Abstract:
A probe member for an undersea hydraulic coupling is disclosed having at least one circumferential depression in its outer cylindrical body, for disengaging one or more radial seals during insertion or withdrawal of the probe member from the receiving member of a coupling. The disengagement of the radial seals allows seawater to bleed from or into the space between the coupling members and thereby balance the coupling and seals to seawater pressure.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates, in general, to hydraulic couplings, and specifically to hydraulic couplings used in undersea drilling and production applications. More particularly, the invention involves a probe member for an undersea hydraulic coupling configured to balance the space between the male and female members to sea pressure. 
     2. Description of the Related Art 
     Subsea hydraulic couplings are old in the art. The couplings generally consist of a male and a female member with sealed fluid passageways connecting therebetween. The female member generally is a cylindrical body with a relatively large diameter longitudinal bore at one end and a relatively small diameter longitudinal bore at the other. The small bore facilitates connections to hydraulic lines, while the large bore seals and slidingly engages the male member of the coupling. The male member includes a cylindrical portion at one end having an outer diameter approximately equal to the diameter of the large bore in the female member of the coupling. The male member also includes a connection at its other end to facilitate connection to hydraulic lines. When the cylindrical portion of the male member is inserted into the large bore of the female member, according to various embodiments of the device, fluid flow is established between the male and female members. 
     Problems arise with the use hydraulic couplings in relatively high pressure systems due to the high axial forces imposed on the male and female members during their coupling operation and during their use. In such couplings, it is necessary for the fluid force opposing the face of the male or female member to be overcome before the fluid communication is established between the members. In a relatively high pressure system, a partial vacuum in the sealed space between the members when disconnecting the coupling members may cause the seal to be sucked out of its position between the members. Also, the seals between the members may result in a hydraulic lock when the coupling members are connected and/or disconnected, as sea water between the members cannot escape from the sealed cavity between the members, or, when the members are disconnected, a vacuum is formed therebetween. 
     Ideally, hydraulic couplings should, as far as possible, be pressure balanced, so that fluid pressure does not hinder connection or urge separation of the male and female members. Preferably, to prevent loss of fluid during coupling or uncoupling, the members should include valve means to open automatically on coupling and close automatically on uncoupling. Further, the coupling member should employ seals which can withstand high pressures as well as the corrosive effects of subsea environments. The present invention solves all of these needs and requirements. 
     SUMMARY OF THE INVENTION 
     The present invention resides in a probe member for a hydraulic coupling of the foregoing type, where the body member of the male member is configured to promote connection or disconnection of the coupling without hydraulic because of the sealed space between the members. The male member of the present invention allows sea water to bleed out between the members to balance the seals to sea pressure during connection or disconnection. In one embodiment, the body of the male member is provided with one or more concave depressions around its outer circumference. The concave depressions are axially spaced from each of the seals in the female member bore when the male member is fully inserted into the bore. When the male member is partially withdrawn from, or partially inserted into, the female member bore, the concave depressions disengage the corresponding seals and provide a space for bleeding sea water around the seals, through a gap between the male and female members. Thus, the concave depressions balance each seal to ambient pressure as the male is partially inserted, or partially removed from the female member bore. 
     Preferably, radially expanding metal seals are used to seal the annular space between the male and female members. Fluid pressure in the coupling urges the seals to expand radially to engage the receiving chamber wall and the circumference of the male member. The concave depressions are located axially in relation to each of the seals to simultaneously disengage each of the seals from the male member circumference as the members are disconnected. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a section view of the male member or probe according to a first embodiment of the present invention. 
     FIG. 2 is a section view of a female member that may be used with the male member of FIG. 1. 
     FIG. 3 is a section view of a portion of the male member fully inserted into the female member, according to the embodiment of FIG. 1. 
     FIG. 4 is a section view of a portion of the male member partially withdrawn from the female member, according to the embodiment of FIG. 1. 
     FIG. 5 is a section view of the male member or probe according to a second embodiment of the present invention. 
     FIG. 6 is a section view of a portion of the male member fully inserted into a female member, according to the embodiment of FIG. 5. 
     FIG. 7 is a section view of a portion of the male member partially withdrawn from the female member, according to the embodiment of FIG. 5. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a preferred embodiment of the present invention comprises a male member 10, or probe, which has an externally threaded handle 11, a flange 12, a tapered shoulder 13, a cylindrical probe wall 14, and a probe face 15. The cylindrical probe wall 14 is adapted for sliding engagement with a receiving chamber or bore in a female coupling member, as will be discussed below. 
     Male member 10 also is provided with a central bore 22, which may have several variations in its diameter as it extends through the body of the male member 10. In a preferred embodiment, the first end of the central bore comprises an internally threaded section 30 adapted for connection to a hydraulic line. Adjacent the threaded section is a cylindrical passageway 31 extending longitudinally within the male member body and terminating at valve seat 32 which is an inclined shoulder. Adjacent the valve seat is cylindrical passage 33 having a reduced diameter. 
     In the embodiment shown in FIG. 1, a valve assembly 43 is slidably received within cylindrical passageway 31 in the male member. The various parts of the valve assembly include a conical valve face 51 dimensioned to seat against valve seat 32, and a hollow cylindrical body section 52 having an outer diameter somewhat less than the diameter of cylindrical passageway 31. A helical valve spring 61 abuts the hollow cylindrical body section 52 to urge the valve face 51 into a closed position against valve seat 32. The helical valve spring is located within the cylindrical passageway and anchored at hollow spring collar 62 which is held in place by collar clip 63 at the inner surface of the cylindrical passageway of male member 10. When conical valve face 51 is in a closed position against the valve seat, the valve assembly seals off hydraulic fluid from flowing through the male member. 
     Shown in FIG. 2 is a female member 20 for use in accordance with the embodiment of the present invention of FIG. 1. The female member comprises an externally threaded handle 79, a body 80, a valve bore 81, a valve assembly 82, 15 and a receiving chamber 83. One or more radial seals 84, 85, 86 are positionable in the annular space between the male member and female member receiving chamber. The seals are held in place with seal retaining members 48, 49, 50. The receiving chamber may have several variations in its diameter, as it extends through the body of the female member. In a preferred embodiment of the present invention, the valve assembly 82 of the female member is substantially similar to the valve assembly 43 of the male member. 
     Preferably, the outer diameter of probe wall 14 is slightly smaller than the inner diameter of the seal retainers 48, 49, 50 located in the female member receiving chamber 83. One or more radial seals 84, 85, 86 may extend radially into the receiving chamber to engage the outer circumference of the probe wall as it is inserted therein. Additionally, one or more of the radial seals may be pressure energized by hydraulic fluid in the coupling to expand the inner circumference of the seal radially inwardly to sealingly engage the probe wall. 
     Probe wall 14 has one or more concave depressions 90, 91, 92 spaced apart around its outer circumference. Preferably, the concave depressions are 0.020 inches in depth from the male member body. For example, in one embodiment of the present invention, the radius of the male member probe wall is 0.645 inches, while the radius of the probe wall at each concave depression is 0.625 inches. 
     When the male member is inserted into the receiving chamber, concave depressions 90, 91, 92 move past the seals. When a concave depression is aligned with a seal, sea water escapes from the receiving chamber through the space created between the concave depression and seal. Thus, the radial seals, in various positions in the receiving chamber, disengage the probe wall when the concave depressions are aligned with the seals, as shown in FIG. 4. The concave depressions allow passage of sea water into or out from the the receiving chamber, to avoid any hydraulic lock between the male and female members. When the male member is fully inserted into the receiving chamber, as shown in FIG. 3, the seals are engaged with the probe wall, as the concave depressions are axially spaced from the seals. 
     In a preferred embodiment, radial seals 84, 85 are pressure-energized hollow metal seals. These seals are retained in the annulus between the male and female members by an inner retainer 48 and an intermediate retainer 49. Retainers 48, 49 may be held in place with a clip or an outer retainer 50 that is threaded to the female member receiving chamber. Optionally, a backup seal 86, which preferably is an elastomeric seal with a dovetail shape, may be used between the intermediate retainer 49 and the outer retainer 50. 
     A second embodiment of the present invention shown in FIGS. 5-7 includes a male member 17 having a probe wall 18 with a stepped outer circumference. The stepped outer circumference has two or more, and preferably four separate diameters 26, 27, 28, 29 with outer shoulders 36, 37, 38 between each diameter. The stepped outer circumference allows passage of sea water into or out from the receiving chamber during insertion or withdrawal of the male member from the receiving chamber of the female member. Further, the stepped body may have one or more concave depressions therein. 
     A female member for use with the second embodiment includes radial seals 56, 57, 58 and seal retainers 52, 53, 54. Preferably, radial seals 56, 57 are hollow, pressure energized metal seals, and radial seal 58 is an elastomeric seal having a dovetail interfit between retainers 53 and 54. 
     The retainers and seals of the second embodiment of the invention are dimensioned to sealingly engage the probe wall when the male member is fully inserted into the receiving chamber, as shown in FIG. 6. During insertion or withdrawal of the male member from the receiving chamber, each of the seals is disengaged to allow sea water to bleed past the seals to or from the receiving chamber, as shown in FIG. 7. 
     Although variations in the embodiment of the present invention may not each realize all the inventions of the invention, certain features may become more important than others in various applications of the device. The invention, accordingly, should be understood to be limited only by the scope of the appended claims.