US245236A - Piston-packing - Google Patents

Description

(No Model.)

W. -W. ST. JOHN.

PISTON PACKING.

Patented Aug. 2,1881,

mi l mm, my! J15.

UNITED STATES PATENT prion.

l/VlLLlAM W. ST. JOHN, OF ST. LOUIS, MISSOURI.

PISTON-PACKING.

SPECIFICATION forming part of Letters Patent No. 245,236, dated August 2, 1881.

Application filed March 30, 1881. (N0 model.)

To all whom it may concern Be it known that I, WILLIAM W. ST. JOHN, a citizen of the United States, residing at St. Louis, in the county of St. Louis and State of Missouri, have invented new and useful Improvements in Piston-Packing, of which the following is a specification.

This invention relates to that class of pistonpackings in which a seat-ring or bull-ring car ries one or more expansible packing-rin gs. Its objects are to prevent the packing-rings from movinglaterally in their seats, to insure the prompt response of the packing-rings to steam-pressure, to facilitate the wearing of the packing-rill gs to form snug joints with the cylinder-face, to prevent the passage of steam between the cleft ends of the packing-rings, and to steady the packingiuits reciprocatorymovement and secure an even wear of the rings.

To these ends it consists in a novel construction and combination of the several parts of the packing, as will be hereinafter fully described with reference tothe accompanying drawings, in which- Figure 1 is a perspective view of a'pistonpacking constructed according to my invention. Fig. 2 is a diametric section of the same in a plane indicated by line at as, Fig. 1. Fig. 3 is a similar section, illustrating a modification of the expansible packing-ring. Fig. 4 illustrates a packing provided with an expansible steadyingring in addition to its packingrings. Fig. 5 shows a modification ofthe same. Fig. 6. is an edge view of Fig. 5. Fig. 7 is a cross-section of Fig. 5 on line y y.

Referring to Figs. 1 and 2, the letter A denotes the cast ring, and G O the expansible metallic packing-rings. The packing-rill gs are each cut transversely at one point, are a little more than half as thick as the seat-ring, and are fitted upon annular seats formed by reducing the thickness of the seat-ring at its margins, so as to form radial walls at d and annular faces 0 concentric with the seat-ring. At the foot of the radial wall 01 of each seat a peripheral groove, f, is formed in each of the faces 6, and into this groove fits an annular rib, g, projecting inwardly from the inner margin of the packing-ring. As the packing-ring expands from the faces 0 under the influence of steam-pressure, the rib 9 still remains partially in the groove, and the ring is thus prevented from being thrown from its seator movinglaterally.

It will be observed that the construction of the annular seat e and of the packing-ring O is such that the margin of the inner surface of the packing-ring is seated directly on and supported by the annular seat 0, which is of great advantage, because the weight of the piston is not sustained solely by the annular rib of the ring, but is uniformly supported and sustained by the annular seat 6, and thereby the rib g serves solely to retain the packingring on its seat, whereby I am enabled to avoid the use of the usual follower-rings, resting against the outer faces of the packing-rings and bolted into place.

Laterall y in ward from the annular rib 9 projects a light annular flange, h, and laterally outward from the outer edge of the radial wall (1 projects a similar flange, It. The former sets against the radial wall d, and the latter impin ges against the adjacent face of the packing-ring. The chamber formed between these two flanges collects theisurplus oil, which would otherwise beforced into the various joints and impair their snugness of fit. By reducing the surfaces in contact I also reduce the friction between the radial wall and the ring, and the latter responds more readily to expanding steam-pressure. The rib 9 also serves the purpose of holding the main portion of the inner periphery of the ring 0 at a little distance from the face 0 of its seat, and thus provides ready access for steam under the ring, so that it will promptly respond to even a light steam-pressure.

In the modification shown in Fig. 3 the inner radial face of the packin g-rin g G is fitted snugly to the plain radial wall of the seat, the flanges h and 71. being omitted. Very good results are got from this construction but Iprefer to use the flanges, especially in packin gs of large size.

At a given point in each outer margin of the seat-rin g is fitted a metallic cylindrical button, I, which sits flush and loosely in a corresponding seat, which seat extends partly into the intermediate part of the seat-ring between the packing-ring seats and partly across the annular circumferential face 0 of the ringseat. That portion of the button which projects laterally beyond the radial wall has its outer portion cut away to form surfaces coinciding with the surfaces of said wall and the annular face 0, except that the vertical face of the button has no flange, as at h, and is simply grooved at its base to receive the flange h of the packing-ring, the walls of the ring and button coming snugly together outwardly from said flange. The cut-away part of the button, in fact, forms a small section of the packingring seat, and it is in it that the two ends of the packing-ring meet or nearly meet, as shown in Fig. 1. The button being loose in its seat, 'and the flange h taking into the groove in said button, the latter will be moved outward as the ring expands and bridges the space between the ends of the ring, so that no steam will pass through said space. The ring is thus rendered practically steam-tight all around, while at the same time its-expansion is not in the least restricted.

I prefer to provide the button I with a stem, I, which projects inwardly through an aper ture in the seatring and has its tip resting upon a spring, is, the other end of which supports the stem of the button at the other side ofthe ring. This spring is supported by the head of a screw, 1, tapped into the seat-ring, and which should be screwed up light enough to force the buttons outward, in order that the expansion of the packin g-rin gs may run no risk of being retarded by the sticking of the buttons. In fact, in the modification shown in Fig. 3 the entire labor of forcing out the but-- tons is devolved upon the springs, as the rings and button are not engaged.

I prefer that the two buttons of each pack ingring shall not be directly opposite each other, as the cutting of both button-seats on one transverse line would possibly weaken the the seat-ring, and, besides, creates too great an interruption of the intermediate face of said ring, which, indeed, is sometimes not wideenough to permit the buttons to be arranged opposite each other. The spring 7a is arranged obliquely, in order to bear upon both the button stems.

In order that the packing rings may not move circumferentially in their seats, a locking-pin, m, for eachis inserted in the seatring in such position that a part of the body of the pin lies in a groove in the radial wall of the ring-seat and part within a groove in the adjacent face of the packing-rin Each of the packing-rings O has in its outer face a wide peripheral groove, leaving projecting two narrrow annular heads, 0 c. The object in forming the ring with these narrow heads is to facilitate its wearing away to conform to the inner surface of a cylinder at the commencement of using the packin I find that with these beads the packing very quickly takes the steam in an etficient manner, and gradually wears to a full seat more quickly than when the full faceis at first presented to the cylinder.

In order to secure an even wear on both packing-rings, avoid thumping, and provide for a steady movement ofthe packing, I provide the seat-ring with an expansible steadying-ring, as shown atNand N in Figs. 4, 5, (i, and 7. For this purpose, as shown in Figs. 4 and 7, a wide peripheral groove is formed in the intermediate face of the seat-ring, leaving stationary only narrow faces a n, as in Fig. 4, and n n, as in Fig. 5. A stationary abutment, O, is, however, shown as inserted in the groove in Fig. 4, to receive the buttonsI I. The ends of the expansible packing-ring N come close to the opposite ends of this abutment.

Screws 1) p p are tapped in the seat-ring from the interior, and their tips impinge against the inner surface of the stead ying-rin g, as shown in dotted lines, Fig. 6. By setting outward these screws the steadyingring is expanded to compensate for wear and to give it a firm bearing against the cylinder-face.

In Figs. 5 and 7 the abutment O is dispensed with, the portions n n of the intermediate face of the seat-ring being wide enough to receive the buttons. In this modification the ends of the steadying-ring N come close together.

Heretofore piston -packin gs have been known in which expansible packingrings are supported away from the radial walls formed on the bull-rin g by intermediate flanges to create intervening spaces; but in such packings, as heretofore known, it has been necessary to employ followers to confine the packing-rings on the bull-ring. Piston-packings have also been provided in which the expansible packing-rings have been provided with an annular flange arranged in an annular groove in the bull-ring; but such, broadly, I do not claim.

hat I claim is 1. A piston-packing consisting of a seatring, A, having an annular face, 0, and radial wall d, provided respectively with a peripheral groove, g, and a lateral flange, h, as dc scribed, combined with an expansible packing-ring having an annular rib,f, and an annular flange, l1, substantially as and for the purpose described.

2. The combination, with the seat-ring and the cleft expansible packing-ring, of the outwardly-movable bridgebntton, forming a seat for the ends of said rings, substantially as and for the purpose set forth.

3. The combination, with scat-ring and expansible metallic packin g-rin gs, of an expansible bearing or steadying ring arranged between the expansible packing-rings, substantially as described.

In testimony whereof I have hereunto set my hand in the presence oftwo subscribing witnesses.

\VM. ST. JOHN.

\Vitnesses:

ALBERT H. NORRIS, J. A. RUTHERFORD.

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