US3687018A

US3687018A - High compression piston ring and piston assembly

Info

Publication number: US3687018A
Application number: US39657A
Authority: US
Inventors: Edward F Sullivan
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-05-22
Filing date: 1970-05-22
Publication date: 1972-08-29
Anticipated expiration: 1989-08-29

Abstract

A piston and ring assembly for internal combustion engines wherein a piston mounts a split piston ring having a portion seated in a groove for the ring and a portion extending radially outwardly of the piston to engage the cylinder wall, the cylinder wall engaging portion projecting longitudinally outwardly beyond the piston end wall a distance such that the fuel explosion forces exert sufficient radial pressure on the longitudinally projecting portion to seal off explosion residuals which otherwise would leak past between the ring and cylinder wall.

Description

United States Patent Sullivan Aug. 29, 1972 [54] HIGH COMPRESSION PISTON RING 3,363,608 1/ 1968 Scherenberg et al. ...92/ 171 X AND PISTON ASSEMBLY FOREIGN PATENTS OR APPLICATIONS [72] Inventor: Edward F. Sullivan, 4465 Bradford S Saginaw, Mich 4 03 843,780 7/1952 Germany" ..277/178 I 587,913 5/1947 Great Britain ..92/246 [221 P119511 May 22,1970 719,537 12/1954 Great Britain ..92/245 [21] Appl. No.: 39,657

Primary Examiner-Edgar W. Geoghegan Assistant Examiner-Irwin C. Cohen [52] US. Cl. ..92/169, 92/181, 92/194', Attorneybemman & M c ll h 92/246, 277/178 [51] Int. Cl .,.....F16j 9/02, F16j 9/08, F16j 11/04 [57] ABSTRACT [58] Field of Search ..92/181,182,184,-185, 195, I

. 92,240, 241 246, 194; 277/178; 92/169 171 'A 1111811011 and ring assembly for lntemal combust on engmes wherein a plston mounts a split p1ston rmg having a portion seated in a groove for the ring and a [56] References cued portion extending radially outwardly of the piston to UNITED STATES PATENTS engage the cylinder wall, the cylinder wall engaging portion proectin lon 'tudinally outwardly beyond 1,159,066 11/1915 Moore ..92/246 the piston 1 walgl a disgtlance Such that the fuel PM 1,453,448 5/1923 Day ..92/246 Sion forces exert Sufficient radial pressure on the 10m 1,616,310 2/1927 Peltene ..92/246 g ny projecting portion to Seal off explosion 1,737,056 1 1/ 1929 Mueller ..92/246 X residuals which otherwise would leak p between h 1,784,505 12/ 1930 Teetor ..92/246 X ring and cylinder walL 1,956,355 4/ 1934 Junkers ..92/246 2,325,556 7/1943 Taylor, Jr. et a1. ..92/241 7 Claims, 3 Drawing Figures Patented Aug. 29, 1972 H 3,687,018

5 ll \lllllll HF" 1 v R .4 6 II C IO P FIGI INVENTOR EDWARD F. SULLIVAN FIG. 2 L manMccullocfi ATTORNEYS HIGH COMPRESSION PISTON RING AND PISTON ASSEMBLY This invention relates to piston rings and more particularly to a novel piston ring and piston assembly which is more efficient than prior art constructions. Presently smog and air pollution are matters of considerable concern in our highly populated cities and these problems are, in large part, due to the emission of incompletely combusted fuel gases from motor vehicles. This is believed due in considerable part to piston ring wear. For example, in a new vehicle the so-called blow-by of explosion gases in the cylinders of the engines is something on the order of to 3 percent. After the vehicle has traveled 25,000 miles, the blow-by is closer to 50 percent, and after 50,000 miles it may be in the neighborhood of as much as 80 percent if the rings have not been replaced. This blow-by of gases between the rings and cylinders from the head end of the pistons rearwardly, is then emitted to atmosphere as a contaminant.

One of the objects of the present invention is to provide a compression ring for the head end of the piston which includes a cylinder engaging portion which extends longitudinally forwardly of the piston and provides sufficient longitudinally projecting surface that explosion forces expand the ring radially to drastically reduce the blowby of gases, even after considerable wear of the rings.

A further object of the invention is to provide a compression ring and piston assembly of economic and efficient construction which does not require re-design of the piston cylinder or cylinder head.

Other objects and advantages of the present invention will become apparent to those of ordinary skill in the art by the following description when considered in relation to the accompanying drawings in which:

FIG. 1 is a sectional elevational view of a typical compression ring and piston assembly fabricated according to the invention;

FIG. 2 is a transverse sectional view taken on the line 22ofFIG.1;and

FIG. 3 is an enlarged view, similar to FIG. 1, showing a slightly modified construction.

Referring now more particularly to the accompanying drawings, wherein only preferred embodiments of the invention are shown, and in the first instance particularly to FIGS. 1 and 2 wherein the simplest form of the invention is illustrated, a letter B generally refers to the engine block of a conventional internal combustion engine which includes a number of cylinders generally indicated C, having cylindrical interior walls which may be provided by a liner as in FIGS. 1 and 2, or simply by a cylinder bore as in FIG. 3. Provided in each of the cylinders C to reciprocate therein is a piston, generally designated P, having, as usual, a compression ring groove 1 1 in its head end for seating a compression piston ring generally designated R. The cylinder head for the engine block and cylinder is schematically depicted at H and, as shown, the liner forming the cylinder surface 10 projects slightly up into the disc shaped recess 12 provided in the head H.

In all the views the piston P is shown in its forwardmost position and it is to be understood that the space 13 provided forwardly of the piston P provides the explosion chamber into which the fuel gases to be exploded are compressed. As is well known, a spark provided by a conventional spark plug ignites the compressed, gasoline vapor in the space 13 in an engine such as a conventional automobile engine and the explosion forces drive the piston P sharply rearwardly. With all the piston P in the engine cylinders connected by connecting rods, not shown, to the usual crankshaft, not shown, power is transmitted in the usual manner.

Each of the piston rings R, which are generally L- shaped or angle-shaped in cross section, include a radially inwardly projecting seating portion 14 which is shaped to fit the contour of the annular groove 11, and a longitudinally or axially projecting wall portion 15 whose peripheral surface is in close engagement with the cylinder wall surface 10.

The ring R is, or course, a split ring, and about a ten thousandths inch clearance is maintained at the gap G. The operating clearance provided between the periphery of wall 15 and the cylinder wall surface 10 is, in high compression engines of this character, maintained at about five thousandths of an inch. Thus, the piston P will be able to move back and forth in its cylinder 10 without undue wear and the ring R will, at the same time, be able to move in a rotary direction in the groove 11, this latter movement preventing deposit of carbons which would freeze the piston ring R in position and lead to the rapid wear and destruction of the ring as an operating element.

-It is to be observed that the wall 15 projects a distance x past the radial end wall 16 of the piston P, the distance x being slightly greater than the portion which does not project beyond the end wall 16. In operation, when an explosion of fuel gases occurs in chamber 13, the forces created by the explosion force the ring R radially in the manner indicated by the arrows y and substantially prevent any tendency for the gaseous products of explosion to pass rearwardly between the ring R and wall 10 and eventually find their way to atmosphere. This prevention of blow-by is accomplished even after the rings R have had considerable use and there has been considerable wear, such that the operating clearance between the periphery of ring R and cylinder wall 10 has considerably increased.

In FIG. 3, wherein a modified and improved preferred form of the invention is disclosed as indicated and identical numerals are used to designate similar parts, an annular groove 17a is shown in the inner or rear portion of the ring R to accommodate an annular coil spring 17, which, in the position shown, is stretched, and which exerts radially constrictive forces tending to close the split ring R. At the same time, the wall 15 is reduced by an annular groove 18 to provide a reduced thickness wall section 18a which extends beyond the end of piston 16. In operation, when explosion gases force the wall 15 radially, the portion 18a has a limited flexibility and the spring 17 tends to hold the rear portion of the ring R inwardly while letting the forward portion thereof radially expand to positively seal the cylinder 10 and prevent the blow-by of residual gases.

It should be understood that the outer peripheral surfaces of the rings R utilized may be chromium plated or sprayed with a molybdenum preparation, if desired.

