US1384854A - Valve-gear for steam-engines - Google Patents

Description

S. ROSENZWEIG.

VALVE GEAR FOR STEAM ENGINE-S.

APPLICAT|0N-HLED NOV. 30. 1920.

Patented July 19, 1921 3 SHEETS-SHEET 1.

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S. ROSENZWEIG.

VALVE GEAR FOR STEAM ENGINES.

APPLICATION FILED NOV. 30. 1920.

Patented July 19, 19210 3 SHEETSSHEET-2.

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VALVE GEAR ron STEAM ENGINES. APPLICATION FILED NOV. 30', 1920.

1,384,854, Patented July 19, 1921.

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rarest VALVE-GEAR FOR STEZ XM ENGINES.

Application filed November 30, 1920.

To all whom it may concern:

Be it known that I, Sincrinno ROSIGNZWEIG, a citizen of the United States, and a resident of the city of New York, in the county and State of New York, have invented certain new and useful Improvements in Valve- Gears for Steam-Engines, of which the following is a specification.

My invention relates to a valve arrangement for reciprocating steam engines of the puppet valve type, and consists in certain improvements in the valve gear for controlling the distribution of steam to the engine cylinders oi such engines, which will first be described in connection with the accom panying drawings, and will then be more particularly pointed out in the claims.

In said drawings Figure 1 is a longitudinal horizontal section of a steam valve chamber with puppet and steam exhaust valves assembled therein, and an operating valve gear therefor, embodying n improvements in their preferred form.

Figs. 2 and 3 are on smaller scale tha Fig. 1, and are designed to illustrate the application of valve chests of the type shown in Fig. 1 to the steam cylinders of a steam engine, there being one chest at each end of the cylinder, placed on top, and crosswise, of the same.

Fig. 2 is a section on line 22 Fig. 3.

Fig. 3 is a section on line 3-8 Fig. 2, the steam piston and internal fittings of the steam cylinder which are shown in Fi z 2 being omittel from Fig. 3, the cross-see tional representation of the steam cylinder in the latter figure being largely diagrammatic and designed to illustrate the location of the steam cylinder relatively to the valve chest and the steam and exhaust port appropriate to the set of valves which control the steam admission and exhaust at that end of the cylinder.

Figs. 4c and 5 are detail views showing on enlarged scale the structural details of the elbow levers for operating the steam valve and exhaust valve spindles, respectively. Fig. t represents in plan and in side elevation the elbow lever which operates the steam valve spindle, and Fig. 5 represents in similar view the elbow lever which opcrates the exhaust valve spindle.

Fig. 6 is a detail elevation on enlarged scale of the telescoped ends of the exhaust Specification of Letters Patent.

Patented July 19, 1921.

Serial No. 427,290.

and steam valve spindles which contact with said elbow levers.

A (Figs. 2 and 3) is the steam cylinder. At each end of the cylinder is a pair of puppet valves-a steam valve V and an exhaust valve Vcontained in a valve chamber 13. The two valve chambers B are preferably formed parallel to one another 111 a unitary casting extending tangential to and crosswise of the steam cylinder, as indicated more plainly in Figs. 2 and 3. The casting is provided with suitable bearings for reception of the reciprocatory cam or tappet shaft E, which fits and is capable of longitudinally reciprocatory movement without rotation therein, extending through the valve chambers, as shown, in position to actuate the valve gear in such valve chambers, for which purpose it is provided on the side facing the valves with cam recesses and lifts c e, for the two sets of valves. The valves, valve fittings and valve gear are the same for each chamber B, so that a description of one will answer for both.

The valve chamber is of cylindrical contour internally, and is formed with a port a through which steam is admitted to and exhausted from that end of the steam cylinder vith which the valve chamber is associated.

The valve chamber machined out internally to provide a seat for a valve cage which is removably but closely fitted therein and abuts at its rear end against an annular shoulder b at or near the end of the valve chamber opposite that from which the valve cage is inserted. It (the valve cage) is provided with a steam and exhaust port corresponding to and registering with a port a in the valve chamber.

The valve cage is formed in two sections C, C, containing, the one the intake valve and valve seats, the other the exhaust valve and valve seats,the section C being seated against the annular shoulder b and the other section C butting up against section C, the meeting ends of the two sections being suitably made fast to one another, or not, as preferred. The valve cage is held in place in the valve chamber by a clamping ring B located at that end of the valve chamber from which the valve cage is inserted, and attached to the inner face of the head or cover B for that end of the valve chamber by legs B as shown in Figs. 1 and 3.

The two seats 1) of the intake valve V are located in the section (I as shown, the one seat upon an annular ledge c and the other upon a diaphragm or partition D; and the seats '0' of the exhaust puppet valve V are correspondingly located in section C upon the annular ledge c and diaphragm D, respectively. The valve chamber is provided with steam intake passage S and exhaust passage X, as indicated in Fig. 1. The communicating port between the ,valve chamber and steam cylinder throughwhich steam enters and leaves the steam cylinder shown at a, Figs. 1 and 3, the course of the steam for intake and exhaust, respectively, being indicated by the arrows.

The pair of valves in each set are arranged tandem fashion 1n axial ahnement, one on the prolongation of the other, with telescopstance the steam valve Vpassing longitudinally and axially through the spindle of the other, and the two, which snugly telescope together, being each capable of independent longitudinal movement relatively to the other. i

The exhaust valve V is located in-the valve cage between the diaphragms or partitions D, D. Its central tubular core fits upon the exterior of and is guided and steadied in its movements by an axial tubular guide as fast on the diaphragm D. The exhaust valve spindle w (which is made tubular for apurpose hereinafter indicated) passes axially through the diaphragm, and

acts to lift the valve from its seat, said valve being held normally in closed position by yielding pressure exerted by a spring a interposed, as shown, between the head of the valve and the diaphragm or partition D.

Similarly, the steam valve V is held in closedposition, by yielding pressure exerted by a spring s interposed between the head of thevalveandthe head or cover B of the valve chamber, and its tubular central core fits upon the exterior of a tubular guide 50 mounted ,upon a nd secured to, or cast in one with, thediaphragm D in exact axial alinementwith the exhaust valve tubular, guide 00 on dlaphragm D. The steam valve spindle wiexten'ds through the diaphragm D into andthrough the tubular exhaust valve spindle rw avhich itflclosely (fits, thence out through asuitable aperture inthe' head of the exhaust valve, thencethrough the diaphragm D ,and tubular guide a: thereon (which it closely fits) until its end brings up against the closed head of'the central core of the steam valve V. The steam valve spindle w may be-a continuous one-piece stem from end to end, but at a point y in 'its length between the two diaphragms D,

the two valvesthat may occur during their operation.

The cam shaft E extends diametrically across between the two valve chambers B, as shown in Fig. 2, in a position to conveniently operate the valve spindles through lift members supported in bearings, between the telescoped ends of the valve spindles and the cam shaft, in position to engage the ends of their respective valve spindles, and actuated by the cam shaft to move their respecthe spindles in a direction. tolift the valves appropriate to those spindles against the stress of their closing springs. Inasmuch as the same means are employed for this purpose with each set of valves, a description of one will answer for both. The telescoped ends of 'the two spindles w, w extend through the diaphragm D of the cageinto the space within the valve chamber intervening between the diaphragm 'D and the cam shaft E. The lift members consistin the present instance of two levers L and M, preferably of the elbow type, pivoted in bearings N, attached to the valve cage, and

preferably to the diaphragm D of the section (1 of that valve cage on that side of said diaphragm facing the cam shaft 'E,,as shown, and designed and arranged to engageand actuate the two valve spindles. .To

this end the two levers face one another,

and are provided with rollers Oat their elbows which are received in the cam recess 0 formed for their reception in the cam shaft E, said. recess terminating at each end in a lift a, the one to actuate the lever L which operates the intake valve V, the other to actuate the lever M which operates the exhaust valve V, the rollers, O, at the elbows of these levers, which contact with the face of the cam lifts ,0 serving to reducefriction.

Thetip Z of the free end of the lever L extends out far, enough toward the telescoping ends to come opposite to and rest against the base of the steam valve spindle w. The

free end of the lever Mjs forked as shown more plainly in Fig. 5, the prongs m of the fork straddlingthe tip Z of the lever L and coming opposite to and in a position tobear against lateral projecting ears w (Fig. 6)

on the annular base of the tubular exhaust are held in incense close contact with the valve spindle and the cam lifts on the cam shaft by the yielding pressure exerted by the steam and exhaust valve closing springs s, 8'.

Owing to the face-to-face arrangement of the two levers it will he noted that the cam lifts for the steam and exhaust valves of each set can be placed at opposite ends of one and the same recess, provided the length of the latter be such, as shown, that, at the maximum stroke of the reciprocating cam shaft, the cam lift at one end of the recess designed to operate one of the two elbow levers, will not reach the elbow roller belonging to the other lever.

The mode of operation of my improved valve gear will be manifest from the description already given, and needs no further explanation.

Under the arrangement described, it will be noted that as the friction rollers which operate directly in connection with the lifts on the cam shafts are carried, not by the valve spindles, but by the elbow levers, the spindles can be made of smaller diameters than would otherwise be practicable, and, inasmuch as they are relieved from any of the side pressures and thrusts due to the action of the cam shaft upon said rollers, they will work with greater freedom and without the friction and wear to which they would otherwise be subjected. The rollers, being carried by the levers, can be made of any width and diameter desired without reference to the size of the valve spindles, and any lateral pressures and thrusts due to the action of the cam shaft upon them are taken up by the bearings N in which the levers are mounted, which bearings may be made of ample size and strength for that purpose. And, due to the lever arrangement shown, in which the power is applied to the lever at a point between the fulcrum and the weight, the range of movement of the'lever at its free end which lifts the valve will be nearly if not quite double that of the lever at the point where the friction roller is situated, to effect the necessary valve lift, thus permitting a reduced and comparatively flat cam lift to be provided on the cam shaft, with correspondingly improved operating conditions. Furthermore, the whole valve gear, it will be observed, is separated from the steam space in the valve chamber and does not come in contact with the steam at all, thus requiring only soft packing of the cam shaft to prevent leakage of the oil used for purposes of lubrication. And inasmuch as the valve gear (with the exception of the cam shaft) is attached to the cages, it can be correctly machined and assembled before being put into place-the valves, the valve gear and cages being removable independently of and without disturbing the cam shaft.

Having described my improvement and the best way now known to me of carrying the same into practical effect, I state in conclusion that I do not limit myself to the structural details hereinbefore set forth in illustration of my invention, since manifestly the same can be considerably varied without departure from the spirit of the invention but what I claim as new and of my own invention and desire to secure by Letters Patent is as follows 1. In a valve gear for steam engines, the combination of the following elements, namelya valve chamber; spring-closed steam and exhaust valves mounted and arranged therein, one upon the axial prolongation of the other; a valve operating cam or tappet shaft extending crosswise through the valve chamber; a diaphragm separating the valve containing portion of the valve chamber from the cam shaft; valve spindles, one for each valve, the one spindle passing axially through and telescoping with the other, and the telescoped ends of the same projecting through and beyond the diaphragm toward the cam shaft; and lift members, one for each spindle, mounted and movable in bearings between the diaphragm and cam shaft, and on opposite sides of the intervening telescoped spindle ends, and formed and arranged to engage and be operated by the cam shaft and, at their free ends, to engage the one the outer, and the other the inner one of the two telescoped ends of the valve spindles which project between themthe combination being and acting substantially as hereinbefore set forth.

2. The combination of elements recited in claim 1, when the lifting members are composed of elbow levers pivoted at their exterior opposite ends in their supporting bearings, facing one another, with their interior opposite free ends in engagement with the telescoped ends of the steam and exhaust valves, respectively, and their elbows in engagement with the cam shaft.

3. In combination with the elements of claim 1, a valve cage removably fitted within the valve chamber, and containing the two valves and also the diaphragm which separates the valve receiving portion from the cam shaft receiving portion of the valve chamber.

In testimony whereof I aflix my signature.

SIEGFRIED ROSENZWEIG.

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