US465576A - Steam-engine valve mechanism - Google Patents

Description

(No Model.) 2 Sheets-Sheet 1.

M. JAGKER.

STEAM ENGINE VALVE MECHANISM.

No. 465,576. Patented Dec. 22, 1891.

(No Model.) 2 Sheets$heet 2.

M. JAGKER. STEAM ENGINE VALVE MECHANISM.

No. 465,576. v Patented Dec. 22, 1891.,

UNITED STATES MAXIMILIAN J'ACKER,

PATENT ()FFIcE.

OF CHICAGO, ILLINOIS.

STEAM-ENGINE VALVE MECHANISM.

SPECIFICATION forming part of Letters Patent No. 465,557 6, dated December 22, 1891.

' Application filed June 22, 1891- Serial No. 397,156. (No model.)

To aZZ whom it may concern:

Be itknown that I, lVIAXIMILIAN JACKER, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Steam- Engine Valve Mechanism, of which the following is a specification.

My invention relates to an improvement in steam-engines, and particularly to an improvement in the operation of the steamvalves.

The matter of primary importance, viewed from an economic standpoint, to be considered in the organization of a steam-engine, Whether for one purpose or another, is the problem of utilizing the expansion of the steam in the greatest possible amount in the actual operation of the engine-that is, to avoid waste of steam by throttling so far as possible and to regulate the introduction of steam into the cylinder according to the amount of work intended and its nature. Besides the waste incident to throttling another source of waste arises from the employment of the ordinary link-motion for regulating the speed. The automatic cut-off engine generally in use namely, the Corliss-employs a wrist-plate with rod, connection with somewhat complicated valve-gear for operating the steamvalve; but there are two important objections to this arrangement. The first is that the valve cuts off at aperiod much in advance of the limit of throw of the piston-*that is, at a point about four-tenths or less than one-half of the throwand in case of a slight increase of resistance, requiring the steam to follow beyond that point, it naturally refuses to V regulate properly, because then it allows the steam to follow until the valve is closed directly by the wrist connection. The second objection is found in the necessary dependence for closing the valves on the action of a spring or vacuum, which, in order to secure promptness of action, involves a certain surplus of power beyond that otherwise required for the same purpose. Besides this, it is well known that the Corliss valve-gear, as generally used, acts automatically only under the normal engine speed.

The object of my invention is, primarily, to provide for the regulation of the expansion during the whole length of the stroke of the piston; secondly, to provide a means whereby the speed of the engine may be regulated enfor any speed while running through the operat-ion of a light lever or hand-wheel..

A further object of my invention is in the particulars above outlined and in other particulars which will presently appear, to effect a material improvement in the operation of the engine, principally for the saving of steam, and to simplify in essential particulars the operation of the steam valve mechanism, whereby the operation of the engine may be more easily and more readily controlled, automatic regulation continuing without regard to the action of the engineer.

Vith the above objects my invention consists, primarily, in a steam-engine in which the steam-ports are closed alternately by the operation of a steam-cylinder and piston or similar auxiliary agent regulated immediately by the governor, the operation of this auxiliary agent being associated with a direct opening and closing operation from a swinging or revolving wrist driven by the engine-shaft.

My invention consists, furthermore, in an arrangement of steam-valve-operating mechanism, by the employment of which the port at one end of the cylinder may be closed when or before the engine-piston arrives at the other end; but its immediate valve-operatin g lever is always held firmly at the right place for a-positive opening of the port, so that the lead of the valve remains constant.

My invention consists, further, in a steamengine in which the steam-valve-operating rods, one of whichviz., the immediate valveoperating rod-is actuated by the motion of the drive-shaft and the other of which is actuated by the auxiliary agent, are connected together in such a manner that each in turn acts as a fulcrum for the throw of the valvelever, thereby affording a differential movement in the valve-lever, the effect of which is to permit the valve to be closed at any time during the movement of the piston without interfering with the position of the immediate valve-operating-rod, which continues to open and close the valve.

My invention consists, further, in the general and specific details of construction and combination of parts, all as hereinafter more fully Set forth.

In the drawings, Figure 1 is a View in elevation of a steam-cylinder, showing the steam and exhaust valve operated in accordance with my invention. Figs. 2. and 3 are sectional views, respectively, of the steam-valves and Fig. 4 a side elevation showing the preferred manner of operating the steam-valves.

A is the steam-cylinder; B, the steam-valves;

C, the exhaust-valves.

D represents a revolving shaft carrying at one end a miter-gear D, through which it is revolved by the driving-shaft E, and at its opposite end a miter-gear F, meshing with a miter-gear carrying on the same shaft a spurgear G, which latter meshes with spur-gears of the same size G G located, respectively, above and below the spur-wheel G. The spur-wheel G2 carries a wristplate H to an eccentric-pin, upon which are connected the rods I and I, which at their opposite ends are connected with the exhau-st-valve-operating levers I I It may be stated, however, that this means of operating the exhaust-valves is capable of such variation as may be deemed desirable, as it does not present an essential feature of my construction. The wrist-plate H, carried by the spur-wheel G, carries an eccentric-pin K, to which are connected rods L L Mounted at a convenient location, preferably over the shaft D, is a small steam-cylinder and piston M, of common construction, the piston of which is steam-cushioned and the steam-valve of which is operated by a rod M, connected with the eccentric M controlled by the governor N. This governor is preferably constructed in accordance with Letters Patent No. 249,630, granted to me November 15, 1881, and is readily adjustable through the medium of the lever N. The piston in the cylinder M carries a jointed connecting-rod O, which extends from the cylinder across the steam-cylinder A at a point opposite the steam-valves therein. To the valve-stem of each steam valve B is connected a short crank P. The opposite end of this crank is pivotally connected, as at P, to the link B, one end of which is pivotally connected to the rod 0 and the other end of which is pivotally connected to the rods L L, respectively.

The operation of my invention is as follows: Under the action of the eccentric M admitting steam behind the piston in the cylinder M, the rod 0 is shifted across the valve 13, carrying with it the upper end of the link R and moving the cranks P to close the valve. By reason of the connection of the link It at its lower end to'the wrist-plate H, which latter is revolved by the shaft D, an obstacle is presented to the opening of the other valve under the sudden and instantaneous action of the rod 0, and the operation of opening 1s effected by the movement of the lower end of the link R as the wrist-plate H revolves and directly actuates it.

In Fig. 1 I have illustrated in full and dotted lines, respectively, the positions of the links R under the operation of the cylinder and piston M whenithe piston is at half-stroke. It will be understood, however, that when the upper end of the links R reaches the point S the lower end of the links may be at any 1nter mediate point, being restrained by the re tarded position of the rodsL L through their connection with the wrist-plate. Steam may thus be admitted during the whole piston; stroke, or nearly so; but when the steam-press ure of the auxiliary piston is reversed durlng any part ofthe piston-stroke then the upper end of the links will at once be shifted the full stroke and will close the valve instantly for the remaining part of the stroke. The valve motion of the auxiliary cylinder is controlled by a governor, which changes the lead of eccentric M Fig. 4.

To extend the range of cut-off the whole length of the piston-stroke, it is necessary to shift the eccentric one hundred and eighty degrees on the shaft,which is accom plish-ed by the normal governor described in my Letters Patent No. 249,630, dated November 15, 1881. The governor-shaft is driven in unison with the engine-shaft by a belt-link. The governor-balls are held together by a spring, and when the centrifugal force of the balls overbalances the tens-ion of the spring then the eccentric M Fig. 4, is driven forward by a train of differential gears. The tension of the governor-spring is for the present purpose regulated by a counter-spring on lever N, Fig. 4. By giving more or less tension to this counter-spring, which can be done while the engine is running, the speed of the engine is varied without interfering with the automatic regulation of the expansion. The governorshaft revolves in the same direction always,

whether the engine runs forward or back. This is effected by a self-acting clutch on the governor-shaft, which at the same time reverses the lead of the eccentric M when the engine is reversed. In this manner the automatic regulation of the expansion for any reasonable resistance within the power of the engine will be maintained at any desired speed. Manipulation of the engine is thereby made less laborious, the engineer controlling the speed by a light lever or hand-wheel, the economical regulation being always automatic and out of his control. It will be un ders-tood that the auxiliary piston always moves to close the port at one endof the cylinder when or before the engine-piston ar- IIO rives at the other end. Therefore at the beginthe right place for the positive opening of the port, so that the lead of the valve remains constant. By regulating in this Way throttling is avoided under any speed, thus maintaining the advantage of expansion.

The reversing of the engine is best done in some manner which excludes a permanent checking of the speed, so as to take the regu' lation of the expansion out of the engineers hands. I have shown my device associated with a rotary valve; but it will be understood that the principle of its operation may easily be applied in connection with any other form of valve which may be adopted. While with the Corliss gear a slow toggle motion is useful at the beginning of the valve-stroke to secure promptn ess in hooking on and the quick backstroke is therein unobjectionable because the motion-rod is kept up by air-pressure to the same side of the wrist, for a quick positive action this is difierent and the uniform rotary motion is preferable.

The cost of making the valve-gear herein described and claimed is moderate when compared with others for a similar purpose. It requires less attention from the engineer. It is suitable forhigh speed, while reduced speed does not interfere with the expansion best adapted to the resistance. As before stated, the valve-gear consumes less power than any automatic cut-oft Where a vacuum must be maintained for closing the valves. .For the same reason it takes less power to reverse the valves.

What I claim as new, and desire to secure by Letters Patent, is,

1. In combination with the steamvalves of a steam-engine, a valve-operating rod driven by a power regulated directly by the governor, and a valve-operating rod driven through the main driving-shaft, and a jointed connection between said rods at each valve, substantially as described.

2. In combination with the steam-valves of a steam-engine, a crank on said valves, links connected at their centers, respectively, to each crank, operating-rods connected, respectively, to the upper and to the lower ends of the links, and a connection between one of said rods and the main driving-shaft, and an auxiliary driver for the other rod, substantially as described.

3. The combination, with the steam-valves B and their operating-cranks P, of the links R, wrist-plate H, driven from the driving shaft, connecting-rods L L, joining the links R at their lower ends to eccentric wrist-pins on the plate H, rod 0, connected to the upper end of the links R, piston and cylinder M, actuating said rod, and governor N, having an eccentric connection with the steam-valves of the steam-cylinder M, said parts being arranged to operate substantially as set forth.

MAXIMILIAN J ACKER.

In presence of J. W. DYRENFORTH, M. J. FROST.

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