US1712003A - Packing - Google Patents

Description

May 7, 1929. c. R. HUBBARD PACKING Filed Deg. 10. 1926 INVENTOR By Attorneys, 41am;

Patented May 7, 1929.

} burrs!) STATES 1,712,003 PATENT OFFICE.

CECIL R. HUBBARD, F NEWARK, NEW YORK, ASSIGNOR TO THE GL'RLOCK PACKING COMPANY, OF PALMYRA, NEW YORK, A CORPORATION OF NEW YORK.

PACKING.

Application filed December 10, 1928. Serial no. 163,090.

This invention relates to improvements in packing of the type having a relatively thin lip portion adapted to be forced into snu engagement with the surface to be packe by the fluid confined in the packed structure. It is an object of the invention to provide a packing of the above-described character,

of which the lip will tend to maintain a normal position with its working surface in intimate contact with the surface to be packed irrespective of the fluid pressure, which need be relied upon only to increase the pressure between the surface of the lip and the surface to be packed.

It is a further object of the invention to provide a packing of, the character described, of which the lip is weakened along the zone of its connection with the body portion of the packing, thereby forming a flexi-' 'ble or hinge-like joint between the lip and the body portion, whereby the fluid pressure may more readily maintain the lip in a sealed relationship with the surface to be packed.

In the drawings illustrating the preferred form of the invention-.-

Figure 1 is a perspective view of a fragmentary strip of packing embodying the invention, a part of which is illustrated in transverse cross-section.

Fig. 2 is a similar view of a strip of material from which packing like that illustrated in Fig. 1 may bemade.

Fig. 3 is a perspective view of a stri of packing like that illustrated in Fig.1, cut

into an annulus or ring, apart of the ring being broken away and a part illustrated in transverse cross-section.

Fig. 4 is an enlarged cross-sectional view of the packing ring illustrated in Fig. 3, the

portion indicated in broken lines being representatiye of the form which would be assumed by the lip if not constructed in accordance with one of the features of the invention.

Referring first to Fig. 1 of the drawings,

a packing embodying the invention herein sought to be protected is illustrated as comprising a relatively massive body portion 20, 59 of L-shaped form in cross-section, of which the two arms 21 and 22 in the form herein represented are perpendicular to each other.

Extending from the free end of the arm 22 is a lip portion23 preferably of wedge-like form in cross-section, said lip having an outer surface portion 24 whichis an extension of the outer surface 25 of the end of the arm 22 of the L. Preferably the surface 24 W-lll be slightly inclined or flared outwardly with respect to the surface 25, for reasons which wlll be explained. The inner surface 26 of the lip 23 may flare inwardly from the free edge portion 27 of the lip, whereby its thickest or most massive portion s located at a distance from the edge 27 and in the region of its zone of connection with the end of the arm 22 of the L. .In accordance with one of the important features of this invention, however, the lip is intended to be weakened in any appropriate manner along this zone of connection between the 11p and the body portion of the packing, thereby forming a relatively flexible or hinge-like joint, the importance of which will hereinafter be made clear. One satisfactory method of weakening the joint between the lip and the body portion, as illustrated in Fig. 1, consists ingrooving the lip along the zone of connection as at 28. Preferably this groove and the angle at the junction of the arms 21, 22 of the L may comprise a gradually rounded surface extending from the base of the inner surface 29 of the arm 21 to the inner surface 26 of the lip portion 27. The form of this groove 5 may be such as to deepl undercut the base portion of the lip, there localizing a zone of weakness therealong a out which the lip as a whole may be flexed.

Packing of the above-described character is preferably made in relatively long strips which may be cut to suitable lengths and bent to ring-like form, as indicated in Fig. 3. The size of the rin will be dependent upon the diameter of t e piston or plunger or other part of the mechanism to be packed.

When bending the strip of packing from its rectilinear form illustrated in Fig. 1 to the ring-like form'in Fig. 3, the packing at the inner circumference of the mug is sub- 100 jected to compression and the packing at the outer circumference is put under tension, since the same length of packing material must be caused to adjust itself to the shorter internal circumferential portion as that 105 which accommodates the outer and relatively longer circumferential portion. In view of this compression the relatively thin lip portion of the packing would have a tendency during the bending of the strip to ring- 110 like form to assume a position of the largest permissible diameter which would only be limited by the stresses set up in the material. For example, if the strip of packing of rectilinear form as indicated in 1g. 1 were to be provided with a li having its working surfaces 24 and 25- 1n the same plane instead of having the portlon 24 flared outwardly, the bending of the packlng to ring-like form would cause the 11p to be forced outwardly, with respect to the center of the ring, to the position indicated in broken lines in Fig. 4. This would be quite unsatisfactory since it? would permit the fluid to enter the gap between the surface 24 and the surface to be packed and thereby defeat the intended purpose of the packing. It is one of the objects of the invention to overcome this undesirable deformation of the lip when bending the acking from rectilinear form to circular orm. This is accomplished, as already explained, by glvmg the packing a normal form illustrated in Fig. 1 in which thesurface 24 of the lip portion is inclined away from the arm 21 of the L. On bending the packing from rectilinear form to circular form, the compression in the lip portion tends to cause such portion to assume a diameter somewhat greater than it would assume if the lip were to retain its normal cross-sectional form relative to the body portion of the packing. This tendency to increase its diameter is overcome by the stresses in the elements of the packing parallel with the axis of the ring, the various elements being brought to a state of e uilibrium when in the form illustrated in ull lines in Fig. 4. The initial inclination of the packing in rectilinear form may be of such de ree that when bent to ring-like form the sur aces 24 and 25 shall be in substantially the same plane. The packing is of course placed in the apparatus to be packed with the channel of V-shaped cross-section lying between the surfaces 26 and 29 opposed to the fluid to be confined. This fluid will be caused to enter the V-shaped channel and will have a tendency to force the lip portion 23 into firm engagement with the surface to be packed, which it may more readily do if the packing is also provided with the flexible or hinge-like joint along the zone of weakness between the lip and the body portion.

