US1174522A - Valve and valve-gear of internal-combustion engines. - Google Patents

Description

J. D. ROOTS. VALVE AND VALVE GEAR OF INTERNAL COMBUSTION ENGINES.

7 APPLICATION FILED FEB. 5, I910. 1,17%,522.

Patented Mar. 7,1916.

2 SHEETSSHEET I- I. D. ROOTS. VALVE AND V ALVE GEAR OF INTERNAL COMBUSTION ENGINES.

I ARPLJ'CATION FILED. FEB. 511910. 1,174,52.

Patented Mali 7, 1916.

2 SHEETS-SHEET 2.

JAMES DENNIS ROOTS, OF WEST KENSiING'I-ON, LQNDON, ENGLAND.

VALVE AND VALVE-GEAR 0F INTERNAL-COMBUSTION ENGINES.

To all whom it may concern:

Be it known that I, JAMEs DENNIS-ROOTS, a subject of the King of Great Britaln, and a resident of 58 Avonmore road, West Kensington, London, W., England, have invented new and useful Improvements in the Valves and Valve-Gear of'Internal-Combustion Engines, of which the following 1s the specification. j

My invention relates to valves for internal combustion engines of the four cycle type and more particularly to a reciprocating piston or sliding valve which is actuated to open and close a port formed in and through the valve casing and into the combustion chamber of the engine.

The construction provides means whereby a .eii-igie valve and its actuating means will open and close the port so that the charge may be drawn into' the working cylinder through a chamber of the valve and through the inlet port of the valve casing, and when the charge has been drawn into the cylinder, the valve closes the port during the compression and power stroke and then upon and just prior to completion of the power stroke the valve opens the port to the working cylinder to discharge the products of combustion, the construction and manner of operating the valve providing silence in operation, simplicity in construction and greater efficiency in operation than is attained by the use of longitudinally movable valves about which the gas or explosive mixture passes to ports.

The" construction also provides means for holding the valve against rotation and in engagement with an actuating cam.

In the accompanying drawings which illustrate the preferred forms of my invention, Figure 1 is a view showing a part of a fourcycle engine, the valves being arranged to be in operative engagement with a cam on a shaft, and in said side view, one of the valves, its casing and a part of one of the cylinders is shown in section; Fig. 2 is a side elevation of a valve as shown in Fig. 1 of the drawings; Fig. 3 is a sectional view taken on the line ab of Fig. 2; Fig. 4 is a longitudinal section showing a modified form of the end of the valve and of a cam for moving the valve, providing other means for holding the valve in contact with its actuating cam from what is shown in Fig. 1; and Fig. 5 is a face elevation of a rim cam Specification of Letters Patent.

Patented Mar. 7,1916.

Application filed February 5, 1910. Serial No. 542,262.

for use with a valve constructed as shown in Flgtl of the drawings.

Referring to the drawings, the cylinder W or cylinders W, W, each have ports C and a cylindrical valve casing B into which the port C opens, such valve casing being open at both ends and having a port'E through which is supplied the explosive mixture of air. The valve casing may be provided with the usual packing rings I, I, and with a water jacket, it being understood that the inlet port E through the valve casing or cylinder is connected to a 'carbureter or mixer and is open to the. atmosphere in cases where air only is supplied, and that the end D of the valve cylinder can be connected with an exhaust pipe.

The supply port E through the valve cylinder may be of any suitable-form but as shown is longer longitudinally than transversely and the port C of the working cylinder is preferably elongated transversely.

In a four cycle enginethe shaft 0 upon which is mounted the valve operating cam or cams will be rotated at half speed relative to the speed or rotation of the main shaft of the engine and the cam on the shaft 0 has approximately one-half of its contact 'surface shaped to be concentric with the center of the shaft 0, about one-quarter of the cam surface being flat or a right line and falls below the said concentric surface that extends from the concentric portion to the end which terminates at a point farthest from the shaft, and K refers to the concentric portion of the cam, M the surface below the concentric and L to that part of the cam which is above the concentric surface, when the cam is positioned as is shown by Figs. 1 and 5 of the drawings.

The valve A as shown is of a piston type and reciprocates in the valve casing B, one end of said valve having a projection A that extends for a sufficient distance from the end of the valve to receive a} pinupon which is mounted a roller A that engages with the face of the cam. When the cam is of the rim hoop or flange type, as'shown by Figs. 4 and 5, the projection A may be of a length to receive a perforation for a second pin upon which is mounted a roller A for engagement with the inner side of the rim J which is bolted to a disk N that is keyed upon the half speed shaft 0.

When a solid cam or several cams are J as an exhaust port, and in practice the carbureter is connected with the port E and an its used, as shown by Fig 1 in' connection with two. or more working cylinders, the projection A on the valve has a single roller A and the'valve casing B is provided with oppositely located slots for the passage therethrough of a pin carried by the end of the valve, and against the endof the pin bears a' s'lidable ring that isengaged by a spring I 'B' which encircles the'valve casing, the opposite end oi the spring contacting with a circumferential shoulder on the casing. The

function of the springyrthe ring and the pinis to force the roller A against the face of exhaust pipe with the open end of the valve casing or vice-versa.

