US3566741A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tubular, seamless, dual-hardness armor plate
Assignee: NIUCLEAR METALS INC A CORP OF MASS
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Filing: 1969-06-09
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Granted: 1971-03-02
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Expires: 1989-06-09
Abstract
Abstract Seamless, dual-hardness, tubular armor plate is formed from a brittle impact-resistant outer shell metallurgically bonded to a ductile inner shell by coextrusion of the two shells. Central hollow cores of either simple or complex shape are readily formed. The resultant structure has superior resistance to impact as compared to homogeneous cylinders or welded bimetallic cylinders.
Inventors
- 👤 Joseph L Sliney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:27
CPC Classifications
B; B21; B21C; B21C23/00; B21C23/22; B21C33/00; B21C33/004; F; F16; F16L; F16L9/00; F16L9/02; F41; F41H; F41H5/00; F41H5/02; F41H5/04; F41H5/0442; F41H5/045
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
117 words
Tubular, seamless, dual-hardness armor for resistance to penetration by ballistic projectiles, said armor comprising a first seamless, continuous cylindrical shell of a tough but ductile metallic material having a hardness on the Rockwell C scale of from 45 to 53, said shell defining a hollow core, encased within a second seamless, continuous cylindrical shell of a hard but brittle metallic material having a hardness on the Rockwell C scale of from 57 to 63, said second shell surrounding said first shell and being joined thereto along lateral mating surfaces by a metallurgical bond whereby the brittle second shell is protected from fracture on impact with a projectile by said ductile first shell to which it is bonded.
Claim 2
Dependent Claim
117 words
Tubular, seamless, dual-hardness armor for resistance to penetration by ballistic projectiles, said armor comprising a first seamless, continuous cylindrical shell of a tough but ductile metallic material having a hardness on the Rockwell C scale of from 45 to 53, said shell defining a hollow core, encased within a second seamless, continuous cylindrical shell of a hard but brittle metallic material having a hardness on the Rockwell C scale of from 57 to 63, said second shell surrounding said first shell and being joined thereto along lateral mating surfaces by a metallurgical bond whereby the brittle second shell is protected from fracture on impact with a projectile by said ductile first shell to which it is bonded.
Claim 3
Dependent Claim
19 words
Tubular armor according to claim 1 in which said second shell has a diameter of less than 3 inches.
Claim 4
Dependent Claim
46 words
Tubular armor according to claim 1 in which said first shell comprises a hardenable carbon steel having a carbon content of from 0.2 to 0.4 percent by weight and in which said second shell has a carbon content of from 0.5 to 0.65 percent by weight.
Claim 5
Dependent Claim
68 words
Tubular armor according to claim 3 in which said first and second shells are formed from alloy steel having: from 0.7 to 1 weight percent Mn; from 0.2 to 0.35 weight percent Si; from 1 to 3.5 weight percent Ni; from 0.5 to 1.25 weight percent Cr; from 0.4 to 0.6 weight percent Mo; not more than 0.01 weight percent P; not more than 0.01 weight percent S.
References Cited (Backward Citations)
US3511283A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |