US595307A - jacoby - Google Patents

Description

(No Model.) 2 Shee ts-Sheet 1 J. H. P. JAOOBY.

VALVE GEAR.

No. 595,307. Patented Dec. 14,1897.

4, III/II/l/l/ f (No Model.) 2 Sheets-Sheet 3.

. J. H. F. JAOOBY.

VALVE GEAR.

No. 595,307. Patented Dec. 14,1897.

UNrTnn STATES PATENT OFFICE.

JOIIANN HEINRICH FRIEDRICH JACOBY, OF SAARGEMUND, GERMANY.

VALVE-G EAR.

SPECIFICATION formingpart of Letters Patent No. 595,307, dated December 14, 1897. Application filed November 20, 1895. Serial No. 569,543, (No model.)

T0 on whom it may concern.-

Be it known that I, J OHANN HEINRICH FRIEDRICH J noon r, a subject of the Grand Duke of Oldenburg, residing at Saargemiind, in the Empire of Germany, have invented new and useful Improvements in Distributing Valve-Gear, of which the following is a specification.

In order to obtain larger channelopenin gs, there is given, according to this invention, besides the known main motion, a secondary motion to the slid e-valve by mechanisms making a triple or more than triple return motion while the piston of the working cylinder makes one single return motion. By this means the cross-section of the admitting-port is increased as an increased motion is given to the slide-valve. The result of this is that the velocity of the motive fluid during the passage through the enlarged channel-opening is less, and in consequence the loss of pressure inherent to the fluid is smaller, so that this pressure can be utilized more advantageously.

Figure 1 is an enlarged view of the turning lever, with a portion of the eccentric-rod and slide-valve rod. Fig. 2 is an enlarged sectional view of the valve. Fig. 3 is a plan view showing the invention as connected up in an engine, and Fig. 4 is a diagrammatic side view of the same.

The wheel A, secured to the driving-shaft shown in Fig. 3, is three times as large as the wheel 13, the shaft of which is provided with two cranks and supported by the lever H, rotatable on the drivingshaft. The vertical mean position of the lever H corresponds to the mean position of the represented Stephensons link-motion. Before the end of the driving-shaft a crank-shaft is firmly supported, and the cranks of the latter are coupled by the coupling-rods F and K with the two cranks of the wheel 13 and by the coupling-rods L and M with the two cranks of the firmly-supported crank-shaft C. On the crank-shaft O is suspended in a rotatable manner by means of fish-plates the crankshaft D, so that it is capable to reciprocate in the direction of the valve-rod and follows the motion of the guide block. The two cranks of the crank-shaft D being coupled with the two cranks of the crank-shaft O by the coupling-rods F and G,

the lever D E, carried by the crank-shaft D, turns exactly in the same manner as wheel B. The crank-shaft C may be used for any optional number of working cylinders. The lever D E is intercalated between the guideblock and the valverod, and it is horizontal to the right hand when the connecting-link in its mean position has reached its largest throw to the right. The piston in the working cylinder is in consequence at the left hand at the dead-point.

If the connecting-link is moved-a. 6., brought from the mean position to the end position in the present case, where the two eccentrics of the driving-shaft are arranged with a lead of thirty degrees-the guide-block will reach its greatest throw to the right-hand when the driving'crank has removed for sixty degrees from the dead-point. The lever D E should then turn through 3. 60, equal to one hundred and eighty, degrees, unless simultaneously with the motion of the connectinglink the lever H would be turned into the corresponding end position, and in consequence a revolution of the leverD E through one hundred and eighty degrees in the opposite direction would be produced. To effectuate such a revolution of the lever D IE, it is necessary to move the lever H through forty-five degrees, because the wheel B, c0upled to the lever D E, turns then through 4.45, equal to one hundred and eighty, degrees. To secure these motions belonging together, and also to obtain for the degrees of filling situated between the end positions of the connecting-link the horizontal position of the lever D E to the right hand approximately simultaneously with the greatest throw of the connecting-link to the right hand, Fig. 4 shows in the slot 0, connected with the lever II, a sliding block turning on a lever Q, while the lever Q is connected with the double lever T T, actuating the connecting-link. The increase of the chann el-ports obtained by these means for the admission on the slide-valve is for each degree of filling equal to the length of the lever D E. The latter length is assumed to be equal to one-third of the total motion of the guide-block in the mean posi tion of the cOnuectingJink.

It results from the preceding that the present link-motion with secondarymovements effectuates at smaller degrees of. filling a width of the inlet-port, which is a multiple of the width to be obtained in the ordinary valve-motion, but at greater fillings prod does a proportionately smaller increase of the channel-port. Should there be necessary for the present example a filling greater than 0.7 34, the lead must become negative; but as the velocity of the piston of the Working cylinder in the beginning of the stroke is very low and the opening of the inlet once commenced takes place very speedily the negative lead cannot exert an essentially prejudicial effect. In steam-engines the fresh steam is cut oif speedily. In employing the present link-n10- tion with secondary movement the duration of the expansion of steam is advantageously lengthened. The escape begins somewhat later, but it takes place more quickly than in the ordinary valve-motion.

The duration of the escape is of course shortened, but the width of the exhaust-port is increased. In the same proportion as the above-mentioned steam expansion is lengthened the duration of the compression is increased. The mass and the pressure of the fluid compressed at the back stroke of the piston serve, as commonly is known, in 00111- bination with the fluid flowing in at the change of the stroke and afterward as the filling for the commencing stroke of the piston in the Working cylinder. They are therefore employed again in a useful manner. The present link-motion allows advantageously of the application of very low degrees of filling at a great velocity of the piston in the Working cylinder.

I claim- The combination with the driving-shaft and slide-valve of an engine, of a two-part pitman, an eccentric-pin connecting said twopart pitman, and means operated by the driving-shaft to rotate said eccentric-pin to vary the throw of the valve, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

JOHANN HEINRICH FRIEDRICH JACOBY.

Witnesses:

J EAN GRUND, FRANK H. MASON.

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