Patent US358432A successfully refreshed from Google Patents.
Patent US3965686A successfully refreshed from Google Patents.
US3965686A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drain sheet material
Assignee: Ohbayashi Gumi Ltd
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Filing: 1975-09-22
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Granted: 1976-06-29
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Expires: 1995-09-22
Abstract
Abstract A flexible elongated member is embedded in a coarse non-woven fabric layer. The flexible elongated member has partially opened circumferential portions through which water enters into the flexible member, the circumferential portions and inside thereof forming a continuous drain passage not blocked by deformation of the flexible member.
Inventors
- 👤 Jiro Saito
- 👤 Kaoru Kimura
- 👤 Hiroshi Kusuhara
- 👤 Kazuyoshi Nakaguma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:33
CPC Classifications
E; E02; E02D; E02D17/00; E02D17/20; E02B; E02B11/00; E02D3/00; E02D3/02; E02D3/10; E02D31/00; E02D31/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
96 words
A drain sheet element comprising: a non-woven fabric layer of coarse and thick structure formed of synthetic fibers of relatively high denier randomly interconnected mainly at their cross points; a plurality of elastic spiral springs linearly and parallelly positioned and embedded in the lengthwise direction of said fabric layer; and two non-woven fabric layers of dense and thin structure, one each entirely attached to and entirely covering opposite surfaces of said coarse and thick fabric layer, each of said dense and thin non-woven fabric layers being formed of randomly interconnected man-made fibers of relatively low denier.
Claim 2
Dependent Claim
96 words
A drain sheet element comprising: a non-woven fabric layer of coarse and thick structure formed of synthetic fibers of relatively high denier randomly interconnected mainly at their cross points; a plurality of elastic spiral springs linearly and parallelly positioned and embedded in the lengthwise direction of said fabric layer; and two non-woven fabric layers of dense and thin structure, one each entirely attached to and entirely covering opposite surfaces of said coarse and thick fabric layer, each of said dense and thin non-woven fabric layers being formed of randomly interconnected man-made fibers of relatively low denier.
Claim 3
Dependent Claim
136 words
A drain structure comprising: a plurality of spaced drain pipes, each composed of a water-permeable mat covering a perforated pipe; and a plurality of drain sheet elements placed to cross over said drain pipes in close contact therewith at their intersections, each of said drain sheet elements comprising a non-woven fabric layer of coarse and thick structure formed of synthetic fibers of relatively high denier randomly interconnected mainly at their cross points, at least one elastic spiral spring linearly positioned and embedded in the lengthwise direction of said fabric layer, and two non-woven fabric layers of dense and thin structure, one each attached to and entirely covering opposite surfaces of said coarse and thick fabric layer, each of said dense and thin non-woven fabric layers being formed of randomly interconnected man-made fibers of relatively low denier.
Claim 4
Dependent Claim
136 words
A drain structure comprising: a plurality of spaced drain pipes, each composed of a water-permeable mat covering a perforated pipe; and a plurality of drain sheet elements placed to cross over said drain pipes in close contact therewith at their intersections, each of said drain sheet elements comprising a non-woven fabric layer of coarse and thick structure formed of synthetic fibers of relatively high denier randomly interconnected mainly at their cross points, at least one elastic spiral spring linearly positioned and embedded in the lengthwise direction of said fabric layer, and two non-woven fabric layers of dense and thin structure, one each attached to and entirely covering opposite surfaces of said coarse and thick fabric layer, each of said dense and thin non-woven fabric layers being formed of randomly interconnected man-made fibers of relatively low denier.
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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) | 1979-06-29 | 1979-12-29 | 1980-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-29 | 1983-12-29 | 1984-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-29 | 1987-12-29 | 1988-06-29 | $7700.00 | Window Closed / Lapsed |