US107867A - Improvement in casting valve-chambers and seats - Google Patents

Description

aware am over JOHN K. *BU-RRE, or `Routern sarna, new ronn.

LettersIateiit` No. 107,867, dated October 4, 1870.

The Schedule referred to inthese Letters Patent and making partof the sama I, JOHN K. BURKE, of Rochester, in the conntyof i Monroeiand State of .New York, have invented a ce1- iainmproved Method of Casting Valve-Chambers x Yand Seats, of which the following is a specication.

My invention relates to a peculiar method of introducing a previously-made valve-seat or seats into the i 1 shell of `their chambersduring the process of casting.4

It iswell known that in the `use of steam and other valves where a stream of nid Orliquid, at a high pressure, `ispassing rapidly, the seats or bearings ,ofl

` the valves soonbecomegrooved or cnt outlbysuch action, rendering ithemuseless tilly repaired. 'ilhis `is particularly the case with steam-governors and throt- `tlc-valves, in which seats are formed upon internal portions `of theshell, since it is difficult, and` sometimes impossible tofcast such shells ,soas to leave the seats of the requisite degree of hardness, and expensive, moreover, to introduce separate seats by any of the ordinary. methods.

g i In the accompyaning drawing I have represented my invention as apliiliedto` the casting of agovernor'- globe vor shell,'but it `is equally valuable in a large class of `similar `constructions.`

i `Figure lisa vertical section-'of a governor-globe andvalve-seats.

` Figure 2 is a sectional elevation of -the core.' Figure 3 shows a modification of the latter. The rings orV valve-seats a are previously' prepared from metal of the requisite degree of hardness, bored i out, or` otherwise made of proper size,.a`nd placedinpon the core A, iig. 2,`so as to -be supportedin suitable y i 4positions in the mold during theprocess of casting.

. .Since, however, in nearly all vvalve-chambers, it is necessary to provide recesses, b, tig. 1, upon one or both sides of .the seat, for the purpose of limiting 'thelengthof t bearing of the valve, and, consequently,- to make the core larger at those points, as shown at b', tig.` 2, itis V obviously impracticable to place the rings upon acore of ordinary formation.

` ,'lo obviate this ldiiicultygl make the core A in two or more sections, according tothe number of valve-seats introduced, the portion br forming the recesses b, being in the formofa hollow cylinder, and

" sliding `over the portion of thecore designed to receive it, asindicated in tlg. 2. rDhus the ring or seat a, the internal diameter of which corresponds to the external diameter of the core at that point may be placedup- 0n vthe core in its proper position, the section b pushed ou behind it, and the whole laid in the mold. After casting, it is plain that the core can be removed in the usual manner, while the metallic ring remains in and forms that portion of the shell constituting the valve-seat.

fAn equivalentlplan, by which the same object is accomplished, is shown in fig. 3, in which the entire end c of the core is made separately from the central the ring in the same position as before, and' held in place by a rod, d,`passing through the whole. This plan, however, is more expensive, and not so uniformly sure to produce good castings as the former.

`The periphery of the seats a may bc provided with grooves or ledges, f0r the purpose'of obtaininga more secure attachment to the metal of the shell. In practice, no difficulty is found inthe leakage of the fluid around the seat-s, since the metal soon becomes oxidized in the4 joint, and the latter thus perfectly closed. vBy my invention I obtain the following advantages:

' The expense of vcasting the shells and seats is but little' more than by the lold method, while the danger of losing castings 'by' flaws is-largelylreduced; the

seats may be made of metal of' any degree of hardness, and bored ont` nearly to the requisite size before fbeing introduced into the mold, thus giving the worlti man an opportunity to` detect iiaws, which, however, are far less liable to occur than when cast' with the shell; the process of boring, in the manner just described, is less expensive than by the usual method.

What I claimas m'y invention isvThe method ot'castng the shells of valve-chambers by means of a core, upon which is placedanl annular metallic seat or seats, to be left in such shells, for the `purposes set forth. JOI-1N K. BURKE.

Witnesses:

D. L. JOHNSTON, I ILOLnMENT.

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