of said initial tube, and said second passage means provides a greater restriction to flow than said first passage means.
Claim 14
Dependent Claim
27 words
An apparatus as set forth in claim 12 wherein similar sleeves are provided on said rod at spaced locations on either side of said second passage means.
Claim 15
Dependent Claim
31 words
An apparatus for forming corrugated tubing as set forth in claim 1 including a support proportioned to receive said intermediate tube in its final shape and support said tube during curing.
Claim 16
Independent Claim
75 words
An apparatus for forming corrugated tubing comprising a separable mold providing an interior mold surface having spaced portions shaped to form the ends of such tube and intermediate portions shaped to form extended corrugations, means to inflate an intermediate tube of plastically deformable material into mating engagement with said mold, said mold including a plurality of similar and separate corrugation forming sections cooperating to provide said intermediate portions, and means releasably securing said sections together.
Claim 17
Independent Claim
75 words
An apparatus for forming corrugated tubing comprising a separable mold providing an interior mold surface having spaced portions shaped to form the ends of such tube and intermediate portions shaped to form extended corrugations, means to inflate an intermediate tube of plastically deformable material into mating engagement with said mold, said mold including a plurality of similar and separate corrugation forming sections cooperating to provide said intermediate portions, and means releasably securing said sections together.
Claim 18
Dependent Claim
31 words
An apparatus as set forth in claim 15 wherein said corrugation forming sections are removable and replaceable in said intermediate portions to change the numbers of corrugations formed in a tube.
Claim 19
Dependent Claim
64 words
An apparatus as set forth in claim 16 wherein said mold includes at least two separable assemblies each of which provides two separate end forming sections and a plurality of corrugation forming sections, and mounting means for releasably clamping said sections together, said mounting means being releasable to permit the changing of the number of corrugation forming sections between the associated end forming sections.
Claim 20
Dependent Claim
54 words
An apparatus as set forth in claim 17 wherein said assemblies each include corrugation forming sections on the side of at least one end forming section remote from said intermediate portion and said one end forming section is removable to allow movement of selected corrugation forming sections into and out of said intermediate portion.
Claim 21
Dependent Claim
17 words
An apparatus as set forth in claim 15 wherein removable end forming sections provide said spaced portions.
References Cited (Backward Citations)
US1358289A
Cited
US1884590A
Cited
US2616129A
Cited
US3194705A
Cited
US3258384A
Cited
US3290728A
Cited
US3371381A
Cited
US3743457A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |