US3822680A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Isothermal valve seat for internal combustion engine
Assignee: Automotive Engine Associates LP
•
Filing: 1973-01-11
•
Granted: 1974-07-09
•
Expires: 1993-01-11
Abstract
Abstract A valve seat for internal combustion engines including a heat pipe passage around the seat to assure that the valve seat is uniformly the same temperature all around even if the cooling of the valve seat from the engine head is not even all around. The heat pipe passage is a gas tight passage including wicked surfaces to assure that the valve seat is uniformly wet and containing a working fluid which is a liquid with a high vapor pressure under the operating temperature range of the valve seat. When the valve seat is heated, fluid evaporates from hot portions, absorbing the heat of vaporization, and the vapor flows hydrodynamically to of vaporization, cooler portions of the heat pipe surface, where the vapor recondenses at the same temperature, giving up its heat of vaporization. The gas contained in the heat pipe volume is totally or predominantly the working fluid vapor, so that the heat pipe always responds to maintain its entire surface area at an even temperature (this temperature will vary from time to time, but at any given time the entire surface of the heat pipe passage will be isothermal). Uniform valve seat temperatures produce uniform expansion so valve seats stay in round, leak less unburned hydrocarbon, and last longer.
Inventors
- 👤 M Showalter
- 👤 S Rhine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:57
CPC Classifications
F; F28; F28D; F28D15/00; F28D15/02; F28D15/04; F01; F01L; F01L3/00; F01L3/22; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49229; Y10T29/49298; Y10T29/49306
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
160 words
A valve seat having no thermal distortion of the valve sealing surface, said valve seat having a valve sealing surface, a gas tight hollow annular passage radially symmetric with the valve sealing surface, said annular passage containing part of its volume as liquid and part as gas, said liquid having a vapor pressure in excess of atmospheric pressure at normal valve seat operating temperatures, said annular passage being substantially free of non-condensable gas pockets, the surface of said annular passage being covered by a wicking means, the annular passage containing sufficient liquid so that all of the wicking means is maintained wet at the highest operating temperature of the annular passage whereby evaporation and condensation of the liquid in the passage virtually eliminates temperature differences between points on the passage surface, and therefore produces a more nearly radially symmetric temperature distribution in said valve seat so that unsymmetric thermal stresses cannot occur to cause distortion of the valve sealing surface.
Claim 2
Dependent Claim
160 words
A valve seat having no thermal distortion of the valve sealing surface, said valve seat having a valve sealing surface, a gas tight hollow annular passage radially symmetric with the valve sealing surface, said annular passage containing part of its volume as liquid and part as gas, said liquid having a vapor pressure in excess of atmospheric pressure at normal valve seat operating temperatures, said annular passage being substantially free of non-condensable gas pockets, the surface of said annular passage being covered by a wicking means, the annular passage containing sufficient liquid so that all of the wicking means is maintained wet at the highest operating temperature of the annular passage whereby evaporation and condensation of the liquid in the passage virtually eliminates temperature differences between points on the passage surface, and therefore produces a more nearly radially symmetric temperature distribution in said valve seat so that unsymmetric thermal stresses cannot occur to cause distortion of the valve sealing surface.
Claim 3
Dependent Claim
25 words
The invention as set forth in claim 1 and wherein a portion of the wicking means is rust formed from the material forming the passage.
Claim 4
Dependent Claim
24 words
introducing into the aforesaid groove a solid substance which sublimes to a gas at a temperature below the melting point of said working fluid,
Claim 5
Dependent Claim
24 words
introducing into the aforesaid groove a solid substance which sublimes to a gas at a temperature below the melting point of said working fluid,
Claim 6
Dependent Claim
24 words
introducing into the aforesaid groove a solid substance which sublimes to a gas at a temperature below the melting point of said working fluid,
Claim 7
Dependent Claim
24 words
introducing into the aforesaid groove a solid substance which sublimes to a gas at a temperature below the melting point of said working fluid,
Claim 8
Dependent Claim
29 words
The invention as set forth in claim 1 and wherein a portion of the wicking means is a chemically formed porous surface formed from the material forming the passage.
Claim 9
Dependent Claim
50 words
introducing a chemical substance which reacts with gas formed by said subliming substance at a temperature above the melting point of said working fluid, C. inserting said valve seat with a cylinder head where the shrink fit contact between said valve seat and said head forms a gas tight seal.
Claim 10
Dependent Claim
50 words
introducing a chemical substance which reacts with gas formed by said subliming substance at a temperature above the melting point of said working fluid, C. inserting said valve seat with a cylinder head where the shrink fit contact between said valve seat and said head forms a gas tight seal.
Claim 11
Dependent Claim
78 words
introducing a chemical substance which reacts with gas formed by said subliming substance at a temperature above the melting point of said working fluid. C. attaching the valve seat to the valve head, D. inserting said valve seat-valve assembly into a cylinder head wherein said valve-valve seat assembly is placed under compression by installation of the valve spring on said valve, where the shrink fit contact between said valve seat and said head forms a gas tight seal.
Claim 12
Dependent Claim
78 words
introducing a chemical substance which reacts with gas formed by said subliming substance at a temperature above the melting point of said working fluid. C. attaching the valve seat to the valve head, D. inserting said valve seat-valve assembly into a cylinder head wherein said valve-valve seat assembly is placed under compression by installation of the valve spring on said valve, where the shrink fit contact between said valve seat and said head forms a gas tight seal.
Claim 13
Dependent Claim
50 words
The invention as set forth in claim 1 and wherein the hollow annular cooling passage radially symmetric with the valve sealing surface of the valve seat structure is formed by the joining of a valve seat insert including an encircling groove with the head structure of an internal combustion engine.
Claim 14
Independent Claim
58 words
A method of assembling a heat pipe valve seat having an encircling groove therein into the head of an internal combustion engine by shrink fit comprising the steps of A. cooling the heat pipe valve seat to a temperature below the freezing point of the heat pipe working fluid, Pg,12 B. introducing into the encircling groove the following:
Claim 15
Independent Claim
58 words
A method of assembling a heat pipe valve seat having an encircling groove therein into the head of an internal combustion engine by shrink fit comprising the steps of A. cooling the heat pipe valve seat to a temperature below the freezing point of the heat pipe working fluid, Pg,12 B. introducing into the encircling groove the following:
Claim 16
Dependent Claim
32 words
The invention as set forth in claim 5 and wherein the chemical substance which reacts with gas formed by said subliming substance is a part of the structure of said valve seat.
Claim 17
Independent Claim
61 words
A method of assembling a heat pipe valve seat having an encircling groove therein and its associated valve into the head of an internal combustion enging of shrink fit comprising the steps of A. cooling the heat pipe valve seat to a temperature below the freezing point of the heat pipe working fluid, B. introducing into the encircling groove the following:
Claim 18
Independent Claim
61 words
A method of assembling a heat pipe valve seat having an encircling groove therein and its associated valve into the head of an internal combustion enging of shrink fit comprising the steps of A. cooling the heat pipe valve seat to a temperature below the freezing point of the heat pipe working fluid, B. introducing into the encircling groove the following:
Claim 19
Dependent Claim
43 words
The invention as set forth in claim 7 and wherein the method of attaching the valve seat to the valve head is by freezing a liquid between said valve head and said valve seat to hold said valve head and valve seat together.
References Cited (Backward Citations)
US1748518A
Cited
US1670965A
Cited
US2369063A
Cited
US2467060A
Cited
US3081754A
Cited
US3701342A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-08 | 1978-01-07 | 1978-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-08 | 1982-01-07 | 1982-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-08 | 1986-01-07 | 1986-07-09 | $7700.00 | Window Closed / Lapsed |