US3285615A - Seal - Google Patents

Description

Nov. 15, 1966 N. D. TRBOVICH SEAL Filed Sept. 20, 1965 United States Patent 3,285,615 SEAL Nicholas D. Trbovich, 59 Fieldcrest Court, West Seneca, N.Y. Filed Sept. 20, 1963, Ser. N0. 310,223 5 Cl aimS. (Cl. 277180) This invention relates generally to the seal art, and more specifically to a new and useful seal of a type particularly adapted for use in place of rubber O-rings.

Metal seals possess certain advantages over rubber 0- rings, but also present a problem in providing the requisite strength and rigidity within the limitations imposed by existing cavity diameters and permissible flange loading. These limitations must be observed, if true interchangeability with rubber O-rings is desired.

Accordingly, the primary object of my invention is to provide a metallic seal of increased strength and rigidity, which seal is interchangeable with rubber O-rings without requiring any increase in cavity diameters and while maintaining a minimum in the compression force required for sealing.

Another object of my invention is to provide a metallic seal having the aforesaid characteristics, and having improved fatigue life and pressure capability.

Still another object of my invention is to provide the foregoing in a seal characterized by ease of manufacture.

In one aspect thereof, a seal constructed in accordance with my invention is characterized by the provision of a member of generally U-shaped transverse section having a base, side walls extending from the base, and laterally outwardly projecting flanges adjacent the outer ends of the side walls, the side walls tapering toward the flanges and the flanges projecting from the outer ends of the side walls a distance greater than the thickness of the side walls adjacent the flanges, the outer ends of the flanges being flat and providing surface engaging sea-ling areas.

In another aspect thereof, a seal constructed in accordance with my invention is characterized by the provision of a member of generally U-shaped transverse section having a base, side walls extending from the base, and laterally projecting flanges adjacent the outer ends of the side walls, the side walls tapering toward the flanges, and the flanges having flat surface engaging outer end portions which are substantially parallel when the member is unstressed.

In still another aspect thereof, a seal constructed in accordance with my invention is characterized by the provision of a member of generally U-shaped transverse section having a base, side walls extending from the base, and laterally projecting flanges adjacent the outer ends of the side walls, the inner surfaces of the side walls being substantially parallel when the member is unstressed, and the outer surfaces of the side walls converging toward the flanges.

The foregoing and other objects, advantages and characterizing features of my invention will becomeclearly apparent from the ensuing detailed description of an illustrative embodiment thereof, considered in conjunction with the accompanying drawing depicting the same, wherein like reference numerals denote like parts throughout and wherein:

FIG. 1 is a fragmentary, longitudinal sectional view of a joint incorporating a seal of my invention; and

FIG. 2 is a view, on an enlarged scale, showing the transverse sectional configuration of the seal.

Referring now in detail to the illustrative embodiment depicted in the accompanying drawing, there is shown a seal of my invention, generally designated 1, positioned in thecavity 2 of atubular member 3, to which anend flange 4 is secured, as bybolts 5. Seal 1 is shown in its installed, stressed condition in FIG. 1, while FIG. 2 shows the transverse sectional configuration thereof in its unstressed condition.

Seal 1 is of generally U-shaped transverse section, having abase 6 andside Walls 7 extending from one side of the base.Side walls 7 terminate, at their outer ends, in laterally outwardly projectingflanges 8 having flatouter ends 9 comprising the surface engaging sealing portions of the seal. That is,end surfaces 9 and particularlyedges 9A thereof are in sealing engagement with the adjacent surfaces ofmembers 3 andend flange 4. Thesealing surfaces 9 and 9A are usually coated or plated with aductile material 9B which will cold flow when the seal is compressed. This further enhances the sealing ability of the seal.

The opposite ends ofbase 6 are flat, as shown at 10, from the outer side 11 ofbase 6 to a point short of theinner side 12 thereof.End surfaces 10 are parallel, and act as mechanical stops preventing overcompression of seal 1, as clearly illustrated in FIG. 1.

In the unstressed condition of the seal, theinner surfaces 13 ofside walls 7 are substantially parallel. Theouter side surfaces 14 thereof are flat, likeinner surfaces 13, but converge from thebase end portions 10 toflanges 8. This providesside walls 7 of tapered form, the degree of taper being such that the thickness ofside walls 7adjacent flanges 8 at the outer ends of the side walls is less than half the thickness of the side wallsadjacent base 6.

This tapered side wall configuration tends to equalize stress distribution throughout the seal, and avoids stress concentrations to provide better fatigue life and pressure capability. Further, the material of the seal member is concentrated at thebase 6, producing a stronger seal without increasing cavity size such as would be required if an attempt were made to strengthen the seal by increasing its size throughout. This design also provides a seal of increased rigidity, without a corresponding increase in the compression force required to effect the seal.

The provision of initially substantially parallelinner wall surfaces 13 facilitates the manufacture of a tapered wall seal, with its advantages, by avoiding the problems introduced by the critical nature of an internal taper. It also facilitates varying the thickness ofbase 6, and consequently the hoop strength of the seal, without affecting either the taper or the outer end wall form of the seal.

Flanges 8 project outwardly beyond thebase end portions 10, in the unstressed condition of the seal, as clearly shown in FIG. 2. The flanges project beyond theside walls 7, at their outer ends, a distance substantially twice the thickness of theside walls 7 at the outer ends thereof. Further,flanges 9 are of substantially square transverse section, in the portion thereof projecting beyond the outer ends ofside walls 7, thereby providing a sealingsurface 9 of substantial area, for increased sealing effect as contrasted with the situation which would prevail ifflange 8 made substantially only point contact withmember 3 andend flange 4. The initially substantiallyparallel ends 9 are important, because as theedges 9A are compressed thematerial 9B is caused to cold flow acrossends 9 and into the irregularities of the sealing surfaces onmembers 3 and 4, as indicated in FIG. 1, to provide a greater area of sealing contact and enhanced sealing effect. If theends 9 were initially tapered, the ductile material cold flowing away fromedges 9A would not be retained in sealing contact withmembers 3 and 4, and its sealing elfect would tend to be lost, leaving substantially only knife edge contacts between the base metal of seal 1 andmembers 3 and 4. It is contemplated that at leastend portions 9, if not the entire seal, will have acoating 9B of malleable material such as silver, gold, nickel, copper or Teflon, for example, which will deform and cold flow under the pressures involved into surface irregularities inmembers 3 and 4, to increase the sealing action.

The corners between the meeting surfaces are rounded, as clearly shown in FIG. 2, except at the sealingend portions 9 offlanges 8. Also, it will be noted that the concentration of material atbase 6 is such that, not only are thewalls 7 much thickeradjacent base 6 than they areadjacent flanges 8, butbase 6 itself is much thicker thanwall members 7 at any point therealong. This provides maximum hoop strength for a given diameter.

Accordingly, it is seen that my invention fully accomplishes its intended objects. While I have disclosed and described in detail only one embodiment of my invention, that has been done by way of illustration, it being my intention that the scope of my invention be defined by the appended claims.

Having fully disclosed and completely described my invention, and its mode of operation, what I claim as new is:

1. A seal comprising an annular unitary metallic member of generally U-shaped, radially facing transverse section having a base and opposite side walls extending from one side thereof, said side Walls terminating at their outer ends in laterally outwardly projecting flanges, the opposite ends of said base comprising stops against overcompression of said seal, the inner surfaces of said side Walls being flat and substantially parallel when said member is unstressed, and the outer surfaces of said walls converging toward said outer ends thereof from said base, the thickness of said side walls adjacent said outer ends thereof being no more than substantially one-half the thickness thereof adjacent said base, said base being thicker than said side walls atany point therealong, said flanges projecting beyond said opposite ends of said base and terminating in flat surface engaging sealing end portions, said surface engaging end portions being substantially parallel when said member is unstressed and having a coating of ductile material which will cold flow into irregularities of the surfaces being sealed.

2. A seal as set forth in claim 1, wherein said coating comprises a malleable metal.

3. A seal as set forth in claim 1, wherein said coating comprises a malleable non-metallic material.

4. A seal as set forth in claim 1, said opposite ends of said base being flat and substantially parallel from the other side of said base to a point substantially short of said one side thereof to comprise said stops against overcompression of said seal.

5. A seal as set forth in claim 1, said opposite ends of said base being flat and substantially parallel to comprise said stops against overcompression of said seal, the outer surfaces of said walls being flat and converging toward said outer ends thereof from said flat ends of said base to said flanges when said member is unstressed, the outwardly projecting portions of said flanges being of substantially rectangular transverse section, and the corners between said other side of said base and said opposite ends thereof and between said inner Wall surfaces and said flanges being rounded.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCES Machine Design The Seals Book, The Pentaton Publishing Co, Jan. 19, 1961 (Copy in Div. 360 (T1 246 M3) SAMUEL ROTHBERG, Primary Examiner.

EDWARD V. BENHAM, LAVERNE D. GEIGER,

Examiners. J. S. MEDNICK, Assistant Examiner.

Claims (1)

1. A SEAL COMPRISING AN ANNULAR UNITARY METALLIC MEMBER OF GENERALLY U-SHAPED, RADIALLY FACING TRANSVERSE SECTION HAVING A BASE AND OPPOSITE SIDE WALLS EXTENDING FROM ONE SIDE THEREOF, SAID SIDE WALLS TERMINATING AT THEIR OUTER ENDS IN LATERALLY OUTWARDLY PROJECTING FLANGES, THE OPPOSITE ENDS OF SAID BASE COMPRISING STOPS AGAINST OVERCOMPRESSION OF SAID SEAL, THE INNER SURFACES OF SAID SIDE WALLS BEING FLAT AND SUBSTANTIALLY PARALLEL WHEN SAID MEMBER IS UNSTRESSED, THE OUTER SURFACES OF SAID WALLS CONVERGING TOWARD SAID OUTER ENDS THEREOF FROM SAID BASE, THE THICKNESS OF SAID SIDE WALL ADJACENT SAID OUTER ENDS THEREOF BEING NO MORE THAN SUBSTANTIALLY ONE-HALF THE THICKNESS THEREOF ADJACENT SAID BASE, SAID BASE BEING THICKER THAN SAID SIDE WALLS AT ANY POINT THEREALONG, SAID FLANGES PROJECTING BEYOND SAID OPPOSITE ENDS OF SAID BASE AND TERMINATING IN FLAT SURFACE ENGAGING SEALING END PORTIONS, SAID SURFACE ENGAGING END PORTIONS BEING SUBSTANTIALLY PARALLEL WHEN SAID MEMBER IS UNSTRESSED AND HAVING A COATING OF DUCTILE MATERIAL WHICH WILL COLD FLOW INTO IRREGULARTIES OF THE SURFACES BEING SEALED.

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