JP2005532526A - Dual function service coupling - Google Patents

Abstract

A service coupling 20 for use with either a push-type or screw-type port valve of the charge port 22 is provided including a body portion 58 and an axially movable valve housing 82. The axial movement of the actuator 70 allows both selective axial movement of the valve housing 82 from the rear position to the front position and selective removal of the port valve 44 to open the flow path. In one embodiment, the actuator 70 has a tip portion 356 that engages a threaded port valve or moves the push-pin valve axially to open the flow path. This operation is the same for any type of valve and the user is not required to know which type of valve is present.

Description

  The present invention relates to a service coupling used to direct refrigerant from a refrigerant supply source, typically attached to and connected to a refrigeration system, to a refrigeration system. This service coupling is also used to discharge refrigerant from the refrigeration system.

  Conventional refrigerants such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are strictly regulated because they cause a decrease in ozone in the atmosphere. Research on new environmentally friendly refrigerants to replace existing CFCs and HCFCs led to the introduction of hydrofluorocarbons (HFCs) such as R134a. However, HFCs still exhibit a relatively high global warming potential (GWP) and high cost of use in comparison to natural refrigerants such as carbon dioxide and ammonia. These concerns have increased the need to investigate alternative refrigeration systems that use refrigerants other than HFCs. The automotive air conditioning industry has already begun to replace HFCs through the development of refrigeration systems that use carbon dioxide as a refrigerant.

  Service couplings, or adapters, used to direct refrigerant from a refrigerant source to the refrigeration system via an inlet or “charge” port of the refrigeration system are well known in the prior art. One known service coupling uses one or more mechanisms that can be “fast coupled” to the charge port of the refrigeration system. Once coupled, the service coupling service valve engages and activates the charge port port valve to open a refrigerant flow path between the charge port and the service coupling. The service valve is typically moved to engage the port valve by a rotary knob that can be threadedly coupled to the service coupling.

  Conventional service couplings, such as those used to service automotive R134a air conditioning systems, are typically designed to function at pressures up to about 100 psi (6.9 bar). However, refrigeration systems that use carbon dioxide as a refrigerant operate at significantly higher pressures than typical R134a refrigeration systems, ie, pressures greater than 100 psi (6.9 bar).

  Due to these relatively high pressures, conventional service coupling is subject to several limitations that make it generally impossible to use it in refrigeration systems that use carbon dioxide. One limitation is that the relatively high refrigerant pressure places a very high load on the service valve, which requires an extremely large torque to rotate the knob.

  Another limitation is that the “rapid coupling” mechanism of the service coupling is virtually inoperable due to the pressurized refrigerant confined between the service coupling and the charge port prior to disengagement. It is. This trapped pressure also causes undesirably severe withdrawal from the service coupling charge port.

  Yet another limitation is the relatively high flow rate of refrigerant through the conventional service coupling during refrigeration system discharge. In refrigeration systems that use carbon dioxide as a refrigerant, a relatively large exhaust flow rate can cause a sudden depressurization of the seal, that is, an undesirable rapid expansion of the gas refrigerant confined in the seal. The relatively large exhaust flow also causes the generation of “dry ice” at the charge port or service coupling, which will inhibit the service valve and port valve reseal and allow refrigerant leakage. .

  Thus, there is a need for an improved service coupling to charge and discharge relatively high pressure refrigeration systems that use carbon dioxide.

  A service coupling is provided for connecting a refrigerant supply to a refrigeration system having a charge port that includes an axially displaceable port valve. The service coupling includes a body portion having a central passage extending along an axis from the adjustment end to the outlet end, and a transverse port disposed between both ends communicating between the central passage and the refrigerant source. Is included. A valve housing that is movable in the axial direction is disposed in the central passage. The valve housing extends from a first end disposed between the lateral port and the outlet end to a second end disposed near the adjustment end. The valve housing includes at least one pressure balance passage therethrough extending from the first end to the second end, and the service valve is hermetically engaged within the valve housing. An actuator is provided for moving the valve housing from a rear position toward the adjustment end to a front position toward the outlet end. Axial movement of the valve housing toward the forward position pushes the service valve, releases the port valve from the charge port seal engagement, releases the service valve from the valve housing seal engagement, open. Further, the axial movement of the valve housing to the front position creates a gap between the second end of the valve housing and the main body portion. This gap is connected to the refrigerant flow path by at least one passage extending through the valve housing so that the pressures at both ends of the valve housing are substantially balanced. As a result of the pressure balance on both sides of the valve housing, only minimal force is required to move the valve housing in the central passage.

  In another embodiment of the invention, the service coupling is provided with at least one bleed passage for venting pressurized refrigerant confined between the service coupling and the charge port prior to disengagement. ing. Movement to the front position of the valve housing seals the bleed passage, whereas movement to the rear position of the valve housing closes the flow path and remains confined between the charge port and the service coupling. The refrigerant is released through the bleed passage.

  In yet another embodiment of the present invention, the lateral port is provided with a coupling member for connecting the service coupling to the refrigerant supply / discharge system. This coupling member restricts the flow of refrigerant in the first direction through the check valve, i.e., the transverse port, and substantially restricts the flow of refrigerant in the second direction opposite the first direction through the transverse port. Including a restrictor configured to allow without.

  In another embodiment of the present invention, the charge port may include either a push-type valve or a screw-type valve. The valve body is a shaft with additional functionality, and the valve housing includes a safety sleeve that cooperates with the fixedly disposed body portion of the valve. This service coupling operates in the same manner as any type of valve in operation.

  Among the advantages, the novel design of the service coupling of the present invention allows the refrigerant flow path to be opened between the charge port of the relatively high pressure system and the service coupling with minimal force. Another advantage is that after the service valve and port valve are closed, the refrigerant confined between the charge port and the service coupling is automatically vented, and the service coupling from the charge port is simply and not severely detached. Is to make it possible. Yet another advantage is that the flow rate of refrigerant discharged from the refrigeration system is easily controlled by a check valve to minimize the occurrence of sudden decompression, i.e., dry ice production.

  Various additional features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read with reference to the accompanying drawings.

  Referring to FIG. 1, a service coupling 20 attached to the charge port 22 is provided, which functions as an inlet for refrigerant introduced into the refrigeration system to which the charge port 22 is connected. When coupled together, service coupling 20 and charge port 22 exhibit a common longitudinal axis AA.

  The charge port 22 may be of a general type and does not form itself and part of the invention therein. However, a better understanding of the charge port 22 will help explain the operation of the service coupling 20.

  The charge port 22 includes a body 24 having a central passage 26 extending therethrough and extending from an inlet end 28 to an outlet end 30. As shown in FIG. 5, the central passage 26 has a reduced diameter cylindrical valve seat 32 provided in the valve core 40, an inner screw 34 for engaging the polymer sealing element 36, and an outer screw 38. Including.

