Abstract:
Male and/or female members of a hydraulic coupling have an internal poppet valve that is held in the closed position by a flat wire, helical compression spring. The spring is configured such that when the poppet valve is moved to its fully open position, the coils of the spring are completely compressed thereby forming a substantially smooth bore tube for the flow of hydraulic fluid. The flat wire, helical compression spring may also act as a valve stop, limiting movement of the poppet valve and providing the necessary resistance to move the valve actuator of a corresponding valve in a mating member.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    NONE 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    NOT APPLICABLE 
       BACKGROUND OF THE INVENTION 
       [0003]    1. Field of the Invention 
         [0004]    This invention relates to hydraulic coupling members. More particularly, it relates to male and female hydraulic coupling members having internal, spring-loaded poppet valves for controlling the flow of hydraulic fluid. 
         [0005]    2. Description of the Related Art Including Information Disclosed under 37 CFR 1.97 and 1.98 
         [0006]    A wide variety of hydraulic couplings include internal poppet valves for preventing the loss of hydraulic fluid when the coupling is disconnected. Hydraulic couplings designed for subsea use also commonly employ poppet valves for preventing seawater from entering the hydraulic system when the coupling members are de-mated. In many designs, the poppet valves include mechanical valve actuators which cause valves that are spring-loaded to the closed position to open upon coupling make-up. 
         [0007]    U.S. Pat. Nos. 4,900,071 and 5,052,439 disclose an undersea hydraulic coupling which includes a male member and female member, and a two-piece retainer for restraining radial movement of a wedge-shaped annular seal into the central bore of the female member. The two-piece retainer includes a cylindrical retainer sleeve member that slides within the female member bore, and a threaded retainer-locking member which engages threads in the wall of the central bore. The retainer-locking member holds the retainer sleeve member in place within the female member bore. The annular seal is restrained from radial movement by a dovetail interfit with a mating shoulder on at least one of the retainer sleeve and the retainer-locking members. 
         [0008]    U.S. Pat. No. 5,360,035 discloses an undersea hydraulic coupling having a poppet valve movable between an open and a closed position. The poppet valve is pressure balanced—i.e., it operates without substantial fluid pressure exerted axially against the face of the poppet valve. When the poppet valve is opened, radial passages are interconnected through an annular cavity between the poppet valve body and the valve bore. 
         [0009]    U.S. Pat. No. 5,692,538 discloses an undersea hydraulic coupling member having angled flow ports to prevent ingress of debris into the hydraulic lines and having a bleed passage to allow trapped hydraulic fluid to bleed off when the coupling members are disconnected. The poppet valve in combination with the angled flow ports helps keep the hydraulic system clear of debris when the members are disconnected. 
         [0010]    U.S. Pat. No. 6,085,785 discloses an undersea hydraulic coupling having an extended probe section. The male member of the coupling houses a valve spring having a larger diameter than the diameter of the valve body. The valve spring is configured to close the valve to prevent ingress of sea water or leakage of hydraulic fluid from the system. One or more seals engage the extended probe section. 
         [0011]    U.S. Pat. No. 6,095,191 discloses an undersea hydraulic coupling having a male member with a tapered, frusta-conical surface and a female member with a tapered, frusta-conical bore. Before radial seals engage the frusta-conical surfaces, trapped seawater is expelled or displaced from the bore through the space between the coupling members, thereby preventing seawater from entering hydraulic lines. 
         [0012]    U.S. Pat. No. 6,474,359 discloses an undersea hydraulic coupling member having a bleed valve which opens to allow hydraulic fluid trapped in the coupling member to escape until the pressure is below a predetermined level. The coupling member employs a poppet valve within a sleeve. 
         [0013]    U.S. Pat. No. 6,375,153 discloses an undersea hydraulic coupling having a stepped internal bore dimensioned to increase the flow rate through the coupling. The coupling allows an increased flow rate without increasing the size or weight of the coupling by positioning the poppet valve in the body section, rather than in the probe section, of the male coupling member. 
         [0014]    U.S. Pat. No. 6,237,632 discloses an undersea hydraulic coupling member having a primary poppet valve and a secondary poppet valve to improve reliability against leakage when the coupling members are separated. A spring extends between the first poppet valve and the actuator for the second poppet valve. The secondary poppet valve remains closed unless the first poppet valve is fully opened, so that debris or other material that could prevent sealing of the first poppet valve will not cause leakage of hydraulic fluid through the second poppet valve. 