The elongated inlet port F of the valve A is of such length that a part of said port will always'be in register with the port E and on the opposite side from the port F I is a port G which may consist of two open- .ings separated by a wall G, such port G being adapted to be brought in register with the, port C of the working cylinder during the suction stroke of the engine.

The valve A has a chamber with an inclined" or curved wall which is concaved on its inner side, such wall extending from the inlet port with an easy curve to a point adjacent the. lower part of the port G, and also with a transverse wall which is curved where it joins the inner wall of the valve.

, The purpose of the curved walls is to deflect the incoming explosive mixture and the I v I outgoing products of combustion to avoid loss of power on the suction and exhaust stroke, as well as to prevent an accumulation of oilin the chamber andan accumulation of carbon about the jointure of the transverse wall above which are the exhaust ports. The exhaust ports H of the valve A arelocated above the transverse wall or piston diaphragm which may be curved at a point g pposite the exhaust port G and the ports are separated by a web H'. The transverse ports H and G both consist of slots through the curved wall of the cylindrical valve A and webs or bridge pieces are present to avoid unduly weakening the valve and either the valve or the valve casing has packing rings and the parts may be water jacketed.

In operation with a valve having ports as shown and a valve casing with which the port of a working cylinder is connected when the roller A engages the straight or lowest face of the cam, the ports H and C isveieaa will be in register during the exhaust stroke of the piston of. the engine; the valve by the part L of the cam will then be moved to bring the port G in register with the port C'where it remains during the suction stroke and at the completion of such stroke the valve will be brought to position by the part K of the cam to cover the port 0, during'the compression and the power stroke thus holding the port C closed by the valve, this completing the cycle. .It will be equally clear that by allowing the cam to slip 90 on the shaft, and providing a stop at each end of the 90, that the cam may enable the engine to be reversed. What I claim as my invention and desire to secure by Letters Patent is 1. In a four'stroke cycle internal combustion engine, a valve casing having therein a port communicating with the combustion chamber of the engine, and having intake and exhaust means, a reciprocating piston valve in the casing, said valve having a partition and ports on opposite sides of the partition for communication with the port oi the casing ,opening into the combustion chamber, and with the intake and exhaust means, and means for reciprocating the valve and for holding it in position for two strokes of the working piston whereby the said port in the said casing is heldclosed.

2. In a four cycle internal combustion engine, a valve casing havingtherein a port communicating with the combustion chamber of the englne, and having intake and exhaust means, a reciprocating piston valve in the casing, said valve having a' -partition, means whereby the piston valve is adapted to permit communication with the intake and exhaust means and with the said port of the casing opening into the combustion chamber alternately on opposite sides of the said partition and then to close said port, and means for reciprocating the piston valve, said means including a cam with means for its rotation, and a roller engaging the said cam.

3. In a four cycle internal combustion engine, the combination with a plurality of working cylinders, of a valve casing for each cylinder having a port therein communicating with the combustion chamber of its cylinder, an intake and an exhaust outlet a valve arranged to reciprocate in each valve casing, and camoperating means for the valves of all of the cylinders, whereby each valve is actuated to establish communication between the port of its casing and the intake thereof during the suction stroke of its working piston, and to close the said port during the compression and explosion strokes thereof, and to open the port to the exhaust o ning during the exhaust stroke thereof or the escape of waste gases through the casing.

4. In a four cycle internal combustion engine, the combination with a plurality ofworking cylinders, of a valve casing for each cylinder having a port therein communicating with the combustion chamber of its cylinder, an intake and an exhaust outlet, a valve in each casing, and means for operating the valves of all of the cylinders, whereby each valve is reciprocated in its casing to establish communication between the port in the casing and the intake during the suction stroke of the working piston, to close the said port during the compression and explosion strokes of same, and to open the port to the exhaust opening during 7 the exhaust stroke for the escape of waste gases through the casing, said 'means in- 5. In a four cycle internal combustion engine, the combination with a plurality of working cylinders, of a valve casing for each cylinder having a port therein communicating with the combustion chamber of its cylinder, an intake and an exhaust outlet, a valve in each valve casing, and means for operating the valves of all of the cylinders whereby each valve is reciprocated in its casing to establish communication between the port in its casing and the intake during thesuction stroke, to close the port during the compression and explosion strokes, and to open the port to the exhaust outlet during the exhaust stroke for the escape of waste gases through the casing, said means including av cam operatively associated with the valves of all of the said cylinders, and a spring on eachvalve. 1

- JAMES DENNIS ROOTS.

Witnesses:

H. D. JAMEsoN, R. WILLIAMS.

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