US1795099A - Internal-combustion engine - Google Patents

Description

March 3, 1931. STUART. 2 1,795,099

INTERNAL comausnon ENGINE Filed Dec. 28. 1928 m o A j 6 .1 a t j z y n P [7? J [7 17 a 1 i g I vlrrwiwir-s.

Patented Mar. 3, 1931 UNITED STATES PATENT OFFICE JOSEPH STUART, 2B, OF WILMINGTON, DELAWARE, ASSIGNOR or ONE-HALF 'ro ALFRED I. DU PONT, or JACKSONVILLE, FLORIDA INTERNAL-COMBUSTION ENGINE.

Application filed December 28, 1928. Serial No. 328,945.

In internal combustion engines it is desirable, in order to secure maximum efficiency,

to expel all the exhaust gases from the cylinder at the completion of the explosion stroke. Difiiculty has been experienced in effecting a thorough expulsion of exhaust gases.

The object of my invention is to provide means for effecting a certain and thorough expulsion of exhaust gases. This I have accomplished by causing air to be blown completely through a plurality of cylinders successively and out'the last cylinder, thereby insuring that all exhaust gases in all the cy inders will be driven ahead of the air and blown out of the last cylinder. The application of my invention to engines of known types involves certain practicable modifications in the construction of the engine, which modifications, however, do not otherwise effect their efficiency.

The figure isan elevation, largely in section, of one embodiment of my invention.

The embodiment of the invention shown is a two cycle engine having two cylinders a and 6, arranged side by side, their plstons, 0

and cl, reciprocating in unison in the same di-.

rection. The pistons are connected with the crank shaft (not shown) in the crank case f. The ends of the two cylinders in which air is compressed and fuel admitted should com municate with one another. This can be effected by different means, but it is preferred to provide the cylinders with a common compression chamber 6, which communicates with a fuel feed pipe g.

The intermittent admission of fuel may be controlled by a needle valve h, which may be operated by a rock lever i which, through a reciprocating rod 1', may be operated from a cam k on the crank shaft or on a shaft driven therefrom.

The engine may be of the Diesel type or may be provided with a spark plug m The cylinder (1, between its ends, is provided with air admission ports n. The cylinder 6, between its ends, is provided with gas and air exhaust ports 0. The ports n and 0 should be so located and the pistons should be of such length that the ports, and particularly the ports a, will be at all times covered except near and at the end of the expansion stroke.

Ports 0 may have free communication with the atmosphere. Ports n communicate with a pipe p connected with an air charging device 1', which may be an air compressor or centrifugal blower or any device adapted to blow air through the pipe 79 at a predetermined pressure. This air feed device may be actuated, directly or indirectly, from the crank shaft through any suitable gearing s. It may be operated constantly to build and store up air pressure, or it may be operated intermittently to forcibly blow air through pipe p when ports n are uncovered.

Near the end of the expansion stroke of the pistons they uncover both sets of ports a and 0 am air rushes through ports a, and thence from one cylinder to another and out ports 0, thereby thoroughly scouring the cylinders of all exhaust gases.

No part of the exhaust gas can be driven toward a dead end of either piston and lodge there while the scouring fluid is flowing through the cylinders; but the entire volume of gas is driven ahead of the air toward and out of ports 0 until it has expelled the gas from both cylinders. To insure this action the communication between the cylinders may be as restricted as may be found necessary.

It may be desirable, in certain cases, to place in the pipe p a suitable timed valve :10, protected from heat by the intermittently formed dead air space y, and operable from mechanism 10, which may be actuated from (say) the shaft carrying the cam is. If ports a are of such length or so positioned as to close shortly after ports 0, this allows the incoming air to be pre-compressed after exhaust ports 0 have been closed. This feature is of value, and may be essential, in engines operating at high altitudes.

It is clear, from the foregoing description, that by means of the descrlbed construction, or such modifications thereof, consistent with the principle of the invention, that may be developed by skilled engineers, both engine cylinders will be thoroughly denuded of exhaust gases by the time the pistons have fairly started on their compression stroke. hat I claim and desire to protect by Letters Patent is An engine comprising a plurality of cylinders, the fuel intake ends of two cylinders being in communiG ition, one of said cylin+- ders having a gas exhaust port and the other of said cylinders having an air admission port, means to blow air through the lZLS port,

and pistons in said two .cyl lfll lh rs,theele ments being so arranged that the pistons of said two cylinders move together in the. same phase in their expansion strokes and their compression strokes andgHQQOVersaid ports at the end portions of their expansion strokes, whereby air is blown into and through one cylinder and thence into, through and out of the other cylinder, the air admission port being positioned to be closed,-in the compression stroke of the piston, afterthe gas exhaust port is closed to allow pro-compression of air-after the closure of the gas exhaust port and before the closure of the air inlet port, and a timed valve controlling the admission of air through said air admission port.

In testimony of which invention, I have hereunto set my hand, at Wilmington, Dela ware, on this 24th day of December, 1928.

' JOSEPH STUART, II.

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