  With continued reference to FIG. 5, the valve core 40 includes a core body 42 in which a port valve 44 is slidably disposed. A first end 46 of the port valve 44 extends outward beyond the core body 42, and a second end 48 of the port valve 44 is connected to the seal member 50. The compression spring 52 extends between the annular lip 54 of the port valve 44 and the radial shoulder 56 of the core body 42, and elastically biases the port valve 44 toward the inlet end 28 to seal the seal member. 50 is hermetically engaged with the core body 42. Movement of the port valve 44 toward the outlet end 30 (left as viewed in FIG. 5) moves the seal member 50 away from the core body 42, thereby opening the valve core 40 (as shown in FIG. 2) The refrigerant flow through the charge port 22 is allowed.

  With reference to FIG. 1, the service coupling 20 includes a body portion 58 that extends from an adjustment end 60 to an exit end 62. The central passage 64 extends from the adjustment end 60 to the outlet end 62 and is connected to a lateral supply hose port 66 formed between the adjustment end 60 and the outlet end 62 of the body portion 58. A threaded portion 68 is disposed outside the main body portion 58 adjacent to the adjustment end portion 60. The rotatable knob 70 includes an inner thread 72 that is disposed at the adjustment end 60 and engages the thread 68 and an enlarged grip 74 that extends axially beyond the adjustment end 60.

  The central passage 64 of the body portion 58 includes a first inner diameter portion 76 near the adjustment end 60, a second inner diameter portion 78 near the outlet end portion 62, and an enlarged annular shape that aligns with the lateral port 66. A groove 80 is provided. In the central passage 64, a valve housing 82 is disposed inside the first inner diameter portion 76 and is dimensioned to be slidably received. The valve housing 82 includes a substantially cylindrical main body 84 having a central axis common to the axis AA, and an adjustment post 86 protruding outward from the main body 84 along the axis AA. The main body 84 includes an inner cavity 88 and an inner threaded portion 92 with the shoulder 90 extending inward. A plurality of flow holes 94 are disposed through the body 84 substantially perpendicular to the axis AA and traverse the cavity 88. The body 84 also includes at least one balance passage 96 (shown in broken lines in FIGS. 1-3) that extends from one end of the body 84 to the other end. The passage 96 is disposed between the plurality of circulation holes 94 so that the passage 96 and the circulation holes 94 do not intersect with each other.

  The valve housing 82 is connected to the knob 70 and moves together with the knob 70 when the knob 70 is screwed into the body portion 58 and loosened. In the preferred embodiment, a portion of the adjustment post 86 extends through a hole 98 in the body portion 58 and an axially aligned hole 100 in the knob 70. A pair of washers 102 are disposed on the adjustment posts 86 on both sides of the knob 70. During assembly of the service coupling 20, the tip 104 of the adjustment post 86 is swaged or deformed so that the washer 102 and knob 70 do not fall off the adjustment post 86 during rotation. The washer 102 slides relative to the knob 70 so that the knob 70 can rotate relative to the adjustment post 86.

  Due to the rotation of the knob 70 and the axial movement caused by the mutual engagement of the screw portion 68 and the screw portion 72, the valve housing 82 is (1) the adjustment end portion 60 (when the knob 70 rotates in a predetermined first direction 1-3, it moves axially to the rear position toward the right), and (2) when the knob 70 rotates in the opposite direction, it moves to the front position toward the outlet end 62. Excessive retraction of the valve housing 82 toward the adjustment end 60 is prevented by the valve housing 82 abutting against a shoulder 106 formed between the first inner diameter 76 of the body portion 58 and the hole 98.

  Depending on the outer diameter of charge port 22 and valve housing 82, body portion 58 may be further divided into two or more portions to facilitate assembly of service coupling 20. As shown in FIGS. 1-3, the body portion 58 is preferably divided into a first portion 108 that includes a first inner diameter 76 and a second portion 110 that includes a second inner diameter 78. The second portion 110 includes an inner threaded portion 112 into which the outer threaded portion 114 of the first portion 108 is screwed during assembly. 1-3, since the outer diameter of the valve housing 82 is greater than the second inner diameter 78, the valve housing 82 may be coupled to the first portion 108 prior to coupling the second portion 110 to the first portion 108. It is assembled to the part 108. However, in other embodiments of the present invention (not shown), the valve housing 82 may have an outer diameter that is smaller than the second inner diameter 78 to allow the body portion 58 to be manufactured as a single piece. .

  A service valve 118 urged against the seal member 116 by an elastic compression member 120 such as a seal member 116 and a compression spring is inserted into the cavity 88 of the valve housing 82. The seal member 116 is preferably made of a polymer material such as EPDM rubber or PTFE and presses the shoulder 90 facing inward. The seal member 116 is preferably a flat annular gasket, as shown in FIGS. 1-3, or may be an O-ring. The service valve 118 includes a generally conical seat 122 that extends therefrom and hermetically engages the seal member 116 to prevent refrigerant flow through the service coupling 20. One end of the elastic compression member 120 presses the shoulder 124 of the sheet 122, and the other end presses the inner wall of the cavity 88.

  In addition, the valve retainer 128 is received in the cavity 88 and holds the seal member 116, the service valve 118, and the elastic compression member 120 in the cavity 88 of the valve housing 82. The valve retainer 128 preferably includes a cylindrical base portion 132 having a guide portion 130 through which the service valve 118 extends and an outer thread 134 that engages the inner thread 92 of the cavity 88. The guide portion 132 is substantially rectangular with a width sufficient to support the service valve 118 and a sufficiently narrow width to allow a refrigerant passage, as shown in FIG. The base portion 132 of the valve retainer 128 presses the seal member 116 and holds the seal member 116 in contact with the shoulder 90.

  6 and 7, another embodiment of the valve housing 82 is shown in detail. In this embodiment, service valve 118, seal member 116, and valve retainer 128 include a valve core assembly 138. The valve core assembly 138 can be substantially similar to the valve core 40 described above at the charge port 22, but need not be limited thereto. Thus, other valve core assembly designs, such as those commonly found in tire stems, can be used in the present invention. The use of the valve core assembly 138 instead of the individual parts 116, 118 and 128 is advantageous in that it eliminates one or more manufacturing steps and simplifies the replacement of worn or damaged seals. is there.

  Referring again to FIG. 1, the annular seal element 140 is disposed in the first inner circumferential groove 142 disposed in the inner wall of the hole 98, and the valve housing 82 is moved toward the outlet end 62 to the advanced position. At this time, leakage of the refrigerant is substantially prevented. Similarly, a pair of annular sealing elements 144 are provided on the body portion 58 on the adjustment end 60 side and on the outlet end side of the lateral port 66. The sealing element 144 presses the valve housing 82 to substantially prevent the refrigerant from flowing between the main body portion 58 and the valve housing 82. The sealing elements 140 and 144 may be conventional rubber O-rings or PTFE spring-biased “U-cups” as is known in the art.

