US459403A - lanchester - Google Patents

Description

(No ModelQ) 3 Sheets-Sheet. 1.

P. W. LANGHESTER.

GAS ENGINE STARTER.

No. 459,403. Patented Sept. 15, 1891.

(No Model.) 3-Sheets-Sheet 2.

' F. W. LANGHESTER.

GAS ENGINE STARTER.

No. 459,403. Patented Sept. 15, 1891'.

(No Model.) 3 Sheets-Sheet 3.

F. W. LANOHBSTER.

GAS ENGINE STARTER Patented sept. 15, 1891.

UNITED STATES PATENT OFFICE.

FREDERICK \V. LANCHESTER, OF LONDON, ENGLAND.

GAS-ENGINE STARTER.

SPECIFICATION forming part of Letters Patent No. 459,403, dated September 15, 1891.

Application filed December 19, 1890. Serial No.3' 75,209. (No model.) P ented in England April 10, 1890, N0. 5 ,4'79 in Belgium November 8, 1890, No. 92,641, and in France November 10, 1890,11'0. 209,400-

T0 at whom it may concern:

Be it known that I, FREDERICK WILLIAM LANCHESTER, a subject of the Queen of Great Britain and Ireland, residing at Bedford Row, London, in the county of Middlesex, England, have invented certain new and useful Improvements in Gas-Engine Starters, (for which I have obtained patents in England, N 0. 5,47 9, dated April 10, 1890; in France, No. 209,400, dated November 10, 1890, and in Belgium, No. 92,641, dated November 8, 1890;) and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention for improvements in gasmotor engines relates to engines of that class in which inflammable gas or vapor, together with a certain proportion of atmospheric air, is introduced into the working cylinder and then or after compression exploded to increase their pressure to propel the piston during the working stroke; and it has for its object to provide improved means for starting the said engines.

This invention consists, substantially, in introducing into the Workin g cylinderwhile the piston is stationary inflammable gas or vapor, which forces out a portion of the air contained therein and mixes with the remaining air until an explosive mixture is formed, and in providing means whereby on cutting oif or reducing the supply of inflammable gas or vapor the said mixture is exploded to start the engine and whereby when the engine is running explosive charges in the cylinder at atmospheric pressure are ignited at the commencement of the working stroke, and when required in compression-engines after starting the engine from rest, as above described, either in keeping the pressure of the explosive charges in the cylinder approximately that of the atmosphere until the engine has attained sufficient speed to overcome the resistance of compression, so that they can be exploded at the commencement of the Working stroke by this device, or in providing means whereby low-pressure charges can be ignited by the said device, the said low pressure of the charges being produced by a relief-cam as ordinarily used in some compression-engines for reducing the amount of compression until asufficient speed has been attained to overcome the resistance of full compression.

In agas-engine of the Beau de Rochas or Otto type provided with a starter constructed according to this invention the compressionchamber is fitted with an attachment communicating with the said chamber and terminating in an expanding nozzle opening to I an external flame. This attachment can be permanently closed by a cock and coutainsa valve which normally remains open by its own weight, but will automatically close by the sudden generation of pressure in the cylinder. In order to start an engine fitted with this improved device for starting. the engine is placed in such a position that its crank is somewhat over .the in-center of the Working stroke, the external flame of the starter is lighted, and the gas or inflammable vapor is turned onto or forced into the working'cylinder through a suitable nozzle or nozzles by the ordinary pressure of the gas or by other suitable means. The gas or vapor first displaces a portion of the air contained in the cylinder, which passes out through the nozzle of the starter, and then a continuously-increasing proportion of gas or vapor passes out with the air until it burns with a characteristic roar in the expanding nozzle, when the auxiliary gas-supply is cut off or reduced and the flame passes back into the cylinder and burns or explodes the charge to increase its pressure to start the engine. The automatic valve in the starter closes immediately on the explosion. The cock of the starter is then turned to put it out of action by cutting off communication with the cylinder, and the engine continues to work in the ordinary manner. I

A relief-cam which keeps the exhaust-port open during more or less of the compressingstroke (as is frequently used to facilitate hand starting) may be used in compression engines to enable the impulse given by the initial charge to overcome with certainty the back-pressure of the compression. In another arrangement arelief-cam is arranged to keep the exhaust-port of the cylinder open until IOC the piston has completed its compressing stroke. The engine is started as described above, and after exhausting the products of the first explosion draws in a fresh charge, a portion of which on the return or compressing stroke is forced out through the exhaustport and through the nozzle of the starter.

As soon as the piston pauses on the crank crossing its center or commences its working stroke, the explosive mixture ceases to pass through the nozzle of the starter or reduces its rate of passing through and the flame passes back into the cylinder and explodes the remaining portion of the charge therein. A series of explosions may be obtained in this manner. WVhen the engine has attained a sufficient speed to overcome the resistance of compression, the auxiliary cam and the starter are thrown out of action and the engine orks in the ordinary manner.

111 the accompanying three sheets of drawings, Figure 1 is an elevation of an auxiliary igniting apparatus constructed according to this invention and hereinafter called the starter. Fig. 2 is a vertical section, and Fig. 3 is a plan, of the same. Figs. 4 and 5 are detail views, and Fig. 6 is a cross-section, of the cylinder of a gas-engine, showing a complete arrangement for starting fitted in place. Fig. 7 is a similar cross-section showing the application of a pump for introducing the charge of gas or inflammable vapor, which may be arranged to deliver the required volume at a single stroke. Fig. 8 is a section of a modified form of the starter suitable for igniting charges under compression. Fig. 9 shows the character of the indicatordiagrams produced in starting an engine of the Beau de Rochas or Otto cycle modified as described above.

The end of the cylinder or compressionchamber 1 is fitted with an attachment consisting of a valve-box 2, of a stop-cock 3,

through which communication is made between the cylinder and valve-box 2, of a valve 4, which normally remains open by its own weight, but is automatically closed by pressure in the engine-cylinder, and of a nozzle 5 which is connected to the valve-box 2 and opens to an external flame 6. The nozzle 5, is preferably conical, expanding toward the direction of discharge. The external flame 6 can beadjusted with reference to the nozzle 5 by means of the thumb-screw 7, and is supplied with gas by means of a tube connected to the nipple 8. A stop-cock 9 serves to regulate or extinguish the flame 6. The compression-chamber l is also fitted with a suitable nozzle 10, by means of which gas can be admitted to the cylinder through the supplycock 11. The gas so admitted may be forced in by the ordinary pressure in the gas-supply pipes, as illustrated in the cross-section, Fig. 6, or it may be supplied by means of a hand-pump 12, as shown in Fig. 7.

In order to start an engine fitted with the starter, it is placed in such position that its crank is somewhat .over the in-center of the working stroke. The external flame 6 of the starter is lighted, and the gas or inflammable vapor is turned onto the working cylinder through the nozzle 10. The pressure in the gas-pipes causes the gas to flow into the cylinder and displace a portion of the air it 0011- tains through the nozzle 5; but the entering jet mixes with the remaining air, as indicated at Fig. 6 by the arrows, and, so produces an explosive mixture, part of which after a time finds its way through the nozzle 5. The external flame 6 then ignites it and the jet burns at the nozzle 5 through the external flame into the atmosphere, increasing in richness of gas or vapor till it burns with the well-known roar characteristic of explosive mixtures. The gas-supply cock 11 is then shut off and the flame passes back into the cylinder and ignites or explodes the charge to increase its pressure to start the engine. The automatic valve 4 in the starter closes immediately on the explosion of the charge, and then the cock 3 is turned to put it out of action, when the engine continues to work in the ordinary manner. The diagram given by this explosion is indicated at Fig. 9 by the lines-a a a a, and in some cases Where the friction of the engine is proportionally small the single impulse so given is sufficient to start the engine even against the compression. An incandescent body or shower of electric sparks or other convenient means may be used in lieu of the flame.

Instead of having a separate means of introducing the inflammable vapor for starting the engine, the supply-valves may be opened and the engine turned in the proper direction by hand to draw in combustible mixture and then slightly turned back in the reverse direction to force a portion of the said mixture through the starter-nozzle, Where it is ignited, the flame traveling back and exploding the mixture, as described above, to start the engine.

WVhen a number of low-pressure explosions are required to get up speed, a cam 13 is arranged on the second motion shaft in such manner that When placed in gear it holds open the exhaust-valve 14 during the whole compression stroke of the engine. This. cam 13 is placed in gear before obtaining the first explosion, as hereinbefore described, and when the engine moves under its influence the modified action of the subsequent strokes is as follows: The burned gases resulting from the first explosion are discharged on the next instroke. Then the exhaust-valve closes, and on the outstroke a charge of gas and air is drawn into'the cylinder. A large proportion of this volume of explosive mixture is discharged on the following instroke, which in ordinary circumstances would be the compression stroke. So long as the exhaust-valve 14 is held open by the special cam 13 the pressure remains near that of the externalatmosphere; but enough back-pressure exists ITO to cause the mixture to flowthrough the starter and burn from the nozzle 5, itbeing ignited at the external flame 6. WVhen the piston arrives at the in end of the'stroke and the exhaust-valve closes, the pressure rapidly falls and the flame passes back to the compressionspace at the end of the cylinder and explodes the mixture to give an additional impulse to the engine. A diagram similar to b b b b, Fig. 9, is thus produced, and the piston moves forward on its working stroke. So long as the starting-cam 13 is in gear and the startercock 3 is open the engine continues in motion and a low-pressure impulse is given at every second revolution. Then the speed has become sufficiently great to allow of the compression, the cock 3 is closed and the starting-cam 13 is put out of gear in any usual manner. The engine then acts by its ordinary igniting arrangement with compres- S1011.

Instead of supplying gas direct from the gas-supply pipes by its ordinary pressure, the hand-pump 12 is sometimes used to force in a charge of gas through the check-valve 15 by the nozzle 10 to the cylinder 1. The action is precisely similar to that hereinbefore described, and the explosion occurs when the hand-pump piston has terminated its discharging stroke. The check-valve 15 prevents the efiects of the explosion from reaching the gas-pump. The charge of the gas-pump and the direction of the jet from the nozzle .10 are so arranged that explosive mixture speedily finds its way to the starter-nozzle 5.

When it is desirable to ignite charges of gas and air under compression by the starter, the modified arrangement shown in Fig. 8 is employed. The starter-nozzle 5 is connected to the compression-space by the tube 16 and opens to a chamber 17. The annular passage 18 is also connected to the compression-space and communicates with the lower side of the automatic valve 19, which can be maintained in its raised position against the resistance of the spring 20 by means of the thumb-screw 21. WVhen the engine is to bestarted,theautomatic valve 19 is released from the screw 21 and is thrust down by the spring 20 or by its own weight and an externalflame 6 is arranged to play into the open space above it. The gas is then turned into the cylinder, and the passage 22 allows the flame 6 to come into contact with any gases proceeding from the nozzle 5, and when they become explosive they are ignited and burn within the chamber 17. When the current ceases, the flame at once passes back to the cylinder through the pipe 16 and the first explosion takes place. This closes the valve 19, and the engine-shaft revolves, the piston discharging the burned gases and taking in a fresh charge, as before. The exhau st-valve in this case, however, closes before the end of the compression stroke, and after the gases proceeding from the nozzle 5 are ignited the rising pressure in the cylinder closes the valve 19, which was opened on the suction stroke. The flame from the nozzle 5 then continues to burn in the chamber 17 till the pressure rises to that in the cylinder, or nearly so, when it passes back and explodes the mixture. The proportions of nozzle 5 and chamber 17 are so arranged that the explosion occurs at the end of the stroke. In this manner a series of explosions under compression is obtained by means of the starter, giving more power than those obtained without compression. The valve 19 is opened when the pressure in the cylinder falls to nearly atmosphere by the spring or its own weight, and an ignition at every second revolution is given.

A pilot-jet 23 is adapted to relight the main external flame 6 as it is blown out at each explosion. The valve 19 is formed with a channel or gutter 2 1 to cause leakage through the valve to be supplied from the annular passage 18 instead of from the chamber 17, so that the action of the nozzle need not be interfered with in the event of the valve leak The proportions of the nozzle 5 in all arrangements may be varied so as to send the flame back to the cylinder on the explosive current being merely reduced instead of cut off, the essential principle affecting these nozzles being the fact that the flame will pass back immediately the velocity of the propagation of the flame from particle to particle exceeds the velocity of efflux.

In the starter shown in Figs. 6 and 7 the valve may be held open bya spring instead of its own weight, and the position may then be varied by placing it at the side or under the cylinder instead of above it. The valve 1, as shown, has grooves 25 to allow the flame to pass; but other obvious modifications may be adopted.

I do not herein claim the construction of the various forms of my devices, as the same is fully described and claimed in concurrent applications filed on May 15, 1891,Serial Nos. 392,895 and 392,896.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The method of starting a gas-engine, which consists in first causing an inflammable mixture of gas and air to pass out of the end of the cylinder through an open nozzle, then igniting the issuing mixture by contact with an exterior incandescent body, such as a gas-flame, and finally reducing the pressure in the end of the cylinder, whereby the flame may be forced backward through the open nozzle by the pressure of the atmosphere,

thereby igniting the charge in the end of the cylinder and propelling the piston, substantially as set forth.

2. The method of starting gas-motor engines, consisting in introducing into the working cylinder inflammable gas or vapor to form explosive mixture and in allowingor forcing a portion of the contents of the said cylinder to escape through a nozzle and through a flame, igniting the explosive mix- IIO ture when it issues, and in cutting off entirely or diminishing sufliciently the amount of gas or Vapor flowing into the cylinder so that the flow through the nozzle diminishes and consequently the flame passes back into the cylinder and ignites the mixture and starts the I engine, substantially asdescribed.

ficiently rich, and in cutting off or reducing the supply of gas Which causesthe flame to pass back into the cylinder and ignite the mixture and start the engine, which will draw in fresh charges to be ignited by the starterflame at the commencement of the Working strokes so long as the exhaust-port iskept open during the usual compressing stroke, so that a sufficient speed is obtained to overcome the compression, substantially as described.

In testimony whereof I affix my signature in presence of two Witn esses.

FREDERICK WV. LANOHEST-ER; Witnesses:

ST. GEORG, ALFRED CHAUKE;

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