US4381639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sheath-core yarn for severe thermal protecting fabrics and method therefor
Assignee: Record Industrial Co
•
Filing: 1980-06-19
•
Granted: 1983-05-03
•
Expires: 2000-06-19
Abstract
Abstract A sheath-core yarn and methods of preparing it are disclosed. A sheath of aramid fibers surrounds a continuous filament core composed of an amorphous silica product containing at least 96% silica and having the thermal performance of a refractory material. The yarn is useful in woven or knitted safety garments which must provide protection under such severe conditions as splattering molten steel.
Inventors
- 👤 Robert R. Kress
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:41
CPC Classifications
D; D02; D02G; D02G3/00; D02G3/44; D02G3/443; D02G3/22; D02G3/36; D10; D10B; D10B2101/00; D10B2101/10; D10B2101/14; D10B2331/00; D10B2331/02; D10B2331/021; Y; Y10; Y10S; Y10S57/00; Y10S57/904
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
36 words
A yarn comprising a sheath spun from a roirng of aramid fibers surrounding a continuous filament core of an amorphous silica product containing at least 96% silica and having the thermal performance of a refractory material.
Claim 2
Dependent Claim
36 words
A yarn comprising a sheath spun from a roirng of aramid fibers surrounding a continuous filament core of an amorphous silica product containing at least 96% silica and having the thermal performance of a refractory material.
Claim 3
Dependent Claim
22 words
The yarn of claim 1 in which the aramid fibers include a substantial proportion having tensile strengths of at least 20 gm/denier.
Claim 4
Dependent Claim
22 words
The yarn of claim 1 in which the aramid fibers constitute about 30% to 50% of the total weight of the yarn.
Claim 5
Dependent Claim
21 words
The yarn of claim 1 in which the proportion of aramid fibers to continuous filament core is about 40:60 by weight.
References Cited (Backward Citations)
US3572397A
Cited
US3952496A
Cited
US3729920A
Cited
US3913309A
Cited
US4074512A
Cited
US3844195A
Cited
US4015038A
Cited
US4159618A
Cited
US4202382A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-02 | 1986-11-01 | 1987-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-02 | 1990-11-01 | 1991-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-02 | 1994-11-01 | 1995-05-03 | $7700.00 | Window Closed / Lapsed |