  The body portion 58, more specifically the second portion 110, preferably includes an inward shoulder 148 that holds an annular seal member 150 such as an O-ring. When the charge port 22 is received in the service coupling 20, the seal member 150 is hermetically engaged with the charge port 22 and seals the refrigerant leakage between the charge port 22 and the service coupling 20. The seal member 150 is limited in axial movement within the passage 64 by a snap ring 152 received in the shoulder 148 and the outward groove 154 of the first inner diameter 76.

  Referring to FIG. 3, the lateral port 66 is preferably provided with a coupling member 156 for connecting the service coupling 20 to a coolant supply (not shown). In a preferred embodiment, the outer end 158 of the coupling member 156 is compatible with a female coupling 160 that mounts a service hose or other conduit fitting 161 for transferring refrigerant from a common refrigerant supply / discharge system. It is formed as follows. The design of the coupling member 156 shown in FIGS. 2 and 3 is not intended to limit the scope of the present invention and includes other structures such as a general threaded female adapter.

  In the coupling member 156, a check valve for adjusting the flow rate of the refrigerant flowing out from the charge port 22 through the service coupling 20, that is, a restrictor 162 is disposed. Referring to FIG. 4, restrictor 162 includes an axially narrow duct 166 having a predetermined diameter corresponding to a desired refrigerant flow rate. The restrictor 162 has a plurality of radial fins 168 that cooperate with the inner surface 170 of the coupling member 156 to form a plurality of flow channels 172 (best shown in FIG. 4) through which the refrigerant flows freely. Is provided. A gap 174 (best shown in FIG. 3) formed between the tapered surface 176 of the coupling member 156 and the shoulder 178 of the female coupling 160 allows for limited axial movement of the restrictor 162. Yes. As shown in FIG. 2, when refrigerant flows into the service coupling 20 from the refrigerant supply / discharge system, the restrictor 162 is pressed against the tapered surface 176 to allow a substantially unrestricted refrigerant flow through the flow channel 172. Allow. Alternatively, when the refrigerant flows into the service coupling 20 from the charge port 22, the restrictor 162 is pressed against the shoulder 178, thereby restricting the flow of the refrigerant through the thin duct 166.

  Referring again to FIG. 1, the service coupling 20 is preferably provided by a plurality of detent balls 180 disposed in radial holes 182 formed in the wall adjacent to the outlet end 62 of the body portion 58. , Connected to the charge port 22. An annular locking sleeve 184 surrounds the body portion 58 adjacent the outlet end 62 and is axially slidable thereon. Lock sleeve 184 is provided with an inward flange 186 having a conical cam surface 188, from which conical cam surface 188 extends outwardly toward outlet end 62. An elastic member 190, such as a compression spring or the like, biases the lock sleeve 184 toward the outlet end 62. A shoulder 192 cooperating with an outwardly directed flange 194 of the body portion 58 extends radially outward from the flange 186 to form a chamber 196 in which the resilient member 190 is disposed and exits the lock sleeve 184 It is elastically biased toward the end 62.

  In the region of the body portion 58 adjacent to the flange 194, an inwardly annular groove 198 in which the retaining ring 200 is disposed is preferably provided. The retaining ring 200 abuts both the flange 194 and the shoulder 202 on the lock sleeve 184 to prevent the lock sleeve 184 from detaching from the body portion 58, as shown in FIG. Alternatively, in combination with the retaining ring 200, a second retaining ring 204 can be provided in the groove 206 near the outlet end 62, so as to prevent the locking sleeve 184 from detaching from the body portion 58. Function.

  The service coupling 20 is preferably provided with an interlock sleeve 208 to prevent unintentional detachment of the service coupling 20 from the charge port 22 when the refrigerant flow path is opened. 1 to 3, the interlock sleeve 208 is a substantially cylindrical member having an inner diameter 210 that is slightly larger than the outer diameter 212 of the main body portion 58. The interlock sleeve 208 is provided with a groove 214 having a width slightly larger than the diameter of the coupling member 156. The first end 216 of the interlock sleeve 208 engages the lock sleeve 184, and the second end 218 of the interlock sleeve 208 engages the knob 70. Referring to FIG. 2, when the knob 70 is rotated to a position that opens the service valve 118 and the port valve 44, the interlock sleeve 208 abuts the lock sleeve 184, and the lock sleeve 184 releases the charge port 22. Prevent back to position. On the other hand, as shown in FIG. 3, when the knob 70 is rotated to a position that closes the service valve 118 and the port valve 44, the interlock sleeve 208 moves to a position where the lock sleeve 184 releases the charge port 22. Can slide on.

  In operation, when the service coupling 20 is disengaged from the charge port 22, as shown in FIG. Retained. The service coupling 20 can be engaged with the charge port 20 by a retracted locking sleeve 184, as shown in FIG. 3, so that when the service coupling 20 is engaged with the charge port 22, the detent ball 180 can move outward.

  When the service coupling 20 is engaged with the charge port 22, the inlet end 28 of the charge port 22 enters into the outlet end 62 of the service coupling 20 and is hermetically engaged with the seal member 150. With further axial movement of the charge port 22 toward the adjustment end 60, the detent ball 180 rides on the shoulder 220 of the charge port 22 until it is radially aligned with the groove 222 of the charge port 22. The detent ball 180 is radially inward by the bias of the elastic member 190 and the biasing of the locking sleeve 184 toward the outlet end 62 in response to the action of the conical cam surface 188 that presses the detent ball 180 radially inward. Is pressed. The detent ball 180 engages one side of the shoulder 220 furthest from the charge port inlet end 28 to fasten the service coupling 20 to the charge port 22.

  It should be noted that, as shown in FIG. 1, the service coupling 20 and the charge port 22 are thus coupled so that there is no refrigerant flow through the coupled components. Thus, in the charge port 22, the seal member 50 is airtightly engaged with the core body 42, and in the service coupling 20, the service valve 118 is airtightly engaged with the seal member 116. Combined.

  Before service valve 118 and port valve 44 are opened, service coupling 20 is pressurized through a service hose or other conduit attached to the refrigerant supply / discharge system. The seal members 144 on both sides of the lateral port 66 prevent refrigerant from passing between the body portion 58 and the valve housing 82. Thus, there is no pressure acting in the axial direction of the valve assembly 82 that prevents rotation of the knob 70 that opens the service coupling 20.

