US1370771A - Packing-bingr and piston - Google Patents

Description

.I. T. WILSON.

PACKING RING AND PISTON. APPLICATION FILED APR. 21. m

3mm efalifl I PVT/son UNITED STATES PATENT OFFICE.

JO HN WILSON, OF ALA MEDA, CALIFORNIA.

1 To allwhom it may concern:

Be it known that 1, JOHN T. W1 soN, a citizen of the United States, residing at Alameda, in the county of. Alameda and State of California, have invented certain new and useful Improvements in Packing- Rings and Pistons; and I do hereby declare the following to be a full, clear, and exact description of the invention, sueh as will enable others skilled in theart to which it appertains to make and use the same.

an integral cylindrical casting provided with circumferential rooves-in its exterior surfaceto receive'pac ing rings which frictionall bear against the interior surface of to great pressurepby the enerated energy.

the cy inder to form tight joints therewith during all periods of the reciprocating motionsof the piston. j a H The front end of the piston and the packing rings which project slightly beyond the exterior surface of the piston are subjected of the ex losive charge. he packing rings necessari y are of small cross sectional area and cut a art so'they can be sprung over the end 0 the pistoninto the grooves. Be-

ing ofsmall dimensions, they soon wear out and the piston bodythen frictionally en gages the interior surface of the cylinder and Wears away the metal of the cylinder and o ens a passageway for the gases generate by the explosion. Also the ends of the rings frequently break and become displaced so the gases can pass. Under the same conditions when explosive charges are drawn into the explosion chamber, a vacu um being formed therein, lubricating oil from the crank chamber is sucked past the packing rings into the explosion chamber, where it becomes carbonized and fouls the cylinder and piston.

These conditions obviously impair the efiicienc ofthe engine, and the remedy therefor oesnot consist simply in using wider packing rings, for the wider the ring, the greater the pressure beneath it ,andrthe greater the friction between the ring and the cylinder.

The object of the present invention is to cure these imperfections by providing a compound or double packing ring, of a shape conforming to the shape of the groove in the piston, and presenting a relatively large area of exterior wearing surface and Specification of Letters ratent.

A gas engine piston usually consists of.

PACKING-BING- AND PISTON.

Patented Mar. 8, 1921.

Application filed April 21, 1919. Serial No. 291,434.

a muchless area of surface at the interior to be acted upon b the pressure of the explo s1ve gases and t a pressure of the explosive lubricatin oil, to pass beneath the entire under surface of the packing.

The invention consists in a compound or double cut resilient expansible packing ring and a piston having a groove ofa sha e in conformity with the shape of the ringw ereby the results above set forth are obtained.

Further, the invention consists incertain novelties of construction and relative ar rangements, as herein set forth, ofthe ring, the groove in the pistonadapted to receive 1tohe ring, and the crank and explosion chamers.

The accompanying drawing illustrates an example of the embodiment of the invention constructed and the parts combined accord ing to the best of the several modes of procedure I have so far devised for the attainment of the ends set forth.

Figure 1 is a vertical section in elevation of a gas engine piston and cylinder showing my invention, several packing rings being in section. Fig. 2 is a "side view in elevation of the spring and pressure rin showing the ends slightly separated and t eprojecting flange to form a bottom lap plate.

Fig. 3 is a cross section. of Fig. 2 on line 33.

Fig. 4 is a side View in elevation of the Wearing ring, the ends beingslightly spaced apart.

Fig. 5 is a section of 'Fig. 4 on line 5-5.

Fig. 6 is a top plan view of the assembled rings as they appear when sprung together and in the cylinder, the lap joint being clearly indicated, g I

Fig. 7 is asection of Fig.6 on line 7-7.

Fig. 8 illustrates the positionofthe packing ring in the groove when the charge is being drawn into the explosion chamber.

Fig. 9 illustrates the position of the ring The last two figures are somewhat out of proportion to more clearly illustrate the positions of the rings.

Referring to the figures, the letter A designates a solid piston of well known general shape and construction. exclusive of the shape of the grooves in its exterior surface. The lines B-B and shading lines represent part of the interior circular surface of the engine cylinder presenting a smooth surface throughout, and part of the metal. of the cylinder. C is the end of the piston forming the movable inclosing boundary of the explosion chamber D, and E is the end of the piston facing the inclosed crank chamber space F which contains a heavy lu bricating oil or other lubricant. G designates the grooves in the exterior surface of the metallic body of the piston. R are the compound or double packing rin s.

Referring to a single combined groove and ring, it will be noted that each is adapted to the shape of the other. The outer part of the groove 1 is of the same width throughout the circumference of the piston. Its depth at 2 adjacent the end of the piston next to the explosion chamber is greater than its depth at 3 adjacent the crank chamber end of the piston. In other words, the groove is of a general L shape and the vertical surfaces defining the same are plain to match the surfaces at the sides of the packing ring.

The ring R is shaped to loosely fit the groove, its exterior portion being wider than its interior portion, and of a general L shape in cross section. The part 4 may be called a flange and in the groove it is remote from the explosion chamber and faces the crank chamber. The ring may project slightly from the groove to engage the interior surface of the cylinder and there should be a slight space as indicated between the side and bottom surfaces and the metal surfaces defining the groove so the ring can float longitudinally relative to the axis of the piston and also at right angles thereto so as to frictionally engage the interior surface of the cylinder throughout.

The ring is comprised of two assembled resilient cut spring rings a and b, the spring and pressure ring a being under greater tension when the rings are united and in the cylinder than the bearing ring b.

Ring a has a flange 0 which is cut at the points d and e to form a bottom lap plate 7. as shown. A dowel pin 9 is located. in the flange. Ring 7) in this instance has a flange h and is cut on a straight line.

When assembled, the wearing ring Z) isin contact with the flange c of the ring a, as shown by Fig. 7, and the ends located at opposite sides of the dowel pin 7 so one ring cannot shift relative to the other. The joint is clearly indicated by full and dotted lines in Fig. 6. The spring ring holds the wearing ring in contact with the inner surface of the cylinder under all conditions of service, as is obvious.

It should be noted here that in gas engine practice, unlike that when steam is the motive power, the packing ring must loosely fit the groove in the piston so that when the ring and groove become fouled by the products of incomplete combustion of the charge, which is always the case more or less, the ring will not stick in the groove. That is, the ring should have some slight side play within the groove so it will not pack and be prevented from expanding against the interior surface of the cylinder.

The ring in the operation of the engine is subjected to three varying pressures.

First, when the charge is drawn in, a vacuum being formed in the explosion chamber, air and oil at atmospheric pressure, at 15 pounds to the square inch or less, pass to the entire under surface of the ring which does not excessively force the ring against the interior surface of the cylinder, but sufficiently to prevent the passage of oil beyond the ring to the explosion chamber. The pressure against the entire under surface of the ring is not sufficient to cause excessive friction and wear of the ring, so a quite wide wearing ring may be employed under these conditions. The ring occupies the position shown in Fig. 8, the surfaces of the ring and groove at m being in frictional contact so as to form a tight joint against the passage of air or oil.

Secondly, when the charge is being compressed, the ring shifts to the position shown in Fig. 9, the mixture under compression passing to the space 0 beneath only part of the under surface of the ring, the surfaces of the ring and groove at s forming a tight joint so the pressure cannot reach the under surface of the ring flange.

Thirdly, when the explosion of the charge is taking place the ring under very great pressure maintains its position shown in Fig. 9 and excludes pressure from the under surface of the flange of the ring.

Under the last two conditions enumerated the pressure under part of the ring is sulficient to force the ring into frictional contact with the interior surface of the cylinder and maintain a tight joint therewith so a much wider ring can be used without occasioning excessive wear thereof or wear of the interior surface of the cylinder.

It is clear that a piston and ring combined and o crating as herein described attain very esirable results. A relatively large bearing surface is secured so the ring will wear much longer than a narrower ring which is liable to break, and the ring is not forced against the interior surface of the cylinder by great or excessive pressure during the explosion of the charge, for the greatest pressure, due to the explosion of the charge, is excluded from part of the under surface of the ring. It is also clear that oil from the crank chamber cannot pass piston than at the bottom, the greatest depth of said groove being adjacent the explosion chamber, of a double cut resilient expansible flanged packing ring of a shape in cross section matching and loosely fitting the roove and its entire exterior surface frictionally engaging the interior surface of the cylinder, the rings comprising the double ring being arranged so as to exclude explosion and charge compression pressure from the flanged portion of the ring.

2. The combination with a piston having acircumferential groove wider adjacent the exterior surface of the piston than at the bottom, the greatest depth of said groove being adjacent the explosion chamber, of a two-part cut resilient expansible packing ring of a shape in cross section matching and loosely fitting the groove, said rings forming a oint closing the open s ace otherwise present between the ends 0 the rings and adapted to allow the ring to be sprung over the end of the piston and seat 1n the groove In testimony whereof I afiix my si nature.

JOHN T. wnfsoN.

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