US63672A - Improvement in piston packing - Google Patents

Description

lllll Ill N.PEIE RS, PHOTO LITHOGRAPHE @with tapes datent @titten IMPROVEMENT IN PISTON PACKING.

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TO .ALL WIIOM IT MAY CONCERN:

Be it known that I, EDWARD SULLIVAN, oi Pittsburg, in the county of Allegheny, and State of Pennsylr Vania, have invented'a new and useful Improvement in Piston-Heads g" and I do hereby declare the following to be a full and exact description thereof, reference being had to the accompanying drawings and to the letters of reference marked thereon.

The nature of my invention consists in the construction and arrangement of the dillerent parts of piston'` heads of steam engines in such a manner lthat the p11-citings are expanded by the pressure of a portion of the steam admitted to the cylinder, and balancing the weight of the head by the pressure of said portion of steam.

'lo ena-ble others skilled in the art to ineke and use my invention, I will proceed to describe its construetion and operation. In the accompanying drawings, making part of this spccifieatonb Figure l is a longitudinal section of a piston-head with the packings and valves in their proper position.

Figure 2 is a transverse section-of the san1e,`cut through the line r, iig. l. l Figure 3 is un end view of the piston-head.

Figure 4 is an edge view of one of the packing1'ings, showing the arrangement of the plates covering the joint of said ring. i i

i Figure isa top or side view of the said ring, showing the arrangement of the plate and the groove in the ring for the purpose of lubricating by means of the steam contained in it.

In lig. 1 J, B, and P constitute a piston-head ofthe ordinary construction intended to receive spring packing. R is the piston-rod; m the follower; 4, 5, and 6, the packing-rings, with the recesses in them-for balancing and lubricating; and ,e :e are the self-operating valves for, the admission of steam to the interior of the pistonhead. AThe piston-head I make in the usual manner, with Awings or ribs radiating from the centre to receive the bolts used for holding the followers to their place, which rest on the pressure-disk B, (being part of the heath) thereby relieving the packing-rings from any pressure that comes on the `followers. The packing-rings I make of any suitable material, and lit them together as shown in iig. 1. Upon the outside of two of them, 4 and G, I- make a groove, j', `about `one-fourth of an inch wide, and' the sume in depth. Between each two adjoining rings on the inside YI make the recess C, which also extends around the ring, and of about the same proportion as the former. I Upon the outside of the middle ring 5 I form the recess A, (see I and and connect said recess with the opening in the interior of the head by means of the hole marked 2, tig. The rings are eut diagonally across their face, as shown at the point marked 3, tig. 5, and the cut or jointis covered by the two plates g and t, which are secured one to each part of the ring by suitable rivets, (see tig. 4.) The union of the edges of the two plates is the arc of a circle, the radius oi" which is equal to the distance from the point at which the plates join to the extreme outside of the ring directly opposite, so `that when the rings wear, and the joint at the point marked 3 becomes wider, the edges of the plates q and t will always coincide and make a steam-tight joint. The valves x t consist ot' a short cylinder, in which there is tted a piston, l, the ends of which present diiferent areas to the action of the steam; the difference of the areas being in proportion to the required difference between the pressure in the cylinder and that within the head, that is, if the pressure in the cylinder be one hundred pounds to the square inch, and it is required te have twenty within the head, the area should be as one is to live, that is to say, the arca oi' the piston upon which the steam within the interior of the head acts should be ve times as great as that upon which the steam in the cylinder acts, so that when thc steam which enters the head exceeds a pressure of twenty pounds te the square inch the piston will move and pro hibit the entrance of any more steam. At the point d upon the valve or cylinder x there is made a number of holes, which enter the small bore of the valve, and which are intended to admit the steam into the interior of l the head when the piston is moved past them by the pressure of the steam in the cylinder. 7 is a cap, which i screws upon the end of the valve 'for the purpose of keeping the piston I in its chamber. Said cap has an opening through it to admit steam to the end of the piston l. l

Having the parts made as described, I put them together in the following manner: The ring 6 I grind to its proper bearing upon the piston-head withemery or other suitable substance, and fasten it there by the small l pin z'. Therings 4 and 5 I now grind, and fasten to their place upon each other and upon the ring 6 in the same manner, the object of' these pins being te keep the rings from turning around and bringing two or more of the cuts or joints 3 opposite each other. I now fit the follower to its place upori the pressureldisk B and ring 4 in the same manner as the other rings, and having the valve-chambers in their proper places in the interior ofthe head, one in the part of the piston P, and the other in the follower, lfasten the. follower to the head b means of the boltsn 'n n, which com letes the `ob, and leaves the hea-:l after beine' laced in the 'cliz,

y P .l a n P .Y

der, ready. for operation, which isas follows:

n Steam, being admitted into the cylinder on the side of the head niarkedP, acts upon the piston 1 in the valve-chamber zr, and moves it back past thc holes uiarked 9, and into the position shown in the valve-chamber which is in the follower, thus allowing the steam to enter the interior of the piston-head and act upon the otherend of the piston 1. When the steam has attained the desired 'pressure within the head it will again move the piston 1 in both of the valve-chambers, and close the holes 9, thereby prevent-ing the admission of more steam.' The steam now within the head and in the recess A of thel packing-ring 5, which it has entered through the hole 2, pressing equally in all directions, forces the rings 4, 5, and (i out against the-'interior surface of theeylinder, and, acting on the shouldeiis of the recesses C in the rings, forces them laterally against 1li: piston-head P, and against the follower m, making all these joints steam-tight. .The steam in the recess A of the ring 5 exerts a downward pressure against the interior 'surface of the cylinder, and an upwardpressure against the ring 5, which, in turn, imparts it to the ring w ofthe head, thereby sustaining the weight of the piston-head and piston-rod, or as much of their weight as may be desired. The area of the recess A should. be in proportion to the weight of the head; for instance, if the head and rod weighed two hundred pounds, with a pressure of twenty pounds of steam within the recess, an d it is required to balance the 'whole weight, the area .should beten square inches. As the rings wear thinner between the ends of the wings w and the surface of the cylinder, it will be necessary to insert pieces of sheet iron or tin, as shownlat the point marked y, in order to prevent any play or looseness among the parts. The steam contained in the 'grooves f of the rings 4 and`6, which has entered the grooves from the interior of the head through the cuts orjoints 3, serves to lubrieate the piston in its passage back and forth through the eylinder.` When, by condensation or otherwise, the pressure of steam within the head falls below the pressure which is regulated by the difference in the areas of the ends of the piston 1,- the. piston I will again act and lill the head to the required pressure.

I wish it understood I do not confine myself `to any particular size or proportions in the construction of my improved piston-head, for the same may be varied to suit thejudgment of the mechanic.l

Having thus described the nature, construction, and operation of my improvement, what I claim as of my invention, is l 1. The recess C between the packing-rings of a piston-head of a cylinder of a steam engine, as herein' described, and for the purpose set forth.

2. The plates g and z, when used in combination with a `joint orjoints in metallic and expansive packing of a piston-head, as herein described and set forth.

3. In connection with the above the valve x, constructed, arranged, and operating substantially as herein described, and for the purpose set forth.

EDWARD SULLIVAN. Witnesses JAMES J. JOHNSTON, ALEXANDER Hays.

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