reame rse. ia, iena PSTON PACKING.
Application tiled .Tune 12, 1923. Serial No. 644,875.
To all whom it may concern.:
Be it known that I, EDWIN A. IsAKsoN, a citizen of the United States, and resident of McKeesport, in the county of Allegheny and State of Pennsylvania., have invente certain new and useful Improvements in Piston Packings, of which the following is a speciication.
This invention relates to piston head packings and whilenot limited thereto relates more particularly to piston head packings especially adapted for use on the' pistons of hydraulic cylinders or the like where they will be subjected to the action of moisture.
One object of this invention is to provide a packin for the pistons of hydraulic cylinders whic will become tighter when subjected to moisture, thus forming a perfect seal between the piston and cylinder walls.
Another object of this invention is 'to provide a packin that will have a materially longer life t an the packings heretofore used in hydraulic cylinders. y
A further object is to provide an improved packing composed of a metal cup and fiber ring such as described in the following speci fica'tion and illustrated in the accompanying` drawings.
In the drawings, Figure 1 is a longitudi. nal sectional elevation through a hydraulic cylinder and piston having my invention applied thereto.
Figure 2 is a sectional elevation through one of the packing rin Referring more partlcularly to the drawings, the numeral 2 designates the barrel or body portion of the cylinder which has a removable head 3. The usual piston, comprisin a rod 4, head 5, follower ring 6, and c cker 7,' is mounted in the cylinder body 3. rllhe follower ring 6 is secured to the piston head 5 by stud bolts 8 and the choker 7 is provided with a screw threaded stem 9 which is threaded into the piston head.
The rear end of the piston head 5 is pros vided .with the usual enlargement orf rim 10 forming a shoulder 11 against which a lower spacing ring 12 abuts. The lower spacing ring 12 is cut away to form a shoulder portion 14, which abuts against the shoulder 11 of the piston head, and a ange portion 15 which overlies the rim 10.
A forward spacing ring 16 and intermediate spacing ring 17 are mounted on the piston head 5 and spaced away from each otherand the rear ring 12 so as to form annular recesses 18 for the reception of packing rings, two of which are mounted 1n each of the recesses. The spacing rings are formed from a suitable anti-friction metal such as brass, and are constructed to form a relatively tight lit between the piston head 5 and cylinder body 2.
Each of the packing rings comprisea metal c u 20 composed of copper or other non-resilient soft metal and comprise an outer band portion 21 and an inwardly directed flange 22. The edge of the band portion 21 opposite the lian'ge 22 is beveled as at 23 so as to permit the pressure within the cylinder to enter and aid in expanding the band portion against the cylinder wall.- The metal cups in the lower annular recess have their beveled edges directed downwardly, while the cups in the upper recess have their beveledl edges directed upwardly.
A hard red fiber ring 24 is tted snugly within each of the metal cups. The hard red fiber is characterized by being expansible( when mostened and this quality is utilized in the functioning of the present packing rings. When the hydraulic cylinder is operated the fiber rings 24: will become wet and immediately expand or swell, and since vthe rings 24 are conned between the soft metal cups and the hard metal piston head, the force of expansion will be exerted on the soft metal cups and force the band portion 21 thereof outwardly into close contact with the cylinder wall, thus forming a ood seal.
eretofore, leather, asbestos and other soft materials have been used for packing the; pistons of hydraulic cylinders, but due to wear it is necessary to replace such packings about every two or three days when the c linder is using high pressure continually.
hile experience has shown that the present packing rings composed of copper cups and red fiber rings will make a better seal and will last about six weeks before they are worn sufiiciently to need replacement.
It will thus be seen that the savings for each high pressure hydraulic cylinder packed in accordance with this invention, will amount-to thousands of dollars each year, andthe operation of the cylinder will be materially improved, due to the seal between the piston and cylinder wall being better than the old forms of soft packing.
` While l have described my invention as liti@ be used in other cylinders without departing from the scopeof m invention as dened in the appendedclalms.
1. The combination with a iston having a plurality of spacing rings t ereon space to form at least one annular recess, of at least one packing ring mounted in said recess, said ring being composed of a non# elastic soft metal cup, and a hard ber ring mounted within said cup, said ring being characterized b being expansible when moistened and ing adapted Awhen moistened to force said metal cup outwardly into contact with the cylinder wall.
2. The combination with a piston, of at least one packing ring comprisin a nonelastic soft metal cup, and a hard ber ring within said cup, -said ber ring being characterized by being expansible when moistened and being adapted when moistened to expand said cup.
3. A packing ring for pistons of hydraulic cylinders, comprising a non-elastic soft vmetal cup, and a hard ber ring within said cup, said ber ring being characterized by being expansible when' moistened and being adapted when moistened to expand said cup.
4. A packing ring for pistons of hydrau- .lic cylinders, comprising a copper cup, and
a hard red ber rin mounted within said cup, said ber rin ing characterized by being expansible w en moistened and being adapted when moistened to expand said cup.
5.- The combination with a piston having a plurality of anti-friction metal spacing rings thereon spaced to form a pluralit of annular recesses, of at least one pac 'n ring mounted in each of s aid recesses, said rings comprising a non-elasticsoft metal cup, and a hard ber ring mounted within said cup, said ring being characterized by being expansible when moistened andbeing adapted when moistened to form said metal cup outwardly into contact with the cylinder wall.
6.` he combination with a piston for a hydraulic cylinder havmg a plurality of anti-friction metal spacing rings thereon and spaced to form a pair of annular recesses, of a pair of packing rings mounted in each of said recesses, each of said packing rings comprisin a copper cup, and a rigid non-resillentv r ring mounted within said cup, said, ring being characterized by bein ex nsible when moistened and being a apte when moistened to force said metal cup outwardly into contact with the cylinder wall. A p
7. The combination with a piston for a hydraulic cylinder having a plurality of anti-friction metal spacing rings remov ably mounted thereon and spaced to form a pair of annular recesses, of a pair of packing rings mounted in each of said recesses, each of said packing rings comprisin a non-resilient 'soft metal cup, and a rigi non-resilient ber rin mounted within said cup, said ring being c aracterized by beingl ex ylisible when moistened and be' adapted when moistened to force said meta cup outwardly into contact with the cylinder wall. A
In testimony whereof I have hereuntol set myhand.
EDWIN A. ISAKSON.