         [0015]    U.S. Pat. No. 6,357,722 discloses an undersea hydraulic coupling having a poppet valve with an actuator extending from the valve and a guide between the actuator and bore. The guide is a sleeve-shaped member around the actuator with flow passages which ensure a smooth flow of hydraulic fluid through the annulus between the coupling bore and actuator. The guide also helps prevent damage to the actuator, and aligns the actuator during connections, disconnections and use. 
         [0016]    U.S. Pat. No. 6,283,444 discloses an undersea hydraulic coupling member having a valve actuator which extends through the probe section and the leading face, and has angled flow ports in the probe section which help keep the hydraulic system clear of debris when the coupling members are disconnected subsea. 
         [0017]    U.S. Pat. No. 6,227,245 discloses an undersea hydraulic coupling member which has angled flow ports to prevent ingress of debris into the hydraulic lines. A port guard attached to the valve actuator closes the flow ports unless the poppet valve is opened by mutual engagement with an opposing coupling member. 
         [0018]    U.S. Pat. No. 6,626,207 discloses an undersea hydraulic coupling with interlocking poppet valve actuators. The actuators extend from the poppet valves of each coupling member and interlock to resist bending and/or other lateral displacement caused by hydraulic fluid flow and turbulence in the coupling member bores and at the junction between the coupling members. 
         [0019]    U.S. Pat. No. 6,631,734 discloses a dummy undersea hydraulic coupling member for protecting an opposing undersea hydraulic coupling member when the hydraulic lines are not operating. The dummy undersea hydraulic coupling member has a water displacement expansion chamber with a piston therein that allows trapped water and/or air to move from the receiving chamber to the water displacement expansion chamber during connection of the dummy coupling member to the opposing coupling member. The dummy coupling member may include a normally-closed poppet valve in the water displacement expansion chamber which blocks water and/or air from moving between the receiving chamber and the water displacement expansion chamber in the closed position. The poppet valve opens in response to water and/or air pressure acting upon it. 
         [0020]    U.S. Pat. No. 7,159,616 discloses a dual-path hydraulic coupling. A female hydraulic coupling member comprises a first flow port; a second flow port; a third flow port in fluid communication with both the first flow port and the second flow port; a first poppet valve for opening and closing the first flow port; and a second poppet valve for opening and closing the second flow port, the second poppet valve being connected to the first poppet valve such that the second poppet valve moves to the closed position when the first poppet valve is open and moves to the open position when the first poppet valve is closed. 
       BRIEF SUMMARY OF THE INVENTION 
       [0021]    A spring-loaded poppet valve within a hydraulic coupling member has a helical, flat wire spring that, when compressed, forms a smooth bore cylinder for the passage of hydraulic fluid and may act as a mechanical stop for the poppet valve travel. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0022]      FIG. 1  is a cross-sectional view of a hydraulic coupling whose members are equipped with poppet valves of the prior art. 
           [0023]      FIG. 2  is a cross-sectional view of a female hydraulic coupling member equipped with a poppet valve according to the invention shown in the closed position. 
           [0024]      FIG. 3  is a cross-sectional view of a female hydraulic coupling member installed in a mounting plate and equipped with a poppet valve according to the invention shown in the open position. 
           [0025]      FIG. 4  is a cross-sectional view of a male hydraulic coupling member equipped with a poppet valve according to the invention shown in the closed position. 
           [0026]      FIG. 5  is a cross-sectional view of a male hydraulic coupling member equipped with a poppet valve according to the invention shown in the open position. 
           [0027]      FIG. 6  is a cross-sectional view of connected male and female hydraulic coupling members each of which is equipped with a poppet valve according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    As shown in  FIG. 1 , in a coupling of the prior art, female member  20  comprises body  21 , handle  48  which may be threaded to a manifold plate, and central bore  32  which has several variations in its diameter as it extends through the female member. The first end of the bore may be internally threaded for connection to a hydraulic line. Other connection means known in the art may be utilized including welding, swaging, compression fittings, and the like. A cylindrical passageway extends longitudinally within the female member body and terminates at valve seat  27 . Adjacent valve seat  27  is shoulder  33  which forms one end of receiving chamber  34 . 
         [0029]    In the coupling illustrated in  FIG. 1 , the receiving chamber which receives the probe of the male member has a stepped internal diameter with internal shoulders  33 ,  35  and  63 . The receiving chamber has a first smaller diameter  43  and a second larger diameter  47 . 
         [0030]    The female member  20  may include optional poppet valve  28  which is sized to slide within the cylindrical passageway. The poppet valve may be conical in shape and is urged by valve spring  41  into a seated position against valve seat  27 . When the poppet valve is in a closed position against the valve seat, it seals fluid from flowing between the male member and the female member. Hollow spring seat  42  anchors the valve spring  41  and is held in place by clip  45 . Actuator  44  extends from the apex of the poppet valve. 
         [0031]    Ring shaped seal  50  is positioned in the receiving chamber of the female member. The ring shaped seal may be an elastomer or other polymer seal that is flexible and resilient. In other couplings of the prior art, seal  50  is fabricated from an engineering plastic such as polyetheretherketone (PEEK). Seal  50  has a first inclined shoulder surface  52  and a second inclined shoulder surface  51 . The axial thickness of the elastomeric seal at its outer circumference (adjacent element  69  in  FIG. 1 ) is greater than the axial thickness of the seal at inner circumference  67 . The seal thus has a generally wedge-shaped cross section. Seal  50  may have one or more radial sealing surfaces  55 ,  56  extending inwardly from the seal&#39;s inner circumference  67 . Each of the radial sealing surfaces extends inwardly from the inner circumference so as to engage the probe of the male member when the probe is inserted through the seal. The radial sealing surfaces may be elastically deformed by the probe when it is inserted through the seal. The radial sealing surfaces  55  and  56  provide guide points to help align and guide the probe of the male member when it is inserted through the seal and into the receiving chamber  34 . 
         [0032]    In the prior art female coupling member illustrated in  FIG. 1 , probe seal  50  has grooves in its outer circumference  66 . O-rings  57 ,  58  or similar seals may be positioned in each of the grooves. Alternatively, seal  50  may have a plurality of integral sealing projections which extend from its outer circumference. 
         [0033]    In the female coupling member shown in  FIG. 1 , implosion of the seal into the receiving chamber due to low pressure or vacuum is resisted because the seal has an interlocking fit with reverse inclined shoulder surface  62  of seal retainer  29  and reverse inclined shoulder surface  61  of locking member  30 . The seal retainer may be a cylindrical sleeve that slides into the second diameter  47  of the receiving chamber. Alternatively, the seal retainer may be threaded to the female member or engaged to the female member by other means. In the illustrated coupling, when the seal retainer is fully engaged with the female member, first end  46  of the seal retainer abuts shoulder  63 . The seal retainer holds hollow radial metal seal  31  on internal shoulder  35 . 
         [0034]    In the illustrated female coupling member, the seal retainer has a first internal circumferential surface  59  adjacent the first end thereof and a second internal circumferential surface  69  adjacent the second end thereof. The internal diameter of the first inner circumferential surface is smaller than the internal diameter of the second internal circumferential surface. Reverse inclined shoulder  62  is situated between the first and second internal circumferential surfaces. The reverse inclined shoulder has an interlocking fit with seal  50  to restrain the seal from moving inwardly in a radial direction. O-ring  49  is positioned in a groove at the first end  46  of the seal retainer to provide a face-type seal between the seal retainer and shoulder  63 . 
         [0035]    In the illustrated prior art coupling, locking member  30  engages the female coupling member with threads  53 . Other engaging means known in the art may be used. When the locking member is fully secured to the female coupling member, first end  64  abuts seal retainer  29  and holds the seal retainer in place. The locking member  30  has a central opening with an internal diameter  54  that allows insertion of the probe of the male member. Reverse inclined shoulder surface  61  holds seal  50  in place and restrains the seal from moving inward in a radial direction. 
         [0036]    The present invention provides an alternative poppet valve design and may best be understood by reference to the exemplary embodiment shown in the drawing figures. 