  In order to open the service coupling 20 and the charge port 22 and allow the refrigerant to flow through the lateral port 66, the knob 70 is rotated in a predetermined first direction and moved axially to the position shown in FIG. Is done. Such rotation of the knob 70 does not cause substantial rotation of the valve housing as a result of frictional resistance to the rotation of the housing 82 due to contact with the seal members 140, 144. Axial movement of the valve housing 82 from the position of FIG. 1 to the position of FIG. 2 causes the service valve 118 to engage the port valve 44 directly.

  Once the service valve 118 contacts the port valve 44, there is resistance to further axial movement of the valves 118, 44 due to the refrigeration system pressure acting on the port valve 44. However, this resistance is generally negligible due to the relatively small diameter of the port valve 44. Referring to FIG. 2, as valves 118 and 44 begin to open, the first cavity 224 formed between charge port 22 and valve housing 82 is rapidly filled with pressurized refrigerant. Almost simultaneously, the passage 96 allows the second cavity or gap 226 formed between the valve housing 82 and the shoulder 106 to reach the same pressure. As a result of the nearly balanced pressure on both sides of the valve housing 82, only minimal axial force (generally, the biasing force of the combined compression valve spring) acts on the knob 70. Thereby, the magnitude of the torque received is all that is necessary for the rotation of the knob 70. Full rotation of the knob 70 in a predetermined first direction causes the service valve 118 and the port valve 44 to be fully retracted, ie, moved to the “open” position.

  Due to the biasing force applied to both service valve 118 and port valve 44, service valve 118 may not be actuated to the full “open” position. To ensure that the service valve 118 is fully activated, a dowel pin 228 may be provided that extends through a portion of the service valve 118 that extends outward beyond the valve housing 82. During insertion of the charge port 22 into the service coupling 20, the inlet end 28 of the charge port 22 engages the dowel pin 228 to actuate the service valve 118 to the full “open” position shown in FIG.

  To disengage the service coupling 20 from the charge port 22, it is simply necessary to rotate the knob 70 and manually retract the lock sleeve 184 to the position shown in FIG. This retraction releases the shoulder 188 of the lock sleeve 184 from engagement with the detent ball 180, thereby aligning the detent ball 180 with the enlarged cylindrical wall 182 and causing the detent ball 180 to move radially. Moving outward, they can be detached from the shoulder 220 of the charge port 22. However, due to the pressure of the refrigerant confined in the first cavity 224, manual retraction of the lock sleeve 184 is difficult if not impossible. This trapped refrigerant applies an axial force to the charge port 22, which is diverted to the lock sleeve 184 via the detent ball 180. For this reason, it is necessary to vent the pressure confined in the first cavity 224 before leaving the service coupling 20.

  In order to reduce the pressure in the first cavity 224, a pressure bleed passage 230 is provided between the first cavity 224 and the outside of the service coupling 20. In the preferred embodiment of the present invention, the pressure bleed passage 230 extends between the passage 96 and the outer surface of the adjustment post 86 as shown in FIGS. When the valve housing 82 is moved to the forward position toward the outlet end 62, the pressure bleed passage 230 assists the longitudinal passage 96 to make the first cavity 224 into the second cavity, as shown in FIG. Connect to H.226. When the valve housing 82 is moved to the rearward position toward the adjustment end 60, the pressure bleed passage 230 extends beyond the seal member 142 as shown in FIG. 3, and the pressure of the first cavity 224 is returned to the atmosphere. Allow to be ventilated. The release of refrigerant into the surrounding environment, which is a characteristic of conventional service coupling, is very small. In other embodiments, as shown in FIG. 8, when the pressure bleed passage 230 'or 230' 'is provided through the adjustment post 86 and the valve housing 82 is moved to the rear position, the second cavity 226 pressure is vented to the atmosphere.

  Alternatively, or in combination with the bleed passage structure shown in FIGS. 1 and 8, at least one bleed passage 232 is provided directly through the body portion 58 as shown in FIGS. Thus, the pressure of the first cavity 224 may be vented to the atmosphere. In this embodiment, an additional seal member 234 is required in the body portion 58 downstream of the pressure bleed passage 232 to provide a seal against the valve housing 82 when the valve housing 82 is moved to the forward position. As shown in FIG. 7, when the valve housing 82 is retracted to the rearward position toward the adjustment end 60, the seal member 234 moves away from the valve housing 82 and causes the pressure confined in the first cavity 224. Open through bleed passage 232.

  Referring to FIG. 8, another embodiment of the present invention is shown in detail. In this embodiment, the service coupling 20 is provided with a rotatable nut 236 in place of the retractable lock sleeve 184 for fastening the service coupling 20 to the charge port 22. The nut 236 is provided with an inner thread surface 238 that engages the outer thread surface 240 of the charge port 22. The nut 236 also includes an anchor portion 241 that engages the inward groove 242 of the body portion 58. Anchor portion 241 allows nut 236 to rotate relative to body portion 58, but prevents axial movement. To prevent inadvertent removal of the charge port 22, the interlock sleeve 208 is engaged with an outer spline surface (not shown) of the nut 236 when the interlock sleeve 208 is moved forward by the rotation of the knob 70. A mating inner spline surface can be provided.

  Referring to FIG. 9, another embodiment of the present invention is shown in detail. In this embodiment, the service coupling 20 does not include an interlock sleeve 208 to prevent inadvertent removal of the charge port 22. Instead, when the valve housing 82 is moved toward the outlet end 62, a radially movable pin 244 extending radially outward is provided on the body portion 58 and the lock sleeve 184 disengages the charge port 22. It prevents sliding to the position. As shown in FIG. 9, a chamfered head portion 248 is provided at the inner end portion 256 of the pin 244. Release of the refrigerant is substantially prevented by the use of at least one seal member 250 such as an O-ring between the pin 240 and the body portion 58. The valve housing 82 is provided with a chamfered end 252 that engages the head 248 when the valve housing 82 is moved forward toward the outlet end 62. This engagement, alone or in combination with the refrigerant pressure present between the valve housing 82 and the body portion 58 by opening the service valve 118 and the port valve 44, to the position where the pin 244 protrudes from the body portion 58. Move outward. The projecting position pin 244 engages the lock sleeve 184 when the valves 118 and 44 are opened to prevent inadvertent retraction of the lock sleeve 184. Once the valve housing 82 is moved to a rearward position toward the adjustment end 60 and the valve 188 is closed, the lock sleeve 184 can be retracted by pushing the pin 244 into the body portion 58.

  As yet another embodiment of the present invention, a dual function service coupling 20 'is shown in FIGS. In the embodiment described above, the male charge port 22 ′ includes a push-pin type valve 44. However, as described below, under certain circumstances it may be desirable to incorporate a screw-type valve. In the above-described embodiment, the “valve assembly” includes the valve housing 82 that is moved in the axial direction by the direct connection of the knob 70. The housing 82 includes a spring-loaded valve 118 having a dowel pin 228 that is pushed open by the male service port body and then pushes the male service port valve.

  The embodiment described below differs from that in which the “valve assembly” consists of a shaft that is moved axially by direct coupling of a knob. A spring-loaded safety sleeve performs the valve function in conjunction with the shaft. The safety sleeve is opened when the male service port valve is pushed open by the shaft and at the same time the safety sleeve contacts the end of the male service port. A typical actuator is a knob. A more detailed description of this embodiment will be made according to the reference numerals of specific elements based on the attached drawings.

  The screw type valve 302 holds the valve in the charge port 22 ′ by using screw portions 303 and 304 that mesh between the inner peripheral surface of the port 22 ′ and the outer peripheral surface of the valve 302. The threaded portions 303 and 304 are threaded in the first direction (eg, left), while the threaded portion associated with the shaft is threaded in the opposite direction (eg, right). Also, the retaining ring 305 is inadvertent from the port 22 ′ of the valve 302 as the valve 302 continues to loosen from the port 22 ′ having the end chamfered portion of the threaded portion 304 that engages the ring 305 It is provided to prevent unintentional withdrawal.

  The inner peripheral surface 306 of the valve 302 and the outer peripheral surface 307 of the tip portion 356 of the shaft 350 are compatible with “hexagonal”, “torx” or other appropriately designed hexagonal drive elements. When this hex drive is engaged, the non-circular male and female elements 306, 307 rotate the valve 302 relative to the port 22 'as the threaded portion 303, 304 so that the valve 302 is in the port 22'. It is possible to move in the vertical direction along the axis AA. Coupling 20 ′ is designed to operate similarly whether the charge port 22 ′ includes a push-pin type valve 44 or a screw type valve 302. This eliminates the need for service technicians to know or be aware of what type of charge port valve is included in the system. For illustration purposes, both types of valve portions are shown in the charge port 22 'of the drawings, but in practice, any of these valves is typically included in the charge port. The above-described element members are included in the coupling 20 ′ in a practical range, and have the same purpose as described above, unless otherwise specified.

As best seen in FIGS. 10, 10A and 10B, the service coupling 20 ′ includes a body portion 58 ′ extending from the adjustment end 60 to the outlet end 62 and fixedly held in place. It is out. Again, for the body portion 58 ', this includes two portions 108' and 110, which portion 110 is essentially the same as described above. However, portion 108 'has a number of differences. First, it has a somewhat “J” cross-sectional shape, a radially outer portion, and a longitudinal formed between an inner surface formed by an inner diameter 76 and an outer surface formed by an outer diameter 212. A leg 308 extending in the direction. The legs 308 include flow holes 94 extending therethrough from at least one outer surface to the inner surface, and radial grooves 310 are disposed on the inner surfaces on opposite sides of the flow holes 94, the grooves 310 being The annular sealing elements A and B are received. Although an elastomeric O-ring is shown, other types of seals such as the above-mentioned PTFE spring-biased “U-cup” are required to eliminate the sudden depressurization, especially for CO ₂ applications It is good. The web 312 connects the leg 308 to a short radially inner leg 314 that ends at the end spaced longitudinally from both grooves. Three-dimensionally, the elements 308 and 314 are substantially cylindrical, with the element 314 being radially inward of the element 308 and the web 312 disposed therebetween. Thus, the two legs 308 and 314 and the web 312 form a cavity 318. The vent 320 extends through the illustrated cross-sectional leg 308 adjacent to the web 312 and terminates in the cavity 318. An elastic member 322 such as a spring is held in the cavity 318, one end engages with the web 312, and the other end extends in the vertical direction to the outside of the cavity 318.

  A safety sleeve 324 acting as a valve housing is positioned adjacent the end of the leg 314 and faces and contacts the inner surface of the outer leg 308 of the cavity 318. A radially outer surface 326 engages sealing elements A and B. A safety sleeve 324 is formed between the first end 328 and the second end 330 and one or more bleed holes 332 cause the safety sleeve 324 to extend longitudinally between the two ends 328, 330. It extends through. The second end 330 selectively contacts the end 316 of the leg 314 of the body portion and always contacts the spring 322 to the closed position and the charge port 22 'as described below. It is biased towards. The safety sleeve 324 also includes one or more flow holes 334 that extend from the outer surface and end at the inner radial surface 336. The flow hole 334 does not intersect the bleed hole 332. The safety sleeve 324 has a thin tip portion 338 adjacent to the first end 328. Between the tip portion 338 and the flow hole 334 is disposed a transition section including an angled chamfered portion 340 and a top portion 342 extending flat in the vertical direction. Preferably, the top 342 includes an inner diameter that is smaller than the inner diameter surface 336. When the end 330 of the safety sleeve 324 contacts the end of the leg 314 of the body portion, a selective interaction between the chamfer 340 and the top 342 that engages the sealing element D is caused to aft of the shaft 350. Restrict movement.

  The inner diameter surface of the sleeve 324 adjacent the second end 330 and the legs 314 adjacent the end 316 include grooves 343 that hold the sealing elements C and F, respectively. Seal elements C and F are located on either side of the boundary point between safety sleeve 324 and leg 314 so that safety sleeve 324 engages leg 314 and seals cavity 318 except for bleed hole 332. Sometimes, a portion of the fluid flow into the cavity 318 is blocked. Further features of the sealing element are described below in combination with the functional position of the service coupling 20 '.

  A longitudinally extending shaft 350 operates as a service valve 118 but includes additional functions. This is received in an inner passage formed radially inward of the pressure balance passage 328 of the safety sleeve 324. The shaft 350 extends between the first end 352 and the second end 354. A hexagonal element 307 is disposed on the outer surface of the shaft 350 adjacent the first end 352 and supplements the corresponding threaded valve 302 when it includes this type of valve, as will be described in more detail below. The hexagonal element 306 is fitted to open and close the charge port 22 '. When a push-pin type valve is used, the first end 352 engages the valve to open and close the valve as will be described in more detail below.

  Shaft 350 includes a tip portion 356 adjacent to a first end 352 having an outer diameter that includes a transition section formed by an angled chamfer 358 and a top 360 adjacent to hexagonal element 307. The top portion 360 has an outer diameter larger than the diameter of the tip portion 356 and a flat portion extending in the longitudinal direction. The groove 362 is positioned adjacent to the transition section and is clearly angled at approximately right angles at a shoulder 364 adjacent the top 360 that forms one of the walls of the groove. The seal member D is disposed in contact with the shoulder portion 364. Generally, the seal member D is bonded to the shoulder 364. However, a groove-type structure can also be used. The relative diameter of each of the tops 342 and 360 is similar to the transition section of the safety sleeve 324 and the respective relative longitudinal position of the shaft 350 so that, as will be described in detail below, The seal member D is selectively engaged with the chamfered portion 340. The shaft 350 uses threaded portions 370, 372 to threadably engage the legs of the valve body portion 108 ′ adjacent to the web 312 and these threaded portions 370, 372 are opposite the threaded portions 303, 304. A screw is formed to allow longitudinal movement of the shaft 350 relative to the valve body 58 '.

