US3608877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for treating circular saw blades
Assignee: United States Steel Corp
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Filing: 1970-11-09
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Granted: 1971-09-28
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Expires: 1990-11-09
Abstract
Abstract An apparatus for hardening the teeth and tooth roots of a saw blade used for cutting hot steel shapes. Blade rotates, while its teeth and roots are heated to the austenitizing temperature and quenched by a stationary induction-heating unit and a stationary quenching device. Shield applied to blade to prevent reheating and softening of portion first heated as it reenters heating unit. The hardening treatment forestalls failure through fatigue cracking at the roots.
Inventors
- 👤 Edward H Dehn
- 👤 Fernand J Dewez Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:40
CPC Classifications
C; C21; C21D; C21D9/00; C21D9/24; B; B23; B23D; B23D65/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
100 words
Apparatus for heat treating the teeth and tooth roots of a circular saw blade comprising: means for rotatably supporting the blade; a stationary induction heating unit supported adjacent the circumferential edge of the blade for heating a localized portion of the blade including a tootH and an adjacent root to the austenitizing temperature; a stationary quenching device supported adjacent the circumferential edge of the blade spaced from said unit; and a shielding device placed over the teeth and roots which already have been heated and quenched as these teeth and roots approach said unit on continued rotation of the blade.
Claim 2
Dependent Claim
100 words
Apparatus for heat treating the teeth and tooth roots of a circular saw blade comprising: means for rotatably supporting the blade; a stationary induction heating unit supported adjacent the circumferential edge of the blade for heating a localized portion of the blade including a tootH and an adjacent root to the austenitizing temperature; a stationary quenching device supported adjacent the circumferential edge of the blade spaced from said unit; and a shielding device placed over the teeth and roots which already have been heated and quenched as these teeth and roots approach said unit on continued rotation of the blade.
Claim 3
Dependent Claim
28 words
An apparatus as defined in claim 1 in which said quenching device is spaced a maximum of about one-fifteenth the circumference of the blade from said heating unit.
Claim 4
Dependent Claim
62 words
An apparatus as defined in claim 1 in which said heating unit includes: a length of copper tubing shaped to provide a pair of spaced-apart circumferential legs, a pair of spaced-apart radial legs extending at right angles to the circumferential legs, and a transverse leg connecting the radial legs; and blocks of nonconducting ferromagnetic material mounted on said circumferential and radial legs.
Claim 5
Dependent Claim
62 words
An apparatus as defined in claim 1 in which said shielding device includes a water-cooled manifold fitting over the circumferential edge of the blade, sideplates depending from said manifold encompassing the sides of the blade, a hook depending from one end of said manifold and fitting over a tooth, and means carried by said sideplates for attaching the shield to a blade.
References Cited (Backward Citations)
US2816848A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |