US1424965A - Robert g-ladstobte wslls - Google Patents

Description

R. G. WELLS.

INTERNALCOIIIIBUS'I'ION ENGINE. APPLICATION FILED .IANI4,'I92I.

154245965 l Patented Aug. 8, 19122.

il! I IIIl IIIIIII P0155@ @lL/@n ROBERT GLADSTONE EVELLS, OF MARPLE, ENGLAND,

INTERNAL-GOIJBUSTIN ENGNE.

Application ied January 4 1925.. Serial No. 434,960.

To all whom if may concern.'

Be it known that l, ROBERT GLADsroNn VELLS, a subject of the King of England, residing at Marple, in the county of Cheshire, England, have invented certain new and useful Improvements in internal-Combustion Engines, of which the following is a specification. l

This invention relates to internal combustion engines of the two-strokel type and it has for its principal object to provide means for controlling the power thereof in such manner that the engine can be started with ease, and is capable of runningr efficiently at low speeds, either idle or during the performance of work. An important feature is that the manner of control does not adversely affect the scavenging action which takes place during mixture transfer, thereby4 avoiding the common ignition troubles known as four-stroking7 which arise when two-stroke engines are throttlech and thus promoting fuel economy.

According to this invention, the full working charge is at all tinies delivered to the working end of the cylinder but any de sired proportionof it is returned before ignition takes place, to the charge pump or its equivalent, by the agency of a control valve, or valves, which may be hand or mechanically operated or a combination of both methods may be employed. Thus the usual scavenging action of the incoming charge is regularly carried out, the mixture ratio is adjusted before transfer but the quantity is not throttled nor otherwise Varied, so that the power output may be determined solely by the quantity of mixture retained for ignition during the working .stroke` ln this way a reduced compression results for starting and slow running, but coinbustibility of the charge, and thus also the economy of the engine, is not adversely affected by the presence of av llarge proportion of inert gases as frequently occurs with the usual control system of throttling the mixture before entry into the charge pump. i

rlhe invention may be carried out in a variety of ways each characterized by the employment of a valve controlled conduit connecting the working end of the cylinder with the charge pump, or in the usual type of engine, with the crank chamber equiva- 'of closure to any desired point during `the pistons in-stioke. The same end may be obtained with an engine employing an automatic valve in the Atransfer port, by the addition of an adjustable engine-actuated control device adapted to delav similarly the closure of the valve until the desired amount of the charge has been expelled from the cylinder.

The manner of carrying out the invention isv'shewn in the accompanying drawings illustrating in outline two example applications' of this invention, wherein Figure l is a central sectional view of the `part of the charge return conduit in which the control valve is located between two ports communicating with the cylinder,

Fig. 2 is a central section through the cylinder and crank case of an engine, show-r ing the control valve andthe associated parts (with slight modifications) applied to Referring first toligure l, the charge return conduit A is situated lengthwise along the outside of the cylinder, the workt ing space of which is indicated at B; A port A? in the wall ofthe cylinder for the expulsion of the charge fromy the cylinder communicates with vthisv conduit and is so situated that the working piston covers it` when the minimum charge desired is present in the cylinder. The conduit is bored from the combustion chamber end to a point somewhat beyond the port A2, for the reception of a piston valve C, preferably of the trunk pattern. The skirt of this piston is adapted to overrun the port A2 to cut o communication of cylinder and conduit, and, if desired the edge C2 of the skirt may be cloned to correspond with a coned seating A3, formed around the Wall or". the conduit `A to receive it when the port is closed, and

thus to promote pressure-tightness.

' A port A4 also is formed to put the space on the other side olf the piston valve C in communication with .the combustion chamber B2, and a cap A5 which closes the end of the return conduit A is provided with a stop A6 to prevent the piston valve from overrunning and covering this port A4. rlhis latter alternatively may, if desired, be so situated that the Working` `piston covers it for a certain` period of Vits linstroke.

Normally the `piston valve Cois thrust by a spring, such as the .coil spring C3 against the stop A, so that the chargemeturii port A2 in uncovered. A second spring C4 Whose loading can be varied as desired kby a convenient form oit hand controlled the Working charge is transferred tothe cylinder in the known manner,'and thereafter, during r`the compression stroke of the Working piston, some of the charge is returned through the valve-controlled port A2 into the charge return conduit, and thus back tothe pump. rlhe action et the hand control on the valve loading is such `that the valve acts as -a throttle yvalve upon the charge outlet --port Abypartially closing it, thus 'regulating `'the quantity oit mixture Which returns -to the pump. As soon Aas the Workingpiston'cover's the charge outlet port 'A2, the riseinpressure of the mixture trapped in the combustion chamber during lthe remainder of the compression. 'stroke so acts through the port A* upon the pistou` valve C as to overcome the net loading; upon it oi' the springs C3, C4 and thereby forces it along' the conduit A so that itcovers the charge-return port A2, a'nd seats` itself at A3, it 'a seating;q 'is there provided. In this position itrests during the remainf der ot the compression stroke and throughout the Working stroke also, until exhaust commences, or the cylinder pressure .acting on it is otherwise lowered to permit the 'spring C3 again to return it'tov the other end o'l" its travel. It will readily be seen that by varying the net loading on the valve C by the hand controllable `means C5, the valve maybeset toi permit just as muc-h 'of the chargeto return to the pump as'may be desired; While onthe other hand when the valve is so loaded vas alwaysto close the'port A2 no charge "Whatever .is expelled from the cylinder and the full power output of the engine is thus obtained.

Figure 2-is an example outline ot an gine incorporating this invention. The crank case and pump chamber are shown at D enclosing the crank disc E With crank pin E2 actuated vby theconnectingrod El; attached at its small end to the engine piston E4 Working in the cylinder B. The pump vinduction port is shown at Cr, the cylinder inlet port at G2, and the exhaust port at G3. The control valve and its associated parts are lettered as in Fig. l. It may also be observed that 'in Fig. 2 the valve C isshownfin its closedfposition, the engine `piston E4' being` at the top kot lthe compression stroke thus covering thev port A2 as shown. l

it Will be understood.` that lthis invention is applicableto orms'of t'vvoestrolre engines other than that indicated by Fig. 2, which is chosen merely by Way of -example o'tthe application ot the invention.

It will be seen that the invention can be carried out in a variety of ways other than those illustrated, all of which have-the same -end in View, namely,-the return tothe sup- .ply source, during the compression stroke,

ot a portion of the Working,` clicrge contained in the cylinder. p v

What l claim as my invention and desire to secure by Letters `.Pa-tent of the vUnited States is f l. In a tivo stroke internal `combustion engine, the combination vot a cylinder, a Working piston therein, av combustion chainber forming part of said cylinder, a pump adapted to deliver 'a Working lcharge into said cylinder, a conduit communicating at one end With said combustionchamber, and at the vother end with said pump, a vport formed in the side of' said cylinder lcomniunicating'ivith said conduit at a point intermediate ot its ends, and adapted 'to be covered by said working `piston during,` a

yportion of the latters stroke, a valveflo-A cated in said conduit between said portand said combustion chamber land adapted to close said port by movementi'inder the pressure of mixture trapped in said combustion chamber aitertheavorking piston has vclosed said port, substantially asV setfliorth.

2. In a tivo stroke internal. combustion engine, the combination 'of a cylinder, =a Working piston therein, a' combustion chamadapted to deliver a Working charge into said cylinder, a conduit communicating at one end with said combustion chamber, and

at the other end with said pump, a port Ell- -ber forming part of saidycylin'der, anpump located in said conduit between seid port and said combustion chamber and adapted to over-run and to close said port under the pressure of mixture trapped in said combustion chamber after the working piston has covered said port, a seating upon which said piston Valve rests pressuretight after closing said port, and means Controllable at will for regulating the eX- tent to which said port is opened by said 10 piston Valve substantially as set forth.

In testimony whereof I have signed my neme to this speoication in the presencek of two subscribing witnesses.

ROBERT GLADSTONE WELLS.

Witnesses:

HARRY E. GEORGE, FREDK. H. BLUGDA.

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