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US3793104A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for restoring and covering suction couch shells

Assignee: Lawron Ind Ltd
•
Filing: 1972-03-31
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Granted: 1974-02-19
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Expires: 1992-03-31
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Abstract

Abstract A process for restoring and covering suction couch shells, which shells consist of a metal cylinder perforated by multiple drainage holes, when the drainage holes have become badly affected by outer surface cavitation due to abrasive particles in the water. The process comprises the steps of: cleaning and roughening the metal surface of the holes as well as the outer surface of the cylinder; winding around the outer surface of the cylinder plural layers of a polyethylene tape; winding a reinforcing layer of a transparent cellulose tape over the polyethylene tape; pouring a thermosetting resin into the drainage holes from the inside of the cylinder and allowing the resin to set; removing the polyethylene and the re-inforcing transparent cellulose tapes; winding under tension on the outer surface of the cylinder successive layers of a woven glass or synthetic fibre tape impregnated with a thermosetting resin; heat treating the cylinder; and redrilling the holes.

Inventors

  • 👤 S Harrowing

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 19:54
CPC Classifications
B; B29; B29C; B29C63/00; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1052; Y10T156/1056; Y10T156/1057

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 25 words
A process as defined in claim 1, wherein the cleaning and roughening step is performed by blasting using either angular steel or aluminum oxide grit.
Claim 2
Dependent Claim 25 words
A process as defined in claim 1, wherein the polyethylene tape is 4 to 6 inches in width and 0.002 to 0.004 inch in thickness.
Claim 3
Dependent Claim 22 words
A process as defined in claim 1, wherein each turn of polyethylene tape overlaps the preceding turn by 50 to 75 percent.
Claim 4
Dependent Claim 19 words
A process as defined in claim 1, wherein the reinforcing tape of transparent cellulose is approximately 4 inches wide.
Claim 5
Dependent Claim 50 words
A process as defined in claim 1, wherein the inside of the cylinder is divided into equal longitudinal segments and the thermosetting resin poured into the holes in each bottom segment, the width of each segment depending on the radius of the cylinder and varying from 6 to 18 inches.
Claim 6
Dependent Claim 39 words
A process as defined in claim 6, wherein the cylinder is rotated until the next segment is in the bottom position and the procedure repeated until all the holes in all the segments are filled and the resin set.
Claim 7
Dependent Claim 30 words
A process as defined in claim 6, wherein the dispersion of the thermosetting resin into the holes is accelerated and made uniform by means of a rubber doctor or squeegee.
Claim 8
Dependent Claim 22 words
A process as defined in claim 1, wherein the woven glass or synthetic fibre tape is 4 to 6 inches in width.
Claim 9
Dependent Claim 26 words
A process as defined in claim 1, wherein the concentratioN of thermosetting resin in the woven glass or synthetic fibre tape is 35 to 40 percent.
Claim 10
Dependent Claim 37 words
A process as defined in claim 1, wherein the turns of woven glass or synthetic fibre tapes are overlapped by 25 to 50 percent and the angle of wrap of such tape is from 10* to 15*.

References Cited (Backward Citations)

US1988640A Cited
US2009848A Cited
US2115543A Cited
US2977269A Cited
US3063888A Cited
US3519520A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-02-18 1977-08-20 1978-02-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-02-18 1981-08-20 1982-02-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-02-18 1985-08-20 1986-02-19 $7700.00 Window Closed / Lapsed

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