US1757907A - Internal-combustion engine - Google Patents

Description

f May 6, 1930. L. JAMESON ET AL 1,757,907

INTERNAL COMBUSTION ENGINE Filedsept. 15, 1927 4 Sheets-sheet l fnl/enfans' Jseph Jameson May 6, 1930. J. JAMESON ET AL y INTERNAL COMBUSTION ENGINE Filedsept. 15, 192'? 4 sheets-Sheet 2 J. L. JAMESON ET Al- INTERNAL COMBUSTION ENGINE May 6, 1930.

Filed septA 15, 1927 4 sheets-sheet 3 lzarles J. Fwer May 6, 17930. J. JAMESON Er AL 1,757,907

INTERNAL COMBUSTION ENGINE Filed sept. 15, 12'7 4 sheets-sheet 4 v Y 'Il III l Q -i' I Q "@h, l J0 I'Il' I i i J?\; "n I t 7521 l ll 'l y?? I E I 4 'l 1| 16,51 @Tg L 73 Ih |7169 'r'- l l l l 'l l MH@ Hlm@ @un Patented May 6, 1930 thiwi STATES earner orifice JOSEPH LAMBERG JAMESON AND CHARLES JOHN FISHER, OF SURREY, ENGLAND INTERNAL-COMB'FSTION ENGINE Application filed September 15, 1927, Serial No. 219,757, and Ein=(-}reat YBritain `April 11, 1927.

rhis invent-ion comprises improvements in or relating to internal-combustion engines of the typewhieh comprises a working cylinder, a main piston therein, a movable head-.piston which is caused to 'approach the main piston closely at the end oi the-exhaust stroke and .sleeveyalve which is interposed between the cylinder bore `and the main piston and headpiston and carries ports to control inlet and exhaust-ports located in the cylinder wall.

lt is'an object of the invention to provide an improved engine of this type.

The invention comprises in an internal CII combustion'engine of the type described the- ?5 combination with a ported sleeve-valve of a cylinder lprovided with inlet and exhaustports situated close together and separated parts are in a position which, when'thelengine4 is running, will involve high pressure in the cylinder. ln this wavy, the pressure is confined between the main piston, the head-piston and the inner walls of the sleeve-valve so that leakage through the sleeveports along the cylinder wall is obviated. Moreover, by employing an obturating lip in this way, it is iound possible so to time the parts that the inlet and exhaust-ports can he kept open for the most desirable periods without employing a double sleeve so that the construction of the engine is simplied.

The inlet and exhaust-ports may extend around the whole periphery of the cylinderwall,1that is to say, the vports may be continuous around the periphery or may be virtually continuous, being subdivided by transverseV ribs at intervals.

i0 The sleeve-valve may-be cam-operated and .in thiscase a wide variety omovements `may `suffice to :open or closelthe ports at the proper times. Preferably however, means are provided or .so reciprocating the sleeve-valve (when the engine is working) `once for each two reciprocatiens or" the main piston thatthe sleeve-valve port 'passes :toward the enhaust side ci the land between the inlet and exhaust-ports Vwhile the obturating-lijp 'on :the head-piston is in a position which shuts oit the port in the sleeve from'the working-space between the pistons so that the exhaust-port may beV opened immediately `the obturatinglip uncovers the port in the sleeve-valve. This movement may be effected by -a simple form of cam or it is Vpossible to eiect it vby suitable timing from an eccentric or crank.

The invention will now be further described with re terence to the accompanying drawings which illustrate specic constructions by way of example.

Referring to the drawings Figure l is a vertical elevation, mainly in section, of one construction;

Figure 2 is a diagram illustrating `a suit- 75 able timing and movement for the sleevevalve;

Figure 3 is a vertical section through the head end of the cylinder of a second construe tion of multicylinder engine, the section be- S0 ing takenalong the line 3--3 of Figure l;

Figure a is a plan ot the interior o the cam-shaft chamber with the head cover removed, showing the parts at the vlevel ofthe line l--lot Figure 3;

Figure 5 'is a diagram showing-the essential Jfeatures of a cross-section upon the line 5 5 of Figure 3, looking upwardly with the pistons and sleeve-valves removed; y 1

Figures 6 and 7 are details of a modified 90 form of sleeve-valve actuating-rocker.

Like reference characters indicate like parts throughout the drawings. y

Referring first to Figures land 2, the engine comprises a working cylinder 11 set with 95 its axis vertical, a crank-shaft l2 below the 1cylinder and a transverse halt-time shaft 13 beyond the cylinder. There is also an intermediate hal-time shaftld at one side oit the cylinder. v

In the cylinder is a thin steel sleeve-valve 15 which is long enough to project beyond the cylinder-bore at both ends and which is operated by means hereinafter described from the intermediate half-time shaft 14. fithin the sleeve-valve there is a main piston 16 and a connecting rod 17L extends from the main piston to the crank-shaft 12. Above the main piston is an auxiliary head-piston 17 operatively connected to a ,crank 18 on the half-time shaft 13 above the cylinder, by a short connecting-rod 19. The operative connections of the head-piston 17 are such that this approaches the main piston 16 as closely as possible once in every two complete reciprocations of the main piston when the latter is at the inner end of its stroke. The parts are shown in this position in Figure 1. In the head-piston there is carried a sparking plug 2O for ignition of an explosive charge.

The lower edge of the head-piston is constituted by a junk-ring 21 which acts as a fluid-tight packing and an obturating-lip. An exhaust-port 22 is cut through the cylinder-walls at a transverse plane across the cylinder which lies just above the plane at which the head-piston and the main-piston most closely approach one another. rI`his exhaustport is continuous around the cylinder-wall. Below the exhaust-port is a narrow land 23 and below the land is a peripheral inletport 24.

The sleeve-valve is ported at 25 around its whole periphery, the port being interrupted by transverse vertical ribs 26 at intervals which serve to unite the upper and lower parts of the valve and to provide a bearingsurface for the pistons. The vertical width of the sleeve-valve port 25 is equal to the vertical width of land 23 between 'the inlet and exhaust-ports.

An eccentric cam or cams 27 upon the intermediate half-time shaft 14 serve to actuate the sleeve-valve 15. A rocking-lever 28 is located below the intermediate half-time shaft 14 and one arm of this lever extends towards the sleeve-valve 15 and is forked into two branches 29. Each branch carries a slideway and in the slideway works a slide-block 30. The slide-blocks are bored transversely at 31 to engage operating-pins 32 which project laterally outward from the wall of the sleeve-valve at its lower end, where it projects below the bottom edge of the cylinder-wall. The rocking-lever 2S has also two upward branches 33, 34 which extend on opposite sides of the cams 27 on the intermediate halftime shaft. Only one of these cams is shown, in dotted lines, in Figure 1. One branch 34 carries a cam-roller 35 to engage one of the cams and the other a cam-roller 36 to engage the other cam. By properly proportioning the cams they are caused to impart positive up and down movement free of back-lash to the sleeve-valve 15.

The upper half-time shaft 13 which operates the head-piston 17 is enclosed within a suitable casing 37 and an air-inlet door 38 is provided in the casing on one side. An outlet opening 39 is provided on the other side of the casing 37, and is connected to the inlet of a carburetor (not shown). The outlet of the carburetor is connected to the inletport 24 of the engine, as indicated by the chain line 40, Figure 1. In this way air is drawn through above the movable head-piston 17 and is preheated before passing to the engine. The rest of the engine, i. e. the cylinder-walls, are water-jacketed as shown both over the working part of the walls and also over the portion which extends around the periphery of the head-piston.

The timing and location of the sleeve-valve and the head-piston in relation to the main piston is such as is indicated diagrammatically in Figure 2, according to which when the main piston reaches the top of its stroke and the head-piston is close to the main piston, the sleeve-valve port is opposite the land between the inlet and exhaust-ports.

In the diagram, Figure 2, horizontal measurements represent time and the chain lines A, B, C and D represent the times in the course ofthe working cycle at which the main piston comes to one of its dead centres. A and C correspond to the times of two outer dead centres and B and D to the times of two inner dead centres of the main piston.

Vertical measurements represent distances measured axially along the cylinder. The horizontal line a represents the height of the upper edge of the exhaust-port 22, the horizontal line b corresponding to the lower edge i of the said port. The horizontal line c corresponds to the upper edge of the inlet-port and d to the lower edge of the said port. Thus the space c corresponds to the land between the inlet and the exhaust ports. movement of the lower edge of the sleevevalve port is indicated by the full line I and the movement of the lower edge of the obturating lip, formed by the junk-ring 21 on the head-piston is indicated by the full line II. The movement of the upper edge of the sleeve-valve port is indicated for a short distance at In.

On study of the diagram it will be seen that this begins on the left-hand side some- "1"/ what before the main-piston reaches its outer dead-centre corresponding to the line A. The curve I is below the curve II, indicating tha-t the lower edge of the sleeve-valve port is below the bottom of the head-piston, and as it is opposite the space between the lines c, d, representing the inlet-port, it will be seen that this port is open. The main-piston in moving forward is therefore drawing in a charge.

The

This condition of affairs con- 'of the sleeve-valve.

Ytakes place from the time B onward.

ti'iiues fsomewhalt beyond the outer deadcentrefat A. A-little beyond the dead-centre, however, `the port in the sleeve-valve in 'rising passes above the-inlet-por't and the bottom of the head-piston. The charge is thereby shut into the working space and compression begins at E. Since the lower edge 4of the sleeve-valve port passes above the `obturatin'g-lip of the4 head-piston (as is indicated by thecurves and II crossing one another) at the same time that the sleevevalve closes the inlet-port, the pressure is held between the main piston, the head-piston and the unported portion of the interior 'lhere is therefore no possibility of leakage except past the pistons, which'can be properly packed to prevent such leakage. Moreover, the sleevevalve by this movement rises above the land '23 and comes opposite the exhaustport 22 in readiness for this port to be opened by the obtura-ting-lip (curve Il) at a later stage.

Y It 'will be noted that during the compression stroke the head-piston (curve H) rises above the level of the exhaust-port (shown by lines a, b). The compression space is,

however, still closed as the sleeve-valve port (curve I) has moved upwardly fur-ther still and lies above the obturating-lip on the headpston. The upward movement of the headpiston ensures that at the inner dead centre of the main piston (line E) there is a suitable Vcompression `space between the two pistons.

At, or Aslightly before, lt-his position the charge is fired by means of the sparklingplug. n

Outward movement of the main piston The head-piston `is still rising and both pistons therefore allow for expansion ofthe charge. A considerably greater expansion ratio is ythereby obtained than is possible in an engine having only one working piston.

During the expansion stroke the sleevevalve ycommences to move downwardly and at the timeF its lower edge passes below the Y bottom of the head-piston and lthereby opens the exhaust port. This takes place shortly before the second outer dead centre (time C) of the Smain piston. While the main piston is returning, between the times C and D the sleeve-valve and the head-piston move downwardly as can be seen from the curves l and II and the exhaust-port remains open. At the second inner dead centre of the main piston, time D, the head-piston has moved downwardly so that it approaches the main piston closely. The point of closest approach is just beyond the dead centre at G and the Aport in the sleeve-valve is arranged to coincide with the land between the inlet and exhaust ports at this instant, as will be seen from vthe-curves.=l and la. rlhe exhaust-port 'is thereby closed 'and further movement of vgiven a simple harmonic motion (which would appear as a sine curve in the diagram) at the expense of not securing Vquite so large an overlap between the head-piston of the port during the compression and expansion strokes. lf the sleeve-valve is to be given an approximately simple harmonic motion, then instead of the cams 27 and rocker 28 a simple eccentric device may be employed for actuating it from the half-time shaft 11i.

Referring now to the multi-cylinder construction illustrated in Figures 3 to 5, the main piston 16, sleeve-valve 15, head-piston .17 and exhaust and inlet-ports'22, 24, re-

main substantially as hereinbefore described. Moreover the relative movement of the parts is the same. rilhe intermediate half-time shaft 11i is, however, dispensed with and the operative connections for actuating the sleeve-valve l5 receive their motion from 'the upper halftime shaft or cam-shaft 18.

llhe cam-shaft 18 carries two eccentrics 50 on which work roller-bearing eccentricsheaves 51 forming part of eccentric-rods 19. The eccentric-rods 19 work upon a gudgeonpin 52 on the head-piston 17. In the construction illustrated in Figures 3 and 5 the head-piston comprises two end sections 53, 54 of cylindrical shape which lit the bore of the sleeve-valve and are united by a central waist 55. The gudgeon-pin 52 is located between ears 56 in the upper part of the headpiston. The sparking-plug 2O fits diagonally f in the side of the waist of the head-piston and communicates with the working space of the cylinder by means of ashort axial bore 57. To accommodate the sparking-plug, which projects beyond the bore of the cylinder latvalve and the head-piston. An air-passage 59V enters the side of the cylinder opposite the port 58 and the sparking-plug projects `into the air-passage.

@n the opposite side of the head-piston the sleeve-valve 22 is orovided with another airport 60, which like the air-port 58 is in constant communication with the space formed by the waist of the head-piston. An airpassage 61 is pierced through the cylinderwall opposite the port 60. The air-passage 61 is connected to a manifold 62 which is in communication with the air-passages of all the cylinders of the engine. The manifold 62 is connected to a Carburettor (not shown) and the outlet from the Carburettor to a second manifold 63 which distributes the mixture to the inlet-ports 24 of Jthe cylinders of the engine. Over the air-port 59 in the cylinder-wall is a gauze 64 which carries an insu lated terminal 65 coupled by a spring 66 to the sparking-plug 20.

On the gudgeon-pin 52 and between the eccentric-rods 19 there is pivoted a sleeve-valve actuating-rocker 67. This rocher has an arm which extends laterally beyond the head-piston and terminates in an eccentric sheave 68. ithin this sheave is an eccentric 69 formed in one piece with a rocking-pin 70. The rockingpin 7 0 is j ournalled in ears 71 which project laterally from the top of the sleeve-valve 22. Thus when the rocker 67 is turned about its pivot on the gudgeon-pin 52 of the headpiston, the sleeve-valve 22 will be raised or lowered relatively to the head-piston.

The rocker 67 has two arms 7 2, 73 which extend upwardly one on either side of the cam-shaft 18 and carry pallets 74, 75, which face inwardly toward the shaft. The shaft is provided with cams 76, 77 one of which engages each of the pallets 74, 7 5, as shown in Figure 3. Thus the cam 76 pressing on the pallet 74 tends to move the rocker 67 to the left while the cam 77 pressing` on the pallet 75 tends to move it to the right, when viewed in the position illustrated in Figure 3. The cams 76, 77 are so shaped that the movement they impart to the rocker 67 supcrimposes upon the sleeve 72, a movement additional to that of the head-piston 17, sufficient to bring about a motion substantially in accord with curve I, Figure 2.

To provide for lubrication of the parts an oil-pipe 8O extends along the top of the interior of the casing 87 and is provided with openings at suitable intervals. Oil propellec through the pipe by a lubricating pump on the engine therefore drips on to the cams and eccentrics of the cam-shaft 18, as well as on to the bearings thereof and it is thrown by the movement of the parts into all the work` ing-joints. A gutter 81 is formed round the upper end of each cylinder-bore and directs the oil into a drainage pipe 82 from which it is directed into a casing 88 surrounding the driving-gear 84 over the cam-shaft 18. Tn this casing it descends to the engine cranlcase. It is to be observed that by the construction described the upper section 54 of the head-piston prevents excess of lubricating oil from accumulating 'upon the sparkingplug 2O and also from admixture with the incoming air for the carburetor. At the saine time the air entering through the passage 29 helps to keep the head-piston and associated parts cool and is itself somewhat preheated.

A further detail to which attention may be directed is that the eccentric sheaves 51 are each in a single piece and their diameter is slightly greater than the largest diameter of the cam-shaft 18, so that they may be passed over the cam-shaft in assembling the parts. The sheaves are held in place over the roller-bearings by means of plates 78 each in two halves which are secured to the ears on the sheaves by set-screws 79. The plates enter grooves in the cam-shaft shown at 85 and they also serve to retain the rollers 86 in place. Between the rocker 67 and gudgeon-pin 52 a roller-bearing is inserted and rollers are also placed between the sheave 68 and eccentric 69.

The arrangement of the water-cooling jacket around the cylinder and the inlet and exhaust-ports can be readily effected in the construction described. Figure 5 shows a cross-section through the cylinder-plug at the level of the exhaust-port and it will be seen that each of the exhaust-ports is nearly surrounded by a waterspace 90 taken in conjunction with water-passages 91 which divide the individual exhaust-passages 92 of each cylinder from one another. ln Figure 5 the cylinder-wall is represented at 11 and it will be seen that the exhaust-port extends all round this wall and is not interrupted at the wall by any transverse ribs. Thus the exhaust passage may be produced by cutting straight through the cylinder-wall on a suitable machine-tool and this facilitates its exact location. A cast passage would not be equally satisfactory. The same applies to the manufacture of the inlet-port in the cylinder-wall. Tn order to prevent exhaust-gases from one cylinder impinging upon the outside of the sleeve-valve of the adjacent cylinder at the moment when the exhaust-port is opened, the exhaust spaces of each cylinder are completely divided from one another by intern'iediate ribs 93.

Figures 6 and 7 show a modified form of sleeve-valve actuating rocker 67. In this case the pallets 74, 75 are provided upon adjustable wedge-shaped pallet- blocks 94, 95. The pallet-blocks are bolted to divergent slots 96, 97' on the arms 72, 7 3 of the rocker and by sliding them up and down their distance apart may be adjusted so as to take up any back-lash which otherwise might exist between the cams 76, 77 and the pallets. It will be understood that the cams 76, 77 are complementary in shape so that back-lash is equally avoided in all positions of the cams.

Vile claim z- 1. An internal-combustion engine comprising in combination a cylinder, a sleeve-valve therein, a main piston and head-piston within the sleeve-valve, means for reciprocating the pistons so that the head-piston approaches the main-piston closely once in each two complete reciprocations of the main-piston, a

rocker pivoted upon the head-piston and operatively connected to the sleeve-valve a transverse half-time shaft beyond the headpiston and operative connections between the rocker and the transverse halt-time shaft.

2. An internal combustion engine comprising in combination a cylinder, a sleeve-valve therein, a main-piston and head-piston within the sleeve-valve, means for reciprocating the main piston, a transverse half-time7 shaft beyond the head-piston, means thereon for reciprocating the head-piston, a rocker pivoted upon the head-piston and operatively connected to the sleeve-valve and means for actuating the rocker comprising operative connections to the said transverse half-time shaft.

3. An internal-combustion engine of the type described as claimed in claim 2 wherein the operative connections between the transverse shaft and the rocker comprise pallets upon the rocker extending one on either side of the transverse shaft and cams upon the shaft to engage said pallets,

4l. An internal-combustion engine of: the type described as claimed in claim 2 wherein the operative connections between the transverse shaft and the rocker comprise pallets upon the rocker extending one on either side of the transverse shaft and cams upon the shaft to engage said pallets, the said pallets being adjustably mounted upon the rocker as to their distance apart, for the purpose-described.

5. In an internal combustion engine the combinati-on of a working cylinder provided with inlet and exhaust ports in the cylinder wall situated close together and separated by a land of small dimensions, a main-piston therein, a connecting rod and crank shaft operatively connected therewith, a sleeve-valve interposed between the cylinder-bore and the main piston, a port in the sleeve-valve, means to impart to and fro motion to the sleeve valve across the said land so that the port in the sleeve valve alternately opens the inlet or the exhaust ports, a movable head piston within the cylinder and sleeve valve, means to cause the head piston to approach the main piston closely at the end of the exhaust stroke and an obturating lip on the head piston so located as to shut oi the port in the sleevevalve from the working space between the pistons when the parts are in a position which when the engine is running will involve highpressure in the working space.

6. In an internal combustion engine, the combination with a ported sleeve valve, of a cylinder provided with inlet and exhaust ports situated close together and separated by a land .of small dimensions in the direction of travel of the sleeve valve, means to actuate in the cylinder wall, a head piston having an obturating lip within the sleeve valve so located as to shut oli' the port in the sleeve valve Jfrom the working space between the pistons when the parts are in a position which when the engine is running will involve high pressure in the cylinder.

7. In an internal combustion engine, the combination with a ported sleeve Valve, of a cylinder provided with inlet and exhaust ports situated close together and separated by a land of small dimensions in the direction of travel of the sleeve valve, means to actuate the sleeve valve so that the port therein alternately opens the inlet and exhaust ports the cylinder wall, a head piston formed with a. central waist, the surrounding sleeve being provided with a port opposite to the waist, said waist and port serving to accommodate a sparking plug.

8. In an internal combustion engine, the combination with a ported sleeve valve, of a cylinder provided with inlet and exhaust ports situated close together and separated by a land of small dimensions in the direction of travel of the sleeve valve, means to actuate the sleeve valve so that the port therein alternately opens the inlet and exhaust ports in the cylinder wall, a head piston having a central waist, said sleeve valve being ported at two places opposite the waist in the head piston, and a gas passage entering the cylinder opposite one of the said ports and leaving it opposite the other of the said ports.

In testimony whereof we have signed our names to this specification.

JOSEPH LAMBERG JAMESON. CHARLES JOI-IN FISI-IER.

Images