US3815558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scavenge porting system
Assignee: Individual
•
Filing: 1972-08-07
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Granted: 1974-06-11
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Expires: 1992-08-07
Abstract
Abstract In a two cycle internal combustion engine of the type which utilizes the underneath side of the power piston as a scavenge pump piston, the improvement which consists of extra height, piston valved scavenge ports which are additionally valved by reed valves located in the transfer passageway close to the scavenge ports, in order to increase the scavenge gas mass flow through capability of the cylinder, improve the scavenge gas flow pattern, or both.
Inventors
- 👤 W Tenney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:17
CPC Classifications
F; F02; F02B; F02B25/00; F02B75/00; F02B75/02; F02B2075/022; F02B2075/025; F02B2700/00; F02B2700/03; F02B2700/037
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
352 words
A two cycle engine having a cylinder and a power piston with a piston head timing edge and an underside, and which utilizes the underside as a piston of a scavenge pump system and which has scavenge ports located in a first portion of the cylinder adjacent a reference line along the piston timing edge with the piston in bottom dead center position, said cylinder having a distal end towards which the piston moves during the compression stroke, transfer passageway means leading from said scavenge pump system to the scavenge ports, said passageway means being elongated and extending close to the cylinder and generally in the same direction as the axis of said cylinder from the underside of said piston to the scavenge ports, said scavenge ports in said cylinder extending from substantially adjacent said reference line toward the distal end of the cylinder and being covered and uncovered by said piston timing edge as the piston reciprocates in the cylinder, significant portions of at least some of said scavenge ports being uncovered by said piston when the distance between the piston timing edge and the reference line is not less than substantially 25 percent of the piston stroke, and reed valve means in said transfer passageway means for said some scavenge ports to substantially prevent reverse flow from said cylinder to said scavenge pump system, and to permit flow from said scavenge pump system into the associated transfer passageway means and then to said some scavenge ports in response to pressure differentials, said reed valve means extending generally longitudinally of said passageway means and including at least one reed member having a supported lower end and a pressure responsive upper end that is movable generally transverse of said passageway means to an open position to permit flow from the scavenge pump system, and means positioning said upper movable end substantially above the bottom of the piston when the latter is in bottom dead center position so that said upper movable end is adjacent said scavenge port means, said reed member in an open position guiding flow toward the associated scavenge ports.
Claim 2
Dependent Claim
352 words
A two cycle engine having a cylinder and a power piston with a piston head timing edge and an underside, and which utilizes the underside as a piston of a scavenge pump system and which has scavenge ports located in a first portion of the cylinder adjacent a reference line along the piston timing edge with the piston in bottom dead center position, said cylinder having a distal end towards which the piston moves during the compression stroke, transfer passageway means leading from said scavenge pump system to the scavenge ports, said passageway means being elongated and extending close to the cylinder and generally in the same direction as the axis of said cylinder from the underside of said piston to the scavenge ports, said scavenge ports in said cylinder extending from substantially adjacent said reference line toward the distal end of the cylinder and being covered and uncovered by said piston timing edge as the piston reciprocates in the cylinder, significant portions of at least some of said scavenge ports being uncovered by said piston when the distance between the piston timing edge and the reference line is not less than substantially 25 percent of the piston stroke, and reed valve means in said transfer passageway means for said some scavenge ports to substantially prevent reverse flow from said cylinder to said scavenge pump system, and to permit flow from said scavenge pump system into the associated transfer passageway means and then to said some scavenge ports in response to pressure differentials, said reed valve means extending generally longitudinally of said passageway means and including at least one reed member having a supported lower end and a pressure responsive upper end that is movable generally transverse of said passageway means to an open position to permit flow from the scavenge pump system, and means positioning said upper movable end substantially above the bottom of the piston when the latter is in bottom dead center position so that said upper movable end is adjacent said scavenge port means, said reed member in an open position guiding flow toward the associated scavenge ports.
Claim 3
Dependent Claim
89 words
The combination as specified in claim 1 wherein said reed valve member comprises a blade like valve member movable from a closed to an open position, and said transfer passageway means is defined by wall surfaces in said engine, a portion of said wall surfaces being positioned adjacent said reed valve means and shaped to support and stop at least one of said blade like valve members in its open position in a shape conforming to the general curve of the blade like member in an unsupported open position.
Claim 4
Dependent Claim
81 words
The combinaTion as specified in claim 1 wherein said reed valve means comprises a body member mounted in said passageway means, and having a plurality of flow channels through said body member, separate blade like resilient members positioned adjacent each of said channels and movable to a closed position to prevent reverse flow through the associated flow channels and yieldingly movable under pressure differentials to an open position to permit flow from the scavenge pump system to said scavenge port means.
Claim 5
Dependent Claim
62 words
The combination as specified in claim 1 wherein the reed valve means include flow passageways having a total effective flow path cross sectional area with the reed valve means fully open that is at least equal to the effective minimum flow path cross sectional area through the associated transfer passageway means without the reed valve means in the associated transfer passageway means.
Claim 6
Dependent Claim
31 words
The combination as specified in claim 1 wherein at least one of said some scavenge ports extends from a distal edge thereof continuously toward a level corresponding to said reference line.
Claim 7
Dependent Claim
117 words
The combination as specified in claim 1 wherein said cylinder has port means including first scavenge port means of no greater than normal height and second extra height scavenge port means, said first scavenge port means opening to separate transfer passageway means from the transfer passageway means for the second scavenge port means, said first scavenge port means being positioned between said second scavenge port means and said reference line, communication between the scavenge pump and the cylinder through said first scavenge port means being controlled by the piston and the piston head timing edge, and wherein said reed valve means is associated with the second scavenge port means and not with said first scavenge port means.
Claim 8
Dependent Claim
22 words
The combination as specified in claim 7 wherein said first and second scavenge port means at least partially overlap in circumferential relationship.
Claim 9
Dependent Claim
62 words
The combination as specified in claim 1 and in which there are separate passageway means open to separate portions of said some scavenge port means to divide at least some of said scavenge port means into separate portions which at least partially overlap circumferentially in the cylinder, said reed valve means being positioned in at least some of said separate transfer passageways.
Claim 10
Dependent Claim
70 words
The combination as specified in claim 1 wherein said cylinder is defined by a wall having a circumference, an exhaust port leading from said cylinder and defined through said wall, and said scavenge ports being defined in said wall to occupy a major portion of the circumference of said wall adjacent said reference line other than the portion of the circumference adjacent the reference line occupied by said exhaust port.
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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) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |