US386209A - Method of opeeating gas engines - Google Patents

Description

(No Model.) 5 Sheets-Sheet 1.

L. H. NASH.

METHOD 0E OPERATING GAS ENGINES.

No. 886,209. Patented July 17, 1888.

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(No Model.) 5 Sheets-Sheet 2.

L. E. NASH.

METHOD 0E OPERATING GAS ENGINES. No. 386,209. Patented July 17, 1888.

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No. 386,209. Patented July 17, 1888.

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K METHOD 0E OPERATING GAS ENGINES. N0.- 386,209. Patented July 17., 1888.

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(No Model.) 5 Sheets-Sheet 5. L. H. NASH.

METHOD 0E OPERATING GAS ENGINES.

N0. 386,209. Patented July 17, 1888.

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UNTTED STATES PATENT trice..

. LEVIS HALLOOK NASH, OF BROOKLYN, ASSIGNOR TO THE NATIONAL METER COMPANY, OF NEV YORK, N. Y.

METHOD OF OPERATING GAS-ENGINES.

SPECIFICATION forming Ypart of Letters Patent No. 386,209, lated July 17, 1888.

Application filed October' 6, 1886. Serial No. 215,420.

To all whom it may concern:

Be it known that 1, Lewis HALLoeK NASH, a citizen ofthe United States, rcsidingat Brooklyn, in the county of Kings and State of New York, have invented new and useful Improvements in Method of Operating Gas-Engines, of which the following is a speciiction.

I have improved the method of operating the gas-engine; and my invention embraces a method in which the engine is operated with a combustible mixture of uniform proportions, a method of operation in which such a combustible mixture is supplied to the engine as fast as it may be used, a method ,of operation in which the premature ignition of the charge is prevented, a method of operation in which the flame from the power-cylinder is prevented from being communicated back to the supplyreservoir, and a method of operation in which the leakage from back-pressure is prevented from fouling the supply for the engine; and for carrying into elfect these several operations I have shown a type of engine of the upright form; but the particular structure and combinations therein shown and found are not claimed herein, as such matter is made the subject of a separate and distinct application for a patent filed by me of even date herewith, under Serial No. 215,419.

Referring to the drawings, Figure 1 represents a gas-engine in vertical section. Fig.

1 shows a cross-section of piston on thc line o 0 of Fig. 1. Fig. 2 represents a vertical section ofthe engine, taken at right angles to the line of section of Fig. 1. Fig. 2*L represents in vertical section the mixing-valve, and Fig. 2b shows a crosssection thereof on the line x2 of Fig. 2*. Fig. 3 represents a longitudinal central section ofthe case of the supply-valve, showing the ports and the passages therein. Fig. 4 is a longitudinal central section of the valve and its case,showing thevalve in theposition to admit the charge. Fig. 5 shows a view like Fig. 4. showing the valve in the position to ignite the charge. Fig. 6 shows alongitndinal section taken at right angles to the section-line of Fig. 5, showing the valve in the position it occupies when the llame is communicated from the external lighter to the ignition-chamber. Fig. 7 shows a crosssection of the valve and its case, taken on the line a: x of (No model.)

Fig. 5; and Fig. 8 shows a similar section taken on the line y y of Fig. 6; and Fig. 9 isa detail face view ofthe valvecase,showing the form of the inlet supply-opening shown in cross section in Fig. 7. The valve is shown in Figs. 10, 11, and 12 in longitudinal and in cross sections, Fig. 11 being taken through the ignition-chamber and Fig. 12 being taken through one ofthe valve-ports. Fig. 13 shows the supply-valvc-operating oblique eccentric in side view, and Fig. 14 shows the same in face view. Figs. 15, 16, and 17 show views of the ily-wheel governor device, Fig. 16 being a detail sectional view ofthe wheel-hub, and Fig. 17 shows the weight-connecting link.

The engine shown is of the vertical type, and the power-cylinder A is surrounded by a cooling-jacket, B. rPhe combustion or power chamber C is formed partly in a separate hood, D, and communicates at one side with the supply-valve port. The forward end of the power or combustion cylinder opens into a casing, E, of the frame, which forms a compression supply-chamber, F, for the engine, of which the piston is the compressor. A11 exhaust-passage, G, is formed by thejacket around the cylinder and opens into the chamber of the latter by a series of ports, 2, at about the middle ofthelcngth of thecylindcr, and the jacket has one or more outlet-ports, 3, for the escape of thc gases. rIhe powertransmitting crank-shaft H is mounted in the engine-casing E, so that its crank H and the piston-connections I of the latter are inclosed and operate within the supply compressionchamber.

The ily-wheel J is secured upon the crankshaft outside of the casing, and the supplyvalve-operating eccentric K is secured upon said shaft within a closed chamber, L, of the easing, Within which the valve-connecting rod M also operates, so that the piston and valve operating parts are inclosed to prevent the splashing ofthe lubricant.

The combustion-chamber G is contracted and has somewhat the form of a bugie, the smaller end, O', communicating with the snpply-port c of a valve, N, which :forms both the supply andthe ignition valve, while the larger end ot' said combustion-chamber is formed by the power-cylinder, so that the supply enters centrally the combustion-chamber from the small end to the larger end, expanding in its flow, while the flame for the ignition of the A.charge follows in the same direction from the same valve, which is arranged at the side of the cylinder. This valve also has provision for preventing the leakage from the power or coinbustion cylinder from fouling the succeeding charge. The rompressionchamber F co1n municates by a passage, Z1, withv a pipe, P, which opens into the valve-chamber port c, Fig. l, and such communication is controlled by a governor-valve, Q, fitted into said passage b, so asV to open and to close the port b', of Vthe passage b to increase or to diminish the iiow of the charge under the action of the governor. This valve N serves to permit the iiowof a certain quantity of the combustible mixture to form the charge and to retain the surplus mixture within the compression-chamber, and such function is preferably controlledby a governor automatically, in a way vthat I will presently describe. It may, however, be controlled by means not automatic, such as an ordinary screw-cock.

The supply-valve case R has a cylindrical longitudinal valve-chamber, R', within which is fitted the cylindrical valve N, within the interior body of which is formed the ignitionchamber d, having a tangential ignition-port, 4,atangential supply-port, 5,and a central ignition-port, 6, opening at right angles to the tangential ports. The ignition-chamber d is ofcircular Iorin, and its central ignition-port, G, has a bushing to give the required size to suchport. A lateral port, 7, opens at the side ofthe valve and communicates with a central longitudinal passage, 8, which opens at the lower end of the valve. The supplypassage P is formed at one end of the valve-ease and opens into the valve-chamber port c, while the engine supply-port a opens at t'nc side of the case and surrounds the valve. Below the supply-port @the ignition-port 9 is formed, so as to communicate the llame from an external lighter-jet, 10, to the ignition-chamber d in the operation of the valve. Au inclosed passage, 11, is formed in the wall of the case and opens into the valve-chamber at two points, 12, which forms an escape for the gases from the ignition-chamber while the ignition-port 4`for the combustion-chamber is opening.

The supply-port a has its inlet-opening formed with a lower enlarged part, c, Fig. 9, in such manner as to form an angular wall projcction, 13, within the said port, into which enlarged part the ignition-port 4 of the valve opens at the point when the valve is turning in its seat to ignite the charge and passes the edge of said proj eetion.

However tight the supply-valve of a gasengine is made to work, itsjointI forming contact will wear so as to permit leaking from back-pressure and foul the charge so as to seriously interfere with the operation of the engine. I provideaperfect remedy for this difficulty, so that however badly the valve may leak the waste gases cannot be forced back of valve--as, for instance, that shown and de` scribed in my patent dated February 17,1885, No. 312,491. This provision consists in providing the valve-case with a separate valvecontrolled portc, opening into the fuel-supply passage-P', and a separate valve-controlled port, a, communicating with the combustionchamber, and between these ports there is an escape-port, 15, which separates lhejoint-forming bearings of the two case-portsand is open to the outer air, as in Figli. Such case-ports are shown as surrounding the valve and the intermediate escape-port, 15. open to the air through the valve-case and also inclosing the valve. The valve has two separated bearingfaces, one controlling each ot' the said ports, anda division-space, 16, Fig. 10, is formed between these bearing-faces,into which the leakage from the separated valve-bearing faces may escape, and thus avoid all possible chance for being forced into the supply-passage, because in such position of the valve both the supply-ports are closed by the valve, and any gases that leakby the bearing-surfaces will pass into and away through the escape-port.

'In the construction shown one of the bearing-face sections N ofthe valve has a central passage which opensinto the division-space 16, whereby to make communication between the 4two ports when the valve is admitting the charge to fthe power-cylinder. In this provision it is immaterial whether the escape-passage 15 be formed in valve case or in the valve,

so long as it separates the joint-forming surfaces of the two supply-ports` when they are closed. The upper end of the valve-chamber is closed by a plug. The case-wall passage 11 is not necessary in a quickly-moving valve.

The supply-valve is operated from the crankshaft by an eccentric, K, of peculiar construction, as I shall now describe. Upon the shaft is secured a hub, K', having aneccentric diskbearing turned with its axis oblique to the axis of the shaft, and having a circumferential V- shaped groove to receive a bearing-ring, S, to which is pivoted the valve-connecting-rod M, which has a universal-joint connection, T,with said valve. It is this peculiar eccentric connection that gives a lcombined reciprocating and turning or twisting movement, which will be hereinafter described, in the opera-tion of the engine. In an engine where the valveconnection can be madeattheend of the crankshaft a crank-pin set obliquely may take the place of the oblique eccentric.

Referring to the function of the valve to prevent back-pressure from the combustion or power chamber fouling the charge, the constructionby which this is effected serves also the important function of preventing the [lame from the combustion-cham ber from being communicated back to the supply.

In my experiments I used a lifting checkvalve in the supply-pipe, which communi- ICO IZO

y Besace cated directly with the combustion-chamber, so that the back-pressure of the gases in the combustion-chamber would act to close said valve. I found that such valve could not be relied upon, however perfect its seating, as the valve would wear out of perfect joint, and that it was also liable to collect foreign matter-such as dirt and lak es of burnt oil-which would prevent its tight closing, and this caused leakage, fouling the supply, as well as allowing the dame to pass under the valve and ignite the mixture in the supply-reservoir. I found that a sudden explosion of the charge in the combustion-chamber would often transmit the tlame under the bearing-face of the lift-valve, however perfect its seating, and that this result would take place from the rebound of the valve, caused by the sudden impact from the explosion. 1 provide against this serious difficulty of a check-valve by the use of a positively-moving (preferably a sliding) valve for controlling the admission of the charge, which can have no such rebound and no uncertain action, and by the provision of an escape-passage for the flame should it leak hy the bearing-surfaces of the valve, because, now, supposing the flame to run along the joint-forming faces of the valve from the cylluder-port e, the flame would enter the escape passage or port 15 and pass out to the air. It could not pass beyond this escapeport into the supply-passage P, because the port c is closed by a portion, N', of the valve, and because the pressure carrying the flame would end in the escape-port, which separates the two supply-ports. I also found that when the pressure in the combustion-chamber had been reduced by reason of the opening of the exhaust-ports below the pressure in the supplypassage the gases from the latter would rush into the combustion-chamber and become prematurely ignited, and the flame would be transmitted under the valve back into the reservoir. My improvement overcomes this very serious defect by a positively-moving valve, and which cannot be opened by the varying pressures of the gas, but which is controlled solely by the connecting mechanism and is only opened at the proper time. Any positively-moving Valve having substantially the functions I have pointed out will be the equivaient and may be used instead of a sliding or plunger valve.

The piston U is of the trunk form and may have any suitable pitman-connection with the crank-shaft. Tre connection shown is preferred, because its construction is such as to provide for taking up lost motion from one end ol' the connectingrod,and to provideafrictionless bearing for the piston and an oiled bearing for the crank, in which the bearingseats are made seltadjusting; but as these matters form the subject of a separate application for a patent by me a more specific description isdeemcd unnecessaryherein. Itis important, however, that the operating-connection with the piston should be by a frictionless bearing, that the crank-pin should be lubricated, and that the valve and its connections should be oiled by automatic means, so as to require no attention and to reduce the friction of the connections, so that the exigirle will work with a perfectly easy linovement. In Figs. 1 and 2 of the drawings I have shown the frictiouless bearing of the connecting-rod with the piston, which consists of an inner bearing block, 25, on thc upper e'nd of the abutment-rod I and an outer bearing-block, 26, and a knife-edge bearing-piece, 27, secured to the piston between the bearing-blocks 26 and 27, the latter of which is secured within openings in two tie-rods, 2S and 29, the lower ends of which are secured to the crank-pin bearing-boxes.

The knife-edge piece 27 of the piston has its under bearing upon the lower block, 25, made convex, and its upper knife-edge bears in a V-shaped groove in the upper block, 26, these two bearing-blocks being retained in position by the tie-rods. The pushing strains are resisted by the abutment-rod I, and the pulling strains upon the abutment-rod are resisted by the two tie-rods, which are formed with enlarged open ends, so as to receive the bearingboxes of the crank-pin and the knife-edge bearing device for the piston. As the connecting-rod I swings back and forth, the upper block, 26, will rock upon the knife-edge bearing piece 27 and the lower bearingblock will roll upon its convex surface, and hence there will be no sliding movements of these parts and no friction or wear, so that they will require no oil; but the piston, the valve, their operating-conn ections, and the crank-shaft are oiled by the operation of thc engine, and in this particular the operation of the engine is facilitated, the frictionless bearing, which requires no oiling, cooperating to facilitate the operation with the parts which are made selfoiling.

The comp ressi on chamber F is supplied with a combustible mixture by a mixing valve placed externally thereto, adapted to automatically regulate the relative proportional supply of gas and air t0 the power-cylinder, so that the charge of combustible mixture shall be of uniform quality and density. This miX- ing device forms an attachment for the cornpression-pump of the engine, as seen in Fig. 2, the connection with the compression-pump being made at 18, so that the pump draws its charge through the mixing device,whi ch connects with the gassupply pipe at 19 and has a perpetual open air-inlet at 20. rIlhe case e ofthe device is formed with an interior chamber, f, and two valve-ports, g and hf, ot' unequal area, with which a conical valve of corresponding separate valve-seats, t3 andy', operates vertically by its weight to control the iiow of gas through the smaller valve-seat, h, and to control thciow ofair through the larger valveseat, g. In the construct-ion shown the chainber j is formed between the valve-seats and the larger ot' the latter is directly above the IOO IIO

IIS

passage It j".

smaller, the valve being central with both. The case e is preferably of circular form and has a horizontal partition-plate, 7c,wl1ich forms the bottom of the chamber f and has a central opening, h, which opens in the small upward-Haring valve-seat and into said chamber and communicates with the gas-supply passage 19 in said partition-plate. The chamber is supplied with air through a series of openings, f', in the bottom plate, 7c,whieh are made ol" deiinite size in relation to the gas supply valve-seat opening. The upper Valve-seat, t', ilares upward and is formed in the top of the chamber j', and the valve has conical seats corresponding with the seat-openings, forming a lifting-valvegnided by a fixed central pin,upon which the valve is itted. The valve chamber is incloscd by a cover which has the guide-pin for the valve. The supply of gas to the chamber is controlled and regulated by a screwplug, l, Fig. 2", iitted in a screw-threaded horizontal opening in the case, so that the inner end of said screw-plug crosses the central opening, h, below the lower valve-seat and is set to open and to close said openings more or less, the adjustment of said plug being made from the outer side ol' the case, as seen in Fig. 2".

The supply of air to the chamber f is controlled and regulated by a screw-cup, m, which screws into the lower open end ofthe case, so as to close more or less the openings in the bottom plaie ol' said chamberf, the in ner end of said cup for this purpose being` formed with an in ward-p rojecti-ng rim, m', wide eno ugh to close said openingsj" when the cup is driven up against the said bottom plate. In the operation of the mixer the force ol' the suction of the pump in drawing its supply through the device lil'ts the valve, so as to open communication ofthe compression-pump with the cham'- berf, which thereby opens communication of the gas and air passages It f with the said, pump.

Now the relative quantity of gas and air that will be drawn into thechamberf will depend upon the relative size of the supply- To increase the supply ot' gas, the screw-plug Z is drawn out to increase the area of the supplyI-opening l1., and the screwcup m is driven in to lessen the supply-openings f. To increase the air-supply over the gas-supply, the reverseot' these adjustments is made, and these adjustments may be made separately to regulate the supply of the gas or of the air. rlhe double seated valve is made of sufeient weight to greatlyovereome the pressure of the gas in the pipe 19, so that whenever the device is in action the force of ithe suction will be considerable, and the slight variations in the pressure of the gas-supply usual in service-pipes of cities will-therefore have little effect, as compared with the suction of the pump, in controlling the ilow of the gas and air. lt is therefore practically necessary only to consider the gas as having approximately the same pressure as the air, and the conditions are obtained whereby the two currents are drawn from separate supply-passages having substantially equal pressures into a chamber in communication with the compressor. Under these conditions the flow of each constituent will be proportional to the capacity of the supply-passages; Vhen the suction of the pump stops, the double-seated valve closes by itsweight, cutting off both gas and air until the next action of the pump. As the size of the openings hf in the bottom of the chamber controls the proportional iiow `of the constituents, the form of the valve-seats should be such as to lift quickly and completelyopen the full capacity of the inlet-openings. I may, however, use any form of fuelmixingvdevice that will supply a mixture in definite proportions of gas and air, and I may `use an independent compressor, if desired, to supply the combustible mixture to the engine.

The iiy-whcel ofthe engine has, preferably,

`the governor device for governing the operation of the engine. In this governing device the liy-wheel has a radial pin, n, secured in the rim of the wheel, and, extending within the `rim, terminates in an enlarged hearing end,

11.', upon which a weight, p, is fitted, having'a chamber, q, longer than the bearing of the piuhead. This construction gives the Weight two cylindrical bearings -one upon the pin n and the other upon its enlarged end n-so as to make a free sliding joint for the weight thereon. The inner end of the chamber,

which forms the larger cylindrical bearing `for that purpose, so that the air will slowly leak through said joint from one chamber to the other and allow of a perfectly easy motion of the weight when it moves slowly, but will offer considerable resistance to a rapid motion. Upon the hub of the wheel is fitted a freelymoving ring, t, Fig. 16, having a circumferential groove, t, into which fits a pin, u, Fig. 1, on the lower end ofa lever, u', pivoted to the engine-frame at u2 and having a free connection with the plug-valve Q. The ring has an interior projecting feather, i?, Whiehstands oblique to its axis and fits into a groove, r', ot' the connecting-link. To retain the lower end of the link in position, it is fitted into a groovebearing, c, formed iu the side of the hub, as seen in Fig. 16, and thereby guides the link in its movements with the weight. A spiral spring, w, connects the free end of the linkrl with the wheel-rim at a point diametrically opposite to the Weight for the purpose ot' balancing the centrifugal force of the Weight, and the tension of the spring is regulated by a screw and nut, w. As the speed of the fly- LOC IIO

wheel increases, the weight p will be moved outward with its link o', so that the groove i" of the latter will move the ringt by its featherconnection outward, and thereby operate the lever a', so as to throw the plug-valve Q inward to close, according to the extent of its movement, the supply-port Z1' to control the supply to the valve. As the speed of the Wheel decreases, the opposite action takes place, and the supply to the cylinder is in-' creased, and thereby increases the power of the engine. By this construction the governor device consists of only one weight and a single balancing-spring, and this simple retarding device is sufficient to prevent all vibrations of a single unbalanced weight without impairing the sensitiveness of the governor.

' I have made provision Yfor lubricating the bearings of the working parts of the engine, which provision I will now describe. The compression-chamber of the engine is supplied with a suitable quantity of oil, from which a portion is forced out and again sucked into it by the action of the compressor. A conduit, x, leads from the bottom of the compression-chamber to the bearing-surfaces to be lubricated. rIhis conduit may consist of a tube or of wall-passages, or of both, as shown. Surrounding the piston is a groove, y, formed in the inner wall of the cylinder, which conimunicates by a wall-passage, c, Fig. l, with the chamber of the supply-valve, and into these the conduit opens. lhedrippings from the piston return to the compression-chamber F through the open end of the latter, while the drippings l'rom the valve-moving parts fall into the closure L of the engine-frame, along the valve-connecting rod M, its eccentric, and the bearings of the shaft and collect in the bottom of said closure. The wall which divides this closure from the compressionchamber has a passage, 2l, Fig. l, containing a cheek-valve, 22, which, while retaining the oil-supply in the compression-chamber, allows that which collects in the bottom of the closure to be returned by suction into the compression-chamber. As the comp ression-chamber contains the elastic gaseous fluid, the alternate pressure and suction in the chamber caused by the action of the piston causes the oil to flow from said chamber and then to be drawn into ift again in a circuit to and from the bearing-surfaces to be oiled. In this action the elastic fluid is first subjected to pressure and then to suction, the first to cause the oil to be forced out through a series of passages connecting the bearing-surfaces, and the second to cause the elastic fluid to have a sucking action upon the drip from the outfow to return it to the source of supply through a passage controlled by a valve opened by the force of the suction and closed by its weight.

It is obvious that the lubricating-circuit may be effected by an independent plunger Working in a separate closure containing air, instead ofthe compression-pump of the engine; but I prefer to use the compression-chamber as the pump, because such provision forms a part of the engine.

For regulating the quantity of the flow of the oil through the conduit a controlling-cock, 23,is provided in said conduit,as seen in Fig. 2.

In the operation of the engine the piston,-

being on its upward stroke, draws into the compression-chamber through the mixing device a uniform combustible mixture, in which the relative proportion of the gas and air is automatically and uniformly determined. The retu r11-stroke of the piston compresses the mixture in the said chamber until the crank has nearly reached its lowest point and the exhaust-ports 2 are opened. Vhile the ports 2 are still open, the supply-valve opens to admit the charge into the combustion-chamber, as shown in Fig. 4, driving out the waste products from the cylinder through the exhaustports. The valve now closes thesupply-ports a and c, and the piston, returning, compresses the charge and begins its next forward stroke, when the charge is ignited, the valve beingin the position shown in Figs. 5, 7, and 9, driving the piston forward. At this point in the operation of the engine it is of the greatest importance to prevent the leakage caused by back -pressure from fouling the succeeding charge; and referring to Fig. 5 it will be seen that the leakage from the cylinder-port a, passing the joint-forming valvefaoes,will flow into the escape passage or ports 15, and thence to the open air through the escape-passage in the case, so that in no condition in the movements of the valve can the waste gases flow back into the supply-port. The provision by which this important result is effected serves also to prevent the flame from being communicated to the supply-chamber, because now, supposing the flame to run along thejoint-forming faces ofthe valve from the cylinder-port, the flame would enter the escape passage or port and pass out to the air. It could not pass beyond the escape-port into the supply-passage, because the latter is closed by the portion N of the valve, and because the pressure carrying the flame would end in the escape-port, which separates the two supply-ports. The piston, continuing forward until it reaches the position shown in Figs. 1 and 2, begins to open the exhaust-ports, and the waste gases escape through the exhaust-ports 2, the supply-valve at this time being closed, and remains closed until the pressure in the cylinder has been reduced to that of the atmosphere and until an interval of time has elapsed to allow the old charge to cool. This is important to prevent the premature ignition of the incoming charge from the hot gases which remain in the cylinder, because when the pressure in the cylinder is reduced by the escape of some of the hot gases the remaining gases do not long retain heat sufficient to endanger a premature ignition of the incoming charge. The supply-valve then opens and admits anew chargefwhieh drives the remaining waste gases out, and the engine continues its operation,

IOO

y as stated.

VIt will be seen that thevalve on its forward movement operates its ports 4, 6, and 7, and then turns ou its axis and returns, so that in its returning movement its ports are not again opened until on its next forward stroke, and it 'is this twisting and reciprocating movement which permits 'a single plungervalve to perform its several functions on its forward stroke without repeating them on the return-stroke.

The quantity of the combustible for each charge is controlled automatically or otherwise by the governor, which opens and closes the passage b, connecting the compressionchamber with the supply-valve. When this passage is nearly closed by the valve Q. only a small quantity ot' combustible mixture can flow into the combustion-chamber from the compression-chamber, so that some of the mixture will remain under pressure in the `supply-chamber and expand again as the piston moves upward. Under this expansion the mixing-valve will remain closed during aportion of the pistons movement, and upon completing its upward movement only a quantity of combustible mixture will be drawn in through the mixing-valve equal to that which flowed out of said chamber to make the charge in the cylinder. In this way a combustible mixture of uniform and constant proportions is supplied to the power-cylinder for all conditions in the operation of the engine, and therefore the operation of igniting the charge and theeftlciency ofthe expanding gases will be the same Whether the engine is running under a high or a lower power. In this operation the compression-pump co-operates with the governor in drawing exactly the quantity of the combustible mixture into the compression-chamber to make good the quantity taken out for each charge.

In cases where the engine is exposed to the collection of dirtand grit it may not be deemed advisable to return the oil which collects in the chamber L to the compression-chamber F, and in such case the valved passage 2l and 22 between thel two chambers will not be used and the chamber F will be supplied with oil as maybe required, it being important to keep the oil free from grit.

Access to the chamber L is had by removable side plates.

As in my improved method of operating a gas-engine the compression pump and the storage-reservoir are in free communication with each other, therefore when the powercylinder has received only a small portion of the charge from the reservoir the balance of the gases therein will be retained and will expand backinto the compression-chamber during a portion of the stroke of its pistou,thus partially filling the compression-chamber from the gases in the reservoir until the pressure therein is reduced below that of the atmosphe're. After this the piston begins to suck in a new charge through the mixing-valve to ll up the space made vacant by the remaining cylinder, after which a new supply just sufcient to supplyconsumption would be drawn in by the next stroke of the compressor.

It is evident that it' a check-valve were placed between the compression-pump and the storage-reservoir the above-stated operation would be impossible, because such an intermediate Valve would prevent the return ol'l the charge from the reservoir into the compressor, and the compressor would only act to force all the charge taken in at each stroke into the rcservoir,whether the charge in the latter has,

been used or not. This operation of my engine is important and advantageous in preventing the accumulation of the charge in the reservoir and avoiding the necessity of providing against an excessive pressure of the charge and providing an automatic means for regulating the supply. Referring now to exhausting the waste gas from the power-cylinder, it will be understood that when the piston first opens the upper edge of the exhaustports the charge will rush out of the ports so quickly as to produce a shock and cause the pressure to be reduced to that of the atmosphere, and frequently produces a suction in the cylinder. Now,whenacheckvalve is used s,

to admit the charge, the fresh combustible mixture will instantly rush into the cylinder while the waste gases are still hot, and they wi ll beignited prematurely; but when the gasesare prevented by my positive-moving valve from entering at this time until the shock of 11o the exhaust is passed and the remaining gases are somewhat cooled the new charge may then be admitted without danger of being prematurely ignited. The did'erence in time is small, but it corresponds to a considerable movement of the crank and is effective in securing the desired result.

From what has been said it is obvious that the upper and lower parts ofthe compressionchamber F perform the functions of a compression-chamber and also of a compressionreservoir, and since they are constantly in free commmunication with each other they may also be properly treated as a single chamber.

I do not conne myself to the precise devices or combination of devices herein described,

since devices or combination of devices hav-A ing the functions substantially of those described may be employed without departing from the spirit or scope of my invention.

kIt will be observed that the fresh gases entering the combustion cylinder or chamber drive before them and out of the exhaust-ports the foul gases remaining in the chamber after combustion has taken place. This is due to the fact that the entrance and exhaust ports are substantially at opposite ends of said chamber and are both open simultaneously for a short period of time. In engines of this type the exhaust ports are usually opened by the piston in what may be termed its forward7 stroke, and I find it convenient to employ this term to designate the type of engine illustrated and described.

In conclusion I desire to explain that by the use ofthe term aduct or passage of constant capacity77 and similar and related expressions in this specification I intend to designate a passage which does not contain a device for governing or controlling the quantity of gas which will flow through it, when open, in a givenintervalof time, but one which, although it may only be opened intermittently, yet while open permits the same quantity of gas to iiow through during a given interval of time.

I am aware that it has been proposed to admit asmall volume of fresh air into the pas sage through which the charge must flow from the reservoir to the power-cylinder in such manner that the fresh-air charge shall travel ahead of the gas charged to prevent the passage of Haine backward tothe said gas-charge and to keep the passage free of spent gases. This manner of avoiding the back passage of the iiame and the dilution of the f'resh charge is not efficient or satisfactory. The fresh air becomes mingled with the fresh charge,injuri onsly diluting it, not only in the entrance-passage to the power-cylinder, but also in the power-cylinder itself, andthe operation of the engine for this and for other reasons is not improved by the adoption of this expedient. On the other hand, it will be observed that I avoid the difficulties above referred to by excluding all fresh gases (air as well as the combusti ble mixture) from the power-cylinder until after the shock of the exhaust is over and nntil the intense heat of the waste gases is reduced.

I have shown and described herein various matters relating to separate and distinct operating parts of a gas-engine, for which I have filed Separate and distinct applications for patents under Serial Nos. 215.417 for fuel-luixing device, 215,422 for ignitor, 215,421 for iiy-wheel governor, and 25,418 for connecting-rods, and I make no claim herein to such specific structures and devices in so far as they do not relate to their functions in carrying out the method which I have described of operating a gas'engine.

rIhe invention embraced in the lubricating device I have described, and have herein limited my claim in connection with a gas-engine, whereby the lubrication of its working parts is rendered continuous under the action of the piston of the engine; but the invention, broadly considered as a device for effecting the lubrication of the working parts of engines or motors of whatever character, is made the subject of a separate and distinct application for a patent filed by me December G, 1887, under Serial No. 257,123, an d such broad claims are not asserted herein.

I claim- 1. The method substantially herein described of operating a gas-engine, which consists in admitting a combustible mixture to a compressor, compressing it into a reservoir having free communication with the compressionchamber, admitting some of the compressed charge to the power-chamber in quantities controlled by a valve, and regulating the supply to said compression-chamber solely by means of the back expansion ofthe gases contained therein.

2. The method substantially herein described of operating a gas-engine, which consists in compressing a combustible mixture, exhausting the waste gases at one end of the combustion-chamber, delaying the admission of fresh gases to the cylinder until a period of time after the shock ofthe exhaust is over and until the intense heat of the waste gases is reduced, and admitting the fresh charge at the other end of the cylinder to drive out the remaining gases.

3. rlhe method substantially herein described of operating a gas-engine, which consists in drawing a combustible mixture in successive charges of uniform density into a compressionchamber during the backstroke of the piston, compressing the mixture in said chamber during the forward stroke of the piston, controlling the How from said compression-chamber lo the supply-valve by a governor, admitting the charges to the combuslion-chamber during a compound movement of the plunger-valve, compressing the charge duri ng the back-stroke ofthe piston, and igniting the charge during a twisting movement of the valve.

4. The method substantially herein described of operating a gas-engine, which consists in drawing into a compression-cllamber successive charges of a combustible mixture by the back stroke of the piston, compressing the charge in said chamber by the forward stroke ofthe piston,ad mitting the chargein the powercylinder, closing communication between the combustion-chamber and the supply-chamber, closing their connectiiig-passages, opening be tween said chambers an escapepassage for the leakage, and igniting the charge upon the next forward stroke of the engine.

5. The method substantiallyherein described of operating a gas-engine, which consists of admitting to the compression-chamber of said engine, by means of an admission-valve controlled solely by the back expansion of gas contained in said chamber, a quantity of mixture of uniform density at each stroke of the piston equal tothe quantity consumed in the engine by the preceding stroke of the pistou.

6. The method substantiallyherein described of operating a gas-engine, which consists in compressing a combustible mixture within a compression-chamber at each stroke of the compressor, drawing from said compression- IOO IIO

IIS

n chamber a quantity of mixture ab each stroke form density at each stroke of the piston equal of the piston proportioned to the power deto the quantity consumed in the engine by the veloped, and regulating the supply to said preceding stroke ofthe piston.

chamber solely by means of the back expan- In testimony whereofI have hereunto set my 15 5 sion of said surplus mixture. hand in the presence of two subscribing wit;-

7. The method substantially herein described nesses. of operating a gas-envine, which consists of admittingto the compession-eh'amber of said LEWIS HALLOGK NASH' engine, by means of au admission-valve con- Vitnesses: ro trolled by the back expansion of gas contained A. E. H. JOHNSON,

in said chamber, a. quantity of mixture of uni I BESSIE B. JOHNSON.

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