It is further to be understood that the drawings and descriptive matter are in all cases to be interpreted as merely illustrative of the principles of the invention, rather than as limiting the same in any way, since it is contemplated that various changes may be made in various elements to achieve like results without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1. A piston and cylinder assembly comprising: engine cylinder means providing a piston-receiving cylinder wall and an explosion chamber; a cylindrical piston axially reciprocable in said cylinder means and having an end wall portion facing said explosion chamber, said piston having an annular groove in its periphery axially inward of said end wall portion; and a piston ring means having a portion seated in said groove, and a longitudinally projecting cylinder wall engaging portion extending axially outwardly beyond said piston end wall portion and exposed to the explosion gases over a distance such that the explosion in said chamber exerts sufficient radial pressure thereon to substantially seal off explosion residuals which otherwise would pass between the ring means and cylinder wall, said ring, including the portion projecting longitudinally outwardly beyond said piston end wall portion having an external circumferential groove providing an axially extending, radially outwardly flexing wall, between axially inner and outer cylinder wall engaging land portions, and the axially outer surface of said inner land portion lying between the axially inner surface of the piston groove and the axially outer surface of said piston end wall portion. i

2. The structure defined in claim 1 wherein the axially inner land portion is substantially radially opposite the groove in the piston axially inward of said piston end wall portion.

3. The combination defined in claim 2 wherein the land portions and groove have axially inner and outer, generally radial walls, and the outer radial wall of the axially inner land portion is spaced inward from the axially outer radial wall of said piston groove.

4. A piston and cylinder assembly for fuel burning engines comprising: engine cylinder means providing a piston-receiving cylinder wall and an explosion chamber; a cylindrical piston axially reciprocable in said cylinder means and having an end wall facing said explosion chamber, said piston having an annular groove adjacent said end wall; and a split piston ring having a'portion seated in said groove, and a longitudinally projecting radially exposed, cylinder wall engaging portion extending axially outwardly beyond said piston end wall a distance such that the explosion in said chamber exerts sufficient radial pressure thereon to substantially seal off explosion residuals which otherwise would pass between the ring andcylinder wall, said ring, including the portion extending longitudinally outwardly beyond said piston end wall, having an external circumferential groove around its entire periphery to provide an axially extending, radially outwardly flexing wall between axially inner and outer cylinder wall engaging land portions, and said external circumferential groove extending axially from a point opposite said annular groove in the piston to a point axially beyond said piston end wall.

5. The combination defined in claim 4 in which said cylinder means includes a cylinder bore having a liner 3. iil fiilliililigila llle'ii ill gfiirfi l in which said groove has parallel radial side walls and the ring portion seated therein is rectangular in cross section and is snugly, but movably, received therein.

7. The combination defined in claim 4 in which an exterior circumferential groove is provided in said inner wall engaging land of said ring adjacent the seating portion thereof; and a constricting annular spring is received therein and exerts a radially compressing force on said ring.

Claims

1. A piston and cylinder assembly comprising: engine cylinder means providing a piston-receiving cylinder wall and an explosion chamber; a cylindrical piston axially reciprocable in said cylinder means and having an end wall portion facing said explosion chamber, said piston having an annular groove in its periphery axially inward of said end wall portion; and a piston ring means having a portion seated in said groove, and a longitudinally projecting cylinder wall engaging portion extending axially outwardly beyond said piston end wall portion and exposed to the explosion gases over a distance such that the explosion in said chamber exerts sufficient radial pressure thereon to substantially seal off explosion residuals which otherwise would pass between the ring means and cylinder wall, said ring, including the portion projecting longitudinally outwardly beyond said piston end wall portion having an external circumferential groove providing an axially extending, radially outwardly flexing wall, between axially inner and outer cylinder wall engaging land portions, and the axially outer surface of said inner land portion lying between the axially inner surface of the piston groove and the axially outer surface of said piston end wall portion.

4. A piston and cylinder assembly for fuel burning engines comprising: engine cylinder means providing a piston-receiving cylinder wall and an explosion chamber; a cylindrical piston axially reciprocable in said cylinder means and having an end wall facing said explosion chamber, said piston having an annular groove adjacent said end wall; and a split piston ring having a portion seated in said groove, and a longitudinally projecting radially exposed, cylinder wall engaging portion extending axially outwardly beyond said piston end wall a distance such that the explosion in said chamber exerts sufficient radial pressure thereon to substantially seal off explosion residuals which otherwise would pass between the ring and cylinder wall, said ring, including the portion extending longitudinally outwardly beyond said piston end wall, having an external circumferential groove around its entire periphery to provide an axially extending, radially outwardly flexing wall between axially inner and outer cylinder wall engaging land portions, and said external circumferential groove extending axially from a point opposite said annular groove in the piston to a point axially beyond said piston end wall.

5. The combination defined in claim 4 in which said cylinder means includes a cylinder bore having a liner sleeve therein providing said cylinder wall.

6. The combination defined in claim 4 in which said groove has parallel radial side walls and the ring portion seated therein is rectangular in cross section and is snugly, but movably, received therein.