US3820419A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of reducing stress concentration and cracking failures in carbide tipped saws
Assignee: The McLagan Co
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Filing: 1973-08-08
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Granted: 1974-06-28
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Expires: 1993-08-08
Abstract
Abstract Stress concentration and cracking failures in the tooth and gullet regions of carbide-tipped saws are eliminated by heating the saw after the carbide tips have been silver soldered thereto to a temperature above the temperature at which the plate hardness is reduced to a hardness at which glass bead peening can achieve penetration of the surface metal and then simultaneously glass bead peening the edge and opposite sides of the saw in the peripheral region thereof.
Inventors
- 👤 Lagan E Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:32
CPC Classifications
B; B23; B23D; B23D63/00; B23D63/18; Y; Y10; Y10T; Y10T29/00; Y10T29/47; Y10T29/479
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
114 words
In the manufacture of circular saws having carbide tips metal-joined to the periphery of a generally circular steel plate and wherein the metal in the gullet regions of said saws becomes excessively hard at least as a result of the metal-joining of the carbide tips and hence, subject to stress concentration failure, the improvement comprising: heating the saw after the carbide tips have been metal-joined to the periphery thereof to reduce its hardness throughout to a hardness at which shot peening can achieve penetration of the metal surface; and then shot peening said saw at least in the gullet regions thereof to relieve surface tension therein and place the surface metal thereof in compression.
Claim 2
Dependent Claim
114 words
In the manufacture of circular saws having carbide tips metal-joined to the periphery of a generally circular steel plate and wherein the metal in the gullet regions of said saws becomes excessively hard at least as a result of the metal-joining of the carbide tips and hence, subject to stress concentration failure, the improvement comprising: heating the saw after the carbide tips have been metal-joined to the periphery thereof to reduce its hardness throughout to a hardness at which shot peening can achieve penetration of the metal surface; and then shot peening said saw at least in the gullet regions thereof to relieve surface tension therein and place the surface metal thereof in compression.
Claim 3
Dependent Claim
17 words
The method of claim 1 in which the peripheral region of said saw is glass bead peened.
Claim 4
Dependent Claim
23 words
The method of claim 2 in which said saw is glass bead peened simultaneously on opposite sides and on the peripheral edge thereof.
Claim 5
Dependent Claim
95 words
In the manufacture of carbide-tipped circular saws, the method comprising silver soldering carbide tips to the periphery of a circular steel plate; then heating the plate to reduce the hardness throughout to a hardness at which glass bead peening can achieve penetration of the steel surface; and then simultaneously glass bead peening the edge and at least the peripheral regions of the plate on opposite sides thereof to relieve surface tension and place the surface metal in compression, thereby to eliminate stress concentration and cracking failures in the tooth and gullet regions of the saw.
Claim 6
Dependent Claim
95 words
In the manufacture of carbide-tipped circular saws, the method comprising silver soldering carbide tips to the periphery of a circular steel plate; then heating the plate to reduce the hardness throughout to a hardness at which glass bead peening can achieve penetration of the steel surface; and then simultaneously glass bead peening the edge and at least the peripheral regions of the plate on opposite sides thereof to relieve surface tension and place the surface metal in compression, thereby to eliminate stress concentration and cracking failures in the tooth and gullet regions of the saw.
Claim 7
Dependent Claim
67 words
The method of claim 4 in which the steel plate is heated by placing the same in a preheated oven; raising the oven temperature to a temperature above the temperature at which the plate hardness is reduced to a hardness at which glass bead peening can achieve penetration of the steel surface; and then slowly reducing the oven temperature at least to that of the preheated oven.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |