US4969262A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making camshaft
Assignee: Nippon Piston Ring Co Ltd
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Filing: 1990-03-20
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Granted: 1990-11-13
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Expires: 2010-03-20
Abstract
Abstract A method of making a camshaft of the type having a cam piece composed of outer and inner layers which comprises the steps of molding a green cam piece in a manner that the outer and inner layers are respectively made from powders of outer-layer and inner-layer forming materials, fitting the green cam piece on a steel shaft to produce a green camshaft assembly, and sintering said green camshaft assembly at a temperature in which the materials shrink and yield a liquid phase to produce a camshaft having a cam piece diffusion-bonded to the outer periphery of the shaft. The outer-layer forming material is prepared to have an axial shrinkage of 4 to 10% and shrink more than said inner-layer forming material prepared to have an axial shrinkage of 2.5 to 6%.
Inventors
- 👤 Takeshi Hiraoka
- 👤 Shunsuke Takeguchi
- 👤 Satoshi Kawai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:41
CPC Classifications
F; F01; F01L; F01L1/00; F01L1/02; F01L1/04; F01L1/047; B; B22; B22F; B22F7/00; B22F7/06; B22F7/062; F16; F16H; F16H53/00; F16H53/02; F16H53/025; B22F2998/00; F01L2301/00; Y; Y10; Y10T; Y10T29/00; Y10T29/17; Y10T29/49; Y10T29/49229; Y10T29/49286; Y10T29/49293; Y10T29/49826; Y10T29/49863; Y10T29/49865; Y10T29/51; Y10T29/5124; Y10T29/5127; Y10T29/5133; Y10T74/00; Y10T74/21; Y10T74/2101
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
113 words
A method of making a camshaft comprising the steps of molding a green cam piece composed of outer and inner layers which are respectively formed from outer-layer and inner-layer forming materials, each being adapted to shrink and yield a liquid phase when sintered, fitting said green cam piece onto a steel shaft, thereby producing a green camshaft assembly, and sintering said green camshaft assembly, thereby axially shrinking said outer layer from 4 to 10% and axially shrinking said inner layer from 2.5 to 6%, so that the outer layer shrinks more than the inner layer, whereby the camshaft assembly has a cam piece which is diffusion-bonded to the outer periphery of said shaft.
Claim 2
Independent Claim
113 words
A method of making a camshaft comprising the steps of molding a green cam piece composed of outer and inner layers which are respectively formed from outer-layer and inner-layer forming materials, each being adapted to shrink and yield a liquid phase when sintered, fitting said green cam piece onto a steel shaft, thereby producing a green camshaft assembly, and sintering said green camshaft assembly, thereby axially shrinking said outer layer from 4 to 10% and axially shrinking said inner layer from 2.5 to 6%, so that the outer layer shrinks more than the inner layer, whereby the camshaft assembly has a cam piece which is diffusion-bonded to the outer periphery of said shaft.
Claim 3
Dependent Claim
18 words
Thee method of claim 1, wherein said inner layer is smaller in axial length than said outer layer.
Claim 4
Dependent Claim
25 words
The method of claim 1, wherein said outer, layer-forming material comprises a Fe-C-Ni-Cr-Mo system alloy, and said inner, layer-forming material comprises a Fe-C-P system alloy.
Claim 5
Dependent Claim
25 words
The method of claim 1, wherein said outer, layer-forming material comprises a Fe-C-Ni-Cr-Mo system alloy, and said inner, layer-forming material comprises a Fe-C-P-Mo system alloy.
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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) | 1993-11-12 | 1994-05-14 | 1994-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-12 | 1998-05-14 | 1998-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-12 | 2002-05-14 | 2002-11-13 | $7700.00 | Window Closed / Lapsed |