US1310446A - Variable-displacement piston - Google Patents

Description

J. SCHAEFFERS. VARIABLE DISPLACEMENT PISTON FOR INTERNAL comausnon mamas.

RPFLICATIUN FILED FEB. 5 \916- 1,319,446, Patented July 22, 1919.

flaw?? 7 M WW 2 Wow 7M M M JOSEPH SCHAEFFEBS, F LAKEWOOD, OHIO.

VARIABLE-DISPIiAGEMENT PISTON FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented July 22, 1919.

Application filed February 5, 1916. Serial N 0. 76,243.

To all whom it may concern:

Be it known that I, JosEPH SOHAEFFERS, a citizen of the United States, residing at Lakewood, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Variable-Displacement Pistons for Internal-Combustion Engines,'.of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

This invention relates generally to internal combustion engines and more particularly to the construction and operation of the piston, the object of the invention being to greatly increase the efliciency and power of the internal combustion engine. With this object in view my invention consists in providing in connectlon with the standard type of internal combustion engine a piston of variable displacement, said piston being of normal displacement during the intake, compression and firing strokes and of abnormal displacement upon the exhaust stroke whereby all of the spent gases are expelled from the cylinder and thereby enabling a purer mixture to be taken in at each intake stroke and the efficiency of the engine correspondingly increased.

I11 the drawings forming a part of this specification I have shown one embodiment of'my invention and in which Figure l is a vertical sectional view of an internal combustion engine cylinder with one form of variable displacement piston operating therein, said piston being shown of normal displacement; and Fi 2 is a similar view showing the parts shi ted so that the piston will have abnormal displacement.

In the standard forms of internal combustion engines the piston has a definite stroke and therefore normally has a definite displacement whereby a definite compression of the gases drawn into the cylinder can be obtained and con uently after the explosion has taken place t e piston on the exhaust stroke moving exactly the same distance as upon the compression stroke leaves within the cylinder a definite amount of the spent gases and this roughly estimated is from one-fifth to one-eighth of the total volume according to the construction of the engine and is sufficient to materially affect the efliciency of the engine and it is With the object of entirely getting rid of all the spent gases that without chan ing or altering any features of the cylin er construction and other parts of the engine except the piston that I have devised my variable displacement piston which as before stated is normally during three cycles of operation and abnormally during the exhausting cycle for the purposes hereinbefore mentioned.

Referring to the drawings A indicates the cylinder of an internal combustion en ine which as before stated is of the standard or any preferred type having an inlet valve B and an exhaust valve C and working within this cylinder is a piston D connected to the crank shaft as usual by the connection E. Upon the inner end of this piston D is arranged a sub-piston F and if desired the main and sub-pistons can both be provided with packing rings or if preferred only the sub-piston. This sub-piston F is movable with reference to the main piston and this movement may be accomplished by momentum pure and simple or it can be automatically accomplished or it can be mechanically operated from the crank shaft or connecting rod or other part of the engine, the manner of shifting or moving said sub-piston being of minor importance'and in the present instance I have shown one form of device for accomplishing the same, this being a bell crank lever G pivoted at its elbow in the end of the main lston and connected at one end to the sub-p1ston and at its other end to a rod operatively connected to any portion of the engine. The sub-piston can be entirely independent of the main piston or it can be constructed with skirt portions adapted to fit around or telescope upon the end of the main piston, but this also is a detail which may be changed or modified as the necessities require without departing from the broad principle of my invention. On the intake stroke the sub-piston will be in contact with the main piston so that both main and sub-pistons will produce a normal displacement and upon the compression stroke the main and sub-pistons will remain in this close or normal condition so that the normal compression is obtained. During the firing stroke they remain in the same relative positions so that the full force of the explosion is transmitted to the power shaft. Upon the exhaust stroke however the subpiston separates or moves away from the main piston and the piston as a whole may be said to expand to its abnormal position so that upon the compression stroke instead of the piston having a normal displacement as on the compression stroke will have the abnormal displacement and practically fill the entire cylinder volume and forcing out through the exhaust valve all of the spent gases. When the exhaust stroke has been completed and the intake stroke begun the sub-piston is brought back or assumes its close or intimate relation with the main piston so that the two together provide a piston of the normal displacement and the intake compression and firing operations are then carried on again with the parts in close relation and there expanded or abnormal positions or relations are brought about only during the exhaust stroke for the purpose of ridding the cylinder of all of the burnt gases and this complete elimination of all the burnt gases materially increases the efficiency and power of the engine as a Whole and it will be noted that this increase in cfliciency and power of the engine as a Whole is accomplished by me Without making any alteration whatever in the engine construction other than the piston and it is obvious that various combinations of pistons and sub-pistons and means for relatively moving the two can be employed Without departing from the broad principle of my invention as covered by the appended claims.

Having thus described my invention, What I claim is:

1. In an internal combustion engine, the combination of a cylinder, a main piston therein, a supplemental piston therein, a connecting rod attached to the main piston,

an extensible connection between said pistons, and actuating means independent of the connecting rod and connected between said extensible connection and the engine shaft for the purpose described.

2. In an internal combustion engine of the four cycle type, the combination of a cylinder, a main therein, a supplemental piston therein, a connecting rod attached to said main piston, said supplemental piston being maintained fixed relation to the mam piston ,dur'ng the C mpression and power strokes, and means operated from the engine shaft for causing a relative displacement between said pistons during the exhaust stroke for the purpose described.

3. In an internal combustion engine of the four cycle type, the cpmbinatipn of a cylinder, a piston thfil'ein, a connecting rod having a variable stroke connection with said (piston, and means actuated from the engine shaft for shifting said connection during the exhaust 'nd intake strokes for the purpose described.

4. In an internal combustion engine, a piston having onnection with a connecting rod, :1 sub piston separate from the main piston, mo able connections between said main and sub'pistons and means operable from the eng ne shaft for moving said movable connections for the purpose set forth.

In testimony whereof I hereunto aifiX my signature.

.1 OS. .S CHAEFFERS.

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