         [0037]      FIG. 2  depicts a female hydraulic coupling member  100  equipped with a poppet valve according to the present invention. The probe seals  150  and  131  and receiving chamber  134  of female coupling member  100  are similar to those of the prior art coupling illustrated in  FIG. 1 . Coupling  100 , however, has a seal cartridge comprised of seal retainer  129  and locking shell  130 . A seal cartridge of this type is disclosed in U.S. Pat. No. 7,163,190 to Robert E. Smith, III. The seal cartridge retains probe seal  150  with a dovetail interlocking fit and optional O-rings  157  and  158  ensure a fluid-tight seal between probe seal  150  and seal retainer  129 . The seal cartridge is held within the body of the female member  100  by threaded portion  153  which engages corresponding threads on the interior distal portion of receiving chamber  134 . Spanner holes  136  in locking member  130  receive a tool for facilitating the installation and removal of the seal cartridge. As in the coupling of  FIG. 1 , seal retainer  129  also retains metal seal  131  on an internal shoulder of receiving chamber  134  and O-ring  149  (housed in a groove in a second shoulder within receiving chamber  134 ) provides a seal between retainer  129  and the body of female coupling  100 . 
         [0038]    Female coupling member  100  has a generally cylindrical body  120  with a central bore  132  having sections of various internal diameter. The portion of body  120  distal from the end having receiving chamber  134  forms handle  148  which may be used to secure coupling  100  in a manifold plate or other such holding device. Clip  139  may engage an external groove on handle  148  to secure thrust washer  141 . As shown in  FIG. 3 , coupling  100  may be mounted in a manifold plate P with shoulder  160  bearing against a first surface thereof and thrust washer  141  bearing against an opposing surface. One end of bore  132  has connector  138  for connecting the coupling to a hydraulic line. Connector  138  may be internally or externally threaded, or the connection may be made by welding, swaging, compression fittings or other means well known in the art. 
         [0039]    A portion of bore  132  may have beveled portion  127  to serve as a seat for poppet valve  128 . In the illustrated embodiment, poppet valve  128  is comprised of valve actuator  144 , spring contactor  180 , poppet seal  170 , radial flow passages  174 , valve spring  140  and valve seat  142 . 
         [0040]    Valve seal  170 , which may be an elastomer or other suitable material, is held between frustum portion  176  of actuator  144  and poppet body  180 . In the illustrated embodiment, one end of actuator  144  is held within body  180  by flaring at cavity  165 . When poppet valve  128  is in the closed position, seal  170  is pressed against beveled surface  127  by the action of compression spring  140 . The flow of hydraulic fluid out of the coupling and seawater into the coupling is thereby prevented when the coupling is disconnected. 
         [0041]    Helical compression spring  140  is formed of flat wire and preferably has an outside diameter slightly smaller than inner diameter  137  of bore  132  to permit spring  140  to compress without binding against the walls of bore  132 . The ends of spring  140  may be closed &amp; ground or open &amp; ground. 
         [0042]    Spring  140  may be formed of any suitable material. Examples of suitable materials include, but are not limited to: spring steel, stainless steel, silicon-chrome, high carbon steel, beryllium-copper, INCONEL® alloys, galvanized wire, mild steel, phosphor bronze and brass. 
         [0043]    At one end, spring  140  acts against spring seat  142  which is retained in bore  132  by retainer clip  145  which may engage a groove in the wall of bore  132 . The internal diameter of spring seat  142  is preferably the same as internal diameter of spring bore  178  when spring  140  is fully compressed. Likewise, the internal diameter  172  of spring contactor  180  is preferably the same as the i.d. of spring bore  178 . 
         [0044]      FIG. 3  shows female coupling member  100  with its poppet valve in the open position. The action of poppet valve  128  is as follows: when coupling  100  is connected to a corresponding male coupling member ( 200 ), valve actuator  144  contacts a corresponding actuator in the male member compressing spring  140  and opening poppet valve  128  by moving seal  170  off of seat  127 . Hydraulic fluid may then flow from receiving chamber  134  past seat  127  and into annular flow passage  182 . From thence the flow is through radial flow ports  174  and into the hollow central cavity of poppet body  128 . When spring  140  is fully compressed, its helical coils contact one another thereby forming a substantially smooth bore tube. This facilitates the flow of hydraulic fluid through the coupling member. In couplings of the prior art such as those illustrated in  FIG. 1 , the round wire valve spring  40  provides a rough inner surface which may hinder the flow of hydraulic fluid. 
         [0045]    It will also be appreciated that when fully compressed flat wire spring  140  provides a load path extending from actuator  144  through poppet body  128  to spring seat  142  which is fixed by retainer clip  145 . This feature enables spring seat  142  to be smaller than those of the prior art since flat wire spring  140  is less susceptible to buckling out of column when fully compressed than a round wire spring. As shown in  FIG. 1 , spring seat  42  of the prior art is equipped with an extension for ensuring positive contact with poppet valve body  28  when spring  40  is compressed. This is unnecessary in a coupling according to the present invention and enables a coupling of a fixed size to have larger internal flow passage for hydraulic fluid. 
         [0046]      FIG. 4  depicts a male hydraulic coupling member  200  equipped with a poppet valve according to the present invention. Male coupling member  200  has a generally cylindrical body  221  with a central bore  232  having sections of various internal diameter. At one end of body  221  is male probe  234  for insertion into the receiving chamber of a corresponding female member ( 100 ). The portion of body  220  distal from probe  234  forms handle  248  which may be used to secure coupling  200  in a manifold plate or other such holding device. One end of bore  232  has connector  238  for connecting the coupling to a hydraulic line. Connector  238  may be internally or externally threaded, or the connection may be made by welding, swaging, compression fittings or other means well known in the art. 
         [0047]    A portion of bore  232  may have beveled portion  227  to serve as a seat for poppet valve  228 . In the illustrated embodiment, poppet valve  228  is comprised of valve actuator  244 , spring contactor  280 , poppet seal  270 , radial flow passages  274 , valve spring  240  and valve seat  242 . 
         [0048]    Valve seal  270  which may be an elastomer or other suitable material is held between frustum portion  276  of actuator  244  and poppet body  280 . When poppet valve  228  is in the closed position, seal  270  is pressed against beveled surface  227  by the action of compression spring  240 . The flow of hydraulic fluid out of the coupling and seawater into the coupling is thereby prevented when the coupling is disconnected. 
         [0049]    Helical compression spring  240  is formed of flat wire and preferably has an outside diameter slightly smaller than inner diameter  237  of bore  232  to permit spring  240  to compress without binding against the walls of bore  232 . The ends of spring  240  may be closed &amp; ground or open &amp; ground. 
         [0050]    Spring  240  may be formed of any suitable material. Examples of suitable materials include, but are not limited to: spring steel, stainless steel, silicon-chrome, high carbon steel, beryllium-copper, INCONEL® alloys, galvanized wire, mild steel, phosphor bronze and brass. 
         [0051]    At one end, spring  240  acts against spring seat  242  which is retained in bore  232  by retainer clip  245  which may engage a groove in the wall of bore  232 . The internal diameter of spring seat  242  is preferably the same as internal diameter of spring bore  278  when spring  240  is fully compressed. Likewise, the internal diameter  272  of spring contactor  280  is preferably the same as the i.d. of spring bore  278 . 
         [0052]      FIG. 5  shows male coupling member  200  with its poppet valve in the open position. The action of poppet valve  228  is as follows: when coupling  200  is connected to a corresponding female coupling member ( 100 ), valve actuator  244  contacts a corresponding actuator in the male member compressing spring  240  and opening poppet valve  228  by moving seal  270  off of seat  227 . Hydraulic fluid may then flow from the receiving chamber of the female member ( 100 ) into opening  286  on the leading face of probe  234  and into annular probe flow passage  284  past seat  227  and into annular flow passage  282 . From thence the flow is through angled flow ports  275  and into the hollow central cavity of poppet body  228 . When spring  240  is fully compressed, its helical coils contact one another thereby forming a substantially smooth bore tube. This facilitates the flow of hydraulic fluid through the coupling member. In couplings of the prior art such as those illustrated in  FIG. 1 , the round wire valve spring  40  provides a rough inner surface which may hinder the flow of hydraulic fluid. 
         [0053]    It will also be appreciated that when fully compressed flat wire spring  240  provides a load path extending from actuator  244  through poppet body  228  to spring seat  242  which is fixed by retainer clip  245 . This feature enables spring seat  242  to be smaller than those of the prior art since flat wire spring  240  is less susceptible to buckling out of column when fully compressed than a round wire spring. As shown in  FIG. 1 , spring seat  42  of the prior art is equipped with an extension for ensuring positive contact with poppet valve body  28  when spring  40  is compressed. This is unnecessary in a coupling according to the present invention and enables a coupling of a fixed size to have larger internal flow passage for hydraulic fluid. 
         [0054]    Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.