US2752212A - Piston for internal combustion engine - Google Patents

Description

June 26, 1956 H. o. HEDGES 2,752,212

PISTON FOR INTERNAL COMBUSTION ENGINE Original Filed May 20, 1949 2 22 I 22 v I 1 O 24 2O 2 l3 000000 2 v 90. j L g Y Z I S 5 l5 2 27 A N I "-P I I j I 3 I I l. J I I 4 x: JO k 3/ J I INVENTOR Harry 0. Hedyes.

ATTORNEY PISTON FOR INTERNAL COMBUSTION ENGINE Divided and this application July 3, 1952, Serial No. 297,024

1 Claim. (Cl. 309-8) This invention relates generally to internal combustion engines and is more particularly concerned with improved means for lubricating and sealing a piston cylinder, this application being a divisional of my original copending application filed May 20, 1949, Serial No. 94,368, and now abandoned.

A principal object of the present invention is to provide in an engine of the aforementioned character a new and improved construction of piston having bafile means provided internally thereof in association with through passages in the cylindrical wall of the piston for effecting positive delivery of oil outwardly of the piston upon each upstroke of the latter to thereby efiectively lubricate and seal the upper reaches of the piston cylinder.

Other objects and advantages of the present invention will appear more fully hereinafter, it being understood that the present invention consists in the combination, construction, location and relative arrangement of parts, all as will appear more fully hereinafter, as shown in the accompanying drawings, and as finally pointed out in the appended claim.

In the accompanying drawings:

Figure 1 is a vertical sectional view of one form of internal combustion engine embodying the piston, construction of the present invention.

Figure 2 is a vertical sectional view of the piston per se; and

Figure 3 is an enlarged view of that portion of the piston embraced by the broken line circle of Figure 2.

Referring now to the drawing and more particularly to Figure 1 thereof wherein is shown one preferred form of an engine constructed in accordance with and embodying the principles of the present invention, it will be observed that the engine is provided with a water-jacketed cylinder suitably mounted upon the upper end of a crank case 11. The cylinder 10 includes in suitable assembly a head 12, an upper body part 13 and a lower body part 14, the aforementioned body parts being laterally extended to provide suitable supports and housing for the several valve mechanisms and fuel delivery passages.

The cylinder 10 is provided at its closed upper end with a suitable spark plug (not shown) and is fitted internally thereof with a reciprocating piston 15 of an improved construction hereinafter specifically described, the piston 15 being connected to the crank shaft 16 of the engine through the intervention of a wrist pin 17 and a connecting rod 13. The crank shaft and the connecting rod are splash-lubricated by oil contained in the crank case 11, which oil is carried upwardly by the piston and then forced outwardly thereof to lubricate the upper reaches of the internal walls of the piston cylinder.

It will be observed that in the particular construction of engine as shown in the drawings hereof, the lower end of the piston is enlarged in diameter to snugly fit within an enlarged diameter lower section of the cylinder, the arrangement being such as to provide an auxiliary fuel pressure chamber 19 in which a charge of fuel may be compressed on each up stroke of the piston and forced through atent O 2,752,212 Patented June'26, 1956 suitable communicating passages to the combustion chamber of a second cylinder associated with that shown, all as is more particularly shown and described in my copendingapplication Serial No. 94,368 aforesaid.

In order to effectually seal the piston 15 within the lower end of the reduced section of its cylinder during reciprocation of the piston therein, each said section of the cylinder is fitted in its lower end with one or more suitable sealing ring sets 19 -49 to provide an effective gaseous and fluid-tight seal between the piston and the bottom end of the reduced diameter portion of the cylinder.

Because of this last-mentioned gaseous and fluid-tight seal, passage of lubricating oil upwardly between the piston and the inner wall of the cylinder is effectually precluded, and, consequently, it becomes necessary to provide some means for internally lubricating the wall of the reduced diameter section of the cylinder above the sealing ring sets 19 -49 thereof.

Such means is shown particularly in Figures 2 and 3 wherein it will be observed that the upper reach of the piston is internally provided adjacent its top end with an upwardly inclined battle element 20 extending circumferentially about the full inner circumference of the hollow piston. This baffle forms conjointly with the inner wall of the piston a V-shaped trough or channel 21 in which oil is accumulated by splash action from the reservoir of oil in the crank case of the engine. The annular groove or channel 21 will receive a complement of oil on each down stroke of the piston. Oil so accumulated in the annular reservoir 21 being subject to the force of inertia upon each up stroke of the piston, it is forced upon each such up stroke toward the bottom of its channeled reservoir. The piston wall is provided with a series of circumferentially spaced openings 22, the inner ends of which communicate with the bottom of the channel 21, while their outer ends are in communication with an oil ring channel 23 in which is fitted one of a series of conventional oil rings 24. The force of inertia acting upon the oil accumulated in the channel 21 during each up stroke of the piston in its cylinder acts to force the oil outwardly of the channeled reservoir through the openings 22 to the oil ring immediately associated therewith and so provides controlled distribution of lubricating oil in the normally inaccessible upper part of the cylinder. The oil is so delivered to the external surface of the piston is returned upon each down stroke of the latter to the interior thereof preferably by way of auxiliary oil passages 25 spaced circumferentially about the piston wall and in communication with the lowermost piston ring groove 26. These auxiliary oil passages 25 may be dispensed with and in such case the oil may be returned to the interior of the piston and thence to the crank case by way of the oil ports 22 upon each down stroke of the piston.

If desired the piston 15 may be externally fitted with a removable steel, or other suitable metal liner or jacket 27, the latter serving not only to externally seal the bores 28-28 of the wrist pin bearing bosses 2929, but also to provide for increased life and wear of the piston. It will be observed that the enlarged lower end of the piston is removably secured to the lower end of the piston 15 by bolts 34} respectively projected through apertured lugs 31 formed in the enlarged lower end of the piston and threadedly engaging tapped bosses 32 provided internally of the piston 15 as integral elements thereof. Consequently, the liner 27 is readily removable for replacement thereof and for any other service that may be required.

It will be understood, of course, that the construction of the present invention, as herein illustrated and described, is susceptible of various changes and modifications which which may be made from time to time without departing from the general principles or real spirit of the present invention, and it is accordingly intended to claim the same broadly, as well as specifically, as indicated in the appended claim.

What is claimed as new and useful is:

In an internal combustion engine 'of the character described, a piston having baffle means formed internally thereof adapted upon each outward (nonpower) stroke thereof to force oil outwardly of the piston by way of openings formed in the side wall of the piston and in communication with an oil ring channel formed externally of the piston, the sidewall of the piston being provided with additional openings in communication with a second oil ring channel disposed below the first mentioned oil ring channel and through which said oil may be forced inwardly of the piston upon each inward (power) stroke thereof.

UNITED STATES PATENTS Hogan Oct. 19, 1915 Jones July 3, 1917 Jones July 3, 1917 Riedler Mar. 12, 1918 Cook Nov. 4, 1924 Brower Apr. 10, 1928 Best et a1. Mar. 3, 1931 Alexandrescu Mar. 20, 1934 Caldwell et a1 June 15, 1937 Stadlman Feb. 22, 1949

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