Lip-seal fitting

Claim 2

An end-fitting for tubular members having an internal pressure of fluid or gas, said fitting comprising a first tubular part, a second tubular part and means for securing the parts together in a fluid or gas-tight seal, one of said parts having a seat therein, the other of said parts having a concave annular seal comprising inner and outer surfaces with a cantilevered deflection beam having a cross section of substantially uniform thickness, said concave seal forming a cavity exposed to the pressure of said fluid or gas, the sealing surface of said cross section being a blend of at least two arcs, one of said arcs forming a first annular sealing point at the heel of the beam, and the toe of the other of said arcs forming a second concentric annular sealing point, said concave beam being arched on both inner and outer surfaces between said two annular sealing points, said first and second sealing points being shaped to form concentric wear resistant contact areas with respect to said seat.

Claim 3

The end-fitting of claim 1 wherein said arch provides a clearance between said annular seal and said seat when said end-fittings are brought together in a fluid or gas-tight seal.

Claim 4

The end-fitting of claim 1 wherein said first annular sealing point provides a stop for limiting the travel of said nipple in said socket.

Claim 5

The end-fitting of claim 1 wherein said flexible hose is a plastic liner covered with a braid cover, said annular seal is at one end of a metal sleeve, the other end of the metal sleeve being shaped to bite into and hold the braided hose.

Claim 6

The end-fitting of claim 1 wherein there is a metal-to-metal seal comprising a configuration wherein said seal is compressed against said seat by a travel of said parts relative to each other, a spring-like elasticity in said arch, and fluid or gas pressure inside said fitting.

Claim 7

The end-fitting of claim 5 wherein said first and second parts are metal tubes, the opposite and mating ends of said tubes being flared and shaped to form said seat on said first part and said concave flange on said second part.

Claim 8

The end-fitting of claim 6 and an annular clamp means fitted over the two flared ends, said clamp having a double wedge V-shaped cross section which presses down over said flared ends, and draws them together.

Claim 9

The end-fitting of claim 5 wherein at least one of said parts is attached to a metal tube.

Claim 10

The end-fitting of claim 5 wherein said arch has a radius R1 described by the following formula: Where I.D. inside diameter of the beam C1 Constant proportional to t delta /E within the limits of 0 to 0.75-normally at 0.41 C2 Constant proportional to C1, theta /R1 within the limits of 0.50 to 0.75-normally at 0.571 C3 Constant proportional to R4 within the limits of 0.004 to 0.020-normally 0.008 R2 The radius R1 plus the thickness of the beam R3 The radius at the heel of the beam theta The travel of a beam during the tightening of the seal which is less than 20* .

Claim 11

The end-fitting of claim 9 wherein said beam is formed by an undercut region terminated by a constant radius R5, within the range of about 0.015 to 0.040 inch, the depth of said undercut region being the inside diameter of said beam plus said radius R5 multiplied by a constant within the range of 0.5 to 1.50.

Claim 12

The end-fitting of claim 10 wherein the beam has a thickness x described by the formula:

Claim 13

The end-fitting of claim 11 wherein said angle theta is about 8.5*.

Claim 14

A hard metal nipple for a braid covered hose fitting of the type having a barrel for insertion in the end of the hose and a portion for effecting a metal-to-metal seal with an independently secured fitting sleeve, said hose having an internal pressure, comprising an annular body, a barrel extending axially from said body on one side thereof, a concave annular flange having a bearing surface at the heel thereof, said flange forming a cavity exposed to the pressure in said hose, said bearing surface being formed with an arc curving oppositely to the arc of said concave flange on said one side of said body adjacent the outer margin thereof, and said annular flange having curved inner and outer surfaces with uniform thickness therebetween and being joined to said body at the inner margin of said bearing surface, said flange making an acute angle with the nipple axis, said flange being arched between said bearing surface and the inner margin of said flange with two concentric sealing areas, said inner margin terminating in a wear resistant contact area, whereby said flange is adapted to be flexed into a position along the projected surface of said bearing surface and resiliently engage a fitting sleeve to form said two concentric sealing areas therewith.

Claim 15

A hard metal nipple for a braid covered hose fitting of the type having a barrel for insertion in the end of the hose and a portion for effecting a metal-to-metal seal with an independently secured fitting sleeve, said hose having an internal pressure, comprising an annular body, a barrel extending axially from said body on one side thereof, a concave annular flange having a bearing surface at the heel thereof, said flange forming a cavity exposed to the pressure in said hose, said bearing surface being formed with an arc curving oppositely to the arc of said concave flange on said one side of said body adjacent the outer margin thereof, and said annular flange having curved inner and outer surfaces with uniform thickness therebetween and being joined to said body at the inner margin of said bearing surface, said flange making an acute angle with the nipple axis, said flange being arched between said bearing surface and the inner margin of said flange with two concentric sealing areas, said inner margin terminating in a wear resistant contact area, whereby said flange is adapted to be flexed into a position along the projected surface of said bearing surface and resiliently engage a fitting sleeve to form said two concentric sealing areas therewith.