Abstract:
A female coupling member of a pipe coupling is provided which has a fluid passage and a vale therein. The fluid passage is separated by the valve into a first-end side adapted to be connected to a conduit and a second-end side adapted to be connected to a male coupling member. The valve is moveable between an open position for permitting a fluid to flow between the first-end side and the second-end side, and a closed position for blocking the flow of fluid. The valve is provided with a purge flow path that allows the second end side of the fluid passage to communicate with the outside when the valve is in the closed position, and that blocks the communication between the fluid passage and the outside when the valve is in the open position. Thus, the present invention simplifies the purge mechanism of the female coupling member which releases the fluid pressure remaining within the fluid passage when the valve is in the closed position.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a pipe coupling, and more specifically relates to a pipe coupling that has a small number of parts, is easy to assemble and is provided with simplified flow adjustment and residual pressure removal functions.  
         [0003]      FIG. 15  is a longitudinal cross section of a female coupling member of a conventional type of this pipe coupling, where  FIG. 16  is a side view of this coupling member.  
         [0004]     2. Description of the Background Art  
         [0005]     This female coupling member is provided with a coupling body  110  that has a fluid passage  114 , such that it is inserted into and connected to a male coupling member (not shown) at the right side when seen in the drawing.  
         [0006]     The coupling body  110  has a valve mechanism  111  provided with a valve  113  that opens or closes the fluid passage  114 , a connecting mechanism  116  that maintains the state of connection to the male coupling member, and a fluid pressure purging mechanism  118  provided with a purge passage  119  for purging the fluid pressure within the fluid passage  114  in the interior of the male coupling member.  
         [0007]     The valve  113  is spherical overall, being supported by valve seats  113   a ,  113   a . When this valve is in the position shown in the drawing, the valve hole  113   b  provided thereon is turned away from the fluid passage  114 , so the valve is closed. When the valve is rotated by 90° from the position shown in the drawing, the valve hole is aligned to the fluid passage  114  so the valve is open. Thus, it is possible to adjust the flow of the fluid flowing through the fluid passage by adjusting the rotary position of the valve.  
         [0008]     The connecting mechanism  116  has a locking member (locking ball)  115  and a sleeve  117 . The locking member engages an engaging groove on the outside surface of the male coupling member inserted into the interior of the male coupling member, thus securing (locking) the male coupling member to the female coupling member. The sleeve  117  is able to move between a position that permits the locking member  115  to assume a position on the outside in the radial direction (unlocked position) shown in the drawing, and a position that holds the locking member from the outside in the radial direction, when the male coupling member is inserted into the interior of the female coupling member while pushing in the locking member support member  120 , and when the locking member  115  engages the engaging groove of the male coupling member and moves to the inside position in the radial direction (locked position), thus moving toward the right side from the illustrated position.  
         [0009]     The purge mechanism has a sleeve  121   b  that contacts the sleeve  117  of the connecting mechanism. A pair of sealing rings  121   a  provided on the inside surface of the sleeve  121   b  are positioned on either side of the outlet of the purge passage  119  on the outside in the radial direction, and are able to move between a position that blocks the fluid pressure within the fluid passage  114  from being released into the outside, and a position to the left of this position, which is a position that permits the fluid pressure within the fluid passage  114  to pass through a gap S between the sleeve  117  and coupling body  110  and be released outside.  
         [0010]     The valve mechanism  111  is provided with a cam  112  that rotates together with the valve, and this cam controls the connecting mechanism  116 , sealing ring support  118  and this valve mechanism. When the valve  113  is in the closed state as illustrated in the drawing, the connecting mechanism  111  is such that the locking member  115  is in the outside position in the radial direction (unlocked position), thus permitting the male coupling member to be inserted into or withdrawn from the female coupling member, and also the purge mechanism  118  allowing the fluid pressure from the fluid passage  114  to be released into the outside. In this state, the sleeve  117  engages the locking member  115 , so the valve cannot be rotated (namely, the cam cannot move the sleeve  121   b  and sleeve  117  to the right). If the male coupling member is inserted in this state, the locking member  115  can be moved to the inside position in the radial direction (unlocked position), and if the valve  113  is rotated to the open state, the cam  112  pushes the sleeve  121   b  and sleeve  117  so that the purge passage  119  of the purge mechanism  118  is blocked by the sealing rings  112   a ,  112   a , and at the same time, the sleeve  117  secures the locking member  115  in the locked position. Conversely, when the valve  113  is returned to the closed state, the sleeve  121   b  is moved to the left by a spring  124  located between it and the sleeve  117  and returned to the position of  FIG. 15 , so the fluid pressure within the fluid passage can be released through the purge mechanism  118  and the connection to the male coupling member can be released.  
         [0011]     These mechanisms are intended to maintain safety during the connection and disconnection of the male coupling members, but their structure is complex and they have various accompanying problems.  
         [0012]     There are couplings that have similar structures used on supply lines for high-pressure fluids, but in this case, valves are provided on both the fluid intake-side end and fluid discharge-side end (male coupling member connection side) of the fluid passage of the male coupling member, but the structure becomes even more complex (see Japanese Patent No. 2694302, for example).  
       SUMMARY OF THE INVENTION  
       [0013]     The present invention was made in consideration of the aforementioned problems with conventional pipe couplings.  
         [0014]     The present invention provides a female coupling member in a pipe coupling having a female coupling member and a male coupling member that is inserted into and connected to the female coupling member, where  
         [0015]     the female coupling member comprises:  
         [0016]     a fluid passage that has a first end for connecting to a conduit and a second end for connecting to the male coupling member, and  
         [0017]     a valve, provided within the fluid passage, that is moveable between an open position that permits the flow of a fluid between the first-end side and the second-end side of the fluid passage, and a closed position that blocks the flow of fluid, and  
         [0018]     wherein,  
         [0019]     the valve is provided with a purge flow path that allows the second-end side of the fluid passage to communicate with the outside when the valve is in the closed position, and that is closed when the valve is in the open position.  
         [0020]     This female coupling member has the purge flow path provided in the valve body of the valve, so the fluid pressure remaining within the fluid passage is released by merely moving this valve from the open state to the closed state, so operation is simplified and the structure of the female coupling member is also simplified.  
         [0021]     This female coupling member more specifically comprises:  
         [0022]     a valve body mounting hole provided such that it crosses the fluid passage, and  
         [0023]     a gasket having a through hole aligned with and communicating with the fluid passage formed on the peripheral wall surface of the valve body mounting hole. The valve body is cylindrical in shape, is mounted coaxially within the valve body mounting hole, is rotatable about its centerline between the open position and closed position, and has an outside peripheral surface that slides in tightly sealing contact with the gasket while rotating between the open position and closed position. The purge flow path has an inside opening at one end that is open to the outside peripheral surface and an outside opening at the other end that communicates to the outside of the pipe coupling, where the inside opening is closed by tightly sealing engagement to the gasket when the valve body is in the open position, but is released from this tightly sealing engagement when the valve body is in the closed position, and thus communicates with the second-end side of the fluid passage.  
         [0024]     More specifically, the valve body mounting hole has a circular cross section and is mounted so as to be perpendicular to the fluid passage. A pair of openings is formed in the peripheral wall surface of the valve body mounting hole with the fluid passages crossing. The gasket has a through hole which aligns to and communicates with one of the pair of openings and a sealing engaging area which extends on the peripheral wall surface around the through hole. The sealing engaging area has a tightly sealing engagement surface in the shape of an arc centered about the axis of the valve body mounting hole. The outside peripheral surface of the valve body has a diameter such that it slides in tightly sealing engagement with the tightly sealing engagement surface of the gasket. A gap is formed between the outside peripheral surface and the peripheral wall surface of the valve body mounting hole and the sealing engaging area of the gasket is positioned on the gap, and the other of the pair of openings is in communication with the gap. The valve body has a valve hole that passes through the valve body extending in the direction of the diameter perpendicular to the axis of the valve body, and opens on the outside peripheral surface of the valve body, the valve hole communicates with the through hole of the gasket when the valve body is in the open position, and the communication with the through hole is cut off when the valve body is in the closed position, and the inside opening of the purge flow path is blocked by the tightly sealing engagement surface of the gasket when the valve body is in the open position, and the engagement with the tightly sealing engagement surface is removed when the valve body is in the closed position, being open to a position communicating with the gap.  
         [0025]     One embodiment comprises:  
         [0026]     a hole formed such that it passes in a radial direction through the peripheral wall of the female coupling member that demarcates the flow path on the second-end side,  
         [0027]     a locking member that is mounted within the hole, that is moveable in the radial direction of the female coupling member, and that can be displaced between: 
        a locked position that engages the male coupling member inserted within the female coupling member and secures the male coupling member to the female member, and     an unlocked position where the engagement with the male coupling member is released and the securing of the male coupling member to the female coupling member is released,        
 
         [0030]     a sleeve that is slidably mounted to the outside periphery of the peripheral wall of the male coupling member, being a sleeve able to slide between: 
        a first position where the locking member is pushed inward in the radial direction and the locking member is put into the locked position, and     a second position where the pushing of the locking member is released toward the side of the valve in comparison to the first position, thus permitting the locking member to assume the unlocked position,        
 
         [0033]     a spring that urges the sleeve toward the first position,  
         [0034]     a cam attached to the valve, which is a cam such that when a male coupling member is inserted into the female coupling member and the sleeve is in the first position, when the valve body is moved from the closed position to the open position, it engages the sleeve and blocks the sleeve from being put into the second position.  
         [0035]     In this female coupling member, when the valve body of the valve is in the open position, the sleeve is prevented from moving to the second position, so it is possible to eliminate the risk of the male coupling member coming off when the valve is in the open position.  
         [0036]     Another embodiment comprises:  
         [0037]     a first hole formed such that it passes in a radial direction through the peripheral wall of the female coupling member that demarcates the flow path on the second-end side,  
         [0038]     a locking member that is mounted within the first hole, that is moveable in the radial direction of the female coupling member, and that can be displaced between: 
        a locked position that engages the male coupling member inserted within the female coupling member and secures the male coupling member to the female coupling member, and     an unlocked position where the engagement with the male coupling member is released and the securing of the male coupling member to the female coupling member is released,        
 
         [0041]     a sleeve that is slidably mounted to the outside periphery of the peripheral wall of the male coupling member, being a sleeve able to slide between: 
        a first position where the locking member is pushed inward in the radial direction and the locking member is put into the locked position, and     a second position where the pushing of the locking member is released toward the side of the valve in comparison to the first position, thus permitting the locking member to assume the unlocked position,        
 
         [0044]     a first spring that urges the sleeve toward the second position,  
         [0045]     a second hole formed such that it passes in a radial direction through the peripheral wall of the female coupling member,  
         [0046]     a securing member that is mounted within the second hole such that it is moveable in the radial direction, and that can be moved between: 
        a secured position that engages the sleeve when at the second position and blocks the sleeve from moving to the first position, and     an unsecured position where it is moved from the secured position toward the inside in the radial direction, permitting the sleeve to move toward the first position,        
 
         [0049]     a securing member holding member that is mounted within the fluid passage on the second-end side, that can be moved between: 
        a first position that holds the securing member in the securing position, and     a second position more toward the side of the valve than the first position, that permits the securing member to assume the unsecured position,        
 
         [0052]     and that is a securing member holding member which, when moved by a male coupling member inserted into the female coupling member as the male coupling member is connected to the female coupling member, is put into the second position, and  
         [0053]     a second spring that urges the securing member holding member toward the first position.  
         [0054]     With this embodiment, the male coupling member is inserted into the female coupling member and when it reaches the position of connecting to the female coupling member, the first spring automatically makes the connection between the male coupling member and female coupling member with the sleeve at the first position.  
         [0055]     Moreover, this embodiment may further comprise:  
         [0056]     a cam that is attached to the valve and engages the sleeve, and the cam is such that:  
         [0057]     when the male coupling member is inserted into the female coupling member and is at a position connected to the female coupling member, 
        when the valve body is moved from the closed position to the open position, the cam moves the sleeve from the second position to the first position against the first spring, and     when the valve body is moved from the open position to the closed position, the first spring moves the sleeve from the first position to the second position,     but when the male coupling member is not inserted into the female coupling member, the movement of the valve body from the closed position to the open position is prevented by the engagement of the sleeve.        
