US392578A - Jacob yotjngman - Google Patents

Description

5MM/Q8,

(No Model.)

J. YOUNGMAN.

BALANCED SLIDE VALVE.

No. 892578.. Patented Nov. 8, 1888.

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lNrTED STATES Artnr rtree,

JACOB YOUNGMAN, OF SUNBURY, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO JONATHAN M. BASTIAN, OF SAME PLACE.

BALANCED SLIDEHVALVE.

SPECIFICATION forming part of Letters Patent No. 392,578, dated November 6, 1888.

l Application filed January Q4, 1888. Serial No. 261,722. (No model.) l

To all whom t may concern: l

Be it known that I, JACOB YoUNGM-AN, a citizen of the United States, residing at Sunbury, in the county of Northumberland and State of Pennsylvania, have invented certain new and useful Improvements in Balanced Slide-Valves for Steam-Eu gines; and I do hereby declare the following to be a full, clear, and

exact description of the invention, such as will 1o enable others skilled in the art to which it appertains to make and use the same.

This invention relates to valves of that class known as balanced slide-valves;77 and it has for its object to provide a more perfectly-bal I 5 anced valve of simple and cheap construction which shall effectually prevent the leakage of steam from the chest to the back of the valve, thus relieving the same of the downward pressure,which is common in the ordinary D-valve 2o and which is the occasion of much wear of the valve and seats for the same; and it consists of the parts and combinations of parts hereinafter described and claimed.

In the accompanying drawings, forming a e 5 part of this speciticatiomFigurel isalongitudinal central section through myimproved valve and steamchest; Fig. 2,a vertical crosssection through the same; Fig. 3, a detail view of the valve proper, showing the arrangement of the 3o packing-strips; Fig. ll, a detail view of the bearing cap or frame for the valve, and Fig. 5 a perspective view of one .of the packing`n strips.

Similarlettcrs refer to similar parts through- 7,5 out the several. views.

A, represents a portion of the cylinder' for the piston of an engine, provided with the usual steam-ports, c, and exhaust-port b. On the cylinder the steam-chest B is secured in the 1.o usual or any desired manner over the ports c vl1. On the chest is secured a lid, C, having a bonnet or arched. head, D, as clearly shown in lliig. 2, in which the balanceplate E is adj ustably suspended by means of screw-bolts c, passing through the bonnet and into lugs formed on the back of the plate. By this construction of the head D, I secure increased capacity of the chest, as I am enabled to locate the plate E entirely within the arched head.

The valve F is provided with the usual exhaust-cavity, d, but differs from all other valves with which Iam familiar in that itis cast hollow or box-shaped, thus providing a chamber,

e, within its walls f, as clearly shown in Fig.

3. At about the center of the upper surface ",5 or top of the wallf, I insert short studs or pins g at suitable distances apart, there being, preferably, two pins in each side and end wall.

G represents the metallic packingstrips, havingslots h formed in theirsides correspond- 6o ing to the pins g in number and location, so that they may be fitted on top ofthe walls with the slots embracing the pins or studs, the slotted sides of the strips being outward. The strips constitute an extension of the walls of the valve, but are movable laterally or inwardly on the tops of said walls. As shown most clearly iu Fig. 5, these strips taper toward their lower sides, so that they are narrower than the upper surface of the walls on 7o which they rest.

The object of thus reducing the strips is to obviate the tendency they would have to hold the overlapping rim or flange m of the bearing cap or rectangular frame II if the two sides were equal, and thus destroy the freedom of movement which the cap should have. It will also be seen, on reference to Fig. 3, that the side walls of the valve have cleats n cast ou their inner sides, the object of which is to give 8o clearance for the tool in dressing said sides to a fit for the downwardly-projecting Walls o of the bearing-cap. rThis cap is `formed of a rectangularframe having the walls o and rim or overlapping ilange in and a eross-piece, p, provided with a downwardly-extending pin,

r, said cross-piece being located with its upper surface below the top of the cap, so that it cannot form part of the abrasive surface.

A. spring, M, is placed within the chamber '9o c so that it will exert its pressure upwardly against the crosspicce p to raise the bearingcap up against the balanceplate when steam is shut off, and also give the necessary elasticity to the cap and valve. The spring shown is an ordinary fiat bow-spring having a perforation at its center, through which the pin r projects to guide and steady said spring; but it may be, if desired, a spiral spring surrounding the pin. The cap I-I is fitted or is tele- Ioo scoped within the chamber e of the valve, filling the same closely, and its rim m rests on the strips G and projects outwardly beyond the same. The bottom of the valve is also provided with flanges s on its four sides, as shown. The perforation w in the center of the bottom of the valve is for the purpose of giv ing an outlet to any steam which may get back of the valve or in its chamber through the exhaustport.

In operation the steam isadmitted to the chest, and from thence to the ports a in the usual manner, and exhausts from the cylinder through port b, and thence to the air or a condenser, as desired. The steam in the chest, however, exerts a powerful lateral pressure on the strips, forcing them in closely against the walls o ofthe bearing-cap, and also lifting the said bearing-cap up against the balanceplate by the pressure which is exerted against the under side of its rim, while at the same time it exerts a downward pressure on the upper surface of said strips, causing t-hc latter to closely hug the walls of the valve, thus closing the joint between the walls and strips by the downward pressure and the joint between the walls o ot' the bearingcap and the strips bythe lateral pressure on the latter, and tinally closing thejoint between the balance-plate and the cap by the upward pressure of the steam ou the rim or flange of said cap, and preventing the admission of live steam to the back of the valve.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The combination, with the steam-chest having an arched head or lid and a balanceplate adjustably secured within said head, of the valve having a chamber formed in its body, the pins rigidly secured to the walls of said chamber, the metallic strips having slots in their sides resting on said walls, the rectangular bearing-cap fitted Within said chamber and having-the overlapping rim, the crosspiece having the downwardly-projecting pin, and a spring guided and steadied by said pin and bearing against said cross-piece, substantially as described.

2. The combination, in a balanced slidevalve, of the valve having the chamber formed in its body, the cleats formed in the walls of said chamber, the pins or studs rigidly secured@ in said walls, the metallic packingstrips having slots formedin their sides, the bearingcap having the downwardly-extending walls and projecting rim, the cross-piece provided with a downwardly-projecting pin, and the spring located within said chamber and exerting its pressure against said cross piece, substantially as described.

8. The combination, iu a balanced slidevalve, with a suitable steam-chest and balanceplate, of a valve having a chamber formed in its body, the pins rigidly secured in the walls of said chamber, the tapering metallic strips having slots formed in their sides, the bearingcap having the outwardly-projecting rim and downwardly-extending walls, the cross-piece having the downwardly-projecting pin, and a spring bearing ou the bottom of said chamber and against said cross-piece and guided and steadied by said pin, substantially as described.

In testimony whereof I at'x my signature in presence of two witnesses.

JACOB YOUNGMAN.

Witnesses:

NATHANIEL FORD, H. D. MILLER.

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