US3760729A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hermetically sealed plastic cartridge case/cap system
Assignee: United States Department of the Army
•
Filing: 1971-12-21
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Granted: 1973-09-25
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Expires: 1991-12-21
Abstract
Abstract A container, such as a cartridge case for an illuminant star signal, comprises a molded case of fiberglass reinforced rigid thermoplastic resin possessing a cap of similar but unreinforced resin ultrasonically welded thereto to provide a hermetically sealed unit. Due to the dissimilarity in fiberglass content of the cap and case materials, the cartridge possesses a line of reproducible weakness along the weld line. Signal cartridges of this type are capable of failing reliably along said weld line to achieve a highly reproducible narrow altitude range of star trajectory and reliable star ignition.
Inventors
- 👤 D Freeman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:40
CPC Classifications
F; F42; F42B; F42B7/00; F42B7/02; F42B7/12; F42B12/00; F42B12/02; F42B12/36; F42B12/40; F42B4/00; F42B4/02; F42B4/24; F42B5/00; F42B5/26; F42B5/30
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
128 words
A signal cartridge which comprises a cylindrical, one piece, molded case consisting essentially of fiberglass reinforced, rigid thermoplastic resin, an illuminant signal and propellant therefor contained in said case, and a molded cap consisting essentially of similar resin containing substantially less fiberglass and being structurally weaker than said case, wherein said cap is thermally welded to said case by fusion of the similar base resin in said cap and case to provide a hermetically sealed unit, said unit possessing a line of weakness along said weld line due to the difference in structural strengths of said cap and case, whereby the cartridge on functioning of the propellant fails along said weld line and provides a highly reproducible, narrow altitude range of illuminant trajectory and reliable illuminant signal ignition.
Claim 2
Dependent Claim
128 words
A signal cartridge which comprises a cylindrical, one piece, molded case consisting essentially of fiberglass reinforced, rigid thermoplastic resin, an illuminant signal and propellant therefor contained in said case, and a molded cap consisting essentially of similar resin containing substantially less fiberglass and being structurally weaker than said case, wherein said cap is thermally welded to said case by fusion of the similar base resin in said cap and case to provide a hermetically sealed unit, said unit possessing a line of weakness along said weld line due to the difference in structural strengths of said cap and case, whereby the cartridge on functioning of the propellant fails along said weld line and provides a highly reproducible, narrow altitude range of illuminant trajectory and reliable illuminant signal ignition.
Claim 3
Dependent Claim
15 words
A cartridge according to claim 1, wherein said cap is ultrasonically welded to said case.
Claim 4
Dependent Claim
28 words
A cartridge according to claim 2, wherein the rigid thermoplastic resin is selected from the group consisting of polyphenylene oxide resins, polycarbonate resins, polystyrene resins, and styrene-acrylonitrile resins.
Claim 5
Dependent Claim
30 words
A cartridge according to claim 3, wherein the amount of fiberglass in the fiberglass reinforced resin of said case is between about 5 percent and about 50 percent by weight.
Claim 6
Dependent Claim
52 words
A cartridge according to claim 4, wherein the fiberglass reinforced resin of said case possesses a tensile strength of at least about 13,000 psi over the temperature range of -65*F to + 160*F. and the cap resin possesses a tensile strength at least about 5000 psi less than that of the case.
Claim 7
Dependent Claim
48 words
A cartridge according to claim 4, wherein the case consists essentially of between about 60 and 80 percent by weight of polyphenylene oxide resin and between about 20 and 40 percent by weight of fiberglass and the cap consists essentially of the same resin containing substantially no fiberglass.
Claim 8
Dependent Claim
30 words
A cartridge according to claim 1, wherein the case possesses a thick cored base and the ratio of base thickness to case wall thickness is not substantially greater than 2.
Claim 9
Dependent Claim
61 words
A cartridge according to claim 7, wherein the cap is a concave disc having a circumferential flange and a thickened center section for preventing cracking of the cap during ultrasonic welding thereof to the case, said flange being seated on and ultrasonically welded to the rim of said case with the concave side of the cap facing outwardly of the case.
Claim 10
Dependent Claim
14 words
A cartridge according to claim 8, wherein the resin is a polyphenylene oxide resin.
References Cited (Backward Citations)
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Cited
US3099958A
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US3144827A
Cited
US3298311A
Cited
US3468731A
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US3537397A
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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) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |