US763000A - Piston-rod packing. - Google Patents

Description

PATE'NTED JUNE 21, 1904.;-

PISTON ROD PACKING.

APPLIGATION FILED HEEL-30, 1903.

N0 MODEL Q j gnuento'c Q/VilMeoaeo Y v 4, attouwys UNITED STAT S Patented June 21, 1904. I

PATENT OFFICE.

PISTON-ROD PACKING.

SPECIFICATION forming partof Letters Patent No. 763,000, dated June 21, 1904.

Application filed September 30, 1903. Serial No. 175,188. (No model.)

To all whom it may concern:

Be it known that I, THOMAS S. INen. of Danville, in the county of Pittsylvania, State of Virginia, have invented certain new and useful Improvements in Piston-Rod Packing; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the letters of reference marked thereon.

This invention relates to improvements in packing particularly designed for use in packing the piston rods of steam-engines, the ob-. ject of the invention being to provide a simple and eificient structure wherein the rod is packed with soft-metal rings with the capacity for a wide range of vibration or lateral movement and adapted to be fitted to a pistonrod having an enlarged cross-head fit.

The invention consists in certain novel details of construction and combinations and arrangements of parts, all as will be now described, and pointed out particularly in the appended claims.

Referring to the accompanying drawings, Figure 1 is a sectional View through a portion of a cylinder-head and packing with a rod and portion of the piston in elevation. Fig. 2 is a perspective view of the rings, follower, and spring removed from the stufiing-box.

Like letters of reference in bothfigures indicate the same parts.

Theletters A and B indicate portions of the steam-cylinder and piston, respectively, while C indicates a cylindrical stufiing or gland box, such as is usually formed in the head of the cylinder, as shown, or, if not formed therein, is attached in proper position for the passage of the piston-rod D therethrough. The cylindrical stuffing-box has a permanent head E at the inner end and a removable head E at the outer end, the latter being a substitute for the usual gland. Each head has a rod-aperture, preferably of somewhat larger diameter than the rod, so as to permit of considerable vibration or lateral play as well as to pass an enlarged cross-head fit should the rod embody this construction. The inner surface of the head E is preferably faced to receive one face 9 of a split or segmental packingoppositely-arranged ring G, the flat face g ofthe latter taking abearing against the face of the follower K, located inthe box and normally advanced with a light pressure by a follower-spring L, located in the inner or pressure end of the box. I g

The follower K itself constitutes a piston fitting in the cylindrical box, and in order to prevent the escape of steam aroundit it is provided with packing-rings K, which may be of the ordinary split spring-ring piston type and of hard metal, the object being to make a steam-tight joint; but as the follower has little or no movement save such as is necessary to set up the packing or take up wear 'there is little wear and the rings may be made as heavy as desired. In the preferred construction the rings K are somewhat loose or are capable of a slight longitudinal play while their forward corners are beveled, as at K and holes,preferably four in number, as shown at K are formed leading from the steam side of the follower into the packing-ring space inthe follower. With such construction the steam-pressure not only serves to keep the ringsexpanded and pushed to the outer end of the chamber when escape of pressure is to be resisted, but it permits air to enter from the outside should a vacuum be formed in the cylinder. In other words, the packing in the follower forms a check-valve for preventing the escape of pressure, but permitting airto enter under atmospheric pressure, as when the engine is running without steam, thereby preventing snapping or injury to the main packings.

The follower K has a central rod-opening, preferably corresponding in diameter to the diameter of the openings in the heads, while the solid ring H has a rod-opening of somewhat larger diameter than the rod or large enough to pass an enlarged cross-head fit, al-

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though this ring partakes of the vibration or transverse movement of the rod, as will be now described, and hence the opening through it is not necessarily of much greater diameter than that of the rod itself.

The flat faces of the packing-rings, head, and follower, respectively, are in planes at right angles to the line of rod movement. Thus the said packing-rings, together with the intermediate solid ring, move transversely of the rod as a body, and as the steam-pressure on the follower operates to press the said faces together, as well as to close the packing-rings around the rod, steam-tight joints are formed at every point of possible escape. Practically no pressure exists in the stuffingbox around the packing-rings, and the outer head need not, therefore, fit the box steamtight, thus obviating a frequent cause of annoyance and a difficult step in replacing or renewing worn packings. The spring employed is preferably of sufficient strength to maintain the parts in position when no steampressure is on the follower in order that the i wear on the rings and rod may be reduced to a minimum when no pressure exists. By varying the angle of the inclined faces of the rings the packing-rings may be caused to bear on the rod with any desired pressure.

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

1. In a rod-packing, the combination with the cylindrical stufling-box having its outer head faced on theinside in a plane at right angles to the line of rod movement, a follower working in said box and having its outer face parallel with the inner face of the said head, said head and follower having rod-openings of greater diameter than the rod to permit of rod vibration, packing forming a steam-tight joint between the follower and box and a spring for moving the follower away from the steamchamber, of soft-metal packing-rings surrounding the rod and having outer parallel faces forming steam-tight joints with the faces of the head and follower and intermediate outwardly-inclined faces and a solid intermediate ring having inclined faces engaging the inclined faces of the packing-rings, the said rings being of less diameter than the internal diameter of the box and capable of movement as a body transversely of the line of rod movement; substantially as described.

2. In a rod-packing, the combination with the cylinder, the cylindrical stufling-box open at one end to the cylinder, a follower working in said box, packing forming a steamtight joint between the follower and box, and a removable head on the outer end of the box, said follower and heads of the box having rod-openings of greater diameter than the rod to permit of rod vibration; of packingrings located between the follower and outer head of the box, the pressure in the inner end of the box keeping the rings set up to form steam-tight joints around the rod, between the rings and between the rings and follower and permitting said rings to move as a body in unison with the vibratory movements of the rod; substantially as described.

3. In a rod-packing, the combination with the cylinder, the cylindrical stuffing-box open at one end to the cylinder, a follower working in said box, a valve in said follower for preventing the escape of steam but permitting ingress of air and a removable head on the outer end of the box, of packing-rings located between the follower and outer head of the box and a spring for holding the follower against the packing-rings; substantially as described.

4. In a rod-packing, the combination with the cylinder, the cylindrical stuffing-box open at one end to the cylinder, a follower working in said box,.a packing around the follower forming a valve for preventing the escape of steam, but permitting ingress of air and a removable head on the outer end of the box, of packing-rings located between the follower and outer head of the box and a spring for holding the follower against the packing-rings; substantially as described.

THOMAS S. INGE.

Witnesses: J. M. FEATHERSTON, C. B. GUERRANT.

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