US4469530A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for reducing the hardening distortion during case hardening of large toothed rims formed of steel and support body members suitable for such purpose
Assignee: Maag Gear Wheel and Machine Co Ltd
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Filing: 1982-06-11
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Granted: 1984-09-04
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Expires: 2002-06-11
Abstract
Abstract To reduce the hardening distortion during the case hardening of large toothed rims or gear wheels formed of steel the toothed rim or the like during cooling thereof, starting from the hardening temperature, is shrunk during the γ/α transformation of its core material upon a support body member, and then there is limited, during the further cooling to room temperature, the increase of the stresses in the toothed rim in that the support body member is inserted into the toothed rim in a pre-heated condition. The material of the support body member has a greater coefficient of thermal expansion than that of the toothed rim.
Inventors
- 👤 Urs Wyss
- 👤 Johannes Federer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:34
CPC Classifications
C; C21; C21D; C21D9/00; C21D9/32; C21D9/0006; C21D9/0025; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49462; Y10T29/49465
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
113 words
A method for the reduction of the distortion on hardening during case hardening of large toothed rims formed of steel, comprising the steps of: shrinking the carburized toothed rim during cooling, starting from its hardening temperature where the steel is in its austenitic condition, and during the γ/α-transformation of its core material, onto a substantially disc-like support body member; further cooling the assembly composed of the toothed rim and the disc-like support body member; and during such further cooling of the assembly of the toothed rim and disc-like support body member down to room temperature limiting the increase of the stress in the toothed rim by means of said disc-like support body member.
Claim 2
Independent Claim
113 words
A method for the reduction of the distortion on hardening during case hardening of large toothed rims formed of steel, comprising the steps of: shrinking the carburized toothed rim during cooling, starting from its hardening temperature where the steel is in its austenitic condition, and during the γ/α-transformation of its core material, onto a substantially disc-like support body member; further cooling the assembly composed of the toothed rim and the disc-like support body member; and during such further cooling of the assembly of the toothed rim and disc-like support body member down to room temperature limiting the increase of the stress in the toothed rim by means of said disc-like support body member.
Claim 3
Dependent Claim
69 words
The method as defined in claim 1, further including the steps of: inserting a pre-heated disc-like support body member into the toothed rim in order to limit the increase of the stress in the toothed rim; and utilizing a disc-like support body member whose material possesses a greater coefficient of thermal expansion than the coefficient of thermal expansion of the material from which there is formed the toothed rim.
Claim 4
Dependent Claim
29 words
The method as defined in claim 2, further including the step of: preheating said disc-like support body member to a temperature in the range of 330° to 400° C.
Claim 5
Dependent Claim
50 words
The method as defined in claim 1, further including the steps of: arranging deformable parts on the outer side of the disc-like support body member; inserting said disc-like support body member into said toothed rim; and positioning said deformable parts intermediate said toothed rim and said disc-like support body member.
Claim 6
Dependent Claim
26 words
The method as defined in claim 1, further including the step of: quenching said toothed rim after said disc-like support body member has been inserted thereinto.
Claim 7
Dependent Claim
23 words
The method as defined in claim 1, wherein: there is used as the disc-like support body member a member formed of austenitic steel.
References Cited (Backward Citations)
CA558616A
Cited
US1561041A
Cited
US4179313A
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DE2652386A1
Cited
US4154628A
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US4376662A
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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) | 1987-09-04 | 1988-03-05 | 1988-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-04 | 1992-03-05 | 1992-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-04 | 1996-03-05 | 1996-09-04 | $7700.00 | Window Closed / Lapsed |