  As best seen in FIG. 10B, one or more circumferentially spaced drive pins 374 disposed within the mating holes in the shaft 350 are threaded portions 370, 372 and the end of the shaft 350. It is arranged between the part 354. The drive pin 374 is adapted to engage a drive slot 376 disposed in the rotatable knob 70 '. A shaft sleeve 378 extending from the end 354 of the shaft and disposed between the drive pins 374 is pinned or fastened to the shaft 350 and is clearly angled substantially perpendicular to the front wall 382. A front groove 380, a fairly angled ramp 384 that forms the rear wall of the front groove 380, a top 386 that extends vertically flat adjacent to the ramp 384, and another vertical top A shoulder 388 having a shallower angle than the ramp 384 adjacent to the directional end, sharply angled at the opposite end of the groove, and ending with a rear groove having a substantially right-angled wall 392. It is out. Rather than relying on the use of a shaft sleeve 378, the shaft 350 can include the elements shown directly.

  The knob 70 'includes a simple retaining ring groove 394 that receives a retaining ring, and as described in detail below, the knob 70' moves longitudinally between a coupled position and a released position, thereby providing A retaining ring 396 is adapted to move between the front groove 380 and the rear groove 390. The shaft sleeve 378 is included in the illustrated embodiment to provide flexibility in the dimensions of the retaining ring 396 that controls torque, but may not be required. The inner diameter surface 392 of the knob 70 ′ includes two grooves 393 arranged in the longitudinal direction for holding the sealing members G and H. The seal members G and H selectively engage the outer surface of the leg 308 of the body portion 58 ′ and a fluid tight seal formed by the diameter 212 when the vent hole 320 is disposed therebetween. I will provide a. The longitudinal inner end 398 of the knob 70 'includes an optimal chamfer 400, and when the knob 70' is in its fully retracted direction, the vent 320 is open to the outside atmosphere.

  FIG. 10 shows the dual function service coupling 20 ′ with the knob 70 ′ in the fully retracted position. Seals A through D serve to prevent leakage from the pressurized supply hose port 66 regardless of the position of the knob 70. Prior to attachment to the charge port 22 ', the coupling 20' is often pressurized through a supply hose 450 attached to the service equipment. Seals A and B on both sides of the flow hole 94 seal with the same diameter to prevent leakage between the safety sleeve 324 and the body portion 58 '. Seals C and D prevent leakage between the shaft 350 and the safety sleeve 350. As a result of this seal structure, the pressure of the safety sleeve 324 is substantially balanced, and only the urging force of the elastic member 322 acts to hold the safety sleeve in contact with the seal D in the closed position. Such an arrangement minimizes the rotational force required to rotate the knob 70 '. In the position of FIG. 10 or 11, the other four seals E to H are not pressurized.

  In FIG. 10, the knob 70 ′ is sequentially fully retracted with the knob retaining ring 396 disposed in the rear groove 390 of the shaft sleeve 378 fixedly connected to the shaft 350. The drive pin 374 held by the shaft 350 and all means therethrough are disengaged from the corresponding drive slot 376 of the knob 70 '. Thereby, the knob 70 can be freely rotated.

  The vent hole 320 is not covered, allowing the trapped pressure to be relieved when the knob 70 'is moved to the illustrated position for service. The release sleeve 184 is retracted, as already described above, to allow connection and disconnection with the male charge port 22 '.

  FIG. 11 illustrates the function of the safety sleeve 324. In the figure, the knob 70 'is advanced from its disengaged position, but the valve is still closed as shown in FIG. The charge port 22 'is not connected to the coupling 20'. The vent hole 320 is closed and sealed between the sealing elements G and H received in the groove 393 on the inner peripheral surface of the knob 70 ′. The retaining ring 396 is disposed in the front groove 380 and the retaining pin 374 is received in the drive slot 376.

  Undesirable pressure relief has not yet taken place. This is because when not fastened to the charge port 22 ′, the safety sleeve 324 is spring-biased to the closed position by the spring 322 and is always held in the closed position.

  In FIG. 12, the coupling 20 'is shown connected to the charge port 22'. During this connection, the hexagonal elements 306, 307, if applicable, are engaged and the valve 302 moves longitudinally toward the end 328 of the safety sleeve 324 as a result of the clockwise rotation of the shaft 350. In the case of the push-pin valve 44, the tip of the shaft 350 engages the end 454 of the valve 44 when the shaft 350 is fully advanced to engage the valve 44 and moved to the left in the figure. A chamfer 452 is included. In the figure, inadequate advancement will result in mutual engagement.

  Knob 70 ′ pushes forward in the longitudinal direction with minimal force until the retaining ring 396 rides on the shallow inclined shoulder 388, out of the groove 390, beyond the top 386 and into the front groove 380. Is done. During this operation, the drive pin 374 engages the drive slot 376 of the knob 70 ', and the engagement of the threads 370, 372 between the shaft 350 and the body portion 58' causes the knob to rotate clockwise. The shaft 350 is rotated and advanced. Further, as described with reference to FIG. 11, the front vent hole 320 is sealed by pressing the knob 70 ′.

  FIG. 13 shows the coupling 20 ′ in the coupled and open position. The interlock sleeve 208 functions in conjunction with the lock sleeve 184 as already described above. Compared with FIG. 12, the knob 70 ′ is rotated clockwise to advance the shaft 350 toward the closed charge port 22 ′. When the coupling 20 ′ is attached to a screw-type valve 320, one or more cross pins 456 extending radially outward from the shaft 350 and adjacent to the chamfer 358 are at the end 28 of the port 22 ′. Until engaged, the screw is loosened about 3 turns without torque. Because when the corresponding shaft thread 370,372 is in the right direction, the thread 303 is in the left direction and the valve 302 is retracted when the shaft 350 is advanced, resulting in the engagement of the hex drive. Is increased.

  On the other hand, when the coupling 20 ′ is attached to the push-pin type valve 44, the chamfer 452 of the shaft 350 moves the end 454 of the valve 44 to the open position. This process operates as follows. As the knob 70 'is rotated clockwise from the position shown in FIG. 12 to the position shown in FIG. 13, the safety sleeve 324 first contacts its shaft 350 and the end 328 contacts the end 28 of the port 22. Then, the shaft 350 moves until the chamfered portion 452 of the shaft 350 is engaged with the end portion 454 of the valve 44. At this point, as the shaft 350 continues to advance to the left, the safety sleeve 324 moves from its closed position to the open position against the force of the elastic member 322, and the seal D on the safety sleeve 324 The seal is released and at about the same time, the shaft 350 pushes open the valve of the port 22 '. This releases the pressure into the cavity 458. The pressure in the cavity 458 can freely pass through the pressure balance hole 322 of the safety valve 324 so that the cavity 318 can quickly move to approximately the same pressure (except for the small area of the limited end 350 of the shaft 350). To reach). The end portion 28 does not block the bleed hole 332. Cross pin 456 selectively engages end 28 to limit movement of shaft 350. This balanced pressure means that only minimal force is required to rotate the knob 70 '.

  In the valve opening operation, the seal E prevents leakage between the body portion 58 'and the male charge port 22'. The seal F prevents leakage between the body portion 58 ′ and the shaft 350. Seals G and H prevent leakage between the outer diameter 212 of the body portion 58 'and the knob 70'. Seals G and H are placed on either side of bleed hole 320 to balance the pressure and minimize the force required to move knob 70 '. Seals A through D are pressurized from all sides but do not perform the necessary sealing functions.

  After servicing, the knob 70 'is rotated counterclockwise to close the valve. When attached to a screw type valve, the shaft 350 rotates with the knob until the screw valve is properly seated. Further rotation of the knob 70 'applies a predetermined torque value to the screw as follows. The coupling structure of the knob 70 ′ is in the form of a “saw blade” having at least two teeth that engage a drive pin 374 that passes through the shaft 350. As the knob 70 ′ is rotated counterclockwise, the pin 374 rides on the inclined surface formed by the saw blade by a cam action. This helps to force the pin 374 out of engagement with the knob 70 '. It is the retaining ring 396 that is retained in the front groove 380 of the shaft sleeve 358 that resists this motion. At a given torque value, the retaining ring 396 climbs a relatively steep angle of the slope 384, is forced beyond the top 386, and moves down the shoulder 388 to the rear groove 390. This allows the knob 70 ′ to move backward relative to the shaft 350 so that the vent 320 can be opened again. The knob 70 'can freely rotate.

  When the charge port 22 ′ includes the push-pin valve 44, the shaft 350 has the safety sleeve 324 as a main body due to the engagement between the sealing member D held in the groove 362 of the shaft 350 and the chamfered portion 340 of the safety sleeve 324. Retract until it touches 58 '. Further rotation of the knob 70 'releases the knob from the shaft, as described above for the threaded type valve.

  A bleed hole 332 connecting between the cavities 458 and 318 allows the pressure confined between the charge port 22 'and the service coupling 20' to be released when the knob 70 'does not close the vent hole 320. To.

  FIG. 14 shows another embodiment of the coupling 20 ′ in which a vent hole 320 ′ is arranged inside the shaft 350 with respect to that shown in FIGS. 10 to 13. Vent hole seal 460 slides off shaft 350 'when knob 70' moves to the retracted position, allowing pressure to be released to the atmosphere.

  While certain preferred embodiments of the invention have been described, the invention is not limited to what has been shown and described herein, which merely represents the best mode of carrying out the invention. It is not considered. Those skilled in the art can implement modifications and variations within the teachings of the present invention, which are within the spirit and scope of the present invention as defined by the claims.

1 is a longitudinal cross-sectional view of a service coupling according to a preferred embodiment of the present invention attached to a charge port of a refrigeration system. It is a longitudinal cross-sectional view similar to FIG. 1 which shows the relative position of the components in the valve opening position which follows the action | operation of a service valve and a port valve. It is the same longitudinal cross-sectional view as FIG. 1 which shows the relative position of the components in the valve closing position in the detachment | leave from the charge port of a service coupling. FIG. 4 is a cross-sectional view of the coupling member along line 4-4 in FIG. 3. FIG. 4 is an enlarged partial cross-sectional view of the charge port of FIGS. FIG. 6 is a longitudinal sectional view of another embodiment of the present invention showing a service coupling attached to a charge port with the service valve and port valve in the open position. FIG. 7 is a longitudinal sectional view of the service coupling of FIG. 6 with the service valve and port valve in the closed position. FIG. 6 is a longitudinal sectional view of another embodiment of the present invention showing a service coupling attached to a charge port with a service valve and a port valve in the open position. FIG. 6 is an enlarged longitudinal sectional view of yet another embodiment of the present invention showing the relative position of the lock sleeve, pin and valve housing during removal of the service coupling from the charge port. FIG. 3 illustrates one embodiment of a dual function service coupling in a detached state that can be used for either push-type or screw-type charge ports. It is the elements on larger scale of the service coupling of FIG. It is the elements on larger scale of the service coupling of FIG. FIG. 11 shows the embodiment of FIG. 10 with the knob in an engaged state without being coupled to the charge port. FIG. 11 illustrates the embodiment of FIG. 10 with service coupling coupled to a charge port. FIG. 11 illustrates the embodiment of FIG. 10 with the service coupling coupled to the charge port and the knob in an engaged state to permit fluid flow. FIG. 6 illustrates another embodiment of a dual function service coupling.

Claims (29)