Packing of the above-described character may be constructed in any appropriate manner and of any suitable material. In the preferred form herein disclosed it is indicated as having been made by first folding a sheet 30 of rubber and asbestos fibre or other ap ropriate fibrous material in a plurality o folds, as indicated in Fig. 2, the last fold being carried entirely. around the mass ofimaterial so as to form a covering or envelope for the internal folds. This folded mass of material may then be pressed in a suitable mold and vulcanized in the form illustrated in Fig. 1. The continuously curved surface at the base of the V-shaped channel tends to the longevity of the packing since it avoids the use of anysharp reentrant angle which would serve as a starting point or a line of rupture between the base of the lip and the body portion. When using a packing reinforced with layers of asbestos material the durability of the packing may be further enhanced, as illustrated in Figs. 1 and 2, by so disposing the fibrous material that the layers 31 will closely follow the curved surface extending from the surface 29 around to the surface 26 without an intermediate break or angle.

t is not essential. that the packing be made in the specific form herein disclosed for pur ses of illustration but should be regard as including modifications and variations within the scope of the appended claims. The more important features, as already described, are the body portion and lip portion united by a weakened portion formin a flexible or hinge-like joint between t e two, and the packing having the surfaces 24 and 25 disposed in different planes but adapted to be brought to substantiall the same plane when the packing is bent rom the form in ,which it is made to the form in which it is intended to be used.

What I claim is: 1. A acking comprising a relatively massive bo y portion, a lip portion, and an intervening zone of weakness and relatively great flexibility forming a hinge-like connection between said lip and body portions, one surface portion of said lip portion being an extension of a surface portion of said body portion and cooperating therewith as a working surface of said packin 2. A acking comprising a relatively massive b0 y portion and a lip portion one surface portion of said lip portion ein an extension of a surface portion of said body portion and cooperatin therewith as a workin surface of said pac ing, the other surface 0 said lip portion being flared from the free edge of said lip to a relatively massive portion adjacent its zone of attachment with the body portion, said lip portion being grooved along said zone of attachment to provide a relatively flexible connection between said lip portion and said body portion.

3. A acking comprising a relatively massive body portion of L-shaped form in crosssection and a tapered lip portion of wedgeshaped form in cross-section extending from one arm of the L in the general direction of its other arm, the external surface of said lip portion being a continuation of the surface of the end of the arm of the L of which the lip is an extension, and its inner surface ,lip portion being a continuation of the surface of the end of the arm of the L of which the lip is an extension, and its inner surface being flared inwardly from its free edge to its zone of attachment with the L-shaped body portion, the inner surface of said body portion being continuously curved from the base of the free arm of the L to the inner surface of the lip portion, the form of such curved portion being such as to provide an internally disposed groove along the zone of attachment between the lip and the body portion, thereby producing a relatively flexible hinge-like connection between said parts.

5. A packing as defined by claim 2, constructed of ru ber composition and reinforcing layers of fibrous material, a part of said reinforcing material being so disposed as to closely follow the surface of the groove along the zone of attachment between the li portion and the body portion.

6. X packing comprising a relatively massive body portion and a lip portion, one surface portion of said lip portion being an extension of a surface portion of said body portion and cooperating therewith as a working surface of. said packing, said packing sion, whereby the distortion of the lip portion, when the packing is bent to circular form, will tend to cause its working surface to become a continuous cylindrical extension of the cylindrical working surface of the body portion, the normal inclination of the lip portion being such that it will be directed towards the axis about which the packing is intended to be bent to circular form.

7. A packing comprising a relatively massive body portion of L-shaped form in crosssection and a tapered lip portion of wedgeshaped form in cross-section extending from one arm of the L in the general direction of its other arm, the external surface of said lip portion being'a continuation of the surface of the end of the arm of the L of which the lip is an extension, and its inner surface being flared inwardly from its free edge to its zone of attachment with the L-shaped body portion, said packing being made in rectiilinear form with the external surface of its i portion normally inclined away from .the rec arm of the L, whereby, when the packing is bent to the form of an annulus,

with the lip portion at the part of smallest diameter the distortion of the lip ortion will tend become a continuous cylindrical extension of the cylindrical surface of the end of the L CECIL R. HUBBARD.

to cause its working sur ace to o

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