Patent US3839133A successfully refreshed from Google Patents.
US3839133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transformer insulating end ring
Assignee: Permali Inc
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Filing: 1973-07-09
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Granted: 1974-10-01
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Expires: 1993-07-09
Abstract
Abstract A transformer end ring is formed from laminated sheets, at least some of which are formed from a rigid synthetic plastic material reinforced with fibers of inorganic insulating material disposed all around the central opening and forming at least one group of fibers in each sheet, the sheets being bonded together by the plastic. Substantially all of the fibers in each group in the end ring are substantially parallel to one another, and cross fibers in the adjoining sheets.
Inventors
- 👤 J Heighes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:27
CPC Classifications
B; B32; B32B; B32B17/00; B32B17/02; H; H01; H01B; H01B3/00; H01B3/18; H01B3/48; H01F; H01F27/00; H01F27/28; H01F27/30; H01F27/303; B32B2363/00; B32B2367/00; Y; Y10; Y10T; Y10T428/00; Y10T428/21; Y10T428/218; Y10T428/24; Y10T428/24058; Y10T428/24074
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
91 words
A transformer insulating end ring comprising laminated sheets provided with a central opening therethrough for a leg of a magnetic core, at least some of said sheets being a rigid synthetic plastic reinforced with fibers of inorganic insulating material, said fibers located all around said opening in at least one group in each sheet, substantially all of the fibers in each group in said laminated sheets being substantially parallel to one another and crossing fibers in the adjoining sheets, and said plastic bonding said sheets together into a rigid insulating ring.
Claim 2
Dependent Claim
91 words
A transformer insulating end ring comprising laminated sheets provided with a central opening therethrough for a leg of a magnetic core, at least some of said sheets being a rigid synthetic plastic reinforced with fibers of inorganic insulating material, said fibers located all around said opening in at least one group in each sheet, substantially all of the fibers in each group in said laminated sheets being substantially parallel to one another and crossing fibers in the adjoining sheets, and said plastic bonding said sheets together into a rigid insulating ring.
Claim 3
Dependent Claim
21 words
A transformer insulating end ring according to claim 1, in which all of the fibers in each sheet are substantially parallel.
Claim 4
Dependent Claim
54 words
A transformer insulating end ring according to claim 1, in which each of said sheets is circular in the form of a plurality of pie-shape sections, and the fibers in each of said sections are substantially parallel to a tangent to that section, whereby the fibers in the sheet extend around its central opening.
Claim 5
Dependent Claim
63 words
A transformer insulating end ring according to claim 1, in which each of said sheets is composed of a plurality of sections joined edge to edge, each section having a straight edge perpendicular to the parallel fibers therein and joined to a straight edge of an adjoining section, and said last-mentioned straight edge being substantially parallel to the fibers in said adjoining section.
Claim 6
Dependent Claim
40 words
A transformer insulating end ring according to claim 1, in which an end ring between 1.5 inches and 2 inches thick has a crossbreaking strength in excess of 80 lbs. per square inch X 103 over a 30 inch span.
Claim 7
Dependent Claim
21 words
A transformer insulating end ring according to claim 1, in which said fibers are resistant to temperatures between 100*C and 150*C.
Claim 8
Dependent Claim
17 words
A transformer insulating end ring according to claim 1, having positive thermal stability over its operating range.
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) | 1977-09-30 | 1978-04-01 | 1978-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-30 | 1982-04-01 | 1982-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-30 | 1986-04-01 | 1986-10-01 | $7700.00 | Window Closed / Lapsed |