US4476824A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mechanical control element having wear-resistant surface
Assignee: Individual
•
Filing: 1981-11-06
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Granted: 1984-10-16
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Expires: 2001-11-06
Abstract
Abstract Arrangement for providing an enhanced wear-resistant contact region for a cast iron mechanical control element such as a rocker arm. The control element is cast in a desired shape. It is then preheated to a temperature between room temperature and the Ms temperature of the iron element (Ms temperature is a function of the carbon content of the iron) to adjust the total hardness of the iron element. A surface region of a cast iron control element, intended for forming the contact region, is partially melted and then cooled to create a hard ledeburitic structure which has a mixed crystal structure and is at least partly martensitic and has a mixed hardness of at least 670 Hv.
Inventors
- 👤 Friedhelm Reinke
- 👤 Friedhelm Emde
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:53
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/06; C21D1/09; C21D5/00; Y; Y10; Y10S; Y10S148/00; Y10S148/902; Y10S148/91; Y10T; Y10T29/00; Y10T29/49; Y10T29/49229; Y10T29/49295
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
85 words
A mechanical control element formed by the following process: casting an iron element in a desired shape; preheating the iron element to a temperature up to about the Ms temperature of the iron element to adjust its total hardness; partially melting a surface region of the control element; and subsequently cooling the partially melted surface region to form a fine-grained, essentially ledeburitic structure which has a mixed crystal structure that is at least partly martensitic and has a mixed hardness of at least 670 Hv.
Claim 2
Dependent Claim
85 words
A mechanical control element formed by the following process: casting an iron element in a desired shape; preheating the iron element to a temperature up to about the Ms temperature of the iron element to adjust its total hardness; partially melting a surface region of the control element; and subsequently cooling the partially melted surface region to form a fine-grained, essentially ledeburitic structure which has a mixed crystal structure that is at least partly martensitic and has a mixed hardness of at least 670 Hv.
Claim 3
Dependent Claim
36 words
A mechanical control element according to claim 1 wherein the step of partially melting is carried out to a degree that causes the formation of the ledeburitic-martensitic contact region having a maximum thickness of 1 mm.
Claim 4
Independent Claim
88 words
A method for forming a mechanical control element comprising the following steps: casting an iron element in a desired shape; preheating the iron element to a temperature up to about the Ms temperature of the iron element to adjust its total hardness; partially melting a surface region of the control element; and subsequently cooling the partially melted surface region to form a fine-grained, essentially ledeburitic structure which has a mixed crystal structure that is at least partly martensitic and has a mixed hardness of at least 670 Hv.
Claim 5
Independent Claim
88 words
A method for forming a mechanical control element comprising the following steps: casting an iron element in a desired shape; preheating the iron element to a temperature up to about the Ms temperature of the iron element to adjust its total hardness; partially melting a surface region of the control element; and subsequently cooling the partially melted surface region to form a fine-grained, essentially ledeburitic structure which has a mixed crystal structure that is at least partly martensitic and has a mixed hardness of at least 670 Hv.
Claim 6
Dependent Claim
35 words
A method according to claim 3 wherein the step of partially melting is carried out to a degree that causes the formation of the ledeburitic-martensitic contact region to have a maximum thickness of 1 mm.
Claim 7
Dependent Claim
99 words
A control element for a control system of an engine, comprising: a cast iron element having a contact region for sliding on the surface of a control cam and having a hard, wear-resistant structure with a mixed hardness of at least 670 Hv and a maximum layer thickness of substantially 1 mm, the control element being formed in part by heating it to a temperature up to about its Ms temperature to adjust the total hardness of the element and then providing the contact region with a ledeburitic-martensitic structure by partially melting the surface region and then cooling it.
Claim 8
Dependent Claim
99 words
A control element for a control system of an engine, comprising: a cast iron element having a contact region for sliding on the surface of a control cam and having a hard, wear-resistant structure with a mixed hardness of at least 670 Hv and a maximum layer thickness of substantially 1 mm, the control element being formed in part by heating it to a temperature up to about its Ms temperature to adjust the total hardness of the element and then providing the contact region with a ledeburitic-martensitic structure by partially melting the surface region and then cooling it.
Claim 9
Dependent Claim
18 words
A control element according to claim 5 wherein the contact region has a maximum thickness of 1 mm.
Claim 10
Dependent Claim
28 words
A control element according to claim 5 wherein the contact region is formed by partially melting a marginal zone of the cast iron element and subsequently cooling it.
Claim 11
Dependent Claim
19 words
A control element according to claim 5 wherein the cast iron element comprises a heat treated cast iron element.
Claim 12
Dependent Claim
27 words
A control element according to claim 8 wherein the cast iron element comprises an element that has been heated up to its Ms temperature and then cooled.
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) | 1987-10-16 | 1988-04-16 | 1988-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-16 | 1992-04-16 | 1992-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-16 | 1996-04-16 | 1996-10-16 | $7700.00 | Window Closed / Lapsed |