US1860673A - Internal combustion engine - Google Patents

Description

May 31 1932. M. B. JACKSON INTERNAL COMBUSTION ENGINE Filed March 18, 1930 LNVEN'I'UR.

Patented May 31, 1932 UNITED STATES,

PATENT KQFF-ICIEF' 5 MAUNsELLB. JAcKsoN, or TonoN'ro, 'oN'rARro, cnNnnAjnssreNon T0 ALBERT-E. DYMENT, JAMES H. LUMBERS, AND WILLIAMS. GRAY, ALL or roaoN'ro, CANADA,

AS TRUSTEES INTERNAL COMBUSTION E GI E Application filed March 13,1939. Serial No. 436,838.

This invention relates to internal combus- 7 tion engines. Heretofore the piston in the conventional type of engine has been depended on to clear the burnt gases from the combustion chamber with the result that a certain percentage. of the burnt gases has been left in the combustion chamber at the end of the exhaust stroke of the piston. These burnt gases mix with'the fresh charge drawn into the chamber onthe following suction or intake stroke of the piston, and decrease the efficiencyof the engine. My object is to provide simple and inexpensive means to overcome this objectionable feature,-.toincrease the rate of flow and the volume of the combustible charge drawn into the combustion chamber. of the engine especially at high speeds thereof,to increase the life of the lubricating oil carried in the crank case .of the engine,-and to eliminate so-called carbon knocks. i

I attain my objects by interposing'a floating displacement member between the cylinder head and'the top of the piston so that the clearance? volume between the top of the displacement member and the cylinder head will be reduced to a minimum. The burnt gases will thus be thoroughly removed at the end of the exhaust stroke, and the member will be positioned to draw in a fresh charge immediately the, piston descends on the suction stroke. This will result in an increase inand an acceleration of the partial vacuum created by the descent of the piston so that a larger volume of the fresh charge will be drawn in, especially at high speeds of the I I cngine,:than, is possible with the conventional type of engine. 4

The constructions are hereinafter more fully described and are illustrated in the accompanying drawings in which Fig. 1 is a vertical section through the cylinder showing the floating displacement member in its position at'the commencement of the suction stroke;

Fig. 2, a section on a reduced scale showing the parts as they are positioned at the end of the suction stroke;

Fig. 3, a section at the end of the compression stroke just before ignition takes place;

Fig. l, a sectionsimilar to Fig. 3 at. the end of the compression stroke Just after ignition takes place; and

Fig. 5, a section at the end of the working: stroke, the exhauststroke being just about i to commence. V v v a Referring to Figs. 1 to'5, the'engine includes a cylinder ,1, cylinder head 2,1combustion chamber 3,intake valve 4, exhaust valve .5," piston 6, wrist pin ,connecting rod 8, and crank shaft 91 The upper end of the piston 6 is provided with an'extension 10 which has an inwardly directed lip or flange 11. In the extension "10 is'freciprocably mounted a displacement member12 which is carried on a stem 13. The stem 13 is slidably carried. in the head of the piston 6 and the outer periphery of the member 12is free ofthe inner periphery of theextension 10. This freedom obviates the necessity of lubri-' .cation between the member 12' and extension 10 and also serves another purpose as hereinafter set forth. When the member 12comes to rest against the lip "11 it makes asubstan-,

tially tight joint therewith. The'lower-en'd of the stem 13 is hollow, and in the wall of the stem is formed ahol'e l l adapted toestablish communication between the space within the skirt of the piston and the space behind the member 12 when'the latter 'is positioned' in engagement with or near the flange 11. The pressure behindthe member is thus brought to that of the atmosphere once in each cycle, and therefore any tendency for leakage past theImember to become accumulative is corrected each cycle. I

A spring 15*bearing against the'wrist pin 7 tends to maintain the member 12 in engagement with the flangell. "Assuming the piston 5 to be just commencing its downward .stroke as shown in Fig. 1, and the intake valve 3 to be opening, the

operation is as follows; The displacement member 12 will be either resting against. or

i Very nearly resting against the flange 11 and the very small space' between the member and the cylinder head 2 will be the clearance volume if the engine beconsidered as an air pump instead of the very considerable space between the piston 6*a'nd the cylinder head suction a longer time to draw in the combustible charge. During the suction: strokesthe hole 14 establishes communication between the s ace behind the=member l2and theatmors p re as hereinbefore described.

gag-Shows the position of the parts at the end of the suction stroke. The space between the member 12.and therc ylinder head 2 'JlS nowfilled withuncontaminated combustible chhrge and'the space between the member and the piston 6 is filled with inert gases at atmospheric pressure. The intake valve 4 is nowjustclosing or is just about to close.

its the iston rises on the compression stroke the resh charge above the member12 will compressed which will result in the member 12be' the piston 6,'the inertv ases below the member 8 Fi'g.,3ishows therelati'ves positions ofthe parts at the end of the compression stroke.

Ignition then takes place and the pressure above the member 12'risesto a maxn'numralmast and-l the member 12. is forced towards the piston as .ilhistrated in It is to be noted that the fiatnessof the member and of the-head of Llthe piston ensures a cushion of'gas betweensthem at all times. 7

7111b piston moves down the cylinder during the .WOl'kl stroke and the shereinbeforedesotibedsm annular s cc between the'onter periphery of theme and th'ednner peof Tthe extensionzwould T ermit a 45 J r I s gixdkage of gasto take place-i there be for any reason a renne'in-pressure. per square inch on the stop, and underside of the member 12. ltfound advisable to cause from above tmbeloWthemember 12 during werkinglstrokeandflthis is. aceomplished properly proportioning: the cross section areaiof fthestem13 and the strength of the springlii.

If we consider the member=l2wasin equiat any moment thesum of the forces acting-to raise it must be equal to the sum of the forces acting to press it down. The

firsfmentioned forces, i. e, those tending to raise'the member, are the gas, pressure on the nndersidofthe member 121'inpounds per squareinch multiplied bythe area of the underside ofthe member which is exposedto the'said pressure, and'the upward pressure of "springyl'fi. The force tending to .snction :intheccylinder tdm'ings, the abo :gi'ves: increased J moved towards the-head of mpressedand "e hole 14 beingrclosed.

counteract these forces is the gas pressure on the upper side of the mennber 12 in pounds per square inch multiplied by the total area of the member 12. That is to say if we assume that The gas pressure above member 12-h lbs. per sq. In. 'I'hegaspresmre below member 12'? lbs; pa sq. in.

Total area of marnherlZ-A. Total cross sectional area of stem 13=Az Force of spring l=F Then 1 when member 12'. is any position of equilibrium P|XA1=P:(A1A1)+F Considering the upward forces (A -A and F, it is evident, since the sum of these two forces has a definite value, that the larger either one is, the smaller the other must be. Thatuisto say if the spring 15 be very strong, the force F will .be sve'rygreat, the force P (A -As) will be very small andrthe pressure P5 consequently will Ibe' (small since A A is a constant quantity,

On the other hand,. if the spring; 15 be weak enoughto bernegl igible we would have the following equation:

Ar-Ar P1 1 I but A is greaterthan' =A --A" and becomes increasingly greater if A; beincreased. Then P must -"'be greater than 1 and beoomesincreasingly so if'A bemade greater.- Itis thus possible, by using astem'j'1'8of small di- 'ameter'and a strong'spring 15, to-mah'e P sstthe of the-combustion chamber, the said member being adapted to rest on said flange to close theupper-end of the extension.

Signed at Toronto, Canada, this 19th day of March, 1930.

MAUNSELL B; JACKSON.

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