Abstract:
An undersea hydraulic coupling member is disclosed having recessed flow passages to facilitate connection to opposing coupling members having radial, angled or longitudinal flow passages. The recessed flow passages of the coupling member permit these connections without reduced hydraulic fluid flow.

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, this invention involves a female hydraulic coupling member having recessed flow passages that facilitate connection to male coupling members. 
     2. Description of Related Art 
     Subsea hydraulic couplings are old in the art. The couplings generally consist of a male member 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 of 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. Couplings of this type are shown in U.S. Pat. No. 4,694,859 to Robert E. Smith, III and other patents owned by National Coupling Company, Inc. of Stafford, Tex. 
     In undersea drilling and production applications, the male member of the coupling may be connected to a manifold plate or other securement at a subsea location at the inside or outside of a well bore. The female members, which also may be secured to a manifold plate, are moved into position over the male members and then lowered onto the male members by a diver or subsea vehicle. When the female members are positioned on the male members, hydraulic fluid flow typically is from the female member to the male member of each coupling. In some cases, only the female member of the coupling has a poppet valve. 
     The poppet valve typically includes a conical valve face which seats, in the closed position, against a valve seat in the coupling member. The poppet valve opens to allow fluid flow, and closes against the valve seat within the bore to arrest the flow. Generally, the poppet valve is spring-biased to the closed position. The valve may include a valve actuator which may be a nose or stem extending from the apex of the valve face along the longitudinal axis of the poppet valve. 
     In the couplings of U.S. Pat. No. 4,694,859, for example, hydraulic fluid flows longitudinally between the male and female coupling members. A number of different improvements and variations have been introduced in the configuration of flow ports and flow passages in couplings used for undersea applications. Some undersea hydraulic couplings are pressure balanced, for example, which may be achieved by hydraulic flow through aligned radial flow passages in the coupling members. The radial flow passages are generally perpendicular to the longitudinal axis of the coupling, so hydraulic pressure tending to separate the coupling members is significantly reduced. In the male coupling members, radial passages typically extend from the central bore outward to the cylindrical outer surface of the probe. Examples of pressure balanced couplings are shown in U.S. Pat. Nos. 4,754,780, 5,099,882, and 4,832,080 to Robert E. Smith III, assigned to National Coupling Company, Inc. 
     Male undersea hydraulic coupling members also may include flow ports that are angled to prevent ingress of debris when the coupling members are disconnected. Frequently, well bores in which the couplings are positioned are full of debris. The male member, which remains subsea when the coupling is disconnected, is subject to debris accumulating in flow passages. The debris may contaminate the hydraulic fluid or cause wear to the seals and sealing surfaces in hydraulic couplings and hydraulic systems. To reduce or eliminate this problem, couplings such as those of U.S. Pat. No. 5,692,538 to Robert E. Smith, III have utilized angled flow ports that prevent ingress of debris into the hydraulic lines. 
     In the past, each of these male coupling members could be effectively connected only to certain female coupling members. For example, pressure balanced male coupling members with radial flow passages could only be connected to female coupling members having matching radial flow passages. Male coupling members with angled flow ports could be connected to conventional female coupling members configured for longitudinal flow of hydraulic fluid, but hydraulic flow between the angled flow passages, through the annulus between the male and female members, and the female member, was somewhat reduced. Accordingly, a female coupling member is needed to be connectable to a variety of different male coupling members without significant reduction in the flow of hydraulic fluid or other performance degradation. 
     SUMMARY OF THE INVENTION 
     The present invention resides in a female undersea hydraulic coupling member having recessed flow passages to facilitate flow of hydraulic fluid with male coupling members having flow passages that are either longitudinal, radial or angled. The recessed flow passages in the female coupling member allow interconnection with various different male member flow passage configurations without significant reduction in volume or flow rates. The recessed flow passages are machined in the body section of the female member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein. 
     FIG. 1 is a section view of a female member of a coupling according to a preferred embodiment of the present invention. 
     FIG. 2 is an expanded section view of a recessed flow passage in a female member of a coupling according to a preferred embodiment of the present invention, with a male coupling member inserted therein. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in FIG. 1, female coupling member  20  includes body section  21  with a first end  62  and second end  63 . The second end of the female member may be threaded for attachment to a manifold plate. The female member has a central bore  41  from the first end to the second end thereof. Adjacent the first end of the female member is the receiving chamber  43 . The female member typically includes one or more seals in the receiving chamber for engagement with the probe section of the male member. As shown in FIG. 1, metal radial seal  26  is held on shoulder  58  in the receiving chamber by seal retainer  23  which is a sleeve-shaped member that is inserted into the receiving chamber. The seal retainer may have a stepped internal diameter  68  with an internal shoulder  33  between the steps. The seal retainer may be locked in the female member by lock ring  35  which has threads  24  for engagement with mating threads of the female member. An additional seal, preferably elastomeric dovetail seal  22  may be included between the seal retainer and lock ring. Additionally, O-ring seal  25  can be used to seal the junction between the seal retainer and internal shoulder  19  in the female member. 
     The second section  34  of the central bore is adjacent and inboard from shoulder  58 . The second section  34  of the bore and the internal diameter  68  of the seal retainer are dimensioned to allow sliding interfit with the probe section of a male coupling member. 
     Valve bore  39  is the section of the central bore adjacent the second end of the female member. The valve bore holds poppet valve  29 . In the closed position, conical valve face  27  seals against valve seat  28 . Valve spring  38  urges the poppet valve into the closed position. Spring collar  37  anchors the valve spring, and is held in place by snap ring or clip  40 . The female member poppet valve slides within valve bore  39  in the female member. Extending from the apex of the conical valve face of the female member is valve actuator  42  which engages the corresponding valve actuator of the male member to urge the valves of both members into the open position. 
     The recessed flow passages  42  of the present invention are in the central bore between the second section  34  and the valve bore  39 . The recessed flow passages are dimensioned between {fraction (1/16)} and ¼ inch greater in radius than the second section of the central bore. In the embodiment of FIGS. 1 and 2, the recessed flow passages form a single annular passage between the second section of the central bore and the valve bore of the female member. 
     Now referring to FIG. 2, male member  10  includes first end or leading face  49  of probe  50 . The probe section terminates at flange  16 . Only the probe section of the male member enters the receiving chamber in the female member of the coupling, and the flange limits further entry of the male member into the receiving chamber. Flow passages  22  may extend from the male member&#39;s internal bore to the outer circumference of the male member. The flow passages in the male coupling member may be radial or may be angled to prevent ingress of debris when the female member is disconnected and the male member remains subsea. Alternatively, the male coupling member may have longitudinal passages wherein the flow of hydraulic fluid is through the leading face. 
     The probe may have a stepped outer diameter, preferably first diameter  11  and second diameter  12  which is larger than the first diameter. The radial metal seal engages the first diameter of the male member and the elastomeric dovetail seal engages the second diameter. Shoulder  13  between the first and second diameters abuts shoulder  33  in the seal retainer. 
     When the male member is fully inserted into the female member, there is a gap  14  between the leading face  49  of the male member and internal shoulder  18 . There also is a gap between the outer circumference of the probe and the internal diameter  70  of the recessed flow passage section of the central bore. These gaps provide the recessed flow passages  41  which are the subject of this invention. Preferably, the gaps are between {fraction (1/16)} inch and ¼ inch measured in radius. These gaps directly in front of and around the leading face of the male member are referred to and defined in this application as recessed flow passages  42 . 
     In a preferred embodiment of the present invention, the recessed flow passages form a single annulus between the leading face of the probe section and the female member bore. Alternatively, multiple recessed flow passages may be used. Each of the recessed flow passages extend between first internal shoulder  17  and second internal shoulder  18 . 
     Accordingly, the present invention provides a female undersea hydraulic coupling member having recessed flow passages to facilitate connection with male coupling members with various flow ports and flow passages. An advantage of the present invention is that it allows higher flow rates in couplings with radial or angled flow passages. 
     Although variations in the embodiment of the present invention may not each realize all of the advantages 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.