A service coupling (20) for connecting a fluid source to a fluid system having a charge port (22) including an axially displaceable port valve (44),
(A) a body portion (58) extending axially from the adjustment end (60) to the outlet end (62), the body portion (58) comprising a central passage (64) and the adjustment end; A transverse port (66) disposed between (60) and the outlet end (62) connecting between the central passage (64) and the fluid source;
(B) a valve housing (82) that is received in the central passage (64) and is movable in the axial direction; the valve housing (82) is connected to the lateral port (66) and has a flow path; A fluid flow opening to form and at least one pressure balance passageway (96) extending longitudinally between the adjusting end (60) and the outlet end (62);
(C) an actuator (70) for enabling movement of the valve housing (82) from a rear position toward the adjustment end (60) to a front position toward the outlet end (62); When the actuator (70) moves in the axial direction, the seal engagement of the port valve (44) is released in the charge port (22), the flow path is opened, and the flow path is opened. Service coupling characterized in that two pressure balancing passages (96) substantially balance the pressure at both ends of the valve housing (82). The charge port (22) includes one of a push-pin type valve (44) and a screw type valve (302), and only one of these valves is necessary for opening and closing the port. The service coupling according to claim 1. A first cavity (224) is disposed on the side of the valve housing (82) adjacent to the port valve (44), and a second cavity (226) is disposed on the opposite side of the valve housing (82). The service coupling of claim 1, wherein the pressure balance passageway (96) is disposed between the first cavity (224) and the second cavity (226). The body portion (58) includes the second cavity (226), which is defined by a second leg (314) disposed radially inward of the first leg (308). The service coupling of claim 3, wherein a portion is formed and the opposite side of the valve housing (82) selectively contacts the first leg (314). An elastic member (322) is received in the second cavity (226), and the elastic member (322) biases the valve housing (82) toward the outlet end (62). The service coupling according to claim 4. The service coupling of claim 5, wherein the valve housing (82) includes an internal passage (324) and the actuator (70) is received in the internal passage (324). The service coupling according to claim 6, wherein the internal passage (324) of the valve housing (82) is radially inward of the pressure balance passage (96). In the closed position, the surface of the actuator (70) is sealed against the corresponding surface of the valve housing (82) to close the flow path, and in the open position, the actuator (70) A service coupling according to claim 6, characterized in that it is displaced with respect to the valve housing (82) and engages the port valve (44) to open the flow path. When the actuator (70) moves to the valve open position for engaging with the port valve (44), one end of the charge port (22) is selectively engaged with the valve housing (82). 9. Service coupling according to claim 8, characterized in that the actuator (70) is selectively moved relative to both the valve housing (82) and the charge port (22). Service coupling according to claim 8, characterized in that a sealing element (144) is arranged between the surface of the actuator (70) and the corresponding surface of the valve housing (82). The service coupling according to claim 10, wherein at least one of the surface of the actuator (70) and the corresponding surface of the valve housing (82) includes a chamfer. A second sealing element (144) is disposed between the second surface of the actuator (70) and the second surface of the valve housing (82), the second sealing element (144) being connected to the actuator 70 and the The service coupling according to claim 10, characterized in that it prevents the flow of fluid to and from the valve housing (82). The service coupling according to claim 4, wherein the surface of the actuator (70) faces the second leg (314). A seal is disposed between the actuator (70) and the second leg (314) to prevent fluid flow between the actuator (70) and the body portion (58). The service coupling according to claim 13. The actuator (70) is a shaft (350) that moves in a longitudinal direction toward the charge port (22) and away from the charge port (22), the shaft (350) being selectively connected to the port valve. The service coupling of claim 1 including a tip portion (356) that engages (44) and moves it between a closed position and a closed position. The tip portion (356) has a non-circular outer shape that engages the corresponding outer shape of the mating port valve, and as a result of rotation of the shaft (350), the valve is in the charge port (22). The service coupling according to claim 15, wherein the service coupling rotates relative to the other. The service coupling according to claim 16, wherein the port valve (44) is threadedly engaged with the charge port (22). The service coupling of claim 15, wherein the tip portion (356) selectively engages a push pin associated with the port valve (44). The method further includes at least one bleed passage (230) for venting fluid confined between the service coupling (20) and the charge port (22) prior to disengagement. Item 1. The service coupling according to Item 1. The transverse port (66) restricts the flow of fluid in the first direction through the service coupling (20) and substantially does not restrict the flow of fluid in the second direction opposite to the first direction. The service coupling according to claim 1, further comprising a coupling member having a restrictor (162) that is allowed to pass through. A service coupling for connecting a fluid source to a fluid system,
(A) a charge port (22) including a port valve (44) displaceable in the axial direction, said valve (44) being either a push-pin type or a screw type;
(B) a body portion (58) extending axially from the adjustment end (60) to the outlet end (62), the body portion (58) comprising a central passage (64) and the adjustment end; A transverse port (66) disposed between (60) and the outlet end (62) connecting between the central passage (64) and the fluid source;
(C) A safety sleeve (324) received in the central passage (64) and axially movable is provided, and the safety sleeve (324) is connected to the lateral port (66) to form a flow path. Fluid flow opening, at least one pressure balance passage (96) extending through both ends of the longitudinal direction, and a safety sleeve (324) disposed adjacent to the port valve (44) side. A first cavity (224) and a second cavity (226) disposed adjacent to the opposite side of the safety sleeve (324), wherein the pressure balance passageway (96) is connected to the first cavity (224). Between the second cavity (226),
(D) an actuator (70) for allowing movement of the safety sleeve (324) from a rear position toward the adjustment end (60) to a front position toward the outlet end (62); When the actuator (70) moves in the axial direction, the seal engagement of the port valve (44) is released in the charge port (22), the flow path is opened, and the flow path is opened. Service coupling, characterized in that two pressure balancing passages (96) substantially balance the pressure at both ends of the safety sleeve (324). The actuator (70) is a shaft (350) that moves in a longitudinal direction toward the port valve (44) and away from the port valve (44), the shaft (350) being selectively connected to the port valve (44). The service coupling of claim 21 including a tip portion (356) that engages (44) and moves it between a closed position and a closed position. The tip portion (356) has a non-circular profile that mutually engages the corresponding profile of a screw-type port valve, and the tip portion (356) is further a push-pin type port valve. 23. The service coupling of claim 22, wherein the service couplings are interengaged with associated push pins. A service coupling for connecting a fluid source to a fluid system,
(A) a valve housing (82) that is received in the central passage (64) and is movable in the axial direction; the valve housing (82) is connected to the lateral port (66) and has a flow path; A fluid flow opening that forms and at least one pressure balance passageway (96) extending through the longitudinal ends (60, 62);
(B) a safety sleeve (34) that is received in the central passage (64) and is axially movable; the safety sleeve (324) is connected to the lateral port (66) to form a flow path; A fluid flow opening and an internal passage (324),
(C) to selectively move the safety sleeve (324) from a rearward position toward the adjusting end (68) of the safety sleeve (324) to a forward position toward the outlet end (62); A shaft (350) movable in the internal passage is provided, and the axial movement of the shaft (350) releases the port valve (44) from sealing engagement with the charge port (22). Opening the passage, the shaft (350) includes a tip portion (356) having a non-circular profile that interengages with a corresponding profile of a first specific type of port valve, the tip portion (356) comprising: The service coupling is further adapted to engage with a push pin associated with the second specific type of port valve. The body portion (58) includes a cavity (318) formed between two legs (308, 314), the end of the safety sleeve (324) being closed by the port valve (44). 25. A service coupling according to claim 24, characterized in that, when done, it selectively contacts one of the legs of the body portion (58). The elastic member (322) is received in the cavity (318) to bias the safety sleeve (324) axially away from the body portion (58). Service coupling. 27. The shaft (350) is threadedly engaged with the body portion (58) such that the shaft (350) moves relative to the body portion (58). Service coupling. As the shaft (350) moves toward the charge port (22), the safety sleeve (324) is urged away from the cavity (318) by the elastic member (322). The service coupling according to claim 27. One end of the charge port (22) is selectively engaged with the safety valve (324) by moving toward an open position where the shaft (350) engages with the port valve (44). As a result, the shaft (350) selectively moves simultaneously with respect to the body portion (58), the safety sleeve (324) and the charge port (22). Service coupling as described in.

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