 
         [0061]     Thereby, it is possible to prevent the valve from opening in the state in which no male coupling member is inserted into the female coupling member, and when the male coupling member is inserted into the female coupling member, the two members will not be disconnected unless the valve is put into the closed state, so it is possible to prevent high-pressure fluids from being sprayed out among other dangers. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0062]      FIG. 1  is a top view of the male coupling member of the pipe coupling according to the present invention;  
         [0063]      FIG. 2  is a cross section along A-A of  FIG. 1 , with a male coupling member connected to the female coupling member of  FIG. 1  and the valve in the “open” state;  
         [0064]      FIG. 3  is a left side view of the valve when the valve is in the “open” state (when the valve hole of the valve is aligned to the hole through the gasket), showing the gasket in cross section;  
         [0065]      FIG. 4  is a cross section along B-B of  FIG. 2 ;  
         [0066]      FIG. 5  is a cross section similar to that of  FIG. 2 , but with the valve in the “closed” state;  
         [0067]      FIG. 6  is a drawing similar to  FIG. 5 , with the valve not shown in section;  
         [0068]      FIG. 7  is a longitudinal cross section of Embodiment 2 of the pipe coupling according to the present invention, showing the state before the male coupling member is connected to the female coupling member;  
         [0069]      FIG. 8  is a cross section along C-C of  FIG. 7 ;  
         [0070]      FIG. 9  is a partial cutaway top view showing the state in which the male coupling member is inserted up until a position at which it can connect to the female coupling member;  
         [0071]      FIG. 10 (A) is a longitudinal cross section illustrating the relationship between the valve and cylindrical gasket of the pipe coupling in the state of  FIG. 7 ;  
         [0072]      FIG. 10 (B) is a lateral cross section of  FIG. 10 (A);  
         [0073]      FIG. 11  is a partial cutaway top view illustrating the state in which the valve is in the processes of opening with the male coupling member inserted into the female coupling member;  
         [0074]      FIG. 12  is a lateral cross section illustrating the relationship between the valve and cylindrical gasket in the state of  FIG. 11 ;  
         [0075]      FIG. 13  is a longitudinal cross section illustrating the state in which the valve is open and the male coupling member is connected to the female coupling member;  
         [0076]      FIG. 14  is a partial cutaway top view of  FIG. 13 ;  
         [0077]      FIG. 15  is a cross section of a conventional pipe coupling; and  
         [0078]      FIG. 16  is a side view of  FIG. 16 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0079]     Here follows a description of embodiments of the pipe coupling according to the present invention made with reference to the appended drawings.  
         [0080]      FIGS. 1-6  illustrate Embodiment 1 of the present invention, while  FIGS. 7-14  illustrate Embodiment 2.  
         [0081]     The pipe coupling according to Embodiment 1 has a female coupling member  1  and a male coupling member P that is inserted into and connected to this female coupling member.  
         [0082]     Female coupling member  1  has a fluid passage  2  that has a first end (seen at the left in the figure) for connecting to a fluid-supply conduit (not shown) and a second end for connecting to the male coupling member P. A valve body mounting hole  4  with a circular cross section is provided such that it is perpendicular to the fluid passage, and within this hole a valve  3  is mounted so as to be rotatable about the centerline of the hole.  FIG. 5  illustrates a gasket provided so as to be in tightly sealing contact with valve  3 , where this gasket has a through hole  7  aligned with the fluid passage  2  and is mounted in a gasket receptacle  6  provided in the fluid passage  2 . This gasket has a sealing engaging area  5   a  that extends toward the outside in the radial direction about the center of the through hole  7 , and the sealing engaging area  5   a  has a sealing engaging surface that is arc-shaped in the top view shown in  FIG. 4  and square-shaped in the side view shown in  FIG. 3 , that seals and engages the cylindrical peripheral surface  3   e  of the valve  3 .  
         [0083]     As shown clearly in  FIG. 4  and  FIG. 5 , the valve  3  has a large-diameter portion that has a control knob  3   a  at its top end and that slidably engages the valve body mounting hole  4 , and a small-diameter portion therebelow that engages the sealing engaging area  5   a  of the gasket  5 . A valve hole  3   b  is provided through the small-diameter portion, and when the valve is in the open position shown in  FIG. 2 , this valve hole  3   b  is aligned to the fluid passage  2  and thus the first-end side communicates with the second-end side. When the valve  3  is in the closed position shown in  FIG. 5 , the alignment with the fluid passage  2  is broken and the first-end and second-end sides are cut off from each other.  
         [0084]     As clearly shown in  FIG. 4 , a circular gap G is formed between the small-diameter portion of the valve and the valve body mounting hole  4 , so the sealing engaging area  5   a  of the gasket  5  elongates in this gap to engage the cylindrical peripheral surface  3   e  of the small-diameter portion of the valve  3 . As shown in  FIG. 5 , the gap G communicates with the second-end side of the fluid passage  2 .  
         [0085]     The valve  3  is provided with a purge flow path that has a first flow path  3   c  which extends from its lower end upward to near the valve hole  3   b  and a second flow path  3   d  that extends from the upper end of this first flow path in the radial direction toward an opening on the cylindrical peripheral surface  3   e  in the small-diameter portion of this valve. When the valve is in the open position illustrated in  FIG. 2 , the second flow path  3   d  of this purge flow path is closed by the sealing engaging area  5   a  of the gasket  5  (see  FIG. 3  and  FIG. 4 ). When this valve is in the closed position illustrated in  FIG. 5 , the second flow path leaves the sealing engaging area of the gasket  5  and is positioned so as to communicate with the gap G (see  FIG. 4 ).  
         [0086]     As shown in  FIG. 2  and  FIG. 5 , the female coupling member  1  has a locking member (locking ball)  10  and a sleeve  9  provided on the periphery of this female coupling member  1 . This locking ball engages an annular engaging groove formed on the outside surface of the male coupling member P inserted within this female coupling member, thereby securing the male coupling member P to the female coupling member  1 . The sleeve  9  is pushed by a spring  11  into the position shown in  FIG. 2  and  FIG. 5 , thus keeping the locking ball in the position of engaging the annular engaging groove of the male coupling member P. When the male coupling member P is inserted into or withdrawn from the female coupling member  1 , the sleeve  9  is moved to the left as seen in the figure, permitting the locking ball  10  to move to the outside in the radial direction, and allowing movement of this male coupling member in the axial direction.  
         [0087]     As is evident from  FIG. 2  and  FIG. 1 , a cam  3   f  is provided on the valve  3 , and when the valve  3  is in the open position shown in  FIG. 2 , the cam engages the sleeve  9  and prevents the sleeve from moving to the left. Namely, when the valve is in the open position, the male coupling member P cannot be inserted into or withdrawn from the female coupling member  1 . When the valve  3  is in the closed position shown in  FIG. 5  and  FIG. 6 , the sleeve  9  is able to move to the left and accordingly the male coupling member  1  can be inserted into or withdrawn from the female coupling member  1 .  
         [0088]     In Embodiment 1,  3   g  and  13  indicate stop rings, while  8  and  12  indicate O-rings.  
         [0089]     In the aforementioned pipe coupling, it is possible to remove residual pressure on the side connected to the male coupling member within the fluid passage  2  by merely putting the valve  3  into the closed state.  
         [0090]     Note that the valve is provided on the female coupling member in this example of a pipe coupling, but the valve may also be provided on the male coupling member.  
         [0091]     Next, Embodiment 2 of the pipe coupling according to the present invention will be described based on  FIGS. 7-14 .  
         [0092]      FIG. 7  is a longitudinal cross section showing the state before the male coupling member  21  is connected to the female coupling member  20 .  FIG. 8  is a cross section along C-C of  FIG. 7 .  FIG. 9  is a partial cutaway top view showing the state in which the male coupling member is inserted up until a position at which it can connect to the female coupling member.  FIG. 10 (A) is a longitudinal cross section illustrating the relationship between the valve  24  and cylindrical gasket  39  in the state of  FIG. 7 .  FIG. 10 (B) is a lateral cross section of  FIG. 10 (A).  FIG. 11  is a partial cutaway top view illustrating the state in which the male coupling member is connected to the female coupling member but the valve is not opened.  FIG. 12  is a lateral cross section of the valve  24  and gasket  29  in an area of the valve hole that illustrates the relationship between the valve and cylindrical seal body in the state of  FIG. 11 .  FIG. 13  is a longitudinal cross section illustrating the state in which the male coupling member  21  is connected to the female coupling member  20  and the valve is open.  FIG. 14  is a partial cutaway top view of  FIG. 14 .  
         [0093]     The female coupling member  20  and male coupling member  21  of the pipe coupling according to this Embodiment 2 have fundamentally the same structure as those of Embodiment 1 except that moveable valves  69  and  82  are provided on each.  
         [0094]     Specifically, female coupling member  20  has: a valve  24 , locking ball  52  that locks the male coupling member  21  to the female coupling member  20 , sleeve  54  for holding this locking ball from the outside in the radial direction, and a cam  44  attached to the valve  24  in order to control the motion of this sleeve.  
         [0095]     The female coupling member  20  consists of a central female coupling member body  22 , a conduit connector  35  linked to the left end of this body  22  when viewed in the  FIG. 7 , an intermediate pipe  48  linked to the right end of this body and a tip pipe  50  linked to this intermediate pipe.  
         [0096]     The conduit connector  35  is secured by screws  38  to a securing ring  33  that is attached to a securing pipe  31  screwed onto the body  22 . In the  FIGS. 34 and 36  are sealing rings.  
         [0097]     The valve  24  is cylindrical overall, having an axial portion  25  extending up and down along the central axis, with an operating lever  43  (see  FIG. 8 ) attached to its top end. In the illustrated example, the valve  24  is inserted from above into a valve body mounting hole  27  provided on the body  22 , being mounted within this body  22  by a securing ring  28  screwed onto the large-diameter hole portion provided at the top end of this hole  27 . In the figure,  29  is a sealing ring mounted around the upper small-diameter portion  25   a  and lower small-diameter portion  25   b , while  30  is a sealing ring mounted around the securing ring  28 .  
         [0098]     In the same manner as the one in Embodiment 1, the valve  24  is provided with a valve hole  26  and purge hole. The purge hole consists of a first portion  45  extending parallel to the valve hole  26  and a second portion  46  extending along the axis of this valve ( FIG. 8 ,  FIG. 10 (A),  FIG. 10 (B)), and the second portion  46  can communicate to a fluid recovery passage  47  formed on the body  22  as shown in  FIG. 8 .  
         [0099]     The gasket  39  engaged to the outside surface of the valve  24  is mounted within the primary side (conduit connector  35  side) of the fluid passage  23  of the body  22 , and pressed against the valve  25  by a cylindrical pressing body  40  urged by a spring  42  (while this is not clear in the figure, the valve  24  is slightly smaller in diameter than the valve body mounting hole  27 , so the gasket  39  intrudes slightly into the valve body mounting hole  27  and contacts the outside surface of this valve).  
         [0100]     As one can see from  FIG. 12 , the first portion  45  of the purge hole is blocked by this gasket prior to the valve hole  26  being aligned with the hole through the gasket  39  constituting the primary-side fluid passage  23   a  (namely, prior to the valve being put into the open state). In addition, the blockage by the gasket is removed after the valve hole  26  is no longer aligned with this through hole (namely, after the valve being put into the closed state), thus communicating with the secondary side of the fluid passage  23  via a minute gap between the outside surface of this valve  24  and the wall surface of the valve body mounting hole  27  surrounding the outside surface of the valve  24 , and thereby, the residual pressure on this secondary side is released to the outside.  
         [0101]     The sleeve  54  that controls the locking ball  52  is in contact with the cam  44  via a regulating tube  66  screwed onto its left-side end (see  FIG. 9 ,  FIG. 11  and  FIG. 14 ). The regulating tube  66  is urged to the left by a compression spring  55  mounted between the regulating tube  66  and a stop ring  67  mounted on the outside surface of the tip pipe  50  of the female coupling member, and pressed toward the cam  44 . The tip pipe  50  has a second locking ball  57  provided within a hole  58  through this tip pipe in the radial direction, and a collar  61  that supports the second locking ball  57  from the inside in the radial direction is provided. This collar is urged to the right by a spring  60 , and a step  64  formed between the large-diameter portion  62  and the small-diameter portion  63  of the outside surface of this collar is halted by a step formed on the inside surface of the tip pipe  50 . When the collar  61  is in this state, the large-diameter portion  62  of the collar engages the second locking ball  57 , and a portion of this locking ball engages a halting groove  59  formed in the inside surface of the sleeve  54 , and thereby this sleeve  54  is in a state fixed to the tip pipe  50 .  
         [0102]     In the figure, a moveable valve  69  is provided on the inside of the collar so that it is able to move in the axial direction of the female coupling member  20 , and a pipe  74  is attached to the outside surface of this moveable valve, being urged toward the right by a spring  75  mounted between this pipe  74  and the intermediate pipe  48  of the female coupling member. A large-diameter portion  76  formed at the left tip of this moveable valve  69  engages a step  77  formed on the inside surface of the through hole of the intermediate pipe (formed on the secondary side  23   b  of the fluid passage  23 ), and thus this moveable valve is halted at the position illustrated in  FIG. 7 . On the moveable valve  69  are formed an axial flow path  72  and a radial flow path  73  communicating to the left end of the axial flow path.  
         [0103]     An annular engaging groove  79  that receives the locking ball  52  at the time of connecting to the female coupling member  20  is formed on the outside surface of the male coupling member  21 , and the moveable valve  82  is mounted such that it is able to move axially within its fluid passage  80 . This moveable valve is urged toward the left by a spring  81 , being normally in the “closed” state (namely, the state in which the fluid passage consisting of the axial flow path extending axially from the left tip surface of this moveable valve and the radial flow path communicating toward its right tip is closed). When this male coupling member  21  is inserted into and connected to the female coupling member  20 , and a fluid is supplied from the fluid passage of the female coupling member, the moveable valve  82  is moved to the right against the spring  81  by the pressure of the fluid and put into the “open” state.  
         [0104]     When this male coupling member  21  is inserted into the female coupling member  20 , the tip of this male coupling member advances while pushing the collar  61  toward the left, and when the engaging groove  79  of this male coupling member is aligned with the locking ball  52  in the radial direction, the small-diameter portion  63  of the collar  61  comes to the inside of the second locking ball  57 . Thereby, the state of engagement between the tip pipe  50  of the female coupling member  20  and the sleeve  54  is released, so this sleeve  54  is moveable in the axial direction.  FIG. 9  illustrates this state.  
         [0105]     Thus, when the lever  43  of the valve  24  is rotated as shown in  FIG. 11 , the sleeve  54  is moved to the right by the cam  44 , assuming a position wherein the locking ball  52  is pressed from the outside in the radial direction. As shown in  FIG. 12 , in this state, the valve hole  26  of the valve  24  does not communicate with the fluid passage  23 , but the purge holes  45 ,  46  are closed by the gasket. Moreover, as the rotation of the lever advances to the position shown in  FIG. 14 , the valve hole  26  of the valve  24  is aligned to the fluid passage  23  so that this pipe coupling is in the open state.  
         [0106]     Conversely, if the lever  43  is rotated in the direction opposite to that described above from this open state, then the valve hole  26  is moved away from the fluid passage  23  so this pipe coupling is put into the closed state, and if the lever rotation advances further, the purge hole is moved away from the gasket and put into the releasing state, and ultimately, as the cam  44  takes the position shown in  FIG. 9 , the sleeve  54  is returned to the position shown in  FIG. 7  by the compression spring  55 . Accordingly, the male coupling member  21  can be withdrawn from the female coupling member  20  and together with this withdrawal, the collar  61  moves to the right, moving the second locking ball  57  to the halting position with the halting groove  59  of the sleeve  54 .