US3689986A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of casting composite cam shafts
Assignee: Nippon Piston Ring Co Ltd
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Filing: 1970-08-26
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Granted: 1972-09-12
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Expires: 1990-08-26
Abstract
Abstract A method of casting a cam shaft with an axial oil passage comprising inserting a core rod into a steel pipe in closely fitted relation, coating the solid core on its outer periphery with a releasing agent of low thermal conductivity, placing the core and pipe assembly in a mould with the solid core aligned with the axis of a cam shaft to be formed, and pouring molten metal around the core assembly in the mould. Thereafter, upon completion of the casting, the solid core is withdrawn from the pipe to thereby form the aligned oil passage, within the cam shaft.
Inventors
- 👤 Kentaro Takahashi
- 👤 Yoshihito Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:28
CPC Classifications
B; B22; B22D; B22D19/00; B22D19/0072; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4998; Y10T29/49988; Y10T29/49989
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
127 words
A method of casting a cam shaft with an axial steel pipe embedded therein to provide an axial oil passage in the cam shaft, said method comprising the steps of forming an assembly of a steel pipe with a solid core rod inserted therein, providing a coating of a releasing agent of low thermal conductivity between the core rod and pipe, placing said assembly in a mold with the solid core rod aligned with the axis of a cam shaft to be formed, pouring molten metal into the mold around the core assembly, allowing the molten metal to solidify on the steel pipe to become united therewith, and thereafter withdrawing said solid core from said assembly thereby to form the aligned oil passage within said steel pipe.
Claim 2
Independent Claim
127 words
A method of casting a cam shaft with an axial steel pipe embedded therein to provide an axial oil passage in the cam shaft, said method comprising the steps of forming an assembly of a steel pipe with a solid core rod inserted therein, providing a coating of a releasing agent of low thermal conductivity between the core rod and pipe, placing said assembly in a mold with the solid core rod aligned with the axis of a cam shaft to be formed, pouring molten metal into the mold around the core assembly, allowing the molten metal to solidify on the steel pipe to become united therewith, and thereafter withdrawing said solid core from said assembly thereby to form the aligned oil passage within said steel pipe.
Claim 3
Dependent Claim
59 words
A method as claimed in claim 1, further including the step of plating the outer cylindrical surface of the steel pipe with a low melting metal before said molten metal is poured around the core assembly, thereby causing the low melting metal to melt, upon said pouring, to bond the steel pipe with the body of the cam shaft.
Claim 4
Dependent Claim
37 words
A method as claimed in claim 1 comprising drilling radial passages in said cam shaft through the cast metal and steel pipe to provide communication between the axial passage and the outer periphery of the cam shaft.
Claim 5
Dependent Claim
31 words
A method as claimed in claim 1 wherein said core rod is made of a heat resisting steel to provide mechanical strength to said assembly to resist bending forces applied thereto.
References Cited (Backward Citations)
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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) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |