US2665151A

US2665151A - V-type packing for eliminating labyrinth flow

Info

Publication number: US2665151A
Application number: US75676A
Authority: US
Inventors: William C Fisler; Summers Otto Murray
Original assignee: Linear Inc
Current assignee: Linear Inc
Priority date: 1949-02-10
Filing date: 1949-02-10
Publication date: 1954-01-05
Anticipated expiration: 1971-01-05

Description

Jan. 5, 1954 w. c. FISLER ET AL V TYPE PACKING FOR ELIMINATING LABYRINTH FLOW Filed Feb. 10. 1949 Patented Jan. 5, 1954 attain UNITED STATES PATENT OFFICE V-TYP-E PACKING FOR ELIMINATING LABYRINTH FLOW Application February 10, 1949, Serial No. 75,676

8 Claims. 1

This invention relates to improvements in packing of the so-called V type adapted for assembly with like packing in a plurality of nested courses or rings, said packing being shaped so that the confronting surfaces of the nested courses contact each other along continuous longitudinal lines at opposite sides respectively of the longitudinal V recess, thereby forming between said courses a confined channel ex tending longitudinally, as hereinafter more fully described. Under circumstances hereinafter described this channel may form a leakage path through the packing and a primary object of the present invention is to provide an improved form of packing of the stated type in which such leakage is positively precluded.

It has been found further that in the more desirable forms of packing of the type involved longitudinal leakage channels are formed at the outer surfaces of the packing, as hereinafter described, and a further object of the invention is to provide an improved form of packing wherein leakage through these external channels is prevented.

A still further object of the invention is'to provide a packing of the stated type exhibiting an improved stability and reduced tendency to roll under operating conditions, as hereinafter fully set forth.

In the attached drawings:

Fig. 1 is a sectional view of a stuffing box illustrating an installation of packing of the type to which the invention relates;

Figs. 2 and 3 are reverse views in perspective of a section of packing made in accordance with the invention;

Fig. 4 is a fragmentary longitudinal sectional view on the line i-e, Fig. 2, showing a detail of the construction;

Fig. 5 is a sectional view showing three packing rings in normal assembly in a stuffing box prior to compression; and

Fig. 6 is an enlarged fragmentary sectional view showing the packing as it appears under compression in the box.

With reference to the drawings, Fig. 1 shows a typical stuffing box containing packing of the type to which the invention relates and formed in accordance with the invention. In the drawing, I may be considered to be a part of a relatively fixed casing wall through which extends a reciprocating shaft or ram 2. 3 is the top of the stufhng box, one side wall of which is formed by the inner surface 4 of the wall I and the opposite side wall by the ram 2, the

outer end of the box being closed by a gland 5 by which the packing, designated generally by the reference numeral 6, may be compressed in the box.

The packing in the present instance consists of three

rings

7, 8 and 9 respectively, of packing of the V type to which the present invention relates. A male adapter it occupies the top of the packing box, and a female adapter I2 is provided at the opposite end for engagement with the gland 5. The rings i, 8 and 9 are identical as to form and consist in the present instance of generally V-shaped strips of rubberized fabric, each bent to the form of a split ring, said strips preferably being dimensioned as to length so that the ends lie in solid abutment with each other, as indicated at it in Fig. l. Preferably also, the rings are positioned with respect to each other so that the juncture of the ends of each ring is offset circumferentially with respect to the juncture of the ends of the adjoining ring or rings.

The three courses represented by the

packing rings

1, 8 and 9 are nested one within another. Thus the ring 1 seats within the V-shaped recess I4 of the ring 8; and the ring 8 seats correspondingly within the V recess E5 of the ring 9. The seating surface it of the ring i is so formed with respect to the recess :4 that the confronting surfaces of the rings i and 8 contact each other along continuous longitudinal lines [7-41, and form between the said confronting surfaces a confined channel it which, except in the respect hereinafter described, extends continuously throughout the circumference of the rings. A corresponding channel is is formed between the confronting surfaces of the

rings

8 and 9; and a somewhat similar channel 2| is formed between the adapter ring i i and the confronting surface of the ring 1'.

It will be noted also that the rings i, e and 9 are formed at their side surfaces with longitu dinal recesses 22 which constitute clearance gr'ooves at the heels, and in operation these grooves remain full of liquid and serve to provide adequate lubrication as well as storage space for the foreign particles that are unavoidable in all hydraulic circuits. Except as hereinafter noted, each of these grooves 2'2 extends continuously around the circumference of the ring.

It will be apparent that each of the channels It, IS and 2i, and "each of the grooves 22, constitutes a potential path for leakage through the packing assembly. Thus if the end surfaces of the rings, and also of the female adapter l2,

should not lie in solid abutment with each other, as is frequently the case, the channels and grooves may form a labyrinth passage through the packing structure through which leakage of the hydraulic medium which acts on the ram 2 escape from the casing l.

In accordance with our invention, the V I6- cesses of the

packing rings

7, 8 and 9 are provided with a plurality of transverse longitudinally spaced flexibl ribs 23 which extend outwardly from the bottom of said V recesses and from side to side thereof so as to engage the confronting surface of an adjoining ring nested in the V recess as previously described and to thereby interrupt the continuity of the longitudinal channels between the confronting surfaces of the rings. The ribs 23 terminate at the sides of the recess approximately at the lines El and, being flexible, do not interfere with the normal contact between the nested rings or courses of packing which, as previously described, occurs at said lines. Thereby the said ribs convert the continuous channel between the confronting surfaces into a longitudinal series of individual sealed cells through which leakage is precluded.

Also, in accordance with the invention, each of the

rings

1, 8 and 9 is provided. at the sides with longitudinal series of projections 24, said projections lying in the grooves 22 and interrupting the continuity of these grooves. The projections 24 are dimensioned so to engage the lip 25 of the mated packing ring or course so as to form in effect spaced dams in the grooves 22. the said projections thereby converting the otherwise continuous grooves into a longitudinal series of cells through which leakage is precluded. The pro ections 2 are preferably mad flexible, as of flexible rubber or rubberized fabric, and are dimensioned for cooperation with the lips 25 of the immediately adjoining course.

The small projections 24 have an additional desirable effect upon the functional characteristics of the packing in that they provide added mechanical support for the sides of the packing tendin to improve stability and to prevent rolling of the ring by action of the reciprocating ram.

It is referred to place the ribs 23 so as to divide the lon itud nal recess into cham ers or cel s of eoual len th. say inches or less, and to provi e an e ual number of the pro ections 2' at each si e located with res ect to the ribs 23 so as to lie substantially half wav bet een said ribs, or in staggered relation with the latter, althou h there is no limitat on with. respect to the number and relative location of these elements.

The ribs may be formed to advanta e as shown in Fig. 4 with one side inclined and the other approximately vertical to the bottom of the recess. With this formation the ribs conform readily and accurately to the curved surface of the mating course of packing and afford highly effective seals between the ad oining cells.

The pro ections 24 are preferably formed as shown in Fi s. 3 and 5. The body portion 26 of the individual projection conforms substantially to the surface of a cylinder and preferably projects slightly beyond the side surface 2'! of the lip as clearly indicated. The portion 25 terminates in a portion 28 which conforms substantially to the surface of a cone and which merges at the apex into the curved surface Hi. the angle of the conical surface to the cylindrical surface of the portion 26 being approximately and conforming closely to the angle of the inner surfac 29 of the lip 25.

Normally, the lip portions 25 of the packing are somewhat spread apart as shown in Figs. 2 and 3 so that the side surfaces 2'! of the lips are not parallel. When assembled in the stufiing box, and prior to compression the packing courses assume positions somewhat as indicated in Fig. When compressive force has been applied through the gland 5, the packing will be as shown in Figs. 1 and 6, it being noted that the portions 26 of the projections 24 are now pressed into the surfaces 21 so that the latter lie flatly against th sides of the box, while the portions 28 lie firmly pressed against the inner surfaces 29 of the lips of the adjoining course.

It will be noted that by use of recision squarecut butt joints at the ends of the individual packing rings it is possible to cut the rings considerably longer than the actual circumference of the packing space and still install the ring without difliculty. Thus, in sizes as small as four feet, the rings may be as much as one inch longer than the circumference of the said space. This helps materially in expanding the packing ring transversely to breach an over-width gland space and also provides an excess of length exceeding a maximum shrinkage that might otherwise cause separation at the joint. Even in. the event that separation of the joint occurs, the aforedescribed construction reduces labyrinth flow to an extremely low point well within practical limits. It is to be noted also that the squarecut joints may readily be made without tools othe than a smooth blade hacksaw, and is well within the capacity of any field maintenance operator. Packing made in accordance with the invention has greatly increased usefulness and adaptability to a relatively wide range of field variations.

Considerable modification in the packing is possible without departure from th principle of the invention. It is possible, for example, to form the primary dams or ribs, whose function it is to preclude labyrinth leakage by way of the longitudinal V recess, on the side of the packing which nests within the v recess, rather than in the bottom of the latter, the ribs in this case projecting into the bottom of the V recess in the opposed course and functioning equally well to the desired end.

We claim:

1. A packing ring having relatively spaced axially directed lips forming the opposite walls of a circumferential channel of substantially V- shaped transverse configuration in one side of the ring, and having in said channel a plurality of relatively spaced resilient webs interrupting the circumferential continuity of the inner portion of the channel, the opposite side of the ring having a generally convex cross-sectional form of a radius such as to fit within the said substantially V-shaped channel so that when said opposite side is placed against the channeled side of an-- other packing ring of substantially the same configuration with the rings in superimposed and axially compressed relation the said convex side of one ring will seat within the channel in the other ring with the said convex side contacting the walls defining said substantially V-shaped channel along lines remote from the bottom of the channel, the said resilient webs extending away from said channel bottom of one ring to an extent insuring sealing engagement between the outer edges of the webs of said one ring and the convex confronting surface of the other ring seated in said substantially V-shaped channel of said one ring when said rings are in said axially compressed relation to thereby effectively separate the portions of said channel at the opposite sides of the web.

2. A packing ring according to claim 1 wherein the ring is split transversely at one side.

3. Packing comprising a plurality of superimposed split rings constructed in accordance with claim 2.

4. A packing ring according to claim 1 wherein the said channeled and opposite sides of the ring converge towards and intersect at the outer terminal edges of the lips, the said seat being confined to circumferential areas of the channel walls remote from. said outer edges with resultant voids between the confronting faces of said superimposed rings in the form of circumferentially extending recesses, and circumferentially spaced protrusions on the said lips arranged to project into said recesses and shaped to conform to the cross sectional form of the recesses so as to effectively interrupt the continuity of the latter when said rings are in said axially compressed relation.

5. A packing ring according to claim 4 wherein the ring is split transversely at one side.

6. A packing ring having relatively spaced axially directed lips forming the opposite walls of a circumferential channel of substantially V- shaped configuration in one side of the ring, the opposite side of said ring having a generally convex cross sectional form of a radius such as to fit within the said substantially V-shaped channel so that when said opposite side is placed against the channeled side of another packing ring of substantially the same configuration with the rings in superimposed and axially compressed relation the said convex side of one ring will seat within the channel in the other ring with the said convex side of said one ring contacting the walls defining said substantially V-shaped channel of said other ring, the said channeled and opposite sides of the one ring converging toward and intersecting at the outer terminal edges of the lips thereof, the contact between the convex side of said one ring and the walls defining the channeled side of the other ring being confined to circumferential areas of the channel walls remote from said outer edges with resultant formation of circumferential recesses between the confronting faces of the superimposed rings, and circumferentially spaced protrusions on the said lips arranged to project into said recesses and shaped to conform to the cross sectional form of the latter so as to effectively interrupt the continuity of said recesses when the rings are in said axially compressed relation.

'7. A packing ring according to claim 6 wherein the protrusions are located on the convex side of said one ring.

8. Packing comprising a plurality of superimposed portions of packing material, said portions each having on one side thereof relatively spaced, longitudinally extending lips forming the opposite walls of a longitudinal channel of substantially V-shaped transverse configuration in said one side of each portion and having in said channel a longitudinal series of relatively spaced resilient webs interrupting the continuity of the inner portion of the channel, the opposite side of each portion having a generally convex cross sectional contour of a radius such as to fit within the said substantially V-shaped channel so that when said opposite side of one portion is placed within the channeled side of another portion of substantially the same configuration with the portions in superimposed relation the said convex side of one portion will seat within the channel in the other portion along longitudinal areas remote from the bottom of the channel, the said resilient webs extending away from said channel bottom of said one portion to an extent insuring sealing engagement between the outer edges of the webs of said one portion and the convex side of the other portion seated in said channel of said one portion when said portions are in axially compressed relation to thereby effectively separate the portions of said channel at opposite sides of the webs, the said channeled and convex sides of each of said portions converging toward and intersecting at the outer terminal edges of the lips thereof, the contact between the said convex side and the walls defining the substantially V-shaped channel being confined to circumferential areas of the channel walls remote from said outer edges with resultant formation of longitudinal recesses between the confronting faces of the superimposed portions, and spaced protrusions on the said lips arranged to project into said recesses and shaped to conform to the cross-sectional form of the latter so as to effectively interrupt the continuity of said recesses when said portions are in axially compressed relation.

WILLIAM C. FISLER. O'ITO MURRAY SUMMERS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,006,602 Muster July 2, 1935 2,443,332 Summers June 15, 194.8 2,465,175 Schwarz et a1. Mar. 22, 1949 FOREIGN PATENTS Number Country Date 398,555 Great Britain Sept. 18, 1933