US1141658A - Internal-combustion engine. - Google Patents

Description

W. SCHMIED'.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED NOV. 2, 1910.

Patented June 1, 1915.

UN TED STATES PATENT OFFICE.

WALTHER SCHMIED, OF GENEVA, SWITZERLAND INTERN AL-CdMBUSTIbLl' ENGINE.

To all whom it may concern Be it known that I, WALTHER SCHMIED, citizen of Switzerland, residing at Avenue de la Servette 9, Geneva, in the Confederation of Switzerland, have invented certain new and useful Improvements in Internal- Oombustion Engines, of which the-following is a specification.

The present invention relates to a device which, during the exhaust stroke and also for the next following suction stroke; length ens automatically the stroke of the working piston of four stroke combustion engines by means of. an eccentric disk or a small crank which is arranged in one of the two cross- -head ends of the connecting rod, in such a manner that in the dead center position of the piston movement atthe end of the exhaust stroke the workin piston is led up to the cylinder head wh1le at the compression stroke'which follows, this lengthening of the stroke does not take place, so that the stroke as well during this compression stroke as during the following expansion stroke .25, maintains its normal length and leaves a free space between the working piston and the cylinder head, which space forms the compression chamber and in which space the admitted gas charge is compressed.

'80} f The object of the present invention is to push out of the cylinder by the exhaust stroke of the working piston all of the combustion gases, in-order that the admission of the new charge may take place without "clearanee or prejudicial space which would reduce the volume efiiciency of the suction stroke.

Another object of the invention is to considerably increase the volume of the gas 40 drawn or sucked in with regard to ordinary motors by the fact that the exhaust stroke and therewith the suction stroke automaticall increases to an amount corresponding to the length of the compression chamber of 4 the cylinder. ltIoreover the gas or gases drawn or sucked in are not heated or contaminated by burnt gases remaining in the cylinder. This allows a higher compression to be obtained and greatly facilitates the ignition of the gas mixture, whereby the efficiency of the motor is increased and a better utilization of the fuel secured.

In the annexed "drawing, several forms of.

the invention are shown.

-5 Figures 1 to 7 show a constructional form Specification of Letters Patent.

in the cross-head of the connectin Patented June 1, 1915.-

Application filed November 2, 1910. Serial No. 590,310. i

in which the eccentric disk is arrangedin the'cross-head of the connecting rod at the crank pin. These figures show also the dif ferent positions of this eccentric during the working of the motor, the'working pistoneo and the cylinder of the motor being shown diagrammatically.

In the Figs. 1 to 7, a designates a cylinder of a motor represented diagrammatically by a line, and b the working piston, being shown in section, 0 designates the piston pin, that is the (fin which connects the connecting rod an the working piston, d theconnecting i'od, e the eccentric which is pivoted rod d. The eccentricity of the eccentric isk e is equal to about the half length of the compression chamber of the cylinder avof the motor. By the term compression chamber, as herein employed, I mean that portion of 76 the cylinder between the head thereof and the face of the piston when in its dead center position at the normal stroke, as shown in Fig. 7, this compression chamber extending between the line a: and the line as 80 in icated n Fig. 7. The eccentric e is mounted freely on the crank pin f of the crank f and further freely rotates in the head of the connecting rod 03. The energy of the piston 12 is transmitted by the crank f to the main shaft 9 of the motor. I

' The device works as follows :-As long as the pressure in the motor-cylinder at the working side is not very different from the atmospheric pressurefor example-during 9 the exhaust-and the suction strokes of the piston, the eccentric 6 takes, under the ac- 'shown in Figs. 1 .to 5. The centrifugal force tends to move the center e of the eccentric disk as far as ossible from the cen-' ter of the ,circle descn ed by the crank pin, 0r from the axle of the driving shaft 9; so that the center 6 of the-eccentric tends to travel outside the crank circle but concentric to it in anew circle, the diameter of which is greater than that of the said crank cycle by twice the eccentricity of the eccentrio 0. I 3ut thereby the stroke of the working piston is also increased by the same amount and as the eccentricity is equal to the halflen th of thecompression chamber as hereinbe ore explained, the working piston travels through the whole length of this chamber, until it reaches the head of the cylmotion of the eccentric centereflis retar with regard to the crank pin dui'mgthe first iaanaes inder ,and'all burnt gases are expelled out of the cylinder a, (Fig. 3). 7

During the first half of the exhaust stroke during which the movement of the piston is 5 accelerated, the inertia of the piston 1) acts acts again and produces, instead, of a re-' tardation of the movement of the centerof.

the eccentric 6, like in the first half-stroke, a certain advance of the movement .of the same, Fig. 2. In the dead center position, Fig. 3, at the end of the exhaust stroke, this 'adva ce however is again equal to zero, the

pist n inertiafand the centrifugal force'h'aving the same direction; The now followingsuction stroke of the workin piston begins directly-at the cylinder hea without any clearance or prejudicial space resultingfrom the existence of an ordinary compression chamber. Owing to the piston react ons, hg

half .of this stroke, Fig. 4, and is in advance during the second half stroke, and is a ain placed radially and outwardly when the following dead center position is reached, at the end of thesuction stroke, Fig.. 5, the eccentric rotating continuously in the cross- ,head-end ofthe connecting rod. Duringthe following compression stroke, the pres sure inthe cylinder at rises very rapidly to 1 several atmospheres. The working piston b exerts therefore upon the cdnnecting' rod d. a strong pressure which is transmitted by space or chamber between the'piston face and the cylinder head," which chamber con tains the compressed gas charge, Fig. 7. Also during the expansion stroke which follows the combustion, the eccentric e, owing to the overpressure'resulting from the pressure inthe cylinder,- cannot change rod, so that when reaching the'following lower dead center position, the parts are in the positions shown in Fig. 5. But now the.

exhaust valve has been opened, so that the pressure in the cylinder has become lower.

its position with regard to the connecting During the following exhaust stroke the centrifugal force and the reactions of the piston can again operate the eccentric and place the same radially outwardly, whereby the stroke of the piston b is increased as shown, and whereafter the'whole described cycle of operations is repeated. It will be understoodthat the crank turns ina clockwise direction In order to obtain a smooth runn'in of the motor without vibrations, a rigidly ed counterweight may act in awell known way, on the crank shaft opposite to the eccentric disk. But as the eccentric'disk e is some times less, sometimes more distant from the driving shaft g its centrifugal force will be counterbalanced only at times by a counterweight fixed on the crank shaft. To avoid this, even-also the eccentric disk 0 may-be provided with a counterweight e, such as s represented in Fig.1; so that the center of gravity of the combinedeccentric andits 0 counterweight, will always assume the sameposition and will remain in the, middle of the crank pin f. The centrifugal force of the combined eccentric and its counterweight,

will now be invariable and may be *corn- 10K pletely counterbalanced by a rigid counter weight fixed onkthe crank shaft opposite to, the eccentric 'diski Notwithstanding the fact that centrifu'gal force also acts at the 'i I i 5 line with the longitudinal axis of the connect;

. 5.the rod to the eccentric e and forces the latter continuously to take such a position that the distance between the crank pin f and'the. piston pine remains a minimum, which hap= -5. #pen's when the center e of the eccentric is in lower art of the, connecting'rod d, the 2.0- tion 0 I the eccentric disk will be certain, because this action is by the inertia of the pisai ed r'mg the period of retardation in, both Q Q the exhaust and suction strokes of the piston. f If there are several. connecting'rods of a -ing rod,-which axis passesthroughthe'center of the piston pin 0 and the crank pin f, Figs. 1

5, 6 and, 7. eThe'eccentric e therefore does multiacylinder motor connected to the crank pin, each connectingi rod is rovidedwith its own'separate eccentric e. or the purpose of renderingmore easydahe assembling or fit 1 Y not change. its position with regardto the v b ting up of the machlne, the eccentrlc may be cross-head-of the connecting rod, as the cen'* trifugal force and the gistoniaccelerating forces are too small to e able to balance e the overpressure produced by the cempresfj p sion; in the interior of the -cylinder, The 013191 my ven m v stroke ofitheworking miston' b is therefore. 1. afour cycle" internal combustlon e n- .12 only of a length which is. ual tothe crank g1ne,-anfd n c9mb1 1on',1acylmde ,-a P -1.: ,1 circle diameter,.- so that il16 PlSi0n when. ton, a connecting rod'securedat'onejend to reaching the upper dead center'jposition has thejp s on, a'cmn ,fa c n p1n,. a d an e l tmveledthrdufgh a part of thecyfli'nder cent r1c on the crank pin and to which the length and there consequently opposite -end, of the'conneetmg rod is se- 13D jg made of several-piece's'connected together by a means of screws orin any other suitable manner.

cured, the said eccentric being loosely mounted on the said crank pin and unassociated with any mechanical parts, except the connecting rod and crank pin, so that by the action of centrifugal force it automatically changes its position in the operation of the engine to lengthen the piston travel during the exhaust and suction strokes, and to shorten the piston travel to its normal length during the compression and expansion strokes,the latter action being effected by the pressure exerted against the piston during these last named strokes.

2. In a four cycle internal combustion engine, and in combination, a cylinder, a piston, a connecting rod secured at one end to the piston, a crank, a crank pin, and an eccentric on the crank pin and to which the opposite end of the connecting rod is secured, and a counter-weight connected to the said eccentric, the said eccentric being loosely mounted on the said crank pin and unassociated with any mechanical parts, except the connecting rod and crank pin, so that by the action of centrifugal force it automatically changes its position in the operation of the engine to lengthen the piston travel during the exhaust and suction strokes, and to shorten the piston travel to its normal length during the compression and expansion strokes, the latter action being effected by the pressure exerted against the piston during these last named strokes.

In testimony whereof I afiix my signature in presence of two witnesses.

WALTHER SCHMIED.

Images