US1418209A - Gas engine - Google Patents

Description

I. E. SMITH.

AGAS ENGINE.

APPLICATION FILED JUNE 8, 1918.

1,418,209. Patented May 3o,- 1922.

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GAS ENGINE. APPLICATION FILED JUNE 8'. I9I8.

Patented May 30, 1922'.

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I. E. SMITH.

GAS ENGINE.

I APPLICATION FILED JUNE 8. I9IB. 1,418,209, v Patented May 30, 1922.

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JOIN E. SMITH, OF NEW YORK, N. Y., AVISSIGNOR 0F ONE-THIRD T0 THOMAS T. GAUNT AND :ONE-THIRD 'ro WILLIAM D.

N. PERINE, BOTH 0F NEW. YORK, N. Y.

GAS ENGINE.

.specification of Letters Patent. vPaix-1,11ted May' 30, 1922.

Application Ailed June 8, 1918. Serial` No. 239,014.

To all whom t may concern.'

Be it known that l, JOHN E. SMITH, a citizen of the United States, residing at New York in the county of NewYork and State of New York, have invented certain new and useful Improvements in Gas Engines, of which the following is a specilication. y

This invention pertains to an improved gas engine and to the method of operating the same.

The invention has to do more particularly with engines of that type designed more es- ;pecially forv use in airplane work, and has for its main objects the simplification of the engine and means whereby the amount of air which is utilized in the explosive charge may be varied according to the altitude at which the machine is employed or running. The invention has for its further object the production of an engine wherein a single combined intake and exhaust valve is em- .ployed for each cylinder, which valve may be readily remoyed for repair or replacement. A further object of the invention is to provide a simple means' for introducing lthe fuel into the cylinder through the single valve, the fuel being vaporized by the air which is drawn in during the intake stroke of the piston. A further object of the invention is to provide valve closing mechanism working in timed relation with the piston so that at low altitudes a portion of the fuel charge may der in order that the mixture may`not become too rich which would cause a premature explosion of-the charge due to the heat of compression.

The invention is illustrated in the annexed drawings, wherein,-l k

Fi is a sectional elevation of an engine cylinder and its allied parts; f

Fig. 2 a side elevation of the cam operating and adjusting mechanisms;

Fig. 3 a longitudinal sectional view taken on the line III-III of Fig. 2;

Fig. 4 an enlar ed end view of the cam;

Fig. '5 a top p an view thereof together with the operating shaft;

Fig. 6 a perspective-view of the cam;

. Figs. 7 to 10 .'nclusive, diagrammatic views showing the relation of the valve and the piston in different operative relations;

and v 'Fig 11 a diagram illustrating the power be driven out of the 'cylinsection 25, said enlarged portion or stroke and its rela-tion to the valve movement both in opening and closing and for the air and fuel intake and the exhaust.

It is to be understood that in practice a plurality of cylinders will be employed, but inasmuch as 'they areJ alike, in form, only one is shown'.

lIn the drawings, 1 denotes the cylinder surmounting the crank case 2. The piston is indicated by 3 and is connected by a pitman 4 to a crank 5 secured upon a crank shaft 6 which extends lengthwise of the various engine'units. The upper end of the cylinder is provided with a large opening'which approximates the bore of the cylinder. A shoulder 7 is provided adjacent the opening upon which is placed a ring-shaped valve 9 screwed into the outer end of the cylinder and bearing directly upon the upper face of the ring. Extending upwardly from the valve seat is a spider frame 1() having a hub 11 in which is mounted the valve stem 12 carrying at its lower end a valve 13 which is adapted to seat against the inner face of the valve seat. wardly from the spider -frame and a rocker arm 15 is fulcrumed therein, the inner end -of the arm being rounded and bearing in a block 16 mounted in the upper slotted end tion of spring 18 which encircles the tap` pet rod 19 connected to the opposite or outer end of the rocker arm 15. Said spring takes against a bushing 20 mounted in the crank casing 2, and against a collar 21 fixed on the rod. The cam shaft is denoted by 22 and secured'thereon is a cam 23, the cam bein .of the form best seen in Figs. 4, 5 and 6.A aid cam is provided with a bearing portion 24 which is concentric shaft and is also provided with an enlarged section extending through a greater distance about the shaft at the inner end of the cam, as denoted by l26,- than it does at the outer or forward l end. This enlarged portion 26 merges into the forward enlarged portion upon an inclined planel or line denoted by 2 7, iny Fig. 6, and as -a consequence of this formation, as the cam shaft 22 is shifted longitudinally, lthe tappet rod- 19 will vbe held upwardly for a greater or less time,

A bracket 14 extends outwith the axis ofthe .seat 8 which is held in place by a ring nut according as it is upon the extended raised portion of the cam or at the outer section where the raised portion is not so extensive. When operating at a high altitude when a greater volume of air must, owin to its rarefied condition, be impounded 'into the cylinder, the cam is so shifted that the tap pet rod works. upon a smaller active portion of the cam than it does when the engine is operating at a lower altitude. ln the former case the valve is closed earlier in the compression stroke and in the latter, later in thecompression stroke of the piston.

A pinion 28, Figs. 2 ,and 3, is secured upon the crank shaft 6 and meshes with a.' gear 29 secured upon the cam shaft 22, lthe gears being in the ratio substantially llto 2, so that for each two revolutions of the engine shaft the cam shaft will make a single revolution.

The cam shaft is so mounted that it may be shifted longitudinally in order to bring the one 0r another portion of the cam into operative position with reference to the tappet rod and to this end l employ a rocker arm or lever 30 fulcrumed at one end,.as at 31, and provided at its' upper end with a draw-bar 32, which has attached to it a handle 33 through which the lever 30 may be manipulated. A thrust bearing 34 is securedto the outer end of the shaft 22 and vswiveled in the arm or lever 30. The pinion 28 being relatively 4wide, the gear 29 is always maintained in mesh' therewith and motlonis transmitted from the engine shaft to the cam shaft at all times when the engine'V pipe 35 (Fig. 1) provided with a nozzle 36 which discharges in a, downward direction over the valve and the valve opening. A pump, not shown, will b e employed to force the fuel from the nozzle, the pump being connected up tothe operative parts 0f the engine and working in timed relation therewith. It has been found in actual use that this method of applying the fuel is all sucient and highly eicacious. The ingoin'g air vaporizes the fuel and a proper charge or admixture of vaporized fuel and air is obtained.

With the parts in the position shown in lig. l, it will be seen that the valve is closed and it may be assumed'that a charge has been compressed and is about to be fired. There is about a 10 lead between the firing point and the upright top center position of the crank. Upon firing the piston descends and the power stroke continues through approximately 140 to 150, as indicated in the diagram Fig. 11. When the piston reaches the point marked No. 2in the dia- Laiaaoe gram, the cam opens the valve and the engine will exhaust from that point on, pr, in other words, will exhaust through apiroxh mately 220 movement of the shaft. n the upper stroke of the piston, the valve being opened, the cylinder will be scavenged fand,

owing to the position of the cam, the valve will remain open uponthe downward stroke, thus drawing in a fresh charge of air and likewise drawing in the fuel which is injected over the valve and valve cage. Assuming that the engine is operating at low altitude, the cam will 4be so positioned that the Valve will remain open during a portion of the lnext or compressionstroke, and a portionv of the .fuel will be ejected in order that the engine may not fire by the heat generated bycompression. The air at the lower altitude being relatively dense as compared to that of high altitude, the cam holds the valve open until the parts reach the position shown in Fig. 9, when, as will be seen, the movement of the cam .(in the direction of the arrow) will permit the valve to close and during the balance of the movement ofthe piston the charge is compressed;

In other words, having reference tol Fig. 11, the air and `fuel intake continues from the point marked No. 3 to the point marked No. 5, where the valve closes. 1 The charge is then again fired and the cycle above recited is repeated. As the machine passes into-higher altitudes, the operator shifts'the cam so as to bring the tappet rod to that position along the inclined face 26 of the cam so that the valve will close earlier during the compression stroke, this for the reason that the air is rarefied and a greater vvolume to produce the proper exploslve charge becomes essential. This position is indicated in Fig. 10 wherein theJ valve is' shown as closed while the piston is substantially at the lowest point in its stroke.' The valve at such time closes at the point marked No. 4, in Fig. 11, so that the air'and fuel intake passes through substantially 200O and the compression stroke thus extends through 150. There is thus obtained a variation of 7 0 between the time of closing of the valve at the low altitude and the time of closing of the valve at the high altitude, and such arrangement enables the operator to control the motor without diiiculty and in accordance with the conditions which obtain at di'erent altitudes.

An index may be employed in conjunction with the valve positioning mechanism so that the operator may bring the same into the proper position indicated by his altitude instruments.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is,-

1. In a gas engine, 'the combination of a cylinder; a piston working therein; a single combined inlet and exhaust valve opening into the c linder and alone controlling the intake an exhaust of the engine; a variable throw cam working in timed relation with the piston and serving to close the valve at different points of the compression stroke; means under the control of the operator for adjusting said cam; and means for injecting fuel directly into the cylinder through the Valve opening when the piston is moving throulgh the intake stroke.

2. n a gas engine, the combination of a cylinder; a pistotn working therein; a single combined inlet andl exhaust valve, of large area, opening directly into the cylinder and alone controlling the intake and exhaust of the engine; means for injecting fuel through the valve opening directly. into the cylinder during the intake stroke of the piston; and a variable throw cam controlling the movement of the valve, said cam being soarranged that it may be adjusted to hold the Valve open during the early part of the compression stroke of the piston, thereby permitting a portion of the fuel charge to be forced out of the cylinder.

3. In a gas engine, the combination of a cylinder; a piston working therein; a single combined inlet and exhaust valve opening into the cylinder and alone controlling the intake and exhaust of the engine; a fuel nozzle for delivering fuel onto the valve structure while the valve is open; and a4 cam mechanism for operating the valve, the cam being shiftableto close the valve at different points in the compression stroke whereby' the explosive charge may be maintained substantially constant irrespective of the density of the surrounding atmosphere.

4. In al gas engine, the combinationv of a cylinder; a piston working therein; a single combined intake and exhaust valve locatedk in the head of the cylinder alone controlling the intake and exhaust of the engine; a fuel supply nozzle located adjacent said valve and adapted to eject fuel thereon during the intake stroke of the piston, the fuel being vaporized by and admixed with the ingoing air; an adjustable variable throw cam controlling the closing ofl the valve during the compression lstroke of the piston; and means under the control of the operator for adjusting the cam.

5. In a gas engine,

cylinder; a piston Working the combination of a thereln; a combined intake and exhaust valve located in' the head of the cylinder and alone controlling the intake and exhaust of the engine; a fuel supply nozzle located adjacent said valve and adapted to eject fuel thereon during the intake stroke of the piston, the fuel being vaporized by and admixed with the ingoing air; and an adjustable cam having a varying degree of pitch for controlling the closing of the valve whereby the valve may be kept open a longer or shorter period durin the compression stroke of the piston.

6. hat method of operating gas engines having a combined single exhaust and intake valve, and adapted for use at different altitudes, which consists in ejecting fuel upon the valve structure; drawing air in through such valve during the intake stroke of the piston of the engine and thereby vaporizing the ,fuel and admixing it with the air to form a combustible charge, and thereafter during the compression stroke varying the time of closing of the valve according to the density of the surrounding atmosphere whereby the effectiveness of the charge w1ll be maintained substantially constant.

In testimony whereof I have signed my name to this specification.

JOHN E